TUN-9467: bump coredns to solve CVE

* TUN-9467: bump coredns to solve CVE

vendor/google.golang.org/genproto/googleapis/api/httpbody/httpbody.pb.go

@@ -1,4 +1,4 @@
-// Copyright 2023 Google LLC
+// Copyright 2025 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.26.0
-// 	protoc        v3.21.9
+// 	protoc        v4.24.4
 // source: google/api/httpbody.proto
 
 package httpbody
@@ -159,14 +159,14 @@ var file_google_api_httpbody_proto_rawDesc = []byte{
 	0x04, 0x64, 0x61, 0x74, 0x61, 0x12, 0x34, 0x0a, 0x0a, 0x65, 0x78, 0x74, 0x65, 0x6e, 0x73, 0x69,
 	0x6f, 0x6e, 0x73, 0x18, 0x03, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x14, 0x2e, 0x67, 0x6f, 0x6f, 0x67,
 	0x6c, 0x65, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2e, 0x41, 0x6e, 0x79, 0x52,
-	0x0a, 0x65, 0x78, 0x74, 0x65, 0x6e, 0x73, 0x69, 0x6f, 0x6e, 0x73, 0x42, 0x68, 0x0a, 0x0e, 0x63,
+	0x0a, 0x65, 0x78, 0x74, 0x65, 0x6e, 0x73, 0x69, 0x6f, 0x6e, 0x73, 0x42, 0x65, 0x0a, 0x0e, 0x63,
 	0x6f, 0x6d, 0x2e, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2e, 0x61, 0x70, 0x69, 0x42, 0x0d, 0x48,
 	0x74, 0x74, 0x70, 0x42, 0x6f, 0x64, 0x79, 0x50, 0x72, 0x6f, 0x74, 0x6f, 0x50, 0x01, 0x5a, 0x3b,
 	0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2e, 0x67, 0x6f, 0x6c, 0x61, 0x6e, 0x67, 0x2e, 0x6f, 0x72,
 	0x67, 0x2f, 0x67, 0x65, 0x6e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2f, 0x67, 0x6f, 0x6f, 0x67, 0x6c,
 	0x65, 0x61, 0x70, 0x69, 0x73, 0x2f, 0x61, 0x70, 0x69, 0x2f, 0x68, 0x74, 0x74, 0x70, 0x62, 0x6f,
-	0x64, 0x79, 0x3b, 0x68, 0x74, 0x74, 0x70, 0x62, 0x6f, 0x64, 0x79, 0xf8, 0x01, 0x01, 0xa2, 0x02,
-	0x04, 0x47, 0x41, 0x50, 0x49, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+	0x64, 0x79, 0x3b, 0x68, 0x74, 0x74, 0x70, 0x62, 0x6f, 0x64, 0x79, 0xa2, 0x02, 0x04, 0x47, 0x41,
+	0x50, 0x49, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (

vendor/google.golang.org/genproto/googleapis/rpc/status/status.pb.go

@@ -1,4 +1,4 @@
-// Copyright 2022 Google LLC
+// Copyright 2025 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.26.0
-// 	protoc        v3.21.9
+// 	protoc        v4.24.4
 // source: google/rpc/status.proto
 
 package status

vendor/google.golang.org/grpc/CONTRIBUTING.md

@@ -4,7 +4,7 @@ We definitely welcome your patches and contributions to gRPC! Please read the gR
 organization's [governance rules](https://github.com/grpc/grpc-community/blob/master/governance.md)
 and [contribution guidelines](https://github.com/grpc/grpc-community/blob/master/CONTRIBUTING.md) before proceeding.
 
-If you are new to github, please start by reading [Pull Request howto](https://help.github.com/articles/about-pull-requests/)
+If you are new to GitHub, please start by reading [Pull Request howto](https://help.github.com/articles/about-pull-requests/)
 
 ## Legal requirements
 
@@ -25,8 +25,8 @@ How to get your contributions merged smoothly and quickly.
   is a great place to start. These issues are well-documented and usually can be
   resolved with a single pull request.
 
-- If you are adding a new file, make sure it has the copyright message template 
-  at the top as a comment. You can copy over the message from an existing file 
+- If you are adding a new file, make sure it has the copyright message template
+  at the top as a comment. You can copy over the message from an existing file
   and update the year.
 
 - The grpc package should only depend on standard Go packages and a small number
@@ -39,12 +39,12 @@ How to get your contributions merged smoothly and quickly.
   proposal](https://github.com/grpc/proposal).
 
 - Provide a good **PR description** as a record of **what** change is being made
-  and **why** it was made. Link to a github issue if it exists.
+  and **why** it was made. Link to a GitHub issue if it exists.
 
-- If you want to fix formatting or style, consider whether your changes are an 
-  obvious improvement or might be considered a personal preference. If a style 
-  change is based on preference, it likely will not be accepted. If it corrects 
-  widely agreed-upon anti-patterns, then please do create a PR and explain the 
+- If you want to fix formatting or style, consider whether your changes are an
+  obvious improvement or might be considered a personal preference. If a style
+  change is based on preference, it likely will not be accepted. If it corrects
+  widely agreed-upon anti-patterns, then please do create a PR and explain the
   benefits of the change.
 
 - Unless your PR is trivial, you should expect there will be reviewer comments
@@ -66,7 +66,7 @@ How to get your contributions merged smoothly and quickly.
 - **All tests need to be passing** before your change can be merged. We
   recommend you **run tests locally** before creating your PR to catch breakages
   early on.
-  - `VET_SKIP_PROTO=1 ./vet.sh` to catch vet errors
+  - `./scripts/vet.sh` to catch vet errors
   - `go test -cpu 1,4 -timeout 7m ./...` to run the tests
   - `go test -race -cpu 1,4 -timeout 7m ./...` to run tests in race mode
 

vendor/google.golang.org/grpc/MAINTAINERS.md

@@ -9,20 +9,28 @@ for general contribution guidelines.
 
 ## Maintainers (in alphabetical order)
 
-- [cesarghali](https://github.com/cesarghali), Google LLC
+- [aranjans](https://github.com/aranjans), Google LLC
+- [arjan-bal](https://github.com/arjan-bal), Google LLC
+- [arvindbr8](https://github.com/arvindbr8), Google LLC
+- [atollena](https://github.com/atollena), Datadog, Inc.
 - [dfawley](https://github.com/dfawley), Google LLC
 - [easwars](https://github.com/easwars), Google LLC
-- [menghanl](https://github.com/menghanl), Google LLC
-- [srini100](https://github.com/srini100), Google LLC
+- [erm-g](https://github.com/erm-g), Google LLC
+- [gtcooke94](https://github.com/gtcooke94), Google LLC
+- [purnesh42h](https://github.com/purnesh42h), Google LLC
+- [zasweq](https://github.com/zasweq), Google LLC
 
 ## Emeritus Maintainers (in alphabetical order)
-- [adelez](https://github.com/adelez), Google LLC
-- [canguler](https://github.com/canguler), Google LLC
-- [iamqizhao](https://github.com/iamqizhao), Google LLC
-- [jadekler](https://github.com/jadekler), Google LLC
-- [jtattermusch](https://github.com/jtattermusch), Google LLC
-- [lyuxuan](https://github.com/lyuxuan), Google LLC
-- [makmukhi](https://github.com/makmukhi), Google LLC
-- [matt-kwong](https://github.com/matt-kwong), Google LLC
-- [nicolasnoble](https://github.com/nicolasnoble), Google LLC
-- [yongni](https://github.com/yongni), Google LLC
+- [adelez](https://github.com/adelez)
+- [canguler](https://github.com/canguler)
+- [cesarghali](https://github.com/cesarghali)
+- [iamqizhao](https://github.com/iamqizhao)
+- [jeanbza](https://github.com/jeanbza)
+- [jtattermusch](https://github.com/jtattermusch)
+- [lyuxuan](https://github.com/lyuxuan)
+- [makmukhi](https://github.com/makmukhi)
+- [matt-kwong](https://github.com/matt-kwong)
+- [menghanl](https://github.com/menghanl)
+- [nicolasnoble](https://github.com/nicolasnoble)
+- [srini100](https://github.com/srini100)
+- [yongni](https://github.com/yongni)

vendor/google.golang.org/grpc/Makefile

@@ -30,17 +30,20 @@ testdeps:
 	GO111MODULE=on go get -d -v -t google.golang.org/grpc/...
 
 vet: vetdeps
-	./vet.sh
+	./scripts/vet.sh
 
 vetdeps:
-	./vet.sh -install
+	./scripts/vet.sh -install
 
 .PHONY: \
 	all \
 	build \
 	clean \
+	deps \
 	proto \
 	test \
+	testsubmodule \
 	testrace \
+	testdeps \
 	vet \
 	vetdeps

vendor/google.golang.org/grpc/README.md

@@ -10,7 +10,7 @@ RPC framework that puts mobile and HTTP/2 first. For more information see the
 
 ## Prerequisites
 
-- **[Go][]**: any one of the **three latest major** [releases][go-releases].
+- **[Go][]**: any one of the **two latest major** [releases][go-releases].
 
 ## Installation
 

vendor/google.golang.org/grpc/SECURITY.md

@@ -1,3 +1,3 @@
 # Security Policy
 
-For information on gRPC Security Policy and reporting potentional security issues, please see [gRPC CVE Process](https://github.com/grpc/proposal/blob/master/P4-grpc-cve-process.md).
+For information on gRPC Security Policy and reporting potential security issues, please see [gRPC CVE Process](https://github.com/grpc/proposal/blob/master/P4-grpc-cve-process.md).

vendor/google.golang.org/grpc/backoff/backoff.go

@@ -39,7 +39,7 @@ type Config struct {
 	MaxDelay time.Duration
 }
 
-// DefaultConfig is a backoff configuration with the default values specfied
+// DefaultConfig is a backoff configuration with the default values specified
 // at https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
 //
 // This should be useful for callers who want to configure backoff with

vendor/google.golang.org/grpc/balancer/balancer.go

@@ -30,6 +30,7 @@ import (
 	"google.golang.org/grpc/channelz"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
+	estats "google.golang.org/grpc/experimental/stats"
 	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/metadata"
@@ -74,6 +75,8 @@ func unregisterForTesting(name string) {
 
 func init() {
 	internal.BalancerUnregister = unregisterForTesting
+	internal.ConnectedAddress = connectedAddress
+	internal.SetConnectedAddress = setConnectedAddress
 }
 
 // Get returns the resolver builder registered with the given name.
@@ -92,54 +95,6 @@ func Get(name string) Builder {
 	return nil
 }
 
-// A SubConn represents a single connection to a gRPC backend service.
-//
-// Each SubConn contains a list of addresses.
-//
-// All SubConns start in IDLE, and will not try to connect. To trigger the
-// connecting, Balancers must call Connect.  If a connection re-enters IDLE,
-// Balancers must call Connect again to trigger a new connection attempt.
-//
-// gRPC will try to connect to the addresses in sequence, and stop trying the
-// remainder once the first connection is successful. If an attempt to connect
-// to all addresses encounters an error, the SubConn will enter
-// TRANSIENT_FAILURE for a backoff period, and then transition to IDLE.
-//
-// Once established, if a connection is lost, the SubConn will transition
-// directly to IDLE.
-//
-// This interface is to be implemented by gRPC. Users should not need their own
-// implementation of this interface. For situations like testing, any
-// implementations should embed this interface. This allows gRPC to add new
-// methods to this interface.
-type SubConn interface {
-	// UpdateAddresses updates the addresses used in this SubConn.
-	// gRPC checks if currently-connected address is still in the new list.
-	// If it's in the list, the connection will be kept.
-	// If it's not in the list, the connection will gracefully closed, and
-	// a new connection will be created.
-	//
-	// This will trigger a state transition for the SubConn.
-	//
-	// Deprecated: this method will be removed.  Create new SubConns for new
-	// addresses instead.
-	UpdateAddresses([]resolver.Address)
-	// Connect starts the connecting for this SubConn.
-	Connect()
-	// GetOrBuildProducer returns a reference to the existing Producer for this
-	// ProducerBuilder in this SubConn, or, if one does not currently exist,
-	// creates a new one and returns it.  Returns a close function which must
-	// be called when the Producer is no longer needed.
-	GetOrBuildProducer(ProducerBuilder) (p Producer, close func())
-	// Shutdown shuts down the SubConn gracefully.  Any started RPCs will be
-	// allowed to complete.  No future calls should be made on the SubConn.
-	// One final state update will be delivered to the StateListener (or
-	// UpdateSubConnState; deprecated) with ConnectivityState of Shutdown to
-	// indicate the shutdown operation.  This may be delivered before
-	// in-progress RPCs are complete and the actual connection is closed.
-	Shutdown()
-}
-
 // NewSubConnOptions contains options to create new SubConn.
 type NewSubConnOptions struct {
 	// CredsBundle is the credentials bundle that will be used in the created
@@ -174,6 +129,13 @@ type State struct {
 // brand new implementation of this interface. For the situations like
 // testing, the new implementation should embed this interface. This allows
 // gRPC to add new methods to this interface.
+//
+// NOTICE: This interface is intended to be implemented by gRPC, or intercepted
+// by custom load balancing polices.  Users should not need their own complete
+// implementation of this interface -- they should always delegate to a
+// ClientConn passed to Builder.Build() by embedding it in their
+// implementations. An embedded ClientConn must never be nil, or runtime panics
+// will occur.
 type ClientConn interface {
 	// NewSubConn is called by balancer to create a new SubConn.
 	// It doesn't block and wait for the connections to be established.
@@ -212,6 +174,17 @@ type ClientConn interface {
 	//
 	// Deprecated: Use the Target field in the BuildOptions instead.
 	Target() string
+
+	// MetricsRecorder provides the metrics recorder that balancers can use to
+	// record metrics. Balancer implementations which do not register metrics on
+	// metrics registry and record on them can ignore this method. The returned
+	// MetricsRecorder is guaranteed to never be nil.
+	MetricsRecorder() estats.MetricsRecorder
+
+	// EnforceClientConnEmbedding is included to force implementers to embed
+	// another implementation of this interface, allowing gRPC to add methods
+	// without breaking users.
+	internal.EnforceClientConnEmbedding
 }
 
 // BuildOptions contains additional information for Build.
@@ -403,15 +376,6 @@ type ExitIdler interface {
 	ExitIdle()
 }
 
-// SubConnState describes the state of a SubConn.
-type SubConnState struct {
-	// ConnectivityState is the connectivity state of the SubConn.
-	ConnectivityState connectivity.State
-	// ConnectionError is set if the ConnectivityState is TransientFailure,
-	// describing the reason the SubConn failed.  Otherwise, it is nil.
-	ConnectionError error
-}
-
 // ClientConnState describes the state of a ClientConn relevant to the
 // balancer.
 type ClientConnState struct {
@@ -424,20 +388,3 @@ type ClientConnState struct {
 // ErrBadResolverState may be returned by UpdateClientConnState to indicate a
 // problem with the provided name resolver data.
 var ErrBadResolverState = errors.New("bad resolver state")
-
-// A ProducerBuilder is a simple constructor for a Producer.  It is used by the
-// SubConn to create producers when needed.
-type ProducerBuilder interface {
-	// Build creates a Producer.  The first parameter is always a
-	// grpc.ClientConnInterface (a type to allow creating RPCs/streams on the
-	// associated SubConn), but is declared as `any` to avoid a dependency
-	// cycle.  Should also return a close function that will be called when all
-	// references to the Producer have been given up.
-	Build(grpcClientConnInterface any) (p Producer, close func())
-}
-
-// A Producer is a type shared among potentially many consumers.  It is
-// associated with a SubConn, and an implementation will typically contain
-// other methods to provide additional functionality, e.g. configuration or
-// subscription registration.
-type Producer any

vendor/google.golang.org/grpc/balancer/base/balancer.go

@@ -36,12 +36,12 @@ type baseBuilder struct {
 	config        Config
 }
 
-func (bb *baseBuilder) Build(cc balancer.ClientConn, opt balancer.BuildOptions) balancer.Balancer {
+func (bb *baseBuilder) Build(cc balancer.ClientConn, _ balancer.BuildOptions) balancer.Balancer {
 	bal := &baseBalancer{
 		cc:            cc,
 		pickerBuilder: bb.pickerBuilder,
 
-		subConns: resolver.NewAddressMap(),
+		subConns: resolver.NewAddressMapV2[balancer.SubConn](),
 		scStates: make(map[balancer.SubConn]connectivity.State),
 		csEvltr:  &balancer.ConnectivityStateEvaluator{},
 		config:   bb.config,
@@ -65,7 +65,7 @@ type baseBalancer struct {
 	csEvltr *balancer.ConnectivityStateEvaluator
 	state   connectivity.State
 
-	subConns *resolver.AddressMap
+	subConns *resolver.AddressMapV2[balancer.SubConn]
 	scStates map[balancer.SubConn]connectivity.State
 	picker   balancer.Picker
 	config   Config
@@ -100,7 +100,7 @@ func (b *baseBalancer) UpdateClientConnState(s balancer.ClientConnState) error {
 	// Successful resolution; clear resolver error and ensure we return nil.
 	b.resolverErr = nil
 	// addrsSet is the set converted from addrs, it's used for quick lookup of an address.
-	addrsSet := resolver.NewAddressMap()
+	addrsSet := resolver.NewAddressMapV2[any]()
 	for _, a := range s.ResolverState.Addresses {
 		addrsSet.Set(a, nil)
 		if _, ok := b.subConns.Get(a); !ok {
@@ -122,8 +122,7 @@ func (b *baseBalancer) UpdateClientConnState(s balancer.ClientConnState) error {
 		}
 	}
 	for _, a := range b.subConns.Keys() {
-		sci, _ := b.subConns.Get(a)
-		sc := sci.(balancer.SubConn)
+		sc, _ := b.subConns.Get(a)
 		// a was removed by resolver.
 		if _, ok := addrsSet.Get(a); !ok {
 			sc.Shutdown()
@@ -133,7 +132,7 @@ func (b *baseBalancer) UpdateClientConnState(s balancer.ClientConnState) error {
 		}
 	}
 	// If resolver state contains no addresses, return an error so ClientConn
-	// will trigger re-resolve. Also records this as an resolver error, so when
+	// will trigger re-resolve. Also records this as a resolver error, so when
 	// the overall state turns transient failure, the error message will have
 	// the zero address information.
 	if len(s.ResolverState.Addresses) == 0 {
@@ -173,8 +172,7 @@ func (b *baseBalancer) regeneratePicker() {
 
 	// Filter out all ready SCs from full subConn map.
 	for _, addr := range b.subConns.Keys() {
-		sci, _ := b.subConns.Get(addr)
-		sc := sci.(balancer.SubConn)
+		sc, _ := b.subConns.Get(addr)
 		if st, ok := b.scStates[sc]; ok && st == connectivity.Ready {
 			readySCs[sc] = SubConnInfo{Address: addr}
 		}
@@ -259,6 +257,6 @@ type errPicker struct {
 	err error // Pick() always returns this err.
 }
 
-func (p *errPicker) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
+func (p *errPicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
 	return balancer.PickResult{}, p.err
 }

vendor/google.golang.org/grpc/balancer/endpointsharding/endpointsharding.go

@@ -0,0 +1,356 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package endpointsharding implements a load balancing policy that manages
+// homogeneous child policies each owning a single endpoint.
+//
+// # Experimental
+//
+// Notice: This package is EXPERIMENTAL and may be changed or removed in a
+// later release.
+package endpointsharding
+
+import (
+	"errors"
+	rand "math/rand/v2"
+	"sync"
+	"sync/atomic"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/resolver"
+)
+
+// ChildState is the balancer state of a child along with the endpoint which
+// identifies the child balancer.
+type ChildState struct {
+	Endpoint resolver.Endpoint
+	State    balancer.State
+
+	// Balancer exposes only the ExitIdler interface of the child LB policy.
+	// Other methods of the child policy are called only by endpointsharding.
+	Balancer balancer.ExitIdler
+}
+
+// Options are the options to configure the behaviour of the
+// endpointsharding balancer.
+type Options struct {
+	// DisableAutoReconnect allows the balancer to keep child balancer in the
+	// IDLE state until they are explicitly triggered to exit using the
+	// ChildState obtained from the endpointsharding picker. When set to false,
+	// the endpointsharding balancer will automatically call ExitIdle on child
+	// connections that report IDLE.
+	DisableAutoReconnect bool
+}
+
+// ChildBuilderFunc creates a new balancer with the ClientConn. It has the same
+// type as the balancer.Builder.Build method.
+type ChildBuilderFunc func(cc balancer.ClientConn, opts balancer.BuildOptions) balancer.Balancer
+
+// NewBalancer returns a load balancing policy that manages homogeneous child
+// policies each owning a single endpoint. The endpointsharding balancer
+// forwards the LoadBalancingConfig in ClientConn state updates to its children.
+func NewBalancer(cc balancer.ClientConn, opts balancer.BuildOptions, childBuilder ChildBuilderFunc, esOpts Options) balancer.Balancer {
+	es := &endpointSharding{
+		cc:           cc,
+		bOpts:        opts,
+		esOpts:       esOpts,
+		childBuilder: childBuilder,
+	}
+	es.children.Store(resolver.NewEndpointMap[*balancerWrapper]())
+	return es
+}
+
+// endpointSharding is a balancer that wraps child balancers. It creates a child
+// balancer with child config for every unique Endpoint received. It updates the
+// child states on any update from parent or child.
+type endpointSharding struct {
+	cc           balancer.ClientConn
+	bOpts        balancer.BuildOptions
+	esOpts       Options
+	childBuilder ChildBuilderFunc
+
+	// childMu synchronizes calls to any single child. It must be held for all
+	// calls into a child. To avoid deadlocks, do not acquire childMu while
+	// holding mu.
+	childMu  sync.Mutex
+	children atomic.Pointer[resolver.EndpointMap[*balancerWrapper]]
+
+	// inhibitChildUpdates is set during UpdateClientConnState/ResolverError
+	// calls (calls to children will each produce an update, only want one
+	// update).
+	inhibitChildUpdates atomic.Bool
+
+	// mu synchronizes access to the state stored in balancerWrappers in the
+	// children field. mu must not be held during calls into a child since
+	// synchronous calls back from the child may require taking mu, causing a
+	// deadlock. To avoid deadlocks, do not acquire childMu while holding mu.
+	mu sync.Mutex
+}
+
+// UpdateClientConnState creates a child for new endpoints and deletes children
+// for endpoints that are no longer present. It also updates all the children,
+// and sends a single synchronous update of the childrens' aggregated state at
+// the end of the UpdateClientConnState operation. If any endpoint has no
+// addresses it will ignore that endpoint. Otherwise, returns first error found
+// from a child, but fully processes the new update.
+func (es *endpointSharding) UpdateClientConnState(state balancer.ClientConnState) error {
+	es.childMu.Lock()
+	defer es.childMu.Unlock()
+
+	es.inhibitChildUpdates.Store(true)
+	defer func() {
+		es.inhibitChildUpdates.Store(false)
+		es.updateState()
+	}()
+	var ret error
+
+	children := es.children.Load()
+	newChildren := resolver.NewEndpointMap[*balancerWrapper]()
+
+	// Update/Create new children.
+	for _, endpoint := range state.ResolverState.Endpoints {
+		if _, ok := newChildren.Get(endpoint); ok {
+			// Endpoint child was already created, continue to avoid duplicate
+			// update.
+			continue
+		}
+		childBalancer, ok := children.Get(endpoint)
+		if ok {
+			// Endpoint attributes may have changed, update the stored endpoint.
+			es.mu.Lock()
+			childBalancer.childState.Endpoint = endpoint
+			es.mu.Unlock()
+		} else {
+			childBalancer = &balancerWrapper{
+				childState: ChildState{Endpoint: endpoint},
+				ClientConn: es.cc,
+				es:         es,
+			}
+			childBalancer.childState.Balancer = childBalancer
+			childBalancer.child = es.childBuilder(childBalancer, es.bOpts)
+		}
+		newChildren.Set(endpoint, childBalancer)
+		if err := childBalancer.updateClientConnStateLocked(balancer.ClientConnState{
+			BalancerConfig: state.BalancerConfig,
+			ResolverState: resolver.State{
+				Endpoints:  []resolver.Endpoint{endpoint},
+				Attributes: state.ResolverState.Attributes,
+			},
+		}); err != nil && ret == nil {
+			// Return first error found, and always commit full processing of
+			// updating children. If desired to process more specific errors
+			// across all endpoints, caller should make these specific
+			// validations, this is a current limitation for simplicity sake.
+			ret = err
+		}
+	}
+	// Delete old children that are no longer present.
+	for _, e := range children.Keys() {
+		child, _ := children.Get(e)
+		if _, ok := newChildren.Get(e); !ok {
+			child.closeLocked()
+		}
+	}
+	es.children.Store(newChildren)
+	if newChildren.Len() == 0 {
+		return balancer.ErrBadResolverState
+	}
+	return ret
+}
+
+// ResolverError forwards the resolver error to all of the endpointSharding's
+// children and sends a single synchronous update of the childStates at the end
+// of the ResolverError operation.
+func (es *endpointSharding) ResolverError(err error) {
+	es.childMu.Lock()
+	defer es.childMu.Unlock()
+	es.inhibitChildUpdates.Store(true)
+	defer func() {
+		es.inhibitChildUpdates.Store(false)
+		es.updateState()
+	}()
+	children := es.children.Load()
+	for _, child := range children.Values() {
+		child.resolverErrorLocked(err)
+	}
+}
+
+func (es *endpointSharding) UpdateSubConnState(balancer.SubConn, balancer.SubConnState) {
+	// UpdateSubConnState is deprecated.
+}
+
+func (es *endpointSharding) Close() {
+	es.childMu.Lock()
+	defer es.childMu.Unlock()
+	children := es.children.Load()
+	for _, child := range children.Values() {
+		child.closeLocked()
+	}
+}
+
+// updateState updates this component's state. It sends the aggregated state,
+// and a picker with round robin behavior with all the child states present if
+// needed.
+func (es *endpointSharding) updateState() {
+	if es.inhibitChildUpdates.Load() {
+		return
+	}
+	var readyPickers, connectingPickers, idlePickers, transientFailurePickers []balancer.Picker
+
+	es.mu.Lock()
+	defer es.mu.Unlock()
+
+	children := es.children.Load()
+	childStates := make([]ChildState, 0, children.Len())
+
+	for _, child := range children.Values() {
+		childState := child.childState
+		childStates = append(childStates, childState)
+		childPicker := childState.State.Picker
+		switch childState.State.ConnectivityState {
+		case connectivity.Ready:
+			readyPickers = append(readyPickers, childPicker)
+		case connectivity.Connecting:
+			connectingPickers = append(connectingPickers, childPicker)
+		case connectivity.Idle:
+			idlePickers = append(idlePickers, childPicker)
+		case connectivity.TransientFailure:
+			transientFailurePickers = append(transientFailurePickers, childPicker)
+			// connectivity.Shutdown shouldn't appear.
+		}
+	}
+
+	// Construct the round robin picker based off the aggregated state. Whatever
+	// the aggregated state, use the pickers present that are currently in that
+	// state only.
+	var aggState connectivity.State
+	var pickers []balancer.Picker
+	if len(readyPickers) >= 1 {
+		aggState = connectivity.Ready
+		pickers = readyPickers
+	} else if len(connectingPickers) >= 1 {
+		aggState = connectivity.Connecting
+		pickers = connectingPickers
+	} else if len(idlePickers) >= 1 {
+		aggState = connectivity.Idle
+		pickers = idlePickers
+	} else if len(transientFailurePickers) >= 1 {
+		aggState = connectivity.TransientFailure
+		pickers = transientFailurePickers
+	} else {
+		aggState = connectivity.TransientFailure
+		pickers = []balancer.Picker{base.NewErrPicker(errors.New("no children to pick from"))}
+	} // No children (resolver error before valid update).
+	p := &pickerWithChildStates{
+		pickers:     pickers,
+		childStates: childStates,
+		next:        uint32(rand.IntN(len(pickers))),
+	}
+	es.cc.UpdateState(balancer.State{
+		ConnectivityState: aggState,
+		Picker:            p,
+	})
+}
+
+// pickerWithChildStates delegates to the pickers it holds in a round robin
+// fashion. It also contains the childStates of all the endpointSharding's
+// children.
+type pickerWithChildStates struct {
+	pickers     []balancer.Picker
+	childStates []ChildState
+	next        uint32
+}
+
+func (p *pickerWithChildStates) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
+	nextIndex := atomic.AddUint32(&p.next, 1)
+	picker := p.pickers[nextIndex%uint32(len(p.pickers))]
+	return picker.Pick(info)
+}
+
+// ChildStatesFromPicker returns the state of all the children managed by the
+// endpoint sharding balancer that created this picker.
+func ChildStatesFromPicker(picker balancer.Picker) []ChildState {
+	p, ok := picker.(*pickerWithChildStates)
+	if !ok {
+		return nil
+	}
+	return p.childStates
+}
+
+// balancerWrapper is a wrapper of a balancer. It ID's a child balancer by
+// endpoint, and persists recent child balancer state.
+type balancerWrapper struct {
+	// The following fields are initialized at build time and read-only after
+	// that and therefore do not need to be guarded by a mutex.
+
+	// child contains the wrapped balancer. Access its methods only through
+	// methods on balancerWrapper to ensure proper synchronization
+	child               balancer.Balancer
+	balancer.ClientConn // embed to intercept UpdateState, doesn't deal with SubConns
+
+	es *endpointSharding
+
+	// Access to the following fields is guarded by es.mu.
+
+	childState ChildState
+	isClosed   bool
+}
+
+func (bw *balancerWrapper) UpdateState(state balancer.State) {
+	bw.es.mu.Lock()
+	bw.childState.State = state
+	bw.es.mu.Unlock()
+	if state.ConnectivityState == connectivity.Idle && !bw.es.esOpts.DisableAutoReconnect {
+		bw.ExitIdle()
+	}
+	bw.es.updateState()
+}
+
+// ExitIdle pings an IDLE child balancer to exit idle in a new goroutine to
+// avoid deadlocks due to synchronous balancer state updates.
+func (bw *balancerWrapper) ExitIdle() {
+	if ei, ok := bw.child.(balancer.ExitIdler); ok {
+		go func() {
+			bw.es.childMu.Lock()
+			if !bw.isClosed {
+				ei.ExitIdle()
+			}
+			bw.es.childMu.Unlock()
+		}()
+	}
+}
+
+// updateClientConnStateLocked delivers the ClientConnState to the child
+// balancer. Callers must hold the child mutex of the parent endpointsharding
+// balancer.
+func (bw *balancerWrapper) updateClientConnStateLocked(ccs balancer.ClientConnState) error {
+	return bw.child.UpdateClientConnState(ccs)
+}
+
+// closeLocked closes the child balancer. Callers must hold the child mutext of
+// the parent endpointsharding balancer.
+func (bw *balancerWrapper) closeLocked() {
+	bw.child.Close()
+	bw.isClosed = true
+}
+
+func (bw *balancerWrapper) resolverErrorLocked(err error) {
+	bw.child.ResolverError(err)
+}

vendor/google.golang.org/grpc/balancer/pickfirst/internal/internal.go

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains code internal to the pickfirst package.
+package internal
+
+import (
+	rand "math/rand/v2"
+	"time"
+)
+
+var (
+	// RandShuffle pseudo-randomizes the order of addresses.
+	RandShuffle = rand.Shuffle
+	// TimeAfterFunc allows mocking the timer for testing connection delay
+	// related functionality.
+	TimeAfterFunc = func(d time.Duration, f func()) func() {
+		timer := time.AfterFunc(d, f)
+		return func() { timer.Stop() }
+	}
+)

vendor/google.golang.org/grpc/balancer/pickfirst/pickfirst.go

@@ -16,45 +16,60 @@
  *
  */
 
-package grpc
+// Package pickfirst contains the pick_first load balancing policy.
+package pickfirst
 
 import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	rand "math/rand/v2"
 
 	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/pickfirst/internal"
 	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/envconfig"
 	internalgrpclog "google.golang.org/grpc/internal/grpclog"
-	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/internal/pretty"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/serviceconfig"
+
+	_ "google.golang.org/grpc/balancer/pickfirst/pickfirstleaf" // For automatically registering the new pickfirst if required.
 )
 
+func init() {
+	if envconfig.NewPickFirstEnabled {
+		return
+	}
+	balancer.Register(pickfirstBuilder{})
+}
+
+var logger = grpclog.Component("pick-first-lb")
+
 const (
-	// PickFirstBalancerName is the name of the pick_first balancer.
-	PickFirstBalancerName = "pick_first"
-	logPrefix             = "[pick-first-lb %p] "
+	// Name is the name of the pick_first balancer.
+	Name      = "pick_first"
+	logPrefix = "[pick-first-lb %p] "
 )
 
 type pickfirstBuilder struct{}
 
-func (pickfirstBuilder) Build(cc balancer.ClientConn, opt balancer.BuildOptions) balancer.Balancer {
+func (pickfirstBuilder) Build(cc balancer.ClientConn, _ balancer.BuildOptions) balancer.Balancer {
 	b := &pickfirstBalancer{cc: cc}
 	b.logger = internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf(logPrefix, b))
 	return b
 }
 
 func (pickfirstBuilder) Name() string {
-	return PickFirstBalancerName
+	return Name
 }
 
 type pfConfig struct {
 	serviceconfig.LoadBalancingConfig `json:"-"`
 
 	// If set to true, instructs the LB policy to shuffle the order of the list
-	// of addresses received from the name resolver before attempting to
+	// of endpoints received from the name resolver before attempting to
 	// connect to them.
 	ShuffleAddressList bool `json:"shuffleAddressList"`
 }
@@ -93,9 +108,17 @@ func (b *pickfirstBalancer) ResolverError(err error) {
 	})
 }
 
+// Shuffler is an interface for shuffling an address list.
+type Shuffler interface {
+	ShuffleAddressListForTesting(n int, swap func(i, j int))
+}
+
+// ShuffleAddressListForTesting pseudo-randomizes the order of addresses.  n
+// is the number of elements.  swap swaps the elements with indexes i and j.
+func ShuffleAddressListForTesting(n int, swap func(i, j int)) { rand.Shuffle(n, swap) }
+
 func (b *pickfirstBalancer) UpdateClientConnState(state balancer.ClientConnState) error {
-	addrs := state.ResolverState.Addresses
-	if len(addrs) == 0 {
+	if len(state.ResolverState.Addresses) == 0 && len(state.ResolverState.Endpoints) == 0 {
 		// The resolver reported an empty address list. Treat it like an error by
 		// calling b.ResolverError.
 		if b.subConn != nil {
@@ -107,22 +130,49 @@ func (b *pickfirstBalancer) UpdateClientConnState(state balancer.ClientConnState
 		b.ResolverError(errors.New("produced zero addresses"))
 		return balancer.ErrBadResolverState
 	}
-
 	// We don't have to guard this block with the env var because ParseConfig
 	// already does so.
 	cfg, ok := state.BalancerConfig.(pfConfig)
 	if state.BalancerConfig != nil && !ok {
 		return fmt.Errorf("pickfirst: received illegal BalancerConfig (type %T): %v", state.BalancerConfig, state.BalancerConfig)
 	}
-	if cfg.ShuffleAddressList {
-		addrs = append([]resolver.Address{}, addrs...)
-		grpcrand.Shuffle(len(addrs), func(i, j int) { addrs[i], addrs[j] = addrs[j], addrs[i] })
-	}
 
 	if b.logger.V(2) {
 		b.logger.Infof("Received new config %s, resolver state %s", pretty.ToJSON(cfg), pretty.ToJSON(state.ResolverState))
 	}
 
+	var addrs []resolver.Address
+	if endpoints := state.ResolverState.Endpoints; len(endpoints) != 0 {
+		// Perform the optional shuffling described in gRFC A62. The shuffling will
+		// change the order of endpoints but not touch the order of the addresses
+		// within each endpoint. - A61
+		if cfg.ShuffleAddressList {
+			endpoints = append([]resolver.Endpoint{}, endpoints...)
+			internal.RandShuffle(len(endpoints), func(i, j int) { endpoints[i], endpoints[j] = endpoints[j], endpoints[i] })
+		}
+
+		// "Flatten the list by concatenating the ordered list of addresses for each
+		// of the endpoints, in order." - A61
+		for _, endpoint := range endpoints {
+			// "In the flattened list, interleave addresses from the two address
+			// families, as per RFC-8304 section 4." - A61
+			// TODO: support the above language.
+			addrs = append(addrs, endpoint.Addresses...)
+		}
+	} else {
+		// Endpoints not set, process addresses until we migrate resolver
+		// emissions fully to Endpoints. The top channel does wrap emitted
+		// addresses with endpoints, however some balancers such as weighted
+		// target do not forward the corresponding correct endpoints down/split
+		// endpoints properly. Once all balancers correctly forward endpoints
+		// down, can delete this else conditional.
+		addrs = state.ResolverState.Addresses
+		if cfg.ShuffleAddressList {
+			addrs = append([]resolver.Address{}, addrs...)
+			rand.Shuffle(len(addrs), func(i, j int) { addrs[i], addrs[j] = addrs[j], addrs[i] })
+		}
+	}
+
 	if b.subConn != nil {
 		b.cc.UpdateAddresses(b.subConn, addrs)
 		return nil

vendor/google.golang.org/grpc/balancer/pickfirst/pickfirstleaf/pickfirstleaf.go

@@ -0,0 +1,927 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package pickfirstleaf contains the pick_first load balancing policy which
+// will be the universal leaf policy after dualstack changes are implemented.
+//
+// # Experimental
+//
+// Notice: This package is EXPERIMENTAL and may be changed or removed in a
+// later release.
+package pickfirstleaf
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"net/netip"
+	"sync"
+	"time"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/pickfirst/internal"
+	"google.golang.org/grpc/connectivity"
+	expstats "google.golang.org/grpc/experimental/stats"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/envconfig"
+	internalgrpclog "google.golang.org/grpc/internal/grpclog"
+	"google.golang.org/grpc/internal/pretty"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+func init() {
+	if envconfig.NewPickFirstEnabled {
+		// Register as the default pick_first balancer.
+		Name = "pick_first"
+	}
+	balancer.Register(pickfirstBuilder{})
+}
+
+type (
+	// enableHealthListenerKeyType is a unique key type used in resolver
+	// attributes to indicate whether the health listener usage is enabled.
+	enableHealthListenerKeyType struct{}
+	// managedByPickfirstKeyType is an attribute key type to inform Outlier
+	// Detection that the generic health listener is being used.
+	// TODO: https://github.com/grpc/grpc-go/issues/7915 - Remove this when
+	// implementing the dualstack design. This is a hack. Once Dualstack is
+	// completed, outlier detection will stop sending ejection updates through
+	// the connectivity listener.
+	managedByPickfirstKeyType struct{}
+)
+
+var (
+	logger = grpclog.Component("pick-first-leaf-lb")
+	// Name is the name of the pick_first_leaf balancer.
+	// It is changed to "pick_first" in init() if this balancer is to be
+	// registered as the default pickfirst.
+	Name                 = "pick_first_leaf"
+	disconnectionsMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+		Name:        "grpc.lb.pick_first.disconnections",
+		Description: "EXPERIMENTAL. Number of times the selected subchannel becomes disconnected.",
+		Unit:        "disconnection",
+		Labels:      []string{"grpc.target"},
+		Default:     false,
+	})
+	connectionAttemptsSucceededMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+		Name:        "grpc.lb.pick_first.connection_attempts_succeeded",
+		Description: "EXPERIMENTAL. Number of successful connection attempts.",
+		Unit:        "attempt",
+		Labels:      []string{"grpc.target"},
+		Default:     false,
+	})
+	connectionAttemptsFailedMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+		Name:        "grpc.lb.pick_first.connection_attempts_failed",
+		Description: "EXPERIMENTAL. Number of failed connection attempts.",
+		Unit:        "attempt",
+		Labels:      []string{"grpc.target"},
+		Default:     false,
+	})
+)
+
+const (
+	// TODO: change to pick-first when this becomes the default pick_first policy.
+	logPrefix = "[pick-first-leaf-lb %p] "
+	// connectionDelayInterval is the time to wait for during the happy eyeballs
+	// pass before starting the next connection attempt.
+	connectionDelayInterval = 250 * time.Millisecond
+)
+
+type ipAddrFamily int
+
+const (
+	// ipAddrFamilyUnknown represents strings that can't be parsed as an IP
+	// address.
+	ipAddrFamilyUnknown ipAddrFamily = iota
+	ipAddrFamilyV4
+	ipAddrFamilyV6
+)
+
+type pickfirstBuilder struct{}
+
+func (pickfirstBuilder) Build(cc balancer.ClientConn, bo balancer.BuildOptions) balancer.Balancer {
+	b := &pickfirstBalancer{
+		cc:              cc,
+		target:          bo.Target.String(),
+		metricsRecorder: cc.MetricsRecorder(),
+
+		subConns:              resolver.NewAddressMapV2[*scData](),
+		state:                 connectivity.Connecting,
+		cancelConnectionTimer: func() {},
+	}
+	b.logger = internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf(logPrefix, b))
+	return b
+}
+
+func (b pickfirstBuilder) Name() string {
+	return Name
+}
+
+func (pickfirstBuilder) ParseConfig(js json.RawMessage) (serviceconfig.LoadBalancingConfig, error) {
+	var cfg pfConfig
+	if err := json.Unmarshal(js, &cfg); err != nil {
+		return nil, fmt.Errorf("pickfirst: unable to unmarshal LB policy config: %s, error: %v", string(js), err)
+	}
+	return cfg, nil
+}
+
+// EnableHealthListener updates the state to configure pickfirst for using a
+// generic health listener.
+func EnableHealthListener(state resolver.State) resolver.State {
+	state.Attributes = state.Attributes.WithValue(enableHealthListenerKeyType{}, true)
+	return state
+}
+
+// IsManagedByPickfirst returns whether an address belongs to a SubConn
+// managed by the pickfirst LB policy.
+// TODO: https://github.com/grpc/grpc-go/issues/7915 - This is a hack to disable
+// outlier_detection via the with connectivity listener when using pick_first.
+// Once Dualstack changes are complete, all SubConns will be created by
+// pick_first and outlier detection will only use the health listener for
+// ejection. This hack can then be removed.
+func IsManagedByPickfirst(addr resolver.Address) bool {
+	return addr.BalancerAttributes.Value(managedByPickfirstKeyType{}) != nil
+}
+
+type pfConfig struct {
+	serviceconfig.LoadBalancingConfig `json:"-"`
+
+	// If set to true, instructs the LB policy to shuffle the order of the list
+	// of endpoints received from the name resolver before attempting to
+	// connect to them.
+	ShuffleAddressList bool `json:"shuffleAddressList"`
+}
+
+// scData keeps track of the current state of the subConn.
+// It is not safe for concurrent access.
+type scData struct {
+	// The following fields are initialized at build time and read-only after
+	// that.
+	subConn balancer.SubConn
+	addr    resolver.Address
+
+	rawConnectivityState connectivity.State
+	// The effective connectivity state based on raw connectivity, health state
+	// and after following sticky TransientFailure behaviour defined in A62.
+	effectiveState              connectivity.State
+	lastErr                     error
+	connectionFailedInFirstPass bool
+}
+
+func (b *pickfirstBalancer) newSCData(addr resolver.Address) (*scData, error) {
+	addr.BalancerAttributes = addr.BalancerAttributes.WithValue(managedByPickfirstKeyType{}, true)
+	sd := &scData{
+		rawConnectivityState: connectivity.Idle,
+		effectiveState:       connectivity.Idle,
+		addr:                 addr,
+	}
+	sc, err := b.cc.NewSubConn([]resolver.Address{addr}, balancer.NewSubConnOptions{
+		StateListener: func(state balancer.SubConnState) {
+			b.updateSubConnState(sd, state)
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+	sd.subConn = sc
+	return sd, nil
+}
+
+type pickfirstBalancer struct {
+	// The following fields are initialized at build time and read-only after
+	// that and therefore do not need to be guarded by a mutex.
+	logger          *internalgrpclog.PrefixLogger
+	cc              balancer.ClientConn
+	target          string
+	metricsRecorder expstats.MetricsRecorder // guaranteed to be non nil
+
+	// The mutex is used to ensure synchronization of updates triggered
+	// from the idle picker and the already serialized resolver,
+	// SubConn state updates.
+	mu sync.Mutex
+	// State reported to the channel based on SubConn states and resolver
+	// updates.
+	state connectivity.State
+	// scData for active subonns mapped by address.
+	subConns              *resolver.AddressMapV2[*scData]
+	addressList           addressList
+	firstPass             bool
+	numTF                 int
+	cancelConnectionTimer func()
+	healthCheckingEnabled bool
+}
+
+// ResolverError is called by the ClientConn when the name resolver produces
+// an error or when pickfirst determined the resolver update to be invalid.
+func (b *pickfirstBalancer) ResolverError(err error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.resolverErrorLocked(err)
+}
+
+func (b *pickfirstBalancer) resolverErrorLocked(err error) {
+	if b.logger.V(2) {
+		b.logger.Infof("Received error from the name resolver: %v", err)
+	}
+
+	// The picker will not change since the balancer does not currently
+	// report an error. If the balancer hasn't received a single good resolver
+	// update yet, transition to TRANSIENT_FAILURE.
+	if b.state != connectivity.TransientFailure && b.addressList.size() > 0 {
+		if b.logger.V(2) {
+			b.logger.Infof("Ignoring resolver error because balancer is using a previous good update.")
+		}
+		return
+	}
+
+	b.updateBalancerState(balancer.State{
+		ConnectivityState: connectivity.TransientFailure,
+		Picker:            &picker{err: fmt.Errorf("name resolver error: %v", err)},
+	})
+}
+
+func (b *pickfirstBalancer) UpdateClientConnState(state balancer.ClientConnState) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.cancelConnectionTimer()
+	if len(state.ResolverState.Addresses) == 0 && len(state.ResolverState.Endpoints) == 0 {
+		// Cleanup state pertaining to the previous resolver state.
+		// Treat an empty address list like an error by calling b.ResolverError.
+		b.closeSubConnsLocked()
+		b.addressList.updateAddrs(nil)
+		b.resolverErrorLocked(errors.New("produced zero addresses"))
+		return balancer.ErrBadResolverState
+	}
+	b.healthCheckingEnabled = state.ResolverState.Attributes.Value(enableHealthListenerKeyType{}) != nil
+	cfg, ok := state.BalancerConfig.(pfConfig)
+	if state.BalancerConfig != nil && !ok {
+		return fmt.Errorf("pickfirst: received illegal BalancerConfig (type %T): %v: %w", state.BalancerConfig, state.BalancerConfig, balancer.ErrBadResolverState)
+	}
+
+	if b.logger.V(2) {
+		b.logger.Infof("Received new config %s, resolver state %s", pretty.ToJSON(cfg), pretty.ToJSON(state.ResolverState))
+	}
+
+	var newAddrs []resolver.Address
+	if endpoints := state.ResolverState.Endpoints; len(endpoints) != 0 {
+		// Perform the optional shuffling described in gRFC A62. The shuffling
+		// will change the order of endpoints but not touch the order of the
+		// addresses within each endpoint. - A61
+		if cfg.ShuffleAddressList {
+			endpoints = append([]resolver.Endpoint{}, endpoints...)
+			internal.RandShuffle(len(endpoints), func(i, j int) { endpoints[i], endpoints[j] = endpoints[j], endpoints[i] })
+		}
+
+		// "Flatten the list by concatenating the ordered list of addresses for
+		// each of the endpoints, in order." - A61
+		for _, endpoint := range endpoints {
+			newAddrs = append(newAddrs, endpoint.Addresses...)
+		}
+	} else {
+		// Endpoints not set, process addresses until we migrate resolver
+		// emissions fully to Endpoints. The top channel does wrap emitted
+		// addresses with endpoints, however some balancers such as weighted
+		// target do not forward the corresponding correct endpoints down/split
+		// endpoints properly. Once all balancers correctly forward endpoints
+		// down, can delete this else conditional.
+		newAddrs = state.ResolverState.Addresses
+		if cfg.ShuffleAddressList {
+			newAddrs = append([]resolver.Address{}, newAddrs...)
+			internal.RandShuffle(len(endpoints), func(i, j int) { endpoints[i], endpoints[j] = endpoints[j], endpoints[i] })
+		}
+	}
+
+	// If an address appears in multiple endpoints or in the same endpoint
+	// multiple times, we keep it only once. We will create only one SubConn
+	// for the address because an AddressMap is used to store SubConns.
+	// Not de-duplicating would result in attempting to connect to the same
+	// SubConn multiple times in the same pass. We don't want this.
+	newAddrs = deDupAddresses(newAddrs)
+	newAddrs = interleaveAddresses(newAddrs)
+
+	prevAddr := b.addressList.currentAddress()
+	prevSCData, found := b.subConns.Get(prevAddr)
+	prevAddrsCount := b.addressList.size()
+	isPrevRawConnectivityStateReady := found && prevSCData.rawConnectivityState == connectivity.Ready
+	b.addressList.updateAddrs(newAddrs)
+
+	// If the previous ready SubConn exists in new address list,
+	// keep this connection and don't create new SubConns.
+	if isPrevRawConnectivityStateReady && b.addressList.seekTo(prevAddr) {
+		return nil
+	}
+
+	b.reconcileSubConnsLocked(newAddrs)
+	// If it's the first resolver update or the balancer was already READY
+	// (but the new address list does not contain the ready SubConn) or
+	// CONNECTING, enter CONNECTING.
+	// We may be in TRANSIENT_FAILURE due to a previous empty address list,
+	// we should still enter CONNECTING because the sticky TF behaviour
+	//  mentioned in A62 applies only when the TRANSIENT_FAILURE is reported
+	// due to connectivity failures.
+	if isPrevRawConnectivityStateReady || b.state == connectivity.Connecting || prevAddrsCount == 0 {
+		// Start connection attempt at first address.
+		b.forceUpdateConcludedStateLocked(balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
+		b.startFirstPassLocked()
+	} else if b.state == connectivity.TransientFailure {
+		// If we're in TRANSIENT_FAILURE, we stay in TRANSIENT_FAILURE until
+		// we're READY. See A62.
+		b.startFirstPassLocked()
+	}
+	return nil
+}
+
+// UpdateSubConnState is unused as a StateListener is always registered when
+// creating SubConns.
+func (b *pickfirstBalancer) UpdateSubConnState(subConn balancer.SubConn, state balancer.SubConnState) {
+	b.logger.Errorf("UpdateSubConnState(%v, %+v) called unexpectedly", subConn, state)
+}
+
+func (b *pickfirstBalancer) Close() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.closeSubConnsLocked()
+	b.cancelConnectionTimer()
+	b.state = connectivity.Shutdown
+}
+
+// ExitIdle moves the balancer out of idle state. It can be called concurrently
+// by the idlePicker and clientConn so access to variables should be
+// synchronized.
+func (b *pickfirstBalancer) ExitIdle() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.state == connectivity.Idle {
+		b.startFirstPassLocked()
+	}
+}
+
+func (b *pickfirstBalancer) startFirstPassLocked() {
+	b.firstPass = true
+	b.numTF = 0
+	// Reset the connection attempt record for existing SubConns.
+	for _, sd := range b.subConns.Values() {
+		sd.connectionFailedInFirstPass = false
+	}
+	b.requestConnectionLocked()
+}
+
+func (b *pickfirstBalancer) closeSubConnsLocked() {
+	for _, sd := range b.subConns.Values() {
+		sd.subConn.Shutdown()
+	}
+	b.subConns = resolver.NewAddressMapV2[*scData]()
+}
+
+// deDupAddresses ensures that each address appears only once in the slice.
+func deDupAddresses(addrs []resolver.Address) []resolver.Address {
+	seenAddrs := resolver.NewAddressMapV2[*scData]()
+	retAddrs := []resolver.Address{}
+
+	for _, addr := range addrs {
+		if _, ok := seenAddrs.Get(addr); ok {
+			continue
+		}
+		retAddrs = append(retAddrs, addr)
+	}
+	return retAddrs
+}
+
+// interleaveAddresses interleaves addresses of both families (IPv4 and IPv6)
+// as per RFC-8305 section 4.
+// Whichever address family is first in the list is followed by an address of
+// the other address family; that is, if the first address in the list is IPv6,
+// then the first IPv4 address should be moved up in the list to be second in
+// the list. It doesn't support configuring "First Address Family Count", i.e.
+// there will always be a single member of the first address family at the
+// beginning of the interleaved list.
+// Addresses that are neither IPv4 nor IPv6 are treated as part of a third
+// "unknown" family for interleaving.
+// See: https://datatracker.ietf.org/doc/html/rfc8305#autoid-6
+func interleaveAddresses(addrs []resolver.Address) []resolver.Address {
+	familyAddrsMap := map[ipAddrFamily][]resolver.Address{}
+	interleavingOrder := []ipAddrFamily{}
+	for _, addr := range addrs {
+		family := addressFamily(addr.Addr)
+		if _, found := familyAddrsMap[family]; !found {
+			interleavingOrder = append(interleavingOrder, family)
+		}
+		familyAddrsMap[family] = append(familyAddrsMap[family], addr)
+	}
+
+	interleavedAddrs := make([]resolver.Address, 0, len(addrs))
+
+	for curFamilyIdx := 0; len(interleavedAddrs) < len(addrs); curFamilyIdx = (curFamilyIdx + 1) % len(interleavingOrder) {
+		// Some IP types may have fewer addresses than others, so we look for
+		// the next type that has a remaining member to add to the interleaved
+		// list.
+		family := interleavingOrder[curFamilyIdx]
+		remainingMembers := familyAddrsMap[family]
+		if len(remainingMembers) > 0 {
+			interleavedAddrs = append(interleavedAddrs, remainingMembers[0])
+			familyAddrsMap[family] = remainingMembers[1:]
+		}
+	}
+
+	return interleavedAddrs
+}
+
+// addressFamily returns the ipAddrFamily after parsing the address string.
+// If the address isn't of the format "ip-address:port", it returns
+// ipAddrFamilyUnknown. The address may be valid even if it's not an IP when
+// using a resolver like passthrough where the address may be a hostname in
+// some format that the dialer can resolve.
+func addressFamily(address string) ipAddrFamily {
+	// Parse the IP after removing the port.
+	host, _, err := net.SplitHostPort(address)
+	if err != nil {
+		return ipAddrFamilyUnknown
+	}
+	ip, err := netip.ParseAddr(host)
+	if err != nil {
+		return ipAddrFamilyUnknown
+	}
+	switch {
+	case ip.Is4() || ip.Is4In6():
+		return ipAddrFamilyV4
+	case ip.Is6():
+		return ipAddrFamilyV6
+	default:
+		return ipAddrFamilyUnknown
+	}
+}
+
+// reconcileSubConnsLocked updates the active subchannels based on a new address
+// list from the resolver. It does this by:
+//   - closing subchannels: any existing subchannels associated with addresses
+//     that are no longer in the updated list are shut down.
+//   - removing subchannels: entries for these closed subchannels are removed
+//     from the subchannel map.
+//
+// This ensures that the subchannel map accurately reflects the current set of
+// addresses received from the name resolver.
+func (b *pickfirstBalancer) reconcileSubConnsLocked(newAddrs []resolver.Address) {
+	newAddrsMap := resolver.NewAddressMapV2[bool]()
+	for _, addr := range newAddrs {
+		newAddrsMap.Set(addr, true)
+	}
+
+	for _, oldAddr := range b.subConns.Keys() {
+		if _, ok := newAddrsMap.Get(oldAddr); ok {
+			continue
+		}
+		val, _ := b.subConns.Get(oldAddr)
+		val.subConn.Shutdown()
+		b.subConns.Delete(oldAddr)
+	}
+}
+
+// shutdownRemainingLocked shuts down remaining subConns. Called when a subConn
+// becomes ready, which means that all other subConn must be shutdown.
+func (b *pickfirstBalancer) shutdownRemainingLocked(selected *scData) {
+	b.cancelConnectionTimer()
+	for _, sd := range b.subConns.Values() {
+		if sd.subConn != selected.subConn {
+			sd.subConn.Shutdown()
+		}
+	}
+	b.subConns = resolver.NewAddressMapV2[*scData]()
+	b.subConns.Set(selected.addr, selected)
+}
+
+// requestConnectionLocked starts connecting on the subchannel corresponding to
+// the current address. If no subchannel exists, one is created. If the current
+// subchannel is in TransientFailure, a connection to the next address is
+// attempted until a subchannel is found.
+func (b *pickfirstBalancer) requestConnectionLocked() {
+	if !b.addressList.isValid() {
+		return
+	}
+	var lastErr error
+	for valid := true; valid; valid = b.addressList.increment() {
+		curAddr := b.addressList.currentAddress()
+		sd, ok := b.subConns.Get(curAddr)
+		if !ok {
+			var err error
+			// We want to assign the new scData to sd from the outer scope,
+			// hence we can't use := below.
+			sd, err = b.newSCData(curAddr)
+			if err != nil {
+				// This should never happen, unless the clientConn is being shut
+				// down.
+				if b.logger.V(2) {
+					b.logger.Infof("Failed to create a subConn for address %v: %v", curAddr.String(), err)
+				}
+				// Do nothing, the LB policy will be closed soon.
+				return
+			}
+			b.subConns.Set(curAddr, sd)
+		}
+
+		switch sd.rawConnectivityState {
+		case connectivity.Idle:
+			sd.subConn.Connect()
+			b.scheduleNextConnectionLocked()
+			return
+		case connectivity.TransientFailure:
+			// The SubConn is being re-used and failed during a previous pass
+			// over the addressList. It has not completed backoff yet.
+			// Mark it as having failed and try the next address.
+			sd.connectionFailedInFirstPass = true
+			lastErr = sd.lastErr
+			continue
+		case connectivity.Connecting:
+			// Wait for the connection attempt to complete or the timer to fire
+			// before attempting the next address.
+			b.scheduleNextConnectionLocked()
+			return
+		default:
+			b.logger.Errorf("SubConn with unexpected state %v present in SubConns map.", sd.rawConnectivityState)
+			return
+
+		}
+	}
+
+	// All the remaining addresses in the list are in TRANSIENT_FAILURE, end the
+	// first pass if possible.
+	b.endFirstPassIfPossibleLocked(lastErr)
+}
+
+func (b *pickfirstBalancer) scheduleNextConnectionLocked() {
+	b.cancelConnectionTimer()
+	if !b.addressList.hasNext() {
+		return
+	}
+	curAddr := b.addressList.currentAddress()
+	cancelled := false // Access to this is protected by the balancer's mutex.
+	closeFn := internal.TimeAfterFunc(connectionDelayInterval, func() {
+		b.mu.Lock()
+		defer b.mu.Unlock()
+		// If the scheduled task is cancelled while acquiring the mutex, return.
+		if cancelled {
+			return
+		}
+		if b.logger.V(2) {
+			b.logger.Infof("Happy Eyeballs timer expired while waiting for connection to %q.", curAddr.Addr)
+		}
+		if b.addressList.increment() {
+			b.requestConnectionLocked()
+		}
+	})
+	// Access to the cancellation callback held by the balancer is guarded by
+	// the balancer's mutex, so it's safe to set the boolean from the callback.
+	b.cancelConnectionTimer = sync.OnceFunc(func() {
+		cancelled = true
+		closeFn()
+	})
+}
+
+func (b *pickfirstBalancer) updateSubConnState(sd *scData, newState balancer.SubConnState) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	oldState := sd.rawConnectivityState
+	sd.rawConnectivityState = newState.ConnectivityState
+	// Previously relevant SubConns can still callback with state updates.
+	// To prevent pickers from returning these obsolete SubConns, this logic
+	// is included to check if the current list of active SubConns includes this
+	// SubConn.
+	if !b.isActiveSCData(sd) {
+		return
+	}
+	if newState.ConnectivityState == connectivity.Shutdown {
+		sd.effectiveState = connectivity.Shutdown
+		return
+	}
+
+	// Record a connection attempt when exiting CONNECTING.
+	if newState.ConnectivityState == connectivity.TransientFailure {
+		sd.connectionFailedInFirstPass = true
+		connectionAttemptsFailedMetric.Record(b.metricsRecorder, 1, b.target)
+	}
+
+	if newState.ConnectivityState == connectivity.Ready {
+		connectionAttemptsSucceededMetric.Record(b.metricsRecorder, 1, b.target)
+		b.shutdownRemainingLocked(sd)
+		if !b.addressList.seekTo(sd.addr) {
+			// This should not fail as we should have only one SubConn after
+			// entering READY. The SubConn should be present in the addressList.
+			b.logger.Errorf("Address %q not found address list in  %v", sd.addr, b.addressList.addresses)
+			return
+		}
+		if !b.healthCheckingEnabled {
+			if b.logger.V(2) {
+				b.logger.Infof("SubConn %p reported connectivity state READY and the health listener is disabled. Transitioning SubConn to READY.", sd.subConn)
+			}
+
+			sd.effectiveState = connectivity.Ready
+			b.updateBalancerState(balancer.State{
+				ConnectivityState: connectivity.Ready,
+				Picker:            &picker{result: balancer.PickResult{SubConn: sd.subConn}},
+			})
+			return
+		}
+		if b.logger.V(2) {
+			b.logger.Infof("SubConn %p reported connectivity state READY. Registering health listener.", sd.subConn)
+		}
+		// Send a CONNECTING update to take the SubConn out of sticky-TF if
+		// required.
+		sd.effectiveState = connectivity.Connecting
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
+		sd.subConn.RegisterHealthListener(func(scs balancer.SubConnState) {
+			b.updateSubConnHealthState(sd, scs)
+		})
+		return
+	}
+
+	// If the LB policy is READY, and it receives a subchannel state change,
+	// it means that the READY subchannel has failed.
+	// A SubConn can also transition from CONNECTING directly to IDLE when
+	// a transport is successfully created, but the connection fails
+	// before the SubConn can send the notification for READY. We treat
+	// this as a successful connection and transition to IDLE.
+	// TODO: https://github.com/grpc/grpc-go/issues/7862 - Remove the second
+	// part of the if condition below once the issue is fixed.
+	if oldState == connectivity.Ready || (oldState == connectivity.Connecting && newState.ConnectivityState == connectivity.Idle) {
+		// Once a transport fails, the balancer enters IDLE and starts from
+		// the first address when the picker is used.
+		b.shutdownRemainingLocked(sd)
+		sd.effectiveState = newState.ConnectivityState
+		// READY SubConn interspliced in between CONNECTING and IDLE, need to
+		// account for that.
+		if oldState == connectivity.Connecting {
+			// A known issue (https://github.com/grpc/grpc-go/issues/7862)
+			// causes a race that prevents the READY state change notification.
+			// This works around it.
+			connectionAttemptsSucceededMetric.Record(b.metricsRecorder, 1, b.target)
+		}
+		disconnectionsMetric.Record(b.metricsRecorder, 1, b.target)
+		b.addressList.reset()
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Idle,
+			Picker:            &idlePicker{exitIdle: sync.OnceFunc(b.ExitIdle)},
+		})
+		return
+	}
+
+	if b.firstPass {
+		switch newState.ConnectivityState {
+		case connectivity.Connecting:
+			// The effective state can be in either IDLE, CONNECTING or
+			// TRANSIENT_FAILURE. If it's  TRANSIENT_FAILURE, stay in
+			// TRANSIENT_FAILURE until it's READY. See A62.
+			if sd.effectiveState != connectivity.TransientFailure {
+				sd.effectiveState = connectivity.Connecting
+				b.updateBalancerState(balancer.State{
+					ConnectivityState: connectivity.Connecting,
+					Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+				})
+			}
+		case connectivity.TransientFailure:
+			sd.lastErr = newState.ConnectionError
+			sd.effectiveState = connectivity.TransientFailure
+			// Since we're re-using common SubConns while handling resolver
+			// updates, we could receive an out of turn TRANSIENT_FAILURE from
+			// a pass over the previous address list. Happy Eyeballs will also
+			// cause out of order updates to arrive.
+
+			if curAddr := b.addressList.currentAddress(); equalAddressIgnoringBalAttributes(&curAddr, &sd.addr) {
+				b.cancelConnectionTimer()
+				if b.addressList.increment() {
+					b.requestConnectionLocked()
+					return
+				}
+			}
+
+			// End the first pass if we've seen a TRANSIENT_FAILURE from all
+			// SubConns once.
+			b.endFirstPassIfPossibleLocked(newState.ConnectionError)
+		}
+		return
+	}
+
+	// We have finished the first pass, keep re-connecting failing SubConns.
+	switch newState.ConnectivityState {
+	case connectivity.TransientFailure:
+		b.numTF = (b.numTF + 1) % b.subConns.Len()
+		sd.lastErr = newState.ConnectionError
+		if b.numTF%b.subConns.Len() == 0 {
+			b.updateBalancerState(balancer.State{
+				ConnectivityState: connectivity.TransientFailure,
+				Picker:            &picker{err: newState.ConnectionError},
+			})
+		}
+		// We don't need to request re-resolution since the SubConn already
+		// does that before reporting TRANSIENT_FAILURE.
+		// TODO: #7534 - Move re-resolution requests from SubConn into
+		// pick_first.
+	case connectivity.Idle:
+		sd.subConn.Connect()
+	}
+}
+
+// endFirstPassIfPossibleLocked ends the first happy-eyeballs pass if all the
+// addresses are tried and their SubConns have reported a failure.
+func (b *pickfirstBalancer) endFirstPassIfPossibleLocked(lastErr error) {
+	// An optimization to avoid iterating over the entire SubConn map.
+	if b.addressList.isValid() {
+		return
+	}
+	// Connect() has been called on all the SubConns. The first pass can be
+	// ended if all the SubConns have reported a failure.
+	for _, sd := range b.subConns.Values() {
+		if !sd.connectionFailedInFirstPass {
+			return
+		}
+	}
+	b.firstPass = false
+	b.updateBalancerState(balancer.State{
+		ConnectivityState: connectivity.TransientFailure,
+		Picker:            &picker{err: lastErr},
+	})
+	// Start re-connecting all the SubConns that are already in IDLE.
+	for _, sd := range b.subConns.Values() {
+		if sd.rawConnectivityState == connectivity.Idle {
+			sd.subConn.Connect()
+		}
+	}
+}
+
+func (b *pickfirstBalancer) isActiveSCData(sd *scData) bool {
+	activeSD, found := b.subConns.Get(sd.addr)
+	return found && activeSD == sd
+}
+
+func (b *pickfirstBalancer) updateSubConnHealthState(sd *scData, state balancer.SubConnState) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	// Previously relevant SubConns can still callback with state updates.
+	// To prevent pickers from returning these obsolete SubConns, this logic
+	// is included to check if the current list of active SubConns includes
+	// this SubConn.
+	if !b.isActiveSCData(sd) {
+		return
+	}
+	sd.effectiveState = state.ConnectivityState
+	switch state.ConnectivityState {
+	case connectivity.Ready:
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Ready,
+			Picker:            &picker{result: balancer.PickResult{SubConn: sd.subConn}},
+		})
+	case connectivity.TransientFailure:
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.TransientFailure,
+			Picker:            &picker{err: fmt.Errorf("pickfirst: health check failure: %v", state.ConnectionError)},
+		})
+	case connectivity.Connecting:
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
+	default:
+		b.logger.Errorf("Got unexpected health update for SubConn %p: %v", state)
+	}
+}
+
+// updateBalancerState stores the state reported to the channel and calls
+// ClientConn.UpdateState(). As an optimization, it avoids sending duplicate
+// updates to the channel.
+func (b *pickfirstBalancer) updateBalancerState(newState balancer.State) {
+	// In case of TransientFailures allow the picker to be updated to update
+	// the connectivity error, in all other cases don't send duplicate state
+	// updates.
+	if newState.ConnectivityState == b.state && b.state != connectivity.TransientFailure {
+		return
+	}
+	b.forceUpdateConcludedStateLocked(newState)
+}
+
+// forceUpdateConcludedStateLocked stores the state reported to the channel and
+// calls ClientConn.UpdateState().
+// A separate function is defined to force update the ClientConn state since the
+// channel doesn't correctly assume that LB policies start in CONNECTING and
+// relies on LB policy to send an initial CONNECTING update.
+func (b *pickfirstBalancer) forceUpdateConcludedStateLocked(newState balancer.State) {
+	b.state = newState.ConnectivityState
+	b.cc.UpdateState(newState)
+}
+
+type picker struct {
+	result balancer.PickResult
+	err    error
+}
+
+func (p *picker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+	return p.result, p.err
+}
+
+// idlePicker is used when the SubConn is IDLE and kicks the SubConn into
+// CONNECTING when Pick is called.
+type idlePicker struct {
+	exitIdle func()
+}
+
+func (i *idlePicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+	i.exitIdle()
+	return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
+}
+
+// addressList manages sequentially iterating over addresses present in a list
+// of endpoints. It provides a 1 dimensional view of the addresses present in
+// the endpoints.
+// This type is not safe for concurrent access.
+type addressList struct {
+	addresses []resolver.Address
+	idx       int
+}
+
+func (al *addressList) isValid() bool {
+	return al.idx < len(al.addresses)
+}
+
+func (al *addressList) size() int {
+	return len(al.addresses)
+}
+
+// increment moves to the next index in the address list.
+// This method returns false if it went off the list, true otherwise.
+func (al *addressList) increment() bool {
+	if !al.isValid() {
+		return false
+	}
+	al.idx++
+	return al.idx < len(al.addresses)
+}
+
+// currentAddress returns the current address pointed to in the addressList.
+// If the list is in an invalid state, it returns an empty address instead.
+func (al *addressList) currentAddress() resolver.Address {
+	if !al.isValid() {
+		return resolver.Address{}
+	}
+	return al.addresses[al.idx]
+}
+
+func (al *addressList) reset() {
+	al.idx = 0
+}
+
+func (al *addressList) updateAddrs(addrs []resolver.Address) {
+	al.addresses = addrs
+	al.reset()
+}
+
+// seekTo returns false if the needle was not found and the current index was
+// left unchanged.
+func (al *addressList) seekTo(needle resolver.Address) bool {
+	for ai, addr := range al.addresses {
+		if !equalAddressIgnoringBalAttributes(&addr, &needle) {
+			continue
+		}
+		al.idx = ai
+		return true
+	}
+	return false
+}
+
+// hasNext returns whether incrementing the addressList will result in moving
+// past the end of the list. If the list has already moved past the end, it
+// returns false.
+func (al *addressList) hasNext() bool {
+	if !al.isValid() {
+		return false
+	}
+	return al.idx+1 < len(al.addresses)
+}
+
+// equalAddressIgnoringBalAttributes returns true is a and b are considered
+// equal. This is different from the Equal method on the resolver.Address type
+// which considers all fields to determine equality. Here, we only consider
+// fields that are meaningful to the SubConn.
+func equalAddressIgnoringBalAttributes(a, b *resolver.Address) bool {
+	return a.Addr == b.Addr && a.ServerName == b.ServerName &&
+		a.Attributes.Equal(b.Attributes)
+}

vendor/google.golang.org/grpc/balancer/roundrobin/roundrobin.go

@@ -22,12 +22,13 @@
 package roundrobin
 
 import (
-	"sync/atomic"
+	"fmt"
 
 	"google.golang.org/grpc/balancer"
-	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/balancer/endpointsharding"
+	"google.golang.org/grpc/balancer/pickfirst/pickfirstleaf"
 	"google.golang.org/grpc/grpclog"
-	"google.golang.org/grpc/internal/grpcrand"
+	internalgrpclog "google.golang.org/grpc/internal/grpclog"
 )
 
 // Name is the name of round_robin balancer.
@@ -35,47 +36,44 @@ const Name = "round_robin"
 
 var logger = grpclog.Component("roundrobin")
 
-// newBuilder creates a new roundrobin balancer builder.
-func newBuilder() balancer.Builder {
-	return base.NewBalancerBuilder(Name, &rrPickerBuilder{}, base.Config{HealthCheck: true})
-}
-
 func init() {
-	balancer.Register(newBuilder())
+	balancer.Register(builder{})
 }
 
-type rrPickerBuilder struct{}
+type builder struct{}
 
-func (*rrPickerBuilder) Build(info base.PickerBuildInfo) balancer.Picker {
-	logger.Infof("roundrobinPicker: Build called with info: %v", info)
-	if len(info.ReadySCs) == 0 {
-		return base.NewErrPicker(balancer.ErrNoSubConnAvailable)
+func (bb builder) Name() string {
+	return Name
+}
+
+func (bb builder) Build(cc balancer.ClientConn, opts balancer.BuildOptions) balancer.Balancer {
+	childBuilder := balancer.Get(pickfirstleaf.Name).Build
+	bal := &rrBalancer{
+		cc:       cc,
+		Balancer: endpointsharding.NewBalancer(cc, opts, childBuilder, endpointsharding.Options{}),
 	}
-	scs := make([]balancer.SubConn, 0, len(info.ReadySCs))
-	for sc := range info.ReadySCs {
-		scs = append(scs, sc)
-	}
-	return &rrPicker{
-		subConns: scs,
-		// Start at a random index, as the same RR balancer rebuilds a new
-		// picker when SubConn states change, and we don't want to apply excess
-		// load to the first server in the list.
-		next: uint32(grpcrand.Intn(len(scs))),
+	bal.logger = internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf("[%p] ", bal))
+	bal.logger.Infof("Created")
+	return bal
+}
+
+type rrBalancer struct {
+	balancer.Balancer
+	cc     balancer.ClientConn
+	logger *internalgrpclog.PrefixLogger
+}
+
+func (b *rrBalancer) UpdateClientConnState(ccs balancer.ClientConnState) error {
+	return b.Balancer.UpdateClientConnState(balancer.ClientConnState{
+		// Enable the health listener in pickfirst children for client side health
+		// checks and outlier detection, if configured.
+		ResolverState: pickfirstleaf.EnableHealthListener(ccs.ResolverState),
+	})
+}
+
+func (b *rrBalancer) ExitIdle() {
+	// Should always be ok, as child is endpoint sharding.
+	if ei, ok := b.Balancer.(balancer.ExitIdler); ok {
+		ei.ExitIdle()
 	}
 }
-
-type rrPicker struct {
-	// subConns is the snapshot of the roundrobin balancer when this picker was
-	// created. The slice is immutable. Each Get() will do a round robin
-	// selection from it and return the selected SubConn.
-	subConns []balancer.SubConn
-	next     uint32
-}
-
-func (p *rrPicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
-	subConnsLen := uint32(len(p.subConns))
-	nextIndex := atomic.AddUint32(&p.next, 1)
-
-	sc := p.subConns[nextIndex%subConnsLen]
-	return balancer.PickResult{SubConn: sc}, nil
-}

vendor/google.golang.org/grpc/balancer/subconn.go

@@ -0,0 +1,134 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package balancer
+
+import (
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/resolver"
+)
+
+// A SubConn represents a single connection to a gRPC backend service.
+//
+// All SubConns start in IDLE, and will not try to connect. To trigger a
+// connection attempt, Balancers must call Connect.
+//
+// If the connection attempt fails, the SubConn will transition to
+// TRANSIENT_FAILURE for a backoff period, and then return to IDLE.  If the
+// connection attempt succeeds, it will transition to READY.
+//
+// If a READY SubConn becomes disconnected, the SubConn will transition to IDLE.
+//
+// If a connection re-enters IDLE, Balancers must call Connect again to trigger
+// a new connection attempt.
+//
+// Each SubConn contains a list of addresses.  gRPC will try to connect to the
+// addresses in sequence, and stop trying the remainder once the first
+// connection is successful.  However, this behavior is deprecated.  SubConns
+// should only use a single address.
+//
+// NOTICE: This interface is intended to be implemented by gRPC, or intercepted
+// by custom load balancing polices.  Users should not need their own complete
+// implementation of this interface -- they should always delegate to a SubConn
+// returned by ClientConn.NewSubConn() by embedding it in their implementations.
+// An embedded SubConn must never be nil, or runtime panics will occur.
+type SubConn interface {
+	// UpdateAddresses updates the addresses used in this SubConn.
+	// gRPC checks if currently-connected address is still in the new list.
+	// If it's in the list, the connection will be kept.
+	// If it's not in the list, the connection will gracefully close, and
+	// a new connection will be created.
+	//
+	// This will trigger a state transition for the SubConn.
+	//
+	// Deprecated: this method will be removed.  Create new SubConns for new
+	// addresses instead.
+	UpdateAddresses([]resolver.Address)
+	// Connect starts the connecting for this SubConn.
+	Connect()
+	// GetOrBuildProducer returns a reference to the existing Producer for this
+	// ProducerBuilder in this SubConn, or, if one does not currently exist,
+	// creates a new one and returns it.  Returns a close function which may be
+	// called when the Producer is no longer needed.  Otherwise the producer
+	// will automatically be closed upon connection loss or subchannel close.
+	// Should only be called on a SubConn in state Ready.  Otherwise the
+	// producer will be unable to create streams.
+	GetOrBuildProducer(ProducerBuilder) (p Producer, close func())
+	// Shutdown shuts down the SubConn gracefully.  Any started RPCs will be
+	// allowed to complete.  No future calls should be made on the SubConn.
+	// One final state update will be delivered to the StateListener (or
+	// UpdateSubConnState; deprecated) with ConnectivityState of Shutdown to
+	// indicate the shutdown operation.  This may be delivered before
+	// in-progress RPCs are complete and the actual connection is closed.
+	Shutdown()
+	// RegisterHealthListener registers a health listener that receives health
+	// updates for a Ready SubConn. Only one health listener can be registered
+	// at a time. A health listener should be registered each time the SubConn's
+	// connectivity state changes to READY. Registering a health listener when
+	// the connectivity state is not READY may result in undefined behaviour.
+	// This method must not be called synchronously while handling an update
+	// from a previously registered health listener.
+	RegisterHealthListener(func(SubConnState))
+	// EnforceSubConnEmbedding is included to force implementers to embed
+	// another implementation of this interface, allowing gRPC to add methods
+	// without breaking users.
+	internal.EnforceSubConnEmbedding
+}
+
+// A ProducerBuilder is a simple constructor for a Producer.  It is used by the
+// SubConn to create producers when needed.
+type ProducerBuilder interface {
+	// Build creates a Producer.  The first parameter is always a
+	// grpc.ClientConnInterface (a type to allow creating RPCs/streams on the
+	// associated SubConn), but is declared as `any` to avoid a dependency
+	// cycle.  Build also returns a close function that will be called when all
+	// references to the Producer have been given up for a SubConn, or when a
+	// connectivity state change occurs on the SubConn.  The close function
+	// should always block until all asynchronous cleanup work is completed.
+	Build(grpcClientConnInterface any) (p Producer, close func())
+}
+
+// SubConnState describes the state of a SubConn.
+type SubConnState struct {
+	// ConnectivityState is the connectivity state of the SubConn.
+	ConnectivityState connectivity.State
+	// ConnectionError is set if the ConnectivityState is TransientFailure,
+	// describing the reason the SubConn failed.  Otherwise, it is nil.
+	ConnectionError error
+	// connectedAddr contains the connected address when ConnectivityState is
+	// Ready. Otherwise, it is indeterminate.
+	connectedAddress resolver.Address
+}
+
+// connectedAddress returns the connected address for a SubConnState. The
+// address is only valid if the state is READY.
+func connectedAddress(scs SubConnState) resolver.Address {
+	return scs.connectedAddress
+}
+
+// setConnectedAddress sets the connected address for a SubConnState.
+func setConnectedAddress(scs *SubConnState, addr resolver.Address) {
+	scs.connectedAddress = addr
+}
+
+// A Producer is a type shared among potentially many consumers.  It is
+// associated with a SubConn, and an implementation will typically contain
+// other methods to provide additional functionality, e.g. configuration or
+// subscription registration.
+type Producer any

vendor/google.golang.org/grpc/balancer_wrapper.go

@@ -24,11 +24,25 @@ import (
 	"sync"
 
 	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/experimental/stats"
+	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/balancer/gracefulswitch"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/status"
+)
+
+var (
+	setConnectedAddress = internal.SetConnectedAddress.(func(*balancer.SubConnState, resolver.Address))
+	// noOpRegisterHealthListenerFn is used when client side health checking is
+	// disabled. It sends a single READY update on the registered listener.
+	noOpRegisterHealthListenerFn = func(_ context.Context, listener func(balancer.SubConnState)) func() {
+		listener(balancer.SubConnState{ConnectivityState: connectivity.Ready})
+		return func() {}
+	}
 )
 
 // ccBalancerWrapper sits between the ClientConn and the Balancer.
@@ -46,6 +60,7 @@ import (
 // It uses the gracefulswitch.Balancer internally to ensure that balancer
 // switches happen in a graceful manner.
 type ccBalancerWrapper struct {
+	internal.EnforceClientConnEmbedding
 	// The following fields are initialized when the wrapper is created and are
 	// read-only afterwards, and therefore can be accessed without a mutex.
 	cc               *ClientConn
@@ -87,12 +102,16 @@ func newCCBalancerWrapper(cc *ClientConn) *ccBalancerWrapper {
 	return ccb
 }
 
+func (ccb *ccBalancerWrapper) MetricsRecorder() stats.MetricsRecorder {
+	return ccb.cc.metricsRecorderList
+}
+
 // updateClientConnState is invoked by grpc to push a ClientConnState update to
 // the underlying balancer.  This is always executed from the serializer, so
 // it is safe to call into the balancer here.
 func (ccb *ccBalancerWrapper) updateClientConnState(ccs *balancer.ClientConnState) error {
 	errCh := make(chan error)
-	ok := ccb.serializer.Schedule(func(ctx context.Context) {
+	uccs := func(ctx context.Context) {
 		defer close(errCh)
 		if ctx.Err() != nil || ccb.balancer == nil {
 			return
@@ -107,17 +126,23 @@ func (ccb *ccBalancerWrapper) updateClientConnState(ccs *balancer.ClientConnStat
 			logger.Infof("error from balancer.UpdateClientConnState: %v", err)
 		}
 		errCh <- err
-	})
-	if !ok {
-		return nil
 	}
+	onFailure := func() { close(errCh) }
+
+	// UpdateClientConnState can race with Close, and when the latter wins, the
+	// serializer is closed, and the attempt to schedule the callback will fail.
+	// It is acceptable to ignore this failure. But since we want to handle the
+	// state update in a blocking fashion (when we successfully schedule the
+	// callback), we have to use the ScheduleOr method and not the MaybeSchedule
+	// method on the serializer.
+	ccb.serializer.ScheduleOr(uccs, onFailure)
 	return <-errCh
 }
 
 // resolverError is invoked by grpc to push a resolver error to the underlying
 // balancer.  The call to the balancer is executed from the serializer.
 func (ccb *ccBalancerWrapper) resolverError(err error) {
-	ccb.serializer.Schedule(func(ctx context.Context) {
+	ccb.serializer.TrySchedule(func(ctx context.Context) {
 		if ctx.Err() != nil || ccb.balancer == nil {
 			return
 		}
@@ -133,7 +158,7 @@ func (ccb *ccBalancerWrapper) close() {
 	ccb.closed = true
 	ccb.mu.Unlock()
 	channelz.Info(logger, ccb.cc.channelz, "ccBalancerWrapper: closing")
-	ccb.serializer.Schedule(func(context.Context) {
+	ccb.serializer.TrySchedule(func(context.Context) {
 		if ccb.balancer == nil {
 			return
 		}
@@ -145,7 +170,7 @@ func (ccb *ccBalancerWrapper) close() {
 
 // exitIdle invokes the balancer's exitIdle method in the serializer.
 func (ccb *ccBalancerWrapper) exitIdle() {
-	ccb.serializer.Schedule(func(ctx context.Context) {
+	ccb.serializer.TrySchedule(func(ctx context.Context) {
 		if ctx.Err() != nil || ccb.balancer == nil {
 			return
 		}
@@ -177,12 +202,13 @@ func (ccb *ccBalancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer
 		ac:            ac,
 		producers:     make(map[balancer.ProducerBuilder]*refCountedProducer),
 		stateListener: opts.StateListener,
+		healthData:    newHealthData(connectivity.Idle),
 	}
 	ac.acbw = acbw
 	return acbw, nil
 }
 
-func (ccb *ccBalancerWrapper) RemoveSubConn(sc balancer.SubConn) {
+func (ccb *ccBalancerWrapper) RemoveSubConn(balancer.SubConn) {
 	// The graceful switch balancer will never call this.
 	logger.Errorf("ccb RemoveSubConn(%v) called unexpectedly, sc")
 }
@@ -198,6 +224,10 @@ func (ccb *ccBalancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resol
 func (ccb *ccBalancerWrapper) UpdateState(s balancer.State) {
 	ccb.cc.mu.Lock()
 	defer ccb.cc.mu.Unlock()
+	if ccb.cc.conns == nil {
+		// The CC has been closed; ignore this update.
+		return
+	}
 
 	ccb.mu.Lock()
 	if ccb.closed {
@@ -238,25 +268,77 @@ func (ccb *ccBalancerWrapper) Target() string {
 // acBalancerWrapper is a wrapper on top of ac for balancers.
 // It implements balancer.SubConn interface.
 type acBalancerWrapper struct {
+	internal.EnforceSubConnEmbedding
 	ac            *addrConn          // read-only
 	ccb           *ccBalancerWrapper // read-only
 	stateListener func(balancer.SubConnState)
 
-	mu        sync.Mutex
-	producers map[balancer.ProducerBuilder]*refCountedProducer
+	producersMu sync.Mutex
+	producers   map[balancer.ProducerBuilder]*refCountedProducer
+
+	// Access to healthData is protected by healthMu.
+	healthMu sync.Mutex
+	// healthData is stored as a pointer to detect when the health listener is
+	// dropped or updated. This is required as closures can't be compared for
+	// equality.
+	healthData *healthData
+}
+
+// healthData holds data related to health state reporting.
+type healthData struct {
+	// connectivityState stores the most recent connectivity state delivered
+	// to the LB policy. This is stored to avoid sending updates when the
+	// SubConn has already exited connectivity state READY.
+	connectivityState connectivity.State
+	// closeHealthProducer stores function to close the ref counted health
+	// producer. The health producer is automatically closed when the SubConn
+	// state changes.
+	closeHealthProducer func()
+}
+
+func newHealthData(s connectivity.State) *healthData {
+	return &healthData{
+		connectivityState:   s,
+		closeHealthProducer: func() {},
+	}
 }
 
 // updateState is invoked by grpc to push a subConn state update to the
 // underlying balancer.
-func (acbw *acBalancerWrapper) updateState(s connectivity.State, err error) {
-	acbw.ccb.serializer.Schedule(func(ctx context.Context) {
+func (acbw *acBalancerWrapper) updateState(s connectivity.State, curAddr resolver.Address, err error) {
+	acbw.ccb.serializer.TrySchedule(func(ctx context.Context) {
 		if ctx.Err() != nil || acbw.ccb.balancer == nil {
 			return
 		}
+		// Invalidate all producers on any state change.
+		acbw.closeProducers()
+
 		// Even though it is optional for balancers, gracefulswitch ensures
 		// opts.StateListener is set, so this cannot ever be nil.
 		// TODO: delete this comment when UpdateSubConnState is removed.
-		acbw.stateListener(balancer.SubConnState{ConnectivityState: s, ConnectionError: err})
+		scs := balancer.SubConnState{ConnectivityState: s, ConnectionError: err}
+		if s == connectivity.Ready {
+			setConnectedAddress(&scs, curAddr)
+		}
+		// Invalidate the health listener by updating the healthData.
+		acbw.healthMu.Lock()
+		// A race may occur if a health listener is registered soon after the
+		// connectivity state is set but before the stateListener is called.
+		// Two cases may arise:
+		// 1. The new state is not READY: RegisterHealthListener has checks to
+		//    ensure no updates are sent when the connectivity state is not
+		//    READY.
+		// 2. The new state is READY: This means that the old state wasn't Ready.
+		//    The RegisterHealthListener API mentions that a health listener
+		//    must not be registered when a SubConn is not ready to avoid such
+		//    races. When this happens, the LB policy would get health updates
+		//    on the old listener. When the LB policy registers a new listener
+		//    on receiving the connectivity update, the health updates will be
+		//    sent to the new health listener.
+		acbw.healthData = newHealthData(scs.ConnectivityState)
+		acbw.healthMu.Unlock()
+
+		acbw.stateListener(scs)
 	})
 }
 
@@ -273,6 +355,7 @@ func (acbw *acBalancerWrapper) Connect() {
 }
 
 func (acbw *acBalancerWrapper) Shutdown() {
+	acbw.closeProducers()
 	acbw.ccb.cc.removeAddrConn(acbw.ac, errConnDrain)
 }
 
@@ -280,9 +363,10 @@ func (acbw *acBalancerWrapper) Shutdown() {
 // ready, blocks until it is or ctx expires.  Returns an error when the context
 // expires or the addrConn is shut down.
 func (acbw *acBalancerWrapper) NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error) {
-	transport, err := acbw.ac.getTransport(ctx)
-	if err != nil {
-		return nil, err
+	transport := acbw.ac.getReadyTransport()
+	if transport == nil {
+		return nil, status.Errorf(codes.Unavailable, "SubConn state is not Ready")
+
 	}
 	return newNonRetryClientStream(ctx, desc, method, transport, acbw.ac, opts...)
 }
@@ -307,15 +391,15 @@ type refCountedProducer struct {
 }
 
 func (acbw *acBalancerWrapper) GetOrBuildProducer(pb balancer.ProducerBuilder) (balancer.Producer, func()) {
-	acbw.mu.Lock()
-	defer acbw.mu.Unlock()
+	acbw.producersMu.Lock()
+	defer acbw.producersMu.Unlock()
 
 	// Look up existing producer from this builder.
 	pData := acbw.producers[pb]
 	if pData == nil {
 		// Not found; create a new one and add it to the producers map.
-		p, close := pb.Build(acbw)
-		pData = &refCountedProducer{producer: p, close: close}
+		p, closeFn := pb.Build(acbw)
+		pData = &refCountedProducer{producer: p, close: closeFn}
 		acbw.producers[pb] = pData
 	}
 	// Account for this new reference.
@@ -325,13 +409,112 @@ func (acbw *acBalancerWrapper) GetOrBuildProducer(pb balancer.ProducerBuilder) (
 	// and delete the refCountedProducer from the map if the total reference
 	// count goes to zero.
 	unref := func() {
-		acbw.mu.Lock()
+		acbw.producersMu.Lock()
+		// If closeProducers has already closed this producer instance, refs is
+		// set to 0, so the check after decrementing will never pass, and the
+		// producer will not be double-closed.
 		pData.refs--
 		if pData.refs == 0 {
 			defer pData.close() // Run outside the acbw mutex
 			delete(acbw.producers, pb)
 		}
-		acbw.mu.Unlock()
+		acbw.producersMu.Unlock()
 	}
-	return pData.producer, grpcsync.OnceFunc(unref)
+	return pData.producer, sync.OnceFunc(unref)
+}
+
+func (acbw *acBalancerWrapper) closeProducers() {
+	acbw.producersMu.Lock()
+	defer acbw.producersMu.Unlock()
+	for pb, pData := range acbw.producers {
+		pData.refs = 0
+		pData.close()
+		delete(acbw.producers, pb)
+	}
+}
+
+// healthProducerRegisterFn is a type alias for the health producer's function
+// for registering listeners.
+type healthProducerRegisterFn = func(context.Context, balancer.SubConn, string, func(balancer.SubConnState)) func()
+
+// healthListenerRegFn returns a function to register a listener for health
+// updates. If client side health checks are disabled, the registered listener
+// will get a single READY (raw connectivity state) update.
+//
+// Client side health checking is enabled when all the following
+// conditions are satisfied:
+// 1. Health checking is not disabled using the dial option.
+// 2. The health package is imported.
+// 3. The health check config is present in the service config.
+func (acbw *acBalancerWrapper) healthListenerRegFn() func(context.Context, func(balancer.SubConnState)) func() {
+	if acbw.ccb.cc.dopts.disableHealthCheck {
+		return noOpRegisterHealthListenerFn
+	}
+	regHealthLisFn := internal.RegisterClientHealthCheckListener
+	if regHealthLisFn == nil {
+		// The health package is not imported.
+		return noOpRegisterHealthListenerFn
+	}
+	cfg := acbw.ac.cc.healthCheckConfig()
+	if cfg == nil {
+		return noOpRegisterHealthListenerFn
+	}
+	return func(ctx context.Context, listener func(balancer.SubConnState)) func() {
+		return regHealthLisFn.(healthProducerRegisterFn)(ctx, acbw, cfg.ServiceName, listener)
+	}
+}
+
+// RegisterHealthListener accepts a health listener from the LB policy. It sends
+// updates to the health listener as long as the SubConn's connectivity state
+// doesn't change and a new health listener is not registered. To invalidate
+// the currently registered health listener, acbw updates the healthData. If a
+// nil listener is registered, the active health listener is dropped.
+func (acbw *acBalancerWrapper) RegisterHealthListener(listener func(balancer.SubConnState)) {
+	acbw.healthMu.Lock()
+	defer acbw.healthMu.Unlock()
+	acbw.healthData.closeHealthProducer()
+	// listeners should not be registered when the connectivity state
+	// isn't Ready. This may happen when the balancer registers a listener
+	// after the connectivityState is updated, but before it is notified
+	// of the update.
+	if acbw.healthData.connectivityState != connectivity.Ready {
+		return
+	}
+	// Replace the health data to stop sending updates to any previously
+	// registered health listeners.
+	hd := newHealthData(connectivity.Ready)
+	acbw.healthData = hd
+	if listener == nil {
+		return
+	}
+
+	registerFn := acbw.healthListenerRegFn()
+	acbw.ccb.serializer.TrySchedule(func(ctx context.Context) {
+		if ctx.Err() != nil || acbw.ccb.balancer == nil {
+			return
+		}
+		// Don't send updates if a new listener is registered.
+		acbw.healthMu.Lock()
+		defer acbw.healthMu.Unlock()
+		if acbw.healthData != hd {
+			return
+		}
+		// Serialize the health updates from the health producer with
+		// other calls into the LB policy.
+		listenerWrapper := func(scs balancer.SubConnState) {
+			acbw.ccb.serializer.TrySchedule(func(ctx context.Context) {
+				if ctx.Err() != nil || acbw.ccb.balancer == nil {
+					return
+				}
+				acbw.healthMu.Lock()
+				defer acbw.healthMu.Unlock()
+				if acbw.healthData != hd {
+					return
+				}
+				listener(scs)
+			})
+		}
+
+		hd.closeHealthProducer = registerFn(ctx, listenerWrapper)
+	})
 }

vendor/google.golang.org/grpc/binarylog/grpc_binarylog_v1/binarylog.pb.go

@@ -18,8 +18,8 @@
 
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.32.0
-// 	protoc        v4.25.2
+// 	protoc-gen-go v1.36.5
+// 	protoc        v5.27.1
 // source: grpc/binlog/v1/binarylog.proto
 
 package grpc_binarylog_v1
@@ -31,6 +31,7 @@ import (
 	timestamppb "google.golang.org/protobuf/types/known/timestamppb"
 	reflect "reflect"
 	sync "sync"
+	unsafe "unsafe"
 )
 
 const (
@@ -233,10 +234,7 @@ func (Address_Type) EnumDescriptor() ([]byte, []int) {
 
 // Log entry we store in binary logs
 type GrpcLogEntry struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
-	unknownFields protoimpl.UnknownFields
-
+	state protoimpl.MessageState `protogen:"open.v1"`
 	// The timestamp of the binary log message
 	Timestamp *timestamppb.Timestamp `protobuf:"bytes,1,opt,name=timestamp,proto3" json:"timestamp,omitempty"`
 	// Uniquely identifies a call. The value must not be 0 in order to disambiguate
@@ -255,7 +253,7 @@ type GrpcLogEntry struct {
 	// The logger uses one of the following fields to record the payload,
 	// according to the type of the log entry.
 	//
-	// Types that are assignable to Payload:
+	// Types that are valid to be assigned to Payload:
 	//
 	//	*GrpcLogEntry_ClientHeader
 	//	*GrpcLogEntry_ServerHeader
@@ -269,16 +267,16 @@ type GrpcLogEntry struct {
 	// EVENT_TYPE_SERVER_HEADER normally or EVENT_TYPE_SERVER_TRAILER in
 	// the case of trailers-only. On server side, peer is always
 	// logged on EVENT_TYPE_CLIENT_HEADER.
-	Peer *Address `protobuf:"bytes,11,opt,name=peer,proto3" json:"peer,omitempty"`
+	Peer          *Address `protobuf:"bytes,11,opt,name=peer,proto3" json:"peer,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *GrpcLogEntry) Reset() {
 	*x = GrpcLogEntry{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[0]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[0]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *GrpcLogEntry) String() string {
@@ -289,7 +287,7 @@ func (*GrpcLogEntry) ProtoMessage() {}
 
 func (x *GrpcLogEntry) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[0]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -339,37 +337,45 @@ func (x *GrpcLogEntry) GetLogger() GrpcLogEntry_Logger {
 	return GrpcLogEntry_LOGGER_UNKNOWN
 }
 
-func (m *GrpcLogEntry) GetPayload() isGrpcLogEntry_Payload {
-	if m != nil {
-		return m.Payload
+func (x *GrpcLogEntry) GetPayload() isGrpcLogEntry_Payload {
+	if x != nil {
+		return x.Payload
 	}
 	return nil
 }
 
 func (x *GrpcLogEntry) GetClientHeader() *ClientHeader {
-	if x, ok := x.GetPayload().(*GrpcLogEntry_ClientHeader); ok {
-		return x.ClientHeader
+	if x != nil {
+		if x, ok := x.Payload.(*GrpcLogEntry_ClientHeader); ok {
+			return x.ClientHeader
+		}
 	}
 	return nil
 }
 
 func (x *GrpcLogEntry) GetServerHeader() *ServerHeader {
-	if x, ok := x.GetPayload().(*GrpcLogEntry_ServerHeader); ok {
-		return x.ServerHeader
+	if x != nil {
+		if x, ok := x.Payload.(*GrpcLogEntry_ServerHeader); ok {
+			return x.ServerHeader
+		}
 	}
 	return nil
 }
 
 func (x *GrpcLogEntry) GetMessage() *Message {
-	if x, ok := x.GetPayload().(*GrpcLogEntry_Message); ok {
-		return x.Message
+	if x != nil {
+		if x, ok := x.Payload.(*GrpcLogEntry_Message); ok {
+			return x.Message
+		}
 	}
 	return nil
 }
 
 func (x *GrpcLogEntry) GetTrailer() *Trailer {
-	if x, ok := x.GetPayload().(*GrpcLogEntry_Trailer); ok {
-		return x.Trailer
+	if x != nil {
+		if x, ok := x.Payload.(*GrpcLogEntry_Trailer); ok {
+			return x.Trailer
+		}
 	}
 	return nil
 }
@@ -418,10 +424,7 @@ func (*GrpcLogEntry_Message) isGrpcLogEntry_Payload() {}
 func (*GrpcLogEntry_Trailer) isGrpcLogEntry_Payload() {}
 
 type ClientHeader struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
-	unknownFields protoimpl.UnknownFields
-
+	state protoimpl.MessageState `protogen:"open.v1"`
 	// This contains only the metadata from the application.
 	Metadata *Metadata `protobuf:"bytes,1,opt,name=metadata,proto3" json:"metadata,omitempty"`
 	// The name of the RPC method, which looks something like:
@@ -435,16 +438,16 @@ type ClientHeader struct {
 	// <host> or <host>:<port> .
 	Authority string `protobuf:"bytes,3,opt,name=authority,proto3" json:"authority,omitempty"`
 	// the RPC timeout
-	Timeout *durationpb.Duration `protobuf:"bytes,4,opt,name=timeout,proto3" json:"timeout,omitempty"`
+	Timeout       *durationpb.Duration `protobuf:"bytes,4,opt,name=timeout,proto3" json:"timeout,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *ClientHeader) Reset() {
 	*x = ClientHeader{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[1]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[1]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *ClientHeader) String() string {
@@ -455,7 +458,7 @@ func (*ClientHeader) ProtoMessage() {}
 
 func (x *ClientHeader) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[1]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -499,21 +502,18 @@ func (x *ClientHeader) GetTimeout() *durationpb.Duration {
 }
 
 type ServerHeader struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
-	unknownFields protoimpl.UnknownFields
-
+	state protoimpl.MessageState `protogen:"open.v1"`
 	// This contains only the metadata from the application.
-	Metadata *Metadata `protobuf:"bytes,1,opt,name=metadata,proto3" json:"metadata,omitempty"`
+	Metadata      *Metadata `protobuf:"bytes,1,opt,name=metadata,proto3" json:"metadata,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *ServerHeader) Reset() {
 	*x = ServerHeader{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[2]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[2]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *ServerHeader) String() string {
@@ -524,7 +524,7 @@ func (*ServerHeader) ProtoMessage() {}
 
 func (x *ServerHeader) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[2]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -547,10 +547,7 @@ func (x *ServerHeader) GetMetadata() *Metadata {
 }
 
 type Trailer struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
-	unknownFields protoimpl.UnknownFields
-
+	state protoimpl.MessageState `protogen:"open.v1"`
 	// This contains only the metadata from the application.
 	Metadata *Metadata `protobuf:"bytes,1,opt,name=metadata,proto3" json:"metadata,omitempty"`
 	// The gRPC status code.
@@ -561,15 +558,15 @@ type Trailer struct {
 	// The value of the 'grpc-status-details-bin' metadata key. If
 	// present, this is always an encoded 'google.rpc.Status' message.
 	StatusDetails []byte `protobuf:"bytes,4,opt,name=status_details,json=statusDetails,proto3" json:"status_details,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *Trailer) Reset() {
 	*x = Trailer{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[3]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[3]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *Trailer) String() string {
@@ -580,7 +577,7 @@ func (*Trailer) ProtoMessage() {}
 
 func (x *Trailer) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[3]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -625,24 +622,21 @@ func (x *Trailer) GetStatusDetails() []byte {
 
 // Message payload, used by CLIENT_MESSAGE and SERVER_MESSAGE
 type Message struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
-	unknownFields protoimpl.UnknownFields
-
+	state protoimpl.MessageState `protogen:"open.v1"`
 	// Length of the message. It may not be the same as the length of the
 	// data field, as the logging payload can be truncated or omitted.
 	Length uint32 `protobuf:"varint,1,opt,name=length,proto3" json:"length,omitempty"`
 	// May be truncated or omitted.
-	Data []byte `protobuf:"bytes,2,opt,name=data,proto3" json:"data,omitempty"`
+	Data          []byte `protobuf:"bytes,2,opt,name=data,proto3" json:"data,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *Message) Reset() {
 	*x = Message{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[4]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[4]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *Message) String() string {
@@ -653,7 +647,7 @@ func (*Message) ProtoMessage() {}
 
 func (x *Message) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[4]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -704,20 +698,17 @@ func (x *Message) GetData() []byte {
 // header is just a normal metadata key.
 // The pair will not count towards the size limit.
 type Metadata struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Entry         []*MetadataEntry       `protobuf:"bytes,1,rep,name=entry,proto3" json:"entry,omitempty"`
 	unknownFields protoimpl.UnknownFields
-
-	Entry []*MetadataEntry `protobuf:"bytes,1,rep,name=entry,proto3" json:"entry,omitempty"`
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *Metadata) Reset() {
 	*x = Metadata{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[5]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[5]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *Metadata) String() string {
@@ -728,7 +719,7 @@ func (*Metadata) ProtoMessage() {}
 
 func (x *Metadata) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[5]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -752,21 +743,18 @@ func (x *Metadata) GetEntry() []*MetadataEntry {
 
 // A metadata key value pair
 type MetadataEntry struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Key           string                 `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
+	Value         []byte                 `protobuf:"bytes,2,opt,name=value,proto3" json:"value,omitempty"`
 	unknownFields protoimpl.UnknownFields
-
-	Key   string `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
-	Value []byte `protobuf:"bytes,2,opt,name=value,proto3" json:"value,omitempty"`
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *MetadataEntry) Reset() {
 	*x = MetadataEntry{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[6]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[6]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *MetadataEntry) String() string {
@@ -777,7 +765,7 @@ func (*MetadataEntry) ProtoMessage() {}
 
 func (x *MetadataEntry) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[6]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -808,23 +796,20 @@ func (x *MetadataEntry) GetValue() []byte {
 
 // Address information
 type Address struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
-	unknownFields protoimpl.UnknownFields
-
-	Type    Address_Type `protobuf:"varint,1,opt,name=type,proto3,enum=grpc.binarylog.v1.Address_Type" json:"type,omitempty"`
-	Address string       `protobuf:"bytes,2,opt,name=address,proto3" json:"address,omitempty"`
+	state   protoimpl.MessageState `protogen:"open.v1"`
+	Type    Address_Type           `protobuf:"varint,1,opt,name=type,proto3,enum=grpc.binarylog.v1.Address_Type" json:"type,omitempty"`
+	Address string                 `protobuf:"bytes,2,opt,name=address,proto3" json:"address,omitempty"`
 	// only for TYPE_IPV4 and TYPE_IPV6
-	IpPort uint32 `protobuf:"varint,3,opt,name=ip_port,json=ipPort,proto3" json:"ip_port,omitempty"`
+	IpPort        uint32 `protobuf:"varint,3,opt,name=ip_port,json=ipPort,proto3" json:"ip_port,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *Address) Reset() {
 	*x = Address{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[7]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[7]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *Address) String() string {
@@ -835,7 +820,7 @@ func (*Address) ProtoMessage() {}
 
 func (x *Address) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_binlog_v1_binarylog_proto_msgTypes[7]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -873,7 +858,7 @@ func (x *Address) GetIpPort() uint32 {
 
 var File_grpc_binlog_v1_binarylog_proto protoreflect.FileDescriptor
 
-var file_grpc_binlog_v1_binarylog_proto_rawDesc = []byte{
+var file_grpc_binlog_v1_binarylog_proto_rawDesc = string([]byte{
 	0x0a, 0x1e, 0x67, 0x72, 0x70, 0x63, 0x2f, 0x62, 0x69, 0x6e, 0x6c, 0x6f, 0x67, 0x2f, 0x76, 0x31,
 	0x2f, 0x62, 0x69, 0x6e, 0x61, 0x72, 0x79, 0x6c, 0x6f, 0x67, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f,
 	0x12, 0x11, 0x67, 0x72, 0x70, 0x63, 0x2e, 0x62, 0x69, 0x6e, 0x61, 0x72, 0x79, 0x6c, 0x6f, 0x67,
@@ -999,23 +984,23 @@ var file_grpc_binlog_v1_binarylog_proto_rawDesc = []byte{
 	0x69, 0x6e, 0x61, 0x72, 0x79, 0x6c, 0x6f, 0x67, 0x2f, 0x67, 0x72, 0x70, 0x63, 0x5f, 0x62, 0x69,
 	0x6e, 0x61, 0x72, 0x79, 0x6c, 0x6f, 0x67, 0x5f, 0x76, 0x31, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74,
 	0x6f, 0x33,
-}
+})
 
 var (
 	file_grpc_binlog_v1_binarylog_proto_rawDescOnce sync.Once
-	file_grpc_binlog_v1_binarylog_proto_rawDescData = file_grpc_binlog_v1_binarylog_proto_rawDesc
+	file_grpc_binlog_v1_binarylog_proto_rawDescData []byte
 )
 
 func file_grpc_binlog_v1_binarylog_proto_rawDescGZIP() []byte {
 	file_grpc_binlog_v1_binarylog_proto_rawDescOnce.Do(func() {
-		file_grpc_binlog_v1_binarylog_proto_rawDescData = protoimpl.X.CompressGZIP(file_grpc_binlog_v1_binarylog_proto_rawDescData)
+		file_grpc_binlog_v1_binarylog_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_grpc_binlog_v1_binarylog_proto_rawDesc), len(file_grpc_binlog_v1_binarylog_proto_rawDesc)))
 	})
 	return file_grpc_binlog_v1_binarylog_proto_rawDescData
 }
 
 var file_grpc_binlog_v1_binarylog_proto_enumTypes = make([]protoimpl.EnumInfo, 3)
 var file_grpc_binlog_v1_binarylog_proto_msgTypes = make([]protoimpl.MessageInfo, 8)
-var file_grpc_binlog_v1_binarylog_proto_goTypes = []interface{}{
+var file_grpc_binlog_v1_binarylog_proto_goTypes = []any{
 	(GrpcLogEntry_EventType)(0),   // 0: grpc.binarylog.v1.GrpcLogEntry.EventType
 	(GrpcLogEntry_Logger)(0),      // 1: grpc.binarylog.v1.GrpcLogEntry.Logger
 	(Address_Type)(0),             // 2: grpc.binarylog.v1.Address.Type
@@ -1057,105 +1042,7 @@ func file_grpc_binlog_v1_binarylog_proto_init() {
 	if File_grpc_binlog_v1_binarylog_proto != nil {
 		return
 	}
-	if !protoimpl.UnsafeEnabled {
-		file_grpc_binlog_v1_binarylog_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*GrpcLogEntry); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-		file_grpc_binlog_v1_binarylog_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*ClientHeader); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-		file_grpc_binlog_v1_binarylog_proto_msgTypes[2].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*ServerHeader); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-		file_grpc_binlog_v1_binarylog_proto_msgTypes[3].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*Trailer); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-		file_grpc_binlog_v1_binarylog_proto_msgTypes[4].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*Message); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-		file_grpc_binlog_v1_binarylog_proto_msgTypes[5].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*Metadata); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-		file_grpc_binlog_v1_binarylog_proto_msgTypes[6].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*MetadataEntry); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-		file_grpc_binlog_v1_binarylog_proto_msgTypes[7].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*Address); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-	}
-	file_grpc_binlog_v1_binarylog_proto_msgTypes[0].OneofWrappers = []interface{}{
+	file_grpc_binlog_v1_binarylog_proto_msgTypes[0].OneofWrappers = []any{
 		(*GrpcLogEntry_ClientHeader)(nil),
 		(*GrpcLogEntry_ServerHeader)(nil),
 		(*GrpcLogEntry_Message)(nil),
@@ -1165,7 +1052,7 @@ func file_grpc_binlog_v1_binarylog_proto_init() {
 	out := protoimpl.TypeBuilder{
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
-			RawDescriptor: file_grpc_binlog_v1_binarylog_proto_rawDesc,
+			RawDescriptor: unsafe.Slice(unsafe.StringData(file_grpc_binlog_v1_binarylog_proto_rawDesc), len(file_grpc_binlog_v1_binarylog_proto_rawDesc)),
 			NumEnums:      3,
 			NumMessages:   8,
 			NumExtensions: 0,
@@ -1177,7 +1064,6 @@ func file_grpc_binlog_v1_binarylog_proto_init() {
 		MessageInfos:      file_grpc_binlog_v1_binarylog_proto_msgTypes,
 	}.Build()
 	File_grpc_binlog_v1_binarylog_proto = out.File
-	file_grpc_binlog_v1_binarylog_proto_rawDesc = nil
 	file_grpc_binlog_v1_binarylog_proto_goTypes = nil
 	file_grpc_binlog_v1_binarylog_proto_depIdxs = nil
 }

vendor/google.golang.org/grpc/clientconn.go

@@ -24,6 +24,7 @@ import (
 	"fmt"
 	"math"
 	"net/url"
+	"slices"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -31,14 +32,15 @@ import (
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/balancer/pickfirst"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/internal/idle"
-	"google.golang.org/grpc/internal/pretty"
 	iresolver "google.golang.org/grpc/internal/resolver"
+	"google.golang.org/grpc/internal/stats"
 	"google.golang.org/grpc/internal/transport"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/resolver"
@@ -73,6 +75,8 @@ var (
 	// invalidDefaultServiceConfigErrPrefix is used to prefix the json parsing error for the default
 	// service config.
 	invalidDefaultServiceConfigErrPrefix = "grpc: the provided default service config is invalid"
+	// PickFirstBalancerName is the name of the pick_first balancer.
+	PickFirstBalancerName = pickfirst.Name
 )
 
 // The following errors are returned from Dial and DialContext
@@ -114,15 +118,30 @@ func (dcs *defaultConfigSelector) SelectConfig(rpcInfo iresolver.RPCInfo) (*ires
 
 // NewClient creates a new gRPC "channel" for the target URI provided.  No I/O
 // is performed.  Use of the ClientConn for RPCs will automatically cause it to
-// connect.  Connect may be used to manually create a connection, but for most
-// users this is unnecessary.
+// connect.  The Connect method may be called to manually create a connection,
+// but for most users this should be unnecessary.
 //
 // The target name syntax is defined in
-// https://github.com/grpc/grpc/blob/master/doc/naming.md.  e.g. to use dns
-// resolver, a "dns:///" prefix should be applied to the target.
+// https://github.com/grpc/grpc/blob/master/doc/naming.md.  E.g. to use the dns
+// name resolver, a "dns:///" prefix may be applied to the target.  The default
+// name resolver will be used if no scheme is detected, or if the parsed scheme
+// is not a registered name resolver.  The default resolver is "dns" but can be
+// overridden using the resolver package's SetDefaultScheme.
 //
-// The DialOptions returned by WithBlock, WithTimeout, and
-// WithReturnConnectionError are ignored by this function.
+// Examples:
+//
+//   - "foo.googleapis.com:8080"
+//   - "dns:///foo.googleapis.com:8080"
+//   - "dns:///foo.googleapis.com"
+//   - "dns:///10.0.0.213:8080"
+//   - "dns:///%5B2001:db8:85a3:8d3:1319:8a2e:370:7348%5D:443"
+//   - "dns://8.8.8.8/foo.googleapis.com:8080"
+//   - "dns://8.8.8.8/foo.googleapis.com"
+//   - "zookeeper://zk.example.com:9900/example_service"
+//
+// The DialOptions returned by WithBlock, WithTimeout,
+// WithReturnConnectionError, and FailOnNonTempDialError are ignored by this
+// function.
 func NewClient(target string, opts ...DialOption) (conn *ClientConn, err error) {
 	cc := &ClientConn{
 		target: target,
@@ -152,6 +171,16 @@ func NewClient(target string, opts ...DialOption) (conn *ClientConn, err error)
 	for _, opt := range opts {
 		opt.apply(&cc.dopts)
 	}
+
+	// Determine the resolver to use.
+	if err := cc.initParsedTargetAndResolverBuilder(); err != nil {
+		return nil, err
+	}
+
+	for _, opt := range globalPerTargetDialOptions {
+		opt.DialOptionForTarget(cc.parsedTarget.URL).apply(&cc.dopts)
+	}
+
 	chainUnaryClientInterceptors(cc)
 	chainStreamClientInterceptors(cc)
 
@@ -160,42 +189,38 @@ func NewClient(target string, opts ...DialOption) (conn *ClientConn, err error)
 	}
 
 	if cc.dopts.defaultServiceConfigRawJSON != nil {
-		scpr := parseServiceConfig(*cc.dopts.defaultServiceConfigRawJSON)
+		scpr := parseServiceConfig(*cc.dopts.defaultServiceConfigRawJSON, cc.dopts.maxCallAttempts)
 		if scpr.Err != nil {
 			return nil, fmt.Errorf("%s: %v", invalidDefaultServiceConfigErrPrefix, scpr.Err)
 		}
 		cc.dopts.defaultServiceConfig, _ = scpr.Config.(*ServiceConfig)
 	}
-	cc.mkp = cc.dopts.copts.KeepaliveParams
+	cc.keepaliveParams = cc.dopts.copts.KeepaliveParams
 
-	// Register ClientConn with channelz.
+	if err = cc.initAuthority(); err != nil {
+		return nil, err
+	}
+
+	// Register ClientConn with channelz. Note that this is only done after
+	// channel creation cannot fail.
 	cc.channelzRegistration(target)
-
-	// TODO: Ideally it should be impossible to error from this function after
-	// channelz registration.  This will require removing some channelz logs
-	// from the following functions that can error.  Errors can be returned to
-	// the user, and successful logs can be emitted here, after the checks have
-	// passed and channelz is subsequently registered.
-
-	// Determine the resolver to use.
-	if err := cc.parseTargetAndFindResolver(); err != nil {
-		channelz.RemoveEntry(cc.channelz.ID)
-		return nil, err
-	}
-	if err = cc.determineAuthority(); err != nil {
-		channelz.RemoveEntry(cc.channelz.ID)
-		return nil, err
-	}
+	channelz.Infof(logger, cc.channelz, "parsed dial target is: %#v", cc.parsedTarget)
+	channelz.Infof(logger, cc.channelz, "Channel authority set to %q", cc.authority)
 
 	cc.csMgr = newConnectivityStateManager(cc.ctx, cc.channelz)
 	cc.pickerWrapper = newPickerWrapper(cc.dopts.copts.StatsHandlers)
 
+	cc.metricsRecorderList = stats.NewMetricsRecorderList(cc.dopts.copts.StatsHandlers)
+
 	cc.initIdleStateLocked() // Safe to call without the lock, since nothing else has a reference to cc.
 	cc.idlenessMgr = idle.NewManager((*idler)(cc), cc.dopts.idleTimeout)
+
 	return cc, nil
 }
 
 // Dial calls DialContext(context.Background(), target, opts...).
+//
+// Deprecated: use NewClient instead.  Will be supported throughout 1.x.
 func Dial(target string, opts ...DialOption) (*ClientConn, error) {
 	return DialContext(context.Background(), target, opts...)
 }
@@ -209,10 +234,17 @@ func Dial(target string, opts ...DialOption) (*ClientConn, error) {
 // "passthrough" for backward compatibility.  This distinction should not matter
 // to most users, but could matter to legacy users that specify a custom dialer
 // and expect it to receive the target string directly.
+//
+// Deprecated: use NewClient instead.  Will be supported throughout 1.x.
 func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *ClientConn, err error) {
 	// At the end of this method, we kick the channel out of idle, rather than
 	// waiting for the first rpc.
-	opts = append([]DialOption{withDefaultScheme("passthrough")}, opts...)
+	//
+	// WithLocalDNSResolution dial option in `grpc.Dial` ensures that it
+	// preserves behavior: when default scheme passthrough is used, skip
+	// hostname resolution, when "dns" is used for resolution, perform
+	// resolution on the client.
+	opts = append([]DialOption{withDefaultScheme("passthrough"), WithLocalDNSResolution()}, opts...)
 	cc, err := NewClient(target, opts...)
 	if err != nil {
 		return nil, err
@@ -582,13 +614,14 @@ type ClientConn struct {
 	cancel context.CancelFunc // Cancelled on close.
 
 	// The following are initialized at dial time, and are read-only after that.
-	target          string            // User's dial target.
-	parsedTarget    resolver.Target   // See parseTargetAndFindResolver().
-	authority       string            // See determineAuthority().
-	dopts           dialOptions       // Default and user specified dial options.
-	channelz        *channelz.Channel // Channelz object.
-	resolverBuilder resolver.Builder  // See parseTargetAndFindResolver().
-	idlenessMgr     *idle.Manager
+	target              string            // User's dial target.
+	parsedTarget        resolver.Target   // See initParsedTargetAndResolverBuilder().
+	authority           string            // See initAuthority().
+	dopts               dialOptions       // Default and user specified dial options.
+	channelz            *channelz.Channel // Channelz object.
+	resolverBuilder     resolver.Builder  // See initParsedTargetAndResolverBuilder().
+	idlenessMgr         *idle.Manager
+	metricsRecorderList *stats.MetricsRecorderList
 
 	// The following provide their own synchronization, and therefore don't
 	// require cc.mu to be held to access them.
@@ -604,7 +637,7 @@ type ClientConn struct {
 	balancerWrapper *ccBalancerWrapper         // Always recreated whenever entering idle to simplify Close.
 	sc              *ServiceConfig             // Latest service config received from the resolver.
 	conns           map[*addrConn]struct{}     // Set to nil on close.
-	mkp             keepalive.ClientParameters // May be updated upon receipt of a GoAway.
+	keepaliveParams keepalive.ClientParameters // May be updated upon receipt of a GoAway.
 	// firstResolveEvent is used to track whether the name resolver sent us at
 	// least one update. RPCs block on this event.  May be accessed without mu
 	// if we know we cannot be asked to enter idle mode while accessing it (e.g.
@@ -618,11 +651,6 @@ type ClientConn struct {
 
 // WaitForStateChange waits until the connectivity.State of ClientConn changes from sourceState or
 // ctx expires. A true value is returned in former case and false in latter.
-//
-// # Experimental
-//
-// Notice: This API is EXPERIMENTAL and may be changed or removed in a
-// later release.
 func (cc *ClientConn) WaitForStateChange(ctx context.Context, sourceState connectivity.State) bool {
 	ch := cc.csMgr.getNotifyChan()
 	if cc.csMgr.getState() != sourceState {
@@ -637,11 +665,6 @@ func (cc *ClientConn) WaitForStateChange(ctx context.Context, sourceState connec
 }
 
 // GetState returns the connectivity.State of ClientConn.
-//
-// # Experimental
-//
-// Notice: This API is EXPERIMENTAL and may be changed or removed in a later
-// release.
 func (cc *ClientConn) GetState() connectivity.State {
 	return cc.csMgr.getState()
 }
@@ -688,8 +711,7 @@ func (cc *ClientConn) waitForResolvedAddrs(ctx context.Context) error {
 var emptyServiceConfig *ServiceConfig
 
 func init() {
-	balancer.Register(pickfirstBuilder{})
-	cfg := parseServiceConfig("{}")
+	cfg := parseServiceConfig("{}", defaultMaxCallAttempts)
 	if cfg.Err != nil {
 		panic(fmt.Sprintf("impossible error parsing empty service config: %v", cfg.Err))
 	}
@@ -772,10 +794,7 @@ func (cc *ClientConn) updateResolverStateAndUnlock(s resolver.State, err error)
 		}
 	}
 
-	var balCfg serviceconfig.LoadBalancingConfig
-	if cc.sc != nil && cc.sc.lbConfig != nil {
-		balCfg = cc.sc.lbConfig
-	}
+	balCfg := cc.sc.lbConfig
 	bw := cc.balancerWrapper
 	cc.mu.Unlock()
 
@@ -805,17 +824,11 @@ func (cc *ClientConn) applyFailingLBLocked(sc *serviceconfig.ParseResult) {
 	cc.csMgr.updateState(connectivity.TransientFailure)
 }
 
-// Makes a copy of the input addresses slice and clears out the balancer
-// attributes field. Addresses are passed during subconn creation and address
-// update operations. In both cases, we will clear the balancer attributes by
-// calling this function, and therefore we will be able to use the Equal method
-// provided by the resolver.Address type for comparison.
-func copyAddressesWithoutBalancerAttributes(in []resolver.Address) []resolver.Address {
+// Makes a copy of the input addresses slice. Addresses are passed during
+// subconn creation and address update operations.
+func copyAddresses(in []resolver.Address) []resolver.Address {
 	out := make([]resolver.Address, len(in))
-	for i := range in {
-		out[i] = in[i]
-		out[i].BalancerAttributes = nil
-	}
+	copy(out, in)
 	return out
 }
 
@@ -830,14 +843,16 @@ func (cc *ClientConn) newAddrConnLocked(addrs []resolver.Address, opts balancer.
 	ac := &addrConn{
 		state:        connectivity.Idle,
 		cc:           cc,
-		addrs:        copyAddressesWithoutBalancerAttributes(addrs),
+		addrs:        copyAddresses(addrs),
 		scopts:       opts,
 		dopts:        cc.dopts,
 		channelz:     channelz.RegisterSubChannel(cc.channelz, ""),
 		resetBackoff: make(chan struct{}),
-		stateChan:    make(chan struct{}),
 	}
 	ac.ctx, ac.cancel = context.WithCancel(cc.ctx)
+	// Start with our address set to the first address; this may be updated if
+	// we connect to different addresses.
+	ac.channelz.ChannelMetrics.Target.Store(&addrs[0].Addr)
 
 	channelz.AddTraceEvent(logger, ac.channelz, 0, &channelz.TraceEvent{
 		Desc:     "Subchannel created",
@@ -871,7 +886,13 @@ func (cc *ClientConn) Target() string {
 	return cc.target
 }
 
-// CanonicalTarget returns the canonical target string of the ClientConn.
+// CanonicalTarget returns the canonical target string used when creating cc.
+//
+// This always has the form "<scheme>://[authority]/<endpoint>".  For example:
+//
+//   - "dns:///example.com:42"
+//   - "dns://8.8.8.8/example.com:42"
+//   - "unix:///path/to/socket"
 func (cc *ClientConn) CanonicalTarget() string {
 	return cc.parsedTarget.String()
 }
@@ -908,32 +929,37 @@ func (ac *addrConn) connect() error {
 		ac.mu.Unlock()
 		return nil
 	}
-	ac.mu.Unlock()
 
-	ac.resetTransport()
+	ac.resetTransportAndUnlock()
 	return nil
 }
 
-func equalAddresses(a, b []resolver.Address) bool {
-	if len(a) != len(b) {
-		return false
-	}
-	for i, v := range a {
-		if !v.Equal(b[i]) {
-			return false
-		}
-	}
-	return true
+// equalAddressIgnoringBalAttributes returns true is a and b are considered equal.
+// This is different from the Equal method on the resolver.Address type which
+// considers all fields to determine equality. Here, we only consider fields
+// that are meaningful to the subConn.
+func equalAddressIgnoringBalAttributes(a, b *resolver.Address) bool {
+	return a.Addr == b.Addr && a.ServerName == b.ServerName &&
+		a.Attributes.Equal(b.Attributes) &&
+		a.Metadata == b.Metadata
+}
+
+func equalAddressesIgnoringBalAttributes(a, b []resolver.Address) bool {
+	return slices.EqualFunc(a, b, func(a, b resolver.Address) bool { return equalAddressIgnoringBalAttributes(&a, &b) })
 }
 
 // updateAddrs updates ac.addrs with the new addresses list and handles active
 // connections or connection attempts.
 func (ac *addrConn) updateAddrs(addrs []resolver.Address) {
-	ac.mu.Lock()
-	channelz.Infof(logger, ac.channelz, "addrConn: updateAddrs curAddr: %v, addrs: %v", pretty.ToJSON(ac.curAddr), pretty.ToJSON(addrs))
+	addrs = copyAddresses(addrs)
+	limit := len(addrs)
+	if limit > 5 {
+		limit = 5
+	}
+	channelz.Infof(logger, ac.channelz, "addrConn: updateAddrs addrs (%d of %d): %v", limit, len(addrs), addrs[:limit])
 
-	addrs = copyAddressesWithoutBalancerAttributes(addrs)
-	if equalAddresses(ac.addrs, addrs) {
+	ac.mu.Lock()
+	if equalAddressesIgnoringBalAttributes(ac.addrs, addrs) {
 		ac.mu.Unlock()
 		return
 	}
@@ -952,7 +978,7 @@ func (ac *addrConn) updateAddrs(addrs []resolver.Address) {
 		// Try to find the connected address.
 		for _, a := range addrs {
 			a.ServerName = ac.cc.getServerName(a)
-			if a.Equal(ac.curAddr) {
+			if equalAddressIgnoringBalAttributes(&a, &ac.curAddr) {
 				// We are connected to a valid address, so do nothing but
 				// update the addresses.
 				ac.mu.Unlock()
@@ -978,11 +1004,9 @@ func (ac *addrConn) updateAddrs(addrs []resolver.Address) {
 		ac.updateConnectivityState(connectivity.Idle, nil)
 	}
 
-	ac.mu.Unlock()
-
 	// Since we were connecting/connected, we should start a new connection
 	// attempt.
-	go ac.resetTransport()
+	go ac.resetTransportAndUnlock()
 }
 
 // getServerName determines the serverName to be used in the connection
@@ -1138,10 +1162,15 @@ func (cc *ClientConn) Close() error {
 
 	<-cc.resolverWrapper.serializer.Done()
 	<-cc.balancerWrapper.serializer.Done()
-
+	var wg sync.WaitGroup
 	for ac := range conns {
-		ac.tearDown(ErrClientConnClosing)
+		wg.Add(1)
+		go func(ac *addrConn) {
+			defer wg.Done()
+			ac.tearDown(ErrClientConnClosing)
+		}(ac)
 	}
+	wg.Wait()
 	cc.addTraceEvent("deleted")
 	// TraceEvent needs to be called before RemoveEntry, as TraceEvent may add
 	// trace reference to the entity being deleted, and thus prevent it from being
@@ -1167,13 +1196,16 @@ type addrConn struct {
 	// is received, transport is closed, ac has been torn down).
 	transport transport.ClientTransport // The current transport.
 
+	// This mutex is used on the RPC path, so its usage should be minimized as
+	// much as possible.
+	// TODO: Find a lock-free way to retrieve the transport and state from the
+	// addrConn.
 	mu      sync.Mutex
 	curAddr resolver.Address   // The current address.
 	addrs   []resolver.Address // All addresses that the resolver resolved to.
 
 	// Use updateConnectivityState for updating addrConn's connectivity state.
-	state     connectivity.State
-	stateChan chan struct{} // closed and recreated on every state change.
+	state connectivity.State
 
 	backoffIdx   int // Needs to be stateful for resetConnectBackoff.
 	resetBackoff chan struct{}
@@ -1186,9 +1218,6 @@ func (ac *addrConn) updateConnectivityState(s connectivity.State, lastErr error)
 	if ac.state == s {
 		return
 	}
-	// When changing states, reset the state change channel.
-	close(ac.stateChan)
-	ac.stateChan = make(chan struct{})
 	ac.state = s
 	ac.channelz.ChannelMetrics.State.Store(&s)
 	if lastErr == nil {
@@ -1196,25 +1225,26 @@ func (ac *addrConn) updateConnectivityState(s connectivity.State, lastErr error)
 	} else {
 		channelz.Infof(logger, ac.channelz, "Subchannel Connectivity change to %v, last error: %s", s, lastErr)
 	}
-	ac.acbw.updateState(s, lastErr)
+	ac.acbw.updateState(s, ac.curAddr, lastErr)
 }
 
 // adjustParams updates parameters used to create transports upon
 // receiving a GoAway.
 func (ac *addrConn) adjustParams(r transport.GoAwayReason) {
-	switch r {
-	case transport.GoAwayTooManyPings:
+	if r == transport.GoAwayTooManyPings {
 		v := 2 * ac.dopts.copts.KeepaliveParams.Time
 		ac.cc.mu.Lock()
-		if v > ac.cc.mkp.Time {
-			ac.cc.mkp.Time = v
+		if v > ac.cc.keepaliveParams.Time {
+			ac.cc.keepaliveParams.Time = v
 		}
 		ac.cc.mu.Unlock()
 	}
 }
 
-func (ac *addrConn) resetTransport() {
-	ac.mu.Lock()
+// resetTransportAndUnlock unconditionally connects the addrConn.
+//
+// ac.mu must be held by the caller, and this function will guarantee it is released.
+func (ac *addrConn) resetTransportAndUnlock() {
 	acCtx := ac.ctx
 	if acCtx.Err() != nil {
 		ac.mu.Unlock()
@@ -1245,6 +1275,8 @@ func (ac *addrConn) resetTransport() {
 	ac.mu.Unlock()
 
 	if err := ac.tryAllAddrs(acCtx, addrs, connectDeadline); err != nil {
+		// TODO: #7534 - Move re-resolution requests into the pick_first LB policy
+		// to ensure one resolution request per pass instead of per subconn failure.
 		ac.cc.resolveNow(resolver.ResolveNowOptions{})
 		ac.mu.Lock()
 		if acCtx.Err() != nil {
@@ -1286,19 +1318,20 @@ func (ac *addrConn) resetTransport() {
 	ac.mu.Unlock()
 }
 
-// tryAllAddrs tries to creates a connection to the addresses, and stop when at
+// tryAllAddrs tries to create a connection to the addresses, and stop when at
 // the first successful one. It returns an error if no address was successfully
 // connected, or updates ac appropriately with the new transport.
 func (ac *addrConn) tryAllAddrs(ctx context.Context, addrs []resolver.Address, connectDeadline time.Time) error {
 	var firstConnErr error
 	for _, addr := range addrs {
+		ac.channelz.ChannelMetrics.Target.Store(&addr.Addr)
 		if ctx.Err() != nil {
 			return errConnClosing
 		}
 		ac.mu.Lock()
 
 		ac.cc.mu.RLock()
-		ac.dopts.copts.KeepaliveParams = ac.cc.mkp
+		ac.dopts.copts.KeepaliveParams = ac.cc.keepaliveParams
 		ac.cc.mu.RUnlock()
 
 		copts := ac.dopts.copts
@@ -1362,7 +1395,7 @@ func (ac *addrConn) createTransport(ctx context.Context, addr resolver.Address,
 	defer cancel()
 	copts.ChannelzParent = ac.channelz
 
-	newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, addr, copts, onClose)
+	newTr, err := transport.NewHTTP2Client(connectCtx, ac.cc.ctx, addr, copts, onClose)
 	if err != nil {
 		if logger.V(2) {
 			logger.Infof("Creating new client transport to %q: %v", addr, err)
@@ -1436,7 +1469,7 @@ func (ac *addrConn) startHealthCheck(ctx context.Context) {
 	if !ac.scopts.HealthCheckEnabled {
 		return
 	}
-	healthCheckFunc := ac.cc.dopts.healthCheckFunc
+	healthCheckFunc := internal.HealthCheckFunc
 	if healthCheckFunc == nil {
 		// The health package is not imported to set health check function.
 		//
@@ -1468,7 +1501,7 @@ func (ac *addrConn) startHealthCheck(ctx context.Context) {
 	}
 	// Start the health checking stream.
 	go func() {
-		err := ac.cc.dopts.healthCheckFunc(ctx, newStream, setConnectivityState, healthCheckConfig.ServiceName)
+		err := healthCheckFunc(ctx, newStream, setConnectivityState, healthCheckConfig.ServiceName)
 		if err != nil {
 			if status.Code(err) == codes.Unimplemented {
 				channelz.Error(logger, ac.channelz, "Subchannel health check is unimplemented at server side, thus health check is disabled")
@@ -1497,29 +1530,6 @@ func (ac *addrConn) getReadyTransport() transport.ClientTransport {
 	return nil
 }
 
-// getTransport waits until the addrconn is ready and returns the transport.
-// If the context expires first, returns an appropriate status.  If the
-// addrConn is stopped first, returns an Unavailable status error.
-func (ac *addrConn) getTransport(ctx context.Context) (transport.ClientTransport, error) {
-	for ctx.Err() == nil {
-		ac.mu.Lock()
-		t, state, sc := ac.transport, ac.state, ac.stateChan
-		ac.mu.Unlock()
-		if state == connectivity.Ready {
-			return t, nil
-		}
-		if state == connectivity.Shutdown {
-			return nil, status.Errorf(codes.Unavailable, "SubConn shutting down")
-		}
-
-		select {
-		case <-ctx.Done():
-		case <-sc:
-		}
-	}
-	return nil, status.FromContextError(ctx.Err()).Err()
-}
-
 // tearDown starts to tear down the addrConn.
 //
 // Note that tearDown doesn't remove ac from ac.cc.conns, so the addrConn struct
@@ -1566,7 +1576,7 @@ func (ac *addrConn) tearDown(err error) {
 		} else {
 			// Hard close the transport when the channel is entering idle or is
 			// being shutdown. In the case where the channel is being shutdown,
-			// closing of transports is also taken care of by cancelation of cc.ctx.
+			// closing of transports is also taken care of by cancellation of cc.ctx.
 			// But in the case where the channel is entering idle, we need to
 			// explicitly close the transports here. Instead of distinguishing
 			// between these two cases, it is simpler to close the transport
@@ -1657,22 +1667,19 @@ func (cc *ClientConn) connectionError() error {
 	return cc.lastConnectionError
 }
 
-// parseTargetAndFindResolver parses the user's dial target and stores the
-// parsed target in `cc.parsedTarget`.
+// initParsedTargetAndResolverBuilder parses the user's dial target and stores
+// the parsed target in `cc.parsedTarget`.
 //
 // The resolver to use is determined based on the scheme in the parsed target
 // and the same is stored in `cc.resolverBuilder`.
 //
 // Doesn't grab cc.mu as this method is expected to be called only at Dial time.
-func (cc *ClientConn) parseTargetAndFindResolver() error {
-	channelz.Infof(logger, cc.channelz, "original dial target is: %q", cc.target)
+func (cc *ClientConn) initParsedTargetAndResolverBuilder() error {
+	logger.Infof("original dial target is: %q", cc.target)
 
 	var rb resolver.Builder
 	parsedTarget, err := parseTarget(cc.target)
-	if err != nil {
-		channelz.Infof(logger, cc.channelz, "dial target %q parse failed: %v", cc.target, err)
-	} else {
-		channelz.Infof(logger, cc.channelz, "parsed dial target is: %#v", parsedTarget)
+	if err == nil {
 		rb = cc.getResolver(parsedTarget.URL.Scheme)
 		if rb != nil {
 			cc.parsedTarget = parsedTarget
@@ -1691,15 +1698,12 @@ func (cc *ClientConn) parseTargetAndFindResolver() error {
 		defScheme = resolver.GetDefaultScheme()
 	}
 
-	channelz.Infof(logger, cc.channelz, "fallback to scheme %q", defScheme)
 	canonicalTarget := defScheme + ":///" + cc.target
 
 	parsedTarget, err = parseTarget(canonicalTarget)
 	if err != nil {
-		channelz.Infof(logger, cc.channelz, "dial target %q parse failed: %v", canonicalTarget, err)
 		return err
 	}
-	channelz.Infof(logger, cc.channelz, "parsed dial target is: %+v", parsedTarget)
 	rb = cc.getResolver(parsedTarget.URL.Scheme)
 	if rb == nil {
 		return fmt.Errorf("could not get resolver for default scheme: %q", parsedTarget.URL.Scheme)
@@ -1739,7 +1743,7 @@ func encodeAuthority(authority string) string {
 			return false
 		case '!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '=': // Subdelim characters
 			return false
-		case ':', '[', ']', '@': // Authority related delimeters
+		case ':', '[', ']', '@': // Authority related delimiters
 			return false
 		}
 		// Everything else must be escaped.
@@ -1789,7 +1793,7 @@ func encodeAuthority(authority string) string {
 // credentials do not match the authority configured through the dial option.
 //
 // Doesn't grab cc.mu as this method is expected to be called only at Dial time.
-func (cc *ClientConn) determineAuthority() error {
+func (cc *ClientConn) initAuthority() error {
 	dopts := cc.dopts
 	// Historically, we had two options for users to specify the serverName or
 	// authority for a channel. One was through the transport credentials
@@ -1822,6 +1826,5 @@ func (cc *ClientConn) determineAuthority() error {
 	} else {
 		cc.authority = encodeAuthority(endpoint)
 	}
-	channelz.Infof(logger, cc.channelz, "Channel authority set to %q", cc.authority)
 	return nil
 }

vendor/google.golang.org/grpc/codec.go

@@ -21,18 +21,73 @@ package grpc
 import (
 	"google.golang.org/grpc/encoding"
 	_ "google.golang.org/grpc/encoding/proto" // to register the Codec for "proto"
+	"google.golang.org/grpc/mem"
 )
 
-// baseCodec contains the functionality of both Codec and encoding.Codec, but
-// omits the name/string, which vary between the two and are not needed for
-// anything besides the registry in the encoding package.
+// baseCodec captures the new encoding.CodecV2 interface without the Name
+// function, allowing it to be implemented by older Codec and encoding.Codec
+// implementations. The omitted Name function is only needed for the register in
+// the encoding package and is not part of the core functionality.
 type baseCodec interface {
-	Marshal(v any) ([]byte, error)
-	Unmarshal(data []byte, v any) error
+	Marshal(v any) (mem.BufferSlice, error)
+	Unmarshal(data mem.BufferSlice, v any) error
 }
 
-var _ baseCodec = Codec(nil)
-var _ baseCodec = encoding.Codec(nil)
+// getCodec returns an encoding.CodecV2 for the codec of the given name (if
+// registered). Initially checks the V2 registry with encoding.GetCodecV2 and
+// returns the V2 codec if it is registered. Otherwise, it checks the V1 registry
+// with encoding.GetCodec and if it is registered wraps it with newCodecV1Bridge
+// to turn it into an encoding.CodecV2. Returns nil otherwise.
+func getCodec(name string) encoding.CodecV2 {
+	if codecV1 := encoding.GetCodec(name); codecV1 != nil {
+		return newCodecV1Bridge(codecV1)
+	}
+
+	return encoding.GetCodecV2(name)
+}
+
+func newCodecV0Bridge(c Codec) baseCodec {
+	return codecV0Bridge{codec: c}
+}
+
+func newCodecV1Bridge(c encoding.Codec) encoding.CodecV2 {
+	return codecV1Bridge{
+		codecV0Bridge: codecV0Bridge{codec: c},
+		name:          c.Name(),
+	}
+}
+
+var _ baseCodec = codecV0Bridge{}
+
+type codecV0Bridge struct {
+	codec interface {
+		Marshal(v any) ([]byte, error)
+		Unmarshal(data []byte, v any) error
+	}
+}
+
+func (c codecV0Bridge) Marshal(v any) (mem.BufferSlice, error) {
+	data, err := c.codec.Marshal(v)
+	if err != nil {
+		return nil, err
+	}
+	return mem.BufferSlice{mem.SliceBuffer(data)}, nil
+}
+
+func (c codecV0Bridge) Unmarshal(data mem.BufferSlice, v any) (err error) {
+	return c.codec.Unmarshal(data.Materialize(), v)
+}
+
+var _ encoding.CodecV2 = codecV1Bridge{}
+
+type codecV1Bridge struct {
+	codecV0Bridge
+	name string
+}
+
+func (c codecV1Bridge) Name() string {
+	return c.name
+}
 
 // Codec defines the interface gRPC uses to encode and decode messages.
 // Note that implementations of this interface must be thread safe;

vendor/google.golang.org/grpc/codegen.sh

@@ -1,17 +0,0 @@
-#!/usr/bin/env bash
-
-# This script serves as an example to demonstrate how to generate the gRPC-Go
-# interface and the related messages from .proto file.
-#
-# It assumes the installation of i) Google proto buffer compiler at
-# https://github.com/google/protobuf (after v2.6.1) and ii) the Go codegen
-# plugin at https://github.com/golang/protobuf (after 2015-02-20). If you have
-# not, please install them first.
-#
-# We recommend running this script at $GOPATH/src.
-#
-# If this is not what you need, feel free to make your own scripts. Again, this
-# script is for demonstration purpose.
-#
-proto=$1
-protoc --go_out=plugins=grpc:. $proto

vendor/google.golang.org/grpc/codes/codes.go

@@ -235,7 +235,7 @@ func (c *Code) UnmarshalJSON(b []byte) error {
 
 	if ci, err := strconv.ParseUint(string(b), 10, 32); err == nil {
 		if ci >= _maxCode {
-			return fmt.Errorf("invalid code: %q", ci)
+			return fmt.Errorf("invalid code: %d", ci)
 		}
 
 		*c = Code(ci)

vendor/google.golang.org/grpc/credentials/credentials.go

@@ -30,7 +30,7 @@ import (
 
 	"google.golang.org/grpc/attributes"
 	icredentials "google.golang.org/grpc/internal/credentials"
-	"google.golang.org/protobuf/protoadapt"
+	"google.golang.org/protobuf/proto"
 )
 
 // PerRPCCredentials defines the common interface for the credentials which need to
@@ -237,7 +237,7 @@ func ClientHandshakeInfoFromContext(ctx context.Context) ClientHandshakeInfo {
 }
 
 // CheckSecurityLevel checks if a connection's security level is greater than or equal to the specified one.
-// It returns success if 1) the condition is satisified or 2) AuthInfo struct does not implement GetCommonAuthInfo() method
+// It returns success if 1) the condition is satisfied or 2) AuthInfo struct does not implement GetCommonAuthInfo() method
 // or 3) CommonAuthInfo.SecurityLevel has an invalid zero value. For 2) and 3), it is for the purpose of backward-compatibility.
 //
 // This API is experimental.
@@ -287,5 +287,5 @@ type ChannelzSecurityValue interface {
 type OtherChannelzSecurityValue struct {
 	ChannelzSecurityValue
 	Name  string
-	Value protoadapt.MessageV1
+	Value proto.Message
 }

vendor/google.golang.org/grpc/credentials/insecure/insecure.go

@@ -40,7 +40,7 @@ func NewCredentials() credentials.TransportCredentials {
 // NoSecurity.
 type insecureTC struct{}
 
-func (insecureTC) ClientHandshake(ctx context.Context, _ string, conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+func (insecureTC) ClientHandshake(_ context.Context, _ string, conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
 	return conn, info{credentials.CommonAuthInfo{SecurityLevel: credentials.NoSecurity}}, nil
 }
 

vendor/google.golang.org/grpc/credentials/tls.go

@@ -27,9 +27,15 @@ import (
 	"net/url"
 	"os"
 
+	"google.golang.org/grpc/grpclog"
 	credinternal "google.golang.org/grpc/internal/credentials"
+	"google.golang.org/grpc/internal/envconfig"
 )
 
+const alpnFailureHelpMessage = "If you upgraded from a grpc-go version earlier than 1.67, your TLS connections may have stopped working due to ALPN enforcement. For more details, see: https://github.com/grpc/grpc-go/issues/434"
+
+var logger = grpclog.Component("credentials")
+
 // TLSInfo contains the auth information for a TLS authenticated connection.
 // It implements the AuthInfo interface.
 type TLSInfo struct {
@@ -112,6 +118,22 @@ func (c *tlsCreds) ClientHandshake(ctx context.Context, authority string, rawCon
 		conn.Close()
 		return nil, nil, ctx.Err()
 	}
+
+	// The negotiated protocol can be either of the following:
+	// 1. h2: When the server supports ALPN. Only HTTP/2 can be negotiated since
+	//    it is the only protocol advertised by the client during the handshake.
+	//    The tls library ensures that the server chooses a protocol advertised
+	//    by the client.
+	// 2. "" (empty string): If the server doesn't support ALPN. ALPN is a requirement
+	//    for using HTTP/2 over TLS. We can terminate the connection immediately.
+	np := conn.ConnectionState().NegotiatedProtocol
+	if np == "" {
+		if envconfig.EnforceALPNEnabled {
+			conn.Close()
+			return nil, nil, fmt.Errorf("credentials: cannot check peer: missing selected ALPN property. %s", alpnFailureHelpMessage)
+		}
+		logger.Warningf("Allowing TLS connection to server %q with ALPN disabled. TLS connections to servers with ALPN disabled will be disallowed in future grpc-go releases", cfg.ServerName)
+	}
 	tlsInfo := TLSInfo{
 		State: conn.ConnectionState(),
 		CommonAuthInfo: CommonAuthInfo{
@@ -131,8 +153,20 @@ func (c *tlsCreds) ServerHandshake(rawConn net.Conn) (net.Conn, AuthInfo, error)
 		conn.Close()
 		return nil, nil, err
 	}
+	cs := conn.ConnectionState()
+	// The negotiated application protocol can be empty only if the client doesn't
+	// support ALPN. In such cases, we can close the connection since ALPN is required
+	// for using HTTP/2 over TLS.
+	if cs.NegotiatedProtocol == "" {
+		if envconfig.EnforceALPNEnabled {
+			conn.Close()
+			return nil, nil, fmt.Errorf("credentials: cannot check peer: missing selected ALPN property. %s", alpnFailureHelpMessage)
+		} else if logger.V(2) {
+			logger.Info("Allowing TLS connection from client with ALPN disabled. TLS connections with ALPN disabled will be disallowed in future grpc-go releases")
+		}
+	}
 	tlsInfo := TLSInfo{
-		State: conn.ConnectionState(),
+		State: cs,
 		CommonAuthInfo: CommonAuthInfo{
 			SecurityLevel: PrivacyAndIntegrity,
 		},
@@ -168,25 +202,40 @@ var tls12ForbiddenCipherSuites = map[uint16]struct{}{
 
 // NewTLS uses c to construct a TransportCredentials based on TLS.
 func NewTLS(c *tls.Config) TransportCredentials {
-	tc := &tlsCreds{credinternal.CloneTLSConfig(c)}
-	tc.config.NextProtos = credinternal.AppendH2ToNextProtos(tc.config.NextProtos)
+	config := applyDefaults(c)
+	if config.GetConfigForClient != nil {
+		oldFn := config.GetConfigForClient
+		config.GetConfigForClient = func(hello *tls.ClientHelloInfo) (*tls.Config, error) {
+			cfgForClient, err := oldFn(hello)
+			if err != nil || cfgForClient == nil {
+				return cfgForClient, err
+			}
+			return applyDefaults(cfgForClient), nil
+		}
+	}
+	return &tlsCreds{config: config}
+}
+
+func applyDefaults(c *tls.Config) *tls.Config {
+	config := credinternal.CloneTLSConfig(c)
+	config.NextProtos = credinternal.AppendH2ToNextProtos(config.NextProtos)
 	// If the user did not configure a MinVersion and did not configure a
 	// MaxVersion < 1.2, use MinVersion=1.2, which is required by
 	// https://datatracker.ietf.org/doc/html/rfc7540#section-9.2
-	if tc.config.MinVersion == 0 && (tc.config.MaxVersion == 0 || tc.config.MaxVersion >= tls.VersionTLS12) {
-		tc.config.MinVersion = tls.VersionTLS12
+	if config.MinVersion == 0 && (config.MaxVersion == 0 || config.MaxVersion >= tls.VersionTLS12) {
+		config.MinVersion = tls.VersionTLS12
 	}
 	// If the user did not configure CipherSuites, use all "secure" cipher
 	// suites reported by the TLS package, but remove some explicitly forbidden
 	// by https://datatracker.ietf.org/doc/html/rfc7540#appendix-A
-	if tc.config.CipherSuites == nil {
+	if config.CipherSuites == nil {
 		for _, cs := range tls.CipherSuites() {
 			if _, ok := tls12ForbiddenCipherSuites[cs.ID]; !ok {
-				tc.config.CipherSuites = append(tc.config.CipherSuites, cs.ID)
+				config.CipherSuites = append(config.CipherSuites, cs.ID)
 			}
 		}
 	}
-	return tc
+	return config
 }
 
 // NewClientTLSFromCert constructs TLS credentials from the provided root

vendor/google.golang.org/grpc/dialoptions.go

@@ -21,6 +21,7 @@ package grpc
 import (
 	"context"
 	"net"
+	"net/url"
 	"time"
 
 	"google.golang.org/grpc/backoff"
@@ -32,10 +33,16 @@ import (
 	"google.golang.org/grpc/internal/binarylog"
 	"google.golang.org/grpc/internal/transport"
 	"google.golang.org/grpc/keepalive"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/stats"
 )
 
+const (
+	// https://github.com/grpc/proposal/blob/master/A6-client-retries.md#limits-on-retries-and-hedges
+	defaultMaxCallAttempts = 5
+)
+
 func init() {
 	internal.AddGlobalDialOptions = func(opt ...DialOption) {
 		globalDialOptions = append(globalDialOptions, opt...)
@@ -43,10 +50,18 @@ func init() {
 	internal.ClearGlobalDialOptions = func() {
 		globalDialOptions = nil
 	}
+	internal.AddGlobalPerTargetDialOptions = func(opt any) {
+		if ptdo, ok := opt.(perTargetDialOption); ok {
+			globalPerTargetDialOptions = append(globalPerTargetDialOptions, ptdo)
+		}
+	}
+	internal.ClearGlobalPerTargetDialOptions = func() {
+		globalPerTargetDialOptions = nil
+	}
 	internal.WithBinaryLogger = withBinaryLogger
 	internal.JoinDialOptions = newJoinDialOption
 	internal.DisableGlobalDialOptions = newDisableGlobalDialOptions
-	internal.WithRecvBufferPool = withRecvBufferPool
+	internal.WithBufferPool = withBufferPool
 }
 
 // dialOptions configure a Dial call. dialOptions are set by the DialOption
@@ -58,7 +73,7 @@ type dialOptions struct {
 	chainUnaryInts  []UnaryClientInterceptor
 	chainStreamInts []StreamClientInterceptor
 
-	cp                          Compressor
+	compressorV0                Compressor
 	dc                          Decompressor
 	bs                          internalbackoff.Strategy
 	block                       bool
@@ -72,14 +87,15 @@ type dialOptions struct {
 	disableServiceConfig        bool
 	disableRetry                bool
 	disableHealthCheck          bool
-	healthCheckFunc             internal.HealthChecker
 	minConnectTimeout           func() time.Duration
 	defaultServiceConfig        *ServiceConfig // defaultServiceConfig is parsed from defaultServiceConfigRawJSON.
 	defaultServiceConfigRawJSON *string
 	resolvers                   []resolver.Builder
 	idleTimeout                 time.Duration
-	recvBufferPool              SharedBufferPool
 	defaultScheme               string
+	maxCallAttempts             int
+	enableLocalDNSResolution    bool // Specifies if target hostnames should be resolved when proxying is enabled.
+	useProxy                    bool // Specifies if a server should be connected via proxy.
 }
 
 // DialOption configures how we set up the connection.
@@ -89,6 +105,19 @@ type DialOption interface {
 
 var globalDialOptions []DialOption
 
+// perTargetDialOption takes a parsed target and returns a dial option to apply.
+//
+// This gets called after NewClient() parses the target, and allows per target
+// configuration set through a returned DialOption. The DialOption will not take
+// effect if specifies a resolver builder, as that Dial Option is factored in
+// while parsing target.
+type perTargetDialOption interface {
+	// DialOption returns a Dial Option to apply.
+	DialOptionForTarget(parsedTarget url.URL) DialOption
+}
+
+var globalPerTargetDialOptions []perTargetDialOption
+
 // EmptyDialOption does not alter the dial configuration. It can be embedded in
 // another structure to build custom dial options.
 //
@@ -229,7 +258,7 @@ func WithCodec(c Codec) DialOption {
 // Deprecated: use UseCompressor instead.  Will be supported throughout 1.x.
 func WithCompressor(cp Compressor) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
-		o.cp = cp
+		o.compressorV0 = cp
 	})
 }
 
@@ -300,6 +329,9 @@ func withBackoff(bs internalbackoff.Strategy) DialOption {
 //
 // Use of this feature is not recommended.  For more information, please see:
 // https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md
+//
+// Deprecated: this DialOption is not supported by NewClient.
+// Will be supported throughout 1.x.
 func WithBlock() DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		o.block = true
@@ -314,10 +346,8 @@ func WithBlock() DialOption {
 // Use of this feature is not recommended.  For more information, please see:
 // https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md
 //
-// # Experimental
-//
-// Notice: This API is EXPERIMENTAL and may be changed or removed in a
-// later release.
+// Deprecated: this DialOption is not supported by NewClient.
+// Will be supported throughout 1.x.
 func WithReturnConnectionError() DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		o.block = true
@@ -349,7 +379,22 @@ func WithInsecure() DialOption {
 // later release.
 func WithNoProxy() DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
-		o.copts.UseProxy = false
+		o.useProxy = false
+	})
+}
+
+// WithLocalDNSResolution forces local DNS name resolution even when a proxy is
+// specified in the environment.  By default, the server name is provided
+// directly to the proxy as part of the CONNECT handshake. This is ignored if
+// WithNoProxy is used.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithLocalDNSResolution() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.enableLocalDNSResolution = true
 	})
 }
 
@@ -387,8 +432,8 @@ func WithCredentialsBundle(b credentials.Bundle) DialOption {
 // WithTimeout returns a DialOption that configures a timeout for dialing a
 // ClientConn initially. This is valid if and only if WithBlock() is present.
 //
-// Deprecated: use DialContext instead of Dial and context.WithTimeout
-// instead.  Will be supported throughout 1.x.
+// Deprecated: this DialOption is not supported by NewClient.
+// Will be supported throughout 1.x.
 func WithTimeout(d time.Duration) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		o.timeout = d
@@ -400,6 +445,11 @@ func WithTimeout(d time.Duration) DialOption {
 // returned by f, gRPC checks the error's Temporary() method to decide if it
 // should try to reconnect to the network address.
 //
+// Note that gRPC by default performs name resolution on the target passed to
+// NewClient. To bypass name resolution and cause the target string to be
+// passed directly to the dialer here instead, use the "passthrough" resolver
+// by specifying it in the target string, e.g. "passthrough:target".
+//
 // Note: All supported releases of Go (as of December 2023) override the OS
 // defaults for TCP keepalive time and interval to 15s. To enable TCP keepalive
 // with OS defaults for keepalive time and interval, use a net.Dialer that sets
@@ -407,7 +457,7 @@ func WithTimeout(d time.Duration) DialOption {
 // option to true from the Control field. For a concrete example of how to do
 // this, see internal.NetDialerWithTCPKeepalive().
 //
-// For more information, please see [issue 23459] in the Go github repo.
+// For more information, please see [issue 23459] in the Go GitHub repo.
 //
 // [issue 23459]: https://github.com/golang/go/issues/23459
 func WithContextDialer(f func(context.Context, string) (net.Conn, error)) DialOption {
@@ -416,10 +466,6 @@ func WithContextDialer(f func(context.Context, string) (net.Conn, error)) DialOp
 	})
 }
 
-func init() {
-	internal.WithHealthCheckFunc = withHealthCheckFunc
-}
-
 // WithDialer returns a DialOption that specifies a function to use for dialing
 // network addresses. If FailOnNonTempDialError() is set to true, and an error
 // is returned by f, gRPC checks the error's Temporary() method to decide if it
@@ -470,9 +516,8 @@ func withBinaryLogger(bl binarylog.Logger) DialOption {
 // Use of this feature is not recommended.  For more information, please see:
 // https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md
 //
-// # Experimental
-//
-// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// Deprecated: this DialOption is not supported by NewClient.
+// This API may be changed or removed in a
 // later release.
 func FailOnNonTempDialError(f bool) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
@@ -490,6 +535,8 @@ func WithUserAgent(s string) DialOption {
 
 // WithKeepaliveParams returns a DialOption that specifies keepalive parameters
 // for the client transport.
+//
+// Keepalive is disabled by default.
 func WithKeepaliveParams(kp keepalive.ClientParameters) DialOption {
 	if kp.Time < internal.KeepaliveMinPingTime {
 		logger.Warningf("Adjusting keepalive ping interval to minimum period of %v", internal.KeepaliveMinPingTime)
@@ -601,12 +648,22 @@ func WithDisableRetry() DialOption {
 	})
 }
 
+// MaxHeaderListSizeDialOption is a DialOption that specifies the maximum
+// (uncompressed) size of header list that the client is prepared to accept.
+type MaxHeaderListSizeDialOption struct {
+	MaxHeaderListSize uint32
+}
+
+func (o MaxHeaderListSizeDialOption) apply(do *dialOptions) {
+	do.copts.MaxHeaderListSize = &o.MaxHeaderListSize
+}
+
 // WithMaxHeaderListSize returns a DialOption that specifies the maximum
 // (uncompressed) size of header list that the client is prepared to accept.
 func WithMaxHeaderListSize(s uint32) DialOption {
-	return newFuncDialOption(func(o *dialOptions) {
-		o.copts.MaxHeaderListSize = &s
-	})
+	return MaxHeaderListSizeDialOption{
+		MaxHeaderListSize: s,
+	}
 }
 
 // WithDisableHealthCheck disables the LB channel health checking for all
@@ -622,33 +679,24 @@ func WithDisableHealthCheck() DialOption {
 	})
 }
 
-// withHealthCheckFunc replaces the default health check function with the
-// provided one. It makes tests easier to change the health check function.
-//
-// For testing purpose only.
-func withHealthCheckFunc(f internal.HealthChecker) DialOption {
-	return newFuncDialOption(func(o *dialOptions) {
-		o.healthCheckFunc = f
-	})
-}
-
 func defaultDialOptions() dialOptions {
 	return dialOptions{
 		copts: transport.ConnectOptions{
 			ReadBufferSize:  defaultReadBufSize,
 			WriteBufferSize: defaultWriteBufSize,
-			UseProxy:        true,
 			UserAgent:       grpcUA,
+			BufferPool:      mem.DefaultBufferPool(),
 		},
-		bs:              internalbackoff.DefaultExponential,
-		healthCheckFunc: internal.HealthCheckFunc,
-		idleTimeout:     30 * time.Minute,
-		recvBufferPool:  nopBufferPool{},
-		defaultScheme:   "dns",
+		bs:                       internalbackoff.DefaultExponential,
+		idleTimeout:              30 * time.Minute,
+		defaultScheme:            "dns",
+		maxCallAttempts:          defaultMaxCallAttempts,
+		useProxy:                 true,
+		enableLocalDNSResolution: false,
 	}
 }
 
-// withGetMinConnectDeadline specifies the function that clientconn uses to
+// withMinConnectDeadline specifies the function that clientconn uses to
 // get minConnectDeadline. This can be used to make connection attempts happen
 // faster/slower.
 //
@@ -702,25 +750,25 @@ func WithIdleTimeout(d time.Duration) DialOption {
 	})
 }
 
-// WithRecvBufferPool returns a DialOption that configures the ClientConn
-// to use the provided shared buffer pool for parsing incoming messages. Depending
-// on the application's workload, this could result in reduced memory allocation.
+// WithMaxCallAttempts returns a DialOption that configures the maximum number
+// of attempts per call (including retries and hedging) using the channel.
+// Service owners may specify a higher value for these parameters, but higher
+// values will be treated as equal to the maximum value by the client
+// implementation. This mitigates security concerns related to the service
+// config being transferred to the client via DNS.
 //
-// If you are unsure about how to implement a memory pool but want to utilize one,
-// begin with grpc.NewSharedBufferPool.
-//
-// Note: The shared buffer pool feature will not be active if any of the following
-// options are used: WithStatsHandler, EnableTracing, or binary logging. In such
-// cases, the shared buffer pool will be ignored.
-//
-// Deprecated: use experimental.WithRecvBufferPool instead.  Will be deleted in
-// v1.60.0 or later.
-func WithRecvBufferPool(bufferPool SharedBufferPool) DialOption {
-	return withRecvBufferPool(bufferPool)
-}
-
-func withRecvBufferPool(bufferPool SharedBufferPool) DialOption {
+// A value of 5 will be used if this dial option is not set or n < 2.
+func WithMaxCallAttempts(n int) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
-		o.recvBufferPool = bufferPool
+		if n < 2 {
+			n = defaultMaxCallAttempts
+		}
+		o.maxCallAttempts = n
+	})
+}
+
+func withBufferPool(bufferPool mem.BufferPool) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.BufferPool = bufferPool
 	})
 }

vendor/google.golang.org/grpc/doc.go

@@ -16,7 +16,7 @@
  *
  */
 
-//go:generate ./regenerate.sh
+//go:generate ./scripts/regenerate.sh
 
 /*
 Package grpc implements an RPC system called gRPC.

vendor/google.golang.org/grpc/encoding/encoding.go

@@ -94,7 +94,7 @@ type Codec interface {
 	Name() string
 }
 
-var registeredCodecs = make(map[string]Codec)
+var registeredCodecs = make(map[string]any)
 
 // RegisterCodec registers the provided Codec for use with all gRPC clients and
 // servers.
@@ -126,5 +126,6 @@ func RegisterCodec(codec Codec) {
 //
 // The content-subtype is expected to be lowercase.
 func GetCodec(contentSubtype string) Codec {
-	return registeredCodecs[contentSubtype]
+	c, _ := registeredCodecs[contentSubtype].(Codec)
+	return c
 }

vendor/google.golang.org/grpc/encoding/encoding_v2.go

@@ -0,0 +1,81 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package encoding
+
+import (
+	"strings"
+
+	"google.golang.org/grpc/mem"
+)
+
+// CodecV2 defines the interface gRPC uses to encode and decode messages. Note
+// that implementations of this interface must be thread safe; a CodecV2's
+// methods can be called from concurrent goroutines.
+type CodecV2 interface {
+	// Marshal returns the wire format of v. The buffers in the returned
+	// [mem.BufferSlice] must have at least one reference each, which will be freed
+	// by gRPC when they are no longer needed.
+	Marshal(v any) (out mem.BufferSlice, err error)
+	// Unmarshal parses the wire format into v. Note that data will be freed as soon
+	// as this function returns. If the codec wishes to guarantee access to the data
+	// after this function, it must take its own reference that it frees when it is
+	// no longer needed.
+	Unmarshal(data mem.BufferSlice, v any) error
+	// Name returns the name of the Codec implementation. The returned string
+	// will be used as part of content type in transmission.  The result must be
+	// static; the result cannot change between calls.
+	Name() string
+}
+
+// RegisterCodecV2 registers the provided CodecV2 for use with all gRPC clients and
+// servers.
+//
+// The CodecV2 will be stored and looked up by result of its Name() method, which
+// should match the content-subtype of the encoding handled by the CodecV2.  This
+// is case-insensitive, and is stored and looked up as lowercase.  If the
+// result of calling Name() is an empty string, RegisterCodecV2 will panic. See
+// Content-Type on
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
+// more details.
+//
+// If both a Codec and CodecV2 are registered with the same name, the CodecV2
+// will be used.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe.  If multiple Codecs are
+// registered with the same name, the one registered last will take effect.
+func RegisterCodecV2(codec CodecV2) {
+	if codec == nil {
+		panic("cannot register a nil CodecV2")
+	}
+	if codec.Name() == "" {
+		panic("cannot register CodecV2 with empty string result for Name()")
+	}
+	contentSubtype := strings.ToLower(codec.Name())
+	registeredCodecs[contentSubtype] = codec
+}
+
+// GetCodecV2 gets a registered CodecV2 by content-subtype, or nil if no CodecV2 is
+// registered for the content-subtype.
+//
+// The content-subtype is expected to be lowercase.
+func GetCodecV2(contentSubtype string) CodecV2 {
+	c, _ := registeredCodecs[contentSubtype].(CodecV2)
+	return c
+}

vendor/google.golang.org/grpc/encoding/proto/proto.go

@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2018 gRPC authors.
+ * Copyright 2024 gRPC authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@ import (
 	"fmt"
 
 	"google.golang.org/grpc/encoding"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/protoadapt"
 )
@@ -32,28 +33,51 @@ import (
 const Name = "proto"
 
 func init() {
-	encoding.RegisterCodec(codec{})
+	encoding.RegisterCodecV2(&codecV2{})
 }
 
-// codec is a Codec implementation with protobuf. It is the default codec for gRPC.
-type codec struct{}
+// codec is a CodecV2 implementation with protobuf. It is the default codec for
+// gRPC.
+type codecV2 struct{}
 
-func (codec) Marshal(v any) ([]byte, error) {
+func (c *codecV2) Marshal(v any) (data mem.BufferSlice, err error) {
 	vv := messageV2Of(v)
 	if vv == nil {
-		return nil, fmt.Errorf("failed to marshal, message is %T, want proto.Message", v)
+		return nil, fmt.Errorf("proto: failed to marshal, message is %T, want proto.Message", v)
 	}
 
-	return proto.Marshal(vv)
+	size := proto.Size(vv)
+	if mem.IsBelowBufferPoolingThreshold(size) {
+		buf, err := proto.Marshal(vv)
+		if err != nil {
+			return nil, err
+		}
+		data = append(data, mem.SliceBuffer(buf))
+	} else {
+		pool := mem.DefaultBufferPool()
+		buf := pool.Get(size)
+		if _, err := (proto.MarshalOptions{}).MarshalAppend((*buf)[:0], vv); err != nil {
+			pool.Put(buf)
+			return nil, err
+		}
+		data = append(data, mem.NewBuffer(buf, pool))
+	}
+
+	return data, nil
 }
 
-func (codec) Unmarshal(data []byte, v any) error {
+func (c *codecV2) Unmarshal(data mem.BufferSlice, v any) (err error) {
 	vv := messageV2Of(v)
 	if vv == nil {
 		return fmt.Errorf("failed to unmarshal, message is %T, want proto.Message", v)
 	}
 
-	return proto.Unmarshal(data, vv)
+	buf := data.MaterializeToBuffer(mem.DefaultBufferPool())
+	defer buf.Free()
+	// TODO: Upgrade proto.Unmarshal to support mem.BufferSlice. Right now, it's not
+	//  really possible without a major overhaul of the proto package, but the
+	//  vtprotobuf library may be able to support this.
+	return proto.Unmarshal(buf.ReadOnlyData(), vv)
 }
 
 func messageV2Of(v any) proto.Message {
@@ -67,6 +91,6 @@ func messageV2Of(v any) proto.Message {
 	return nil
 }
 
-func (codec) Name() string {
+func (c *codecV2) Name() string {
 	return Name
 }

vendor/google.golang.org/grpc/experimental/stats/metricregistry.go

@@ -0,0 +1,270 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package stats
+
+import (
+	"maps"
+
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/stats"
+)
+
+func init() {
+	internal.SnapshotMetricRegistryForTesting = snapshotMetricsRegistryForTesting
+}
+
+var logger = grpclog.Component("metrics-registry")
+
+// DefaultMetrics are the default metrics registered through global metrics
+// registry. This is written to at initialization time only, and is read only
+// after initialization.
+var DefaultMetrics = stats.NewMetricSet()
+
+// MetricDescriptor is the data for a registered metric.
+type MetricDescriptor struct {
+	// The name of this metric. This name must be unique across the whole binary
+	// (including any per call metrics). See
+	// https://github.com/grpc/proposal/blob/master/A79-non-per-call-metrics-architecture.md#metric-instrument-naming-conventions
+	// for metric naming conventions.
+	Name string
+	// The description of this metric.
+	Description string
+	// The unit (e.g. entries, seconds) of this metric.
+	Unit string
+	// The required label keys for this metric. These are intended to
+	// metrics emitted from a stats handler.
+	Labels []string
+	// The optional label keys for this metric. These are intended to attached
+	// to metrics emitted from a stats handler if configured.
+	OptionalLabels []string
+	// Whether this metric is on by default.
+	Default bool
+	// The type of metric. This is set by the metric registry, and not intended
+	// to be set by a component registering a metric.
+	Type MetricType
+	// Bounds are the bounds of this metric. This only applies to histogram
+	// metrics. If unset or set with length 0, stats handlers will fall back to
+	// default bounds.
+	Bounds []float64
+}
+
+// MetricType is the type of metric.
+type MetricType int
+
+// Type of metric supported by this instrument registry.
+const (
+	MetricTypeIntCount MetricType = iota
+	MetricTypeFloatCount
+	MetricTypeIntHisto
+	MetricTypeFloatHisto
+	MetricTypeIntGauge
+)
+
+// Int64CountHandle is a typed handle for a int count metric. This handle
+// is passed at the recording point in order to know which metric to record
+// on.
+type Int64CountHandle MetricDescriptor
+
+// Descriptor returns the int64 count handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Int64CountHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the int64 count value on the metrics recorder provided.
+func (h *Int64CountHandle) Record(recorder MetricsRecorder, incr int64, labels ...string) {
+	recorder.RecordInt64Count(h, incr, labels...)
+}
+
+// Float64CountHandle is a typed handle for a float count metric. This handle is
+// passed at the recording point in order to know which metric to record on.
+type Float64CountHandle MetricDescriptor
+
+// Descriptor returns the float64 count handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Float64CountHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the float64 count value on the metrics recorder provided.
+func (h *Float64CountHandle) Record(recorder MetricsRecorder, incr float64, labels ...string) {
+	recorder.RecordFloat64Count(h, incr, labels...)
+}
+
+// Int64HistoHandle is a typed handle for an int histogram metric. This handle
+// is passed at the recording point in order to know which metric to record on.
+type Int64HistoHandle MetricDescriptor
+
+// Descriptor returns the int64 histo handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Int64HistoHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the int64 histo value on the metrics recorder provided.
+func (h *Int64HistoHandle) Record(recorder MetricsRecorder, incr int64, labels ...string) {
+	recorder.RecordInt64Histo(h, incr, labels...)
+}
+
+// Float64HistoHandle is a typed handle for a float histogram metric. This
+// handle is passed at the recording point in order to know which metric to
+// record on.
+type Float64HistoHandle MetricDescriptor
+
+// Descriptor returns the float64 histo handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Float64HistoHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the float64 histo value on the metrics recorder provided.
+func (h *Float64HistoHandle) Record(recorder MetricsRecorder, incr float64, labels ...string) {
+	recorder.RecordFloat64Histo(h, incr, labels...)
+}
+
+// Int64GaugeHandle is a typed handle for an int gauge metric. This handle is
+// passed at the recording point in order to know which metric to record on.
+type Int64GaugeHandle MetricDescriptor
+
+// Descriptor returns the int64 gauge handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Int64GaugeHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the int64 histo value on the metrics recorder provided.
+func (h *Int64GaugeHandle) Record(recorder MetricsRecorder, incr int64, labels ...string) {
+	recorder.RecordInt64Gauge(h, incr, labels...)
+}
+
+// registeredMetrics are the registered metric descriptor names.
+var registeredMetrics = make(map[string]bool)
+
+// metricsRegistry contains all of the registered metrics.
+//
+// This is written to only at init time, and read only after that.
+var metricsRegistry = make(map[string]*MetricDescriptor)
+
+// DescriptorForMetric returns the MetricDescriptor from the global registry.
+//
+// Returns nil if MetricDescriptor not present.
+func DescriptorForMetric(metricName string) *MetricDescriptor {
+	return metricsRegistry[metricName]
+}
+
+func registerMetric(metricName string, def bool) {
+	if registeredMetrics[metricName] {
+		logger.Fatalf("metric %v already registered", metricName)
+	}
+	registeredMetrics[metricName] = true
+	if def {
+		DefaultMetrics = DefaultMetrics.Add(metricName)
+	}
+}
+
+// RegisterInt64Count registers the metric description onto the global registry.
+// It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterInt64Count(descriptor MetricDescriptor) *Int64CountHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeIntCount
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Int64CountHandle)(descPtr)
+}
+
+// RegisterFloat64Count registers the metric description onto the global
+// registry. It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterFloat64Count(descriptor MetricDescriptor) *Float64CountHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeFloatCount
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Float64CountHandle)(descPtr)
+}
+
+// RegisterInt64Histo registers the metric description onto the global registry.
+// It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterInt64Histo(descriptor MetricDescriptor) *Int64HistoHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeIntHisto
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Int64HistoHandle)(descPtr)
+}
+
+// RegisterFloat64Histo registers the metric description onto the global
+// registry. It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterFloat64Histo(descriptor MetricDescriptor) *Float64HistoHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeFloatHisto
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Float64HistoHandle)(descPtr)
+}
+
+// RegisterInt64Gauge registers the metric description onto the global registry.
+// It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterInt64Gauge(descriptor MetricDescriptor) *Int64GaugeHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeIntGauge
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Int64GaugeHandle)(descPtr)
+}
+
+// snapshotMetricsRegistryForTesting snapshots the global data of the metrics
+// registry. Returns a cleanup function that sets the metrics registry to its
+// original state.
+func snapshotMetricsRegistryForTesting() func() {
+	oldDefaultMetrics := DefaultMetrics
+	oldRegisteredMetrics := registeredMetrics
+	oldMetricsRegistry := metricsRegistry
+
+	registeredMetrics = make(map[string]bool)
+	metricsRegistry = make(map[string]*MetricDescriptor)
+	maps.Copy(registeredMetrics, registeredMetrics)
+	maps.Copy(metricsRegistry, metricsRegistry)
+
+	return func() {
+		DefaultMetrics = oldDefaultMetrics
+		registeredMetrics = oldRegisteredMetrics
+		metricsRegistry = oldMetricsRegistry
+	}
+}

vendor/google.golang.org/grpc/experimental/stats/metrics.go

@@ -0,0 +1,54 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package stats contains experimental metrics/stats API's.
+package stats
+
+import "google.golang.org/grpc/stats"
+
+// MetricsRecorder records on metrics derived from metric registry.
+type MetricsRecorder interface {
+	// RecordInt64Count records the measurement alongside labels on the int
+	// count associated with the provided handle.
+	RecordInt64Count(handle *Int64CountHandle, incr int64, labels ...string)
+	// RecordFloat64Count records the measurement alongside labels on the float
+	// count associated with the provided handle.
+	RecordFloat64Count(handle *Float64CountHandle, incr float64, labels ...string)
+	// RecordInt64Histo records the measurement alongside labels on the int
+	// histo associated with the provided handle.
+	RecordInt64Histo(handle *Int64HistoHandle, incr int64, labels ...string)
+	// RecordFloat64Histo records the measurement alongside labels on the float
+	// histo associated with the provided handle.
+	RecordFloat64Histo(handle *Float64HistoHandle, incr float64, labels ...string)
+	// RecordInt64Gauge records the measurement alongside labels on the int
+	// gauge associated with the provided handle.
+	RecordInt64Gauge(handle *Int64GaugeHandle, incr int64, labels ...string)
+}
+
+// Metrics is an experimental legacy alias of the now-stable stats.MetricSet.
+// Metrics will be deleted in a future release.
+type Metrics = stats.MetricSet
+
+// Metric was replaced by direct usage of strings.
+type Metric = string
+
+// NewMetrics is an experimental legacy alias of the now-stable
+// stats.NewMetricSet.  NewMetrics will be deleted in a future release.
+func NewMetrics(metrics ...Metric) *Metrics {
+	return stats.NewMetricSet(metrics...)
+}

vendor/google.golang.org/grpc/grpclog/component.go

@@ -20,8 +20,6 @@ package grpclog
 
 import (
 	"fmt"
-
-	"google.golang.org/grpc/internal/grpclog"
 )
 
 // componentData records the settings for a component.
@@ -33,22 +31,22 @@ var cache = map[string]*componentData{}
 
 func (c *componentData) InfoDepth(depth int, args ...any) {
 	args = append([]any{"[" + string(c.name) + "]"}, args...)
-	grpclog.InfoDepth(depth+1, args...)
+	InfoDepth(depth+1, args...)
 }
 
 func (c *componentData) WarningDepth(depth int, args ...any) {
 	args = append([]any{"[" + string(c.name) + "]"}, args...)
-	grpclog.WarningDepth(depth+1, args...)
+	WarningDepth(depth+1, args...)
 }
 
 func (c *componentData) ErrorDepth(depth int, args ...any) {
 	args = append([]any{"[" + string(c.name) + "]"}, args...)
-	grpclog.ErrorDepth(depth+1, args...)
+	ErrorDepth(depth+1, args...)
 }
 
 func (c *componentData) FatalDepth(depth int, args ...any) {
 	args = append([]any{"[" + string(c.name) + "]"}, args...)
-	grpclog.FatalDepth(depth+1, args...)
+	FatalDepth(depth+1, args...)
 }
 
 func (c *componentData) Info(args ...any) {

vendor/google.golang.org/grpc/grpclog/grpclog.go

@@ -18,18 +18,15 @@
 
 // Package grpclog defines logging for grpc.
 //
-// All logs in transport and grpclb packages only go to verbose level 2.
-// All logs in other packages in grpc are logged in spite of the verbosity level.
-//
-// In the default logger,
-// severity level can be set by environment variable GRPC_GO_LOG_SEVERITY_LEVEL,
-// verbosity level can be set by GRPC_GO_LOG_VERBOSITY_LEVEL.
-package grpclog // import "google.golang.org/grpc/grpclog"
+// In the default logger, severity level can be set by environment variable
+// GRPC_GO_LOG_SEVERITY_LEVEL, verbosity level can be set by
+// GRPC_GO_LOG_VERBOSITY_LEVEL.
+package grpclog
 
 import (
 	"os"
 
-	"google.golang.org/grpc/internal/grpclog"
+	"google.golang.org/grpc/grpclog/internal"
 )
 
 func init() {
@@ -38,58 +35,58 @@ func init() {
 
 // V reports whether verbosity level l is at least the requested verbose level.
 func V(l int) bool {
-	return grpclog.Logger.V(l)
+	return internal.LoggerV2Impl.V(l)
 }
 
 // Info logs to the INFO log.
 func Info(args ...any) {
-	grpclog.Logger.Info(args...)
+	internal.LoggerV2Impl.Info(args...)
 }
 
 // Infof logs to the INFO log. Arguments are handled in the manner of fmt.Printf.
 func Infof(format string, args ...any) {
-	grpclog.Logger.Infof(format, args...)
+	internal.LoggerV2Impl.Infof(format, args...)
 }
 
 // Infoln logs to the INFO log. Arguments are handled in the manner of fmt.Println.
 func Infoln(args ...any) {
-	grpclog.Logger.Infoln(args...)
+	internal.LoggerV2Impl.Infoln(args...)
 }
 
 // Warning logs to the WARNING log.
 func Warning(args ...any) {
-	grpclog.Logger.Warning(args...)
+	internal.LoggerV2Impl.Warning(args...)
 }
 
 // Warningf logs to the WARNING log. Arguments are handled in the manner of fmt.Printf.
 func Warningf(format string, args ...any) {
-	grpclog.Logger.Warningf(format, args...)
+	internal.LoggerV2Impl.Warningf(format, args...)
 }
 
 // Warningln logs to the WARNING log. Arguments are handled in the manner of fmt.Println.
 func Warningln(args ...any) {
-	grpclog.Logger.Warningln(args...)
+	internal.LoggerV2Impl.Warningln(args...)
 }
 
 // Error logs to the ERROR log.
 func Error(args ...any) {
-	grpclog.Logger.Error(args...)
+	internal.LoggerV2Impl.Error(args...)
 }
 
 // Errorf logs to the ERROR log. Arguments are handled in the manner of fmt.Printf.
 func Errorf(format string, args ...any) {
-	grpclog.Logger.Errorf(format, args...)
+	internal.LoggerV2Impl.Errorf(format, args...)
 }
 
 // Errorln logs to the ERROR log. Arguments are handled in the manner of fmt.Println.
 func Errorln(args ...any) {
-	grpclog.Logger.Errorln(args...)
+	internal.LoggerV2Impl.Errorln(args...)
 }
 
 // Fatal logs to the FATAL log. Arguments are handled in the manner of fmt.Print.
 // It calls os.Exit() with exit code 1.
 func Fatal(args ...any) {
-	grpclog.Logger.Fatal(args...)
+	internal.LoggerV2Impl.Fatal(args...)
 	// Make sure fatal logs will exit.
 	os.Exit(1)
 }
@@ -97,15 +94,15 @@ func Fatal(args ...any) {
 // Fatalf logs to the FATAL log. Arguments are handled in the manner of fmt.Printf.
 // It calls os.Exit() with exit code 1.
 func Fatalf(format string, args ...any) {
-	grpclog.Logger.Fatalf(format, args...)
+	internal.LoggerV2Impl.Fatalf(format, args...)
 	// Make sure fatal logs will exit.
 	os.Exit(1)
 }
 
 // Fatalln logs to the FATAL log. Arguments are handled in the manner of fmt.Println.
-// It calle os.Exit()) with exit code 1.
+// It calls os.Exit() with exit code 1.
 func Fatalln(args ...any) {
-	grpclog.Logger.Fatalln(args...)
+	internal.LoggerV2Impl.Fatalln(args...)
 	// Make sure fatal logs will exit.
 	os.Exit(1)
 }
@@ -114,19 +111,76 @@ func Fatalln(args ...any) {
 //
 // Deprecated: use Info.
 func Print(args ...any) {
-	grpclog.Logger.Info(args...)
+	internal.LoggerV2Impl.Info(args...)
 }
 
 // Printf prints to the logger. Arguments are handled in the manner of fmt.Printf.
 //
 // Deprecated: use Infof.
 func Printf(format string, args ...any) {
-	grpclog.Logger.Infof(format, args...)
+	internal.LoggerV2Impl.Infof(format, args...)
 }
 
 // Println prints to the logger. Arguments are handled in the manner of fmt.Println.
 //
 // Deprecated: use Infoln.
 func Println(args ...any) {
-	grpclog.Logger.Infoln(args...)
+	internal.LoggerV2Impl.Infoln(args...)
+}
+
+// InfoDepth logs to the INFO log at the specified depth.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func InfoDepth(depth int, args ...any) {
+	if internal.DepthLoggerV2Impl != nil {
+		internal.DepthLoggerV2Impl.InfoDepth(depth, args...)
+	} else {
+		internal.LoggerV2Impl.Infoln(args...)
+	}
+}
+
+// WarningDepth logs to the WARNING log at the specified depth.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WarningDepth(depth int, args ...any) {
+	if internal.DepthLoggerV2Impl != nil {
+		internal.DepthLoggerV2Impl.WarningDepth(depth, args...)
+	} else {
+		internal.LoggerV2Impl.Warningln(args...)
+	}
+}
+
+// ErrorDepth logs to the ERROR log at the specified depth.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func ErrorDepth(depth int, args ...any) {
+	if internal.DepthLoggerV2Impl != nil {
+		internal.DepthLoggerV2Impl.ErrorDepth(depth, args...)
+	} else {
+		internal.LoggerV2Impl.Errorln(args...)
+	}
+}
+
+// FatalDepth logs to the FATAL log at the specified depth.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func FatalDepth(depth int, args ...any) {
+	if internal.DepthLoggerV2Impl != nil {
+		internal.DepthLoggerV2Impl.FatalDepth(depth, args...)
+	} else {
+		internal.LoggerV2Impl.Fatalln(args...)
+	}
+	os.Exit(1)
 }

vendor/google.golang.org/grpc/grpclog/internal/grpclog.go

@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2022 gRPC authors.
+ * Copyright 2024 gRPC authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,17 +16,11 @@
  *
  */
 
-package grpcsync
+// Package internal contains functionality internal to the grpclog package.
+package internal
 
-import (
-	"sync"
-)
+// LoggerV2Impl is the logger used for the non-depth log functions.
+var LoggerV2Impl LoggerV2
 
-// OnceFunc returns a function wrapping f which ensures f is only executed
-// once even if the returned function is executed multiple times.
-func OnceFunc(f func()) func() {
-	var once sync.Once
-	return func() {
-		once.Do(f)
-	}
-}
+// DepthLoggerV2Impl is the logger used for the depth log functions.
+var DepthLoggerV2Impl DepthLoggerV2

vendor/google.golang.org/grpc/grpclog/internal/logger.go

@@ -0,0 +1,87 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package internal
+
+// Logger mimics golang's standard Logger as an interface.
+//
+// Deprecated: use LoggerV2.
+type Logger interface {
+	Fatal(args ...any)
+	Fatalf(format string, args ...any)
+	Fatalln(args ...any)
+	Print(args ...any)
+	Printf(format string, args ...any)
+	Println(args ...any)
+}
+
+// LoggerWrapper wraps Logger into a LoggerV2.
+type LoggerWrapper struct {
+	Logger
+}
+
+// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
+func (l *LoggerWrapper) Info(args ...any) {
+	l.Logger.Print(args...)
+}
+
+// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
+func (l *LoggerWrapper) Infoln(args ...any) {
+	l.Logger.Println(args...)
+}
+
+// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
+func (l *LoggerWrapper) Infof(format string, args ...any) {
+	l.Logger.Printf(format, args...)
+}
+
+// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
+func (l *LoggerWrapper) Warning(args ...any) {
+	l.Logger.Print(args...)
+}
+
+// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
+func (l *LoggerWrapper) Warningln(args ...any) {
+	l.Logger.Println(args...)
+}
+
+// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
+func (l *LoggerWrapper) Warningf(format string, args ...any) {
+	l.Logger.Printf(format, args...)
+}
+
+// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+func (l *LoggerWrapper) Error(args ...any) {
+	l.Logger.Print(args...)
+}
+
+// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+func (l *LoggerWrapper) Errorln(args ...any) {
+	l.Logger.Println(args...)
+}
+
+// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+func (l *LoggerWrapper) Errorf(format string, args ...any) {
+	l.Logger.Printf(format, args...)
+}
+
+// V reports whether verbosity level l is at least the requested verbose level.
+func (*LoggerWrapper) V(int) bool {
+	// Returns true for all verbose level.
+	return true
+}

vendor/google.golang.org/grpc/grpclog/internal/loggerv2.go

@@ -0,0 +1,267 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package internal
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"os"
+)
+
+// LoggerV2 does underlying logging work for grpclog.
+type LoggerV2 interface {
+	// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
+	Info(args ...any)
+	// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
+	Infoln(args ...any)
+	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
+	Infof(format string, args ...any)
+	// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
+	Warning(args ...any)
+	// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
+	Warningln(args ...any)
+	// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
+	Warningf(format string, args ...any)
+	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+	Error(args ...any)
+	// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+	Errorln(args ...any)
+	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+	Errorf(format string, args ...any)
+	// Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatal(args ...any)
+	// Fatalln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatalln(args ...any)
+	// Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatalf(format string, args ...any)
+	// V reports whether verbosity level l is at least the requested verbose level.
+	V(l int) bool
+}
+
+// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
+// DepthLoggerV2, the below functions will be called with the appropriate stack
+// depth set for trivial functions the logger may ignore.
+//
+// # Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
+type DepthLoggerV2 interface {
+	LoggerV2
+	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	InfoDepth(depth int, args ...any)
+	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	WarningDepth(depth int, args ...any)
+	// ErrorDepth logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	ErrorDepth(depth int, args ...any)
+	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	FatalDepth(depth int, args ...any)
+}
+
+const (
+	// infoLog indicates Info severity.
+	infoLog int = iota
+	// warningLog indicates Warning severity.
+	warningLog
+	// errorLog indicates Error severity.
+	errorLog
+	// fatalLog indicates Fatal severity.
+	fatalLog
+)
+
+// severityName contains the string representation of each severity.
+var severityName = []string{
+	infoLog:    "INFO",
+	warningLog: "WARNING",
+	errorLog:   "ERROR",
+	fatalLog:   "FATAL",
+}
+
+// sprintf is fmt.Sprintf.
+// These vars exist to make it possible to test that expensive format calls aren't made unnecessarily.
+var sprintf = fmt.Sprintf
+
+// sprint is fmt.Sprint.
+// These vars exist to make it possible to test that expensive format calls aren't made unnecessarily.
+var sprint = fmt.Sprint
+
+// sprintln is fmt.Sprintln.
+// These vars exist to make it possible to test that expensive format calls aren't made unnecessarily.
+var sprintln = fmt.Sprintln
+
+// exit is os.Exit.
+// This var exists to make it possible to test functions calling os.Exit.
+var exit = os.Exit
+
+// loggerT is the default logger used by grpclog.
+type loggerT struct {
+	m          []*log.Logger
+	v          int
+	jsonFormat bool
+}
+
+func (g *loggerT) output(severity int, s string) {
+	sevStr := severityName[severity]
+	if !g.jsonFormat {
+		g.m[severity].Output(2, sevStr+": "+s)
+		return
+	}
+	// TODO: we can also include the logging component, but that needs more
+	// (API) changes.
+	b, _ := json.Marshal(map[string]string{
+		"severity": sevStr,
+		"message":  s,
+	})
+	g.m[severity].Output(2, string(b))
+}
+
+func (g *loggerT) printf(severity int, format string, args ...any) {
+	// Note the discard check is duplicated in each print func, rather than in
+	// output, to avoid the expensive Sprint calls.
+	// De-duplicating this by moving to output would be a significant performance regression!
+	if lg := g.m[severity]; lg.Writer() == io.Discard {
+		return
+	}
+	g.output(severity, sprintf(format, args...))
+}
+
+func (g *loggerT) print(severity int, v ...any) {
+	if lg := g.m[severity]; lg.Writer() == io.Discard {
+		return
+	}
+	g.output(severity, sprint(v...))
+}
+
+func (g *loggerT) println(severity int, v ...any) {
+	if lg := g.m[severity]; lg.Writer() == io.Discard {
+		return
+	}
+	g.output(severity, sprintln(v...))
+}
+
+func (g *loggerT) Info(args ...any) {
+	g.print(infoLog, args...)
+}
+
+func (g *loggerT) Infoln(args ...any) {
+	g.println(infoLog, args...)
+}
+
+func (g *loggerT) Infof(format string, args ...any) {
+	g.printf(infoLog, format, args...)
+}
+
+func (g *loggerT) Warning(args ...any) {
+	g.print(warningLog, args...)
+}
+
+func (g *loggerT) Warningln(args ...any) {
+	g.println(warningLog, args...)
+}
+
+func (g *loggerT) Warningf(format string, args ...any) {
+	g.printf(warningLog, format, args...)
+}
+
+func (g *loggerT) Error(args ...any) {
+	g.print(errorLog, args...)
+}
+
+func (g *loggerT) Errorln(args ...any) {
+	g.println(errorLog, args...)
+}
+
+func (g *loggerT) Errorf(format string, args ...any) {
+	g.printf(errorLog, format, args...)
+}
+
+func (g *loggerT) Fatal(args ...any) {
+	g.print(fatalLog, args...)
+	exit(1)
+}
+
+func (g *loggerT) Fatalln(args ...any) {
+	g.println(fatalLog, args...)
+	exit(1)
+}
+
+func (g *loggerT) Fatalf(format string, args ...any) {
+	g.printf(fatalLog, format, args...)
+	exit(1)
+}
+
+func (g *loggerT) V(l int) bool {
+	return l <= g.v
+}
+
+// LoggerV2Config configures the LoggerV2 implementation.
+type LoggerV2Config struct {
+	// Verbosity sets the verbosity level of the logger.
+	Verbosity int
+	// FormatJSON controls whether the logger should output logs in JSON format.
+	FormatJSON bool
+}
+
+// combineLoggers returns a combined logger for both higher & lower severity logs,
+// or only one if the other is io.Discard.
+//
+// This uses io.Discard instead of io.MultiWriter when all loggers
+// are set to io.Discard. Both this package and the standard log package have
+// significant optimizations for io.Discard, which io.MultiWriter lacks (as of
+// this writing).
+func combineLoggers(lower, higher io.Writer) io.Writer {
+	if lower == io.Discard {
+		return higher
+	}
+	if higher == io.Discard {
+		return lower
+	}
+	return io.MultiWriter(lower, higher)
+}
+
+// NewLoggerV2 creates a new LoggerV2 instance with the provided configuration.
+// The infoW, warningW, and errorW writers are used to write log messages of
+// different severity levels.
+func NewLoggerV2(infoW, warningW, errorW io.Writer, c LoggerV2Config) LoggerV2 {
+	flag := log.LstdFlags
+	if c.FormatJSON {
+		flag = 0
+	}
+
+	warningW = combineLoggers(infoW, warningW)
+	errorW = combineLoggers(errorW, warningW)
+
+	fatalW := errorW
+
+	m := []*log.Logger{
+		log.New(infoW, "", flag),
+		log.New(warningW, "", flag),
+		log.New(errorW, "", flag),
+		log.New(fatalW, "", flag),
+	}
+	return &loggerT{m: m, v: c.Verbosity, jsonFormat: c.FormatJSON}
+}

vendor/google.golang.org/grpc/grpclog/logger.go

@@ -18,70 +18,17 @@
 
 package grpclog
 
-import "google.golang.org/grpc/internal/grpclog"
+import "google.golang.org/grpc/grpclog/internal"
 
 // Logger mimics golang's standard Logger as an interface.
 //
 // Deprecated: use LoggerV2.
-type Logger interface {
-	Fatal(args ...any)
-	Fatalf(format string, args ...any)
-	Fatalln(args ...any)
-	Print(args ...any)
-	Printf(format string, args ...any)
-	Println(args ...any)
-}
+type Logger internal.Logger
 
 // SetLogger sets the logger that is used in grpc. Call only from
 // init() functions.
 //
 // Deprecated: use SetLoggerV2.
 func SetLogger(l Logger) {
-	grpclog.Logger = &loggerWrapper{Logger: l}
-}
-
-// loggerWrapper wraps Logger into a LoggerV2.
-type loggerWrapper struct {
-	Logger
-}
-
-func (g *loggerWrapper) Info(args ...any) {
-	g.Logger.Print(args...)
-}
-
-func (g *loggerWrapper) Infoln(args ...any) {
-	g.Logger.Println(args...)
-}
-
-func (g *loggerWrapper) Infof(format string, args ...any) {
-	g.Logger.Printf(format, args...)
-}
-
-func (g *loggerWrapper) Warning(args ...any) {
-	g.Logger.Print(args...)
-}
-
-func (g *loggerWrapper) Warningln(args ...any) {
-	g.Logger.Println(args...)
-}
-
-func (g *loggerWrapper) Warningf(format string, args ...any) {
-	g.Logger.Printf(format, args...)
-}
-
-func (g *loggerWrapper) Error(args ...any) {
-	g.Logger.Print(args...)
-}
-
-func (g *loggerWrapper) Errorln(args ...any) {
-	g.Logger.Println(args...)
-}
-
-func (g *loggerWrapper) Errorf(format string, args ...any) {
-	g.Logger.Printf(format, args...)
-}
-
-func (g *loggerWrapper) V(l int) bool {
-	// Returns true for all verbose level.
-	return true
+	internal.LoggerV2Impl = &internal.LoggerWrapper{Logger: l}
 }

vendor/google.golang.org/grpc/grpclog/loggerv2.go

@@ -19,52 +19,16 @@
 package grpclog
 
 import (
-	"encoding/json"
-	"fmt"
 	"io"
-	"log"
 	"os"
 	"strconv"
 	"strings"
 
-	"google.golang.org/grpc/internal/grpclog"
+	"google.golang.org/grpc/grpclog/internal"
 )
 
 // LoggerV2 does underlying logging work for grpclog.
-type LoggerV2 interface {
-	// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
-	Info(args ...any)
-	// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
-	Infoln(args ...any)
-	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
-	Infof(format string, args ...any)
-	// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
-	Warning(args ...any)
-	// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
-	Warningln(args ...any)
-	// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
-	Warningf(format string, args ...any)
-	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
-	Error(args ...any)
-	// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
-	Errorln(args ...any)
-	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
-	Errorf(format string, args ...any)
-	// Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Print.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatal(args ...any)
-	// Fatalln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatalln(args ...any)
-	// Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatalf(format string, args ...any)
-	// V reports whether verbosity level l is at least the requested verbose level.
-	V(l int) bool
-}
+type LoggerV2 internal.LoggerV2
 
 // SetLoggerV2 sets logger that is used in grpc to a V2 logger.
 // Not mutex-protected, should be called before any gRPC functions.
@@ -72,34 +36,8 @@ func SetLoggerV2(l LoggerV2) {
 	if _, ok := l.(*componentData); ok {
 		panic("cannot use component logger as grpclog logger")
 	}
-	grpclog.Logger = l
-	grpclog.DepthLogger, _ = l.(grpclog.DepthLoggerV2)
-}
-
-const (
-	// infoLog indicates Info severity.
-	infoLog int = iota
-	// warningLog indicates Warning severity.
-	warningLog
-	// errorLog indicates Error severity.
-	errorLog
-	// fatalLog indicates Fatal severity.
-	fatalLog
-)
-
-// severityName contains the string representation of each severity.
-var severityName = []string{
-	infoLog:    "INFO",
-	warningLog: "WARNING",
-	errorLog:   "ERROR",
-	fatalLog:   "FATAL",
-}
-
-// loggerT is the default logger used by grpclog.
-type loggerT struct {
-	m          []*log.Logger
-	v          int
-	jsonFormat bool
+	internal.LoggerV2Impl = l
+	internal.DepthLoggerV2Impl, _ = l.(internal.DepthLoggerV2)
 }
 
 // NewLoggerV2 creates a loggerV2 with the provided writers.
@@ -108,32 +46,13 @@ type loggerT struct {
 // Warning logs will be written to warningW and infoW.
 // Info logs will be written to infoW.
 func NewLoggerV2(infoW, warningW, errorW io.Writer) LoggerV2 {
-	return newLoggerV2WithConfig(infoW, warningW, errorW, loggerV2Config{})
+	return internal.NewLoggerV2(infoW, warningW, errorW, internal.LoggerV2Config{})
 }
 
 // NewLoggerV2WithVerbosity creates a loggerV2 with the provided writers and
 // verbosity level.
 func NewLoggerV2WithVerbosity(infoW, warningW, errorW io.Writer, v int) LoggerV2 {
-	return newLoggerV2WithConfig(infoW, warningW, errorW, loggerV2Config{verbose: v})
-}
-
-type loggerV2Config struct {
-	verbose    int
-	jsonFormat bool
-}
-
-func newLoggerV2WithConfig(infoW, warningW, errorW io.Writer, c loggerV2Config) LoggerV2 {
-	var m []*log.Logger
-	flag := log.LstdFlags
-	if c.jsonFormat {
-		flag = 0
-	}
-	m = append(m, log.New(infoW, "", flag))
-	m = append(m, log.New(io.MultiWriter(infoW, warningW), "", flag))
-	ew := io.MultiWriter(infoW, warningW, errorW) // ew will be used for error and fatal.
-	m = append(m, log.New(ew, "", flag))
-	m = append(m, log.New(ew, "", flag))
-	return &loggerT{m: m, v: c.verbose, jsonFormat: c.jsonFormat}
+	return internal.NewLoggerV2(infoW, warningW, errorW, internal.LoggerV2Config{Verbosity: v})
 }
 
 // newLoggerV2 creates a loggerV2 to be used as default logger.
@@ -161,82 +80,12 @@ func newLoggerV2() LoggerV2 {
 
 	jsonFormat := strings.EqualFold(os.Getenv("GRPC_GO_LOG_FORMATTER"), "json")
 
-	return newLoggerV2WithConfig(infoW, warningW, errorW, loggerV2Config{
-		verbose:    v,
-		jsonFormat: jsonFormat,
+	return internal.NewLoggerV2(infoW, warningW, errorW, internal.LoggerV2Config{
+		Verbosity:  v,
+		FormatJSON: jsonFormat,
 	})
 }
 
-func (g *loggerT) output(severity int, s string) {
-	sevStr := severityName[severity]
-	if !g.jsonFormat {
-		g.m[severity].Output(2, fmt.Sprintf("%v: %v", sevStr, s))
-		return
-	}
-	// TODO: we can also include the logging component, but that needs more
-	// (API) changes.
-	b, _ := json.Marshal(map[string]string{
-		"severity": sevStr,
-		"message":  s,
-	})
-	g.m[severity].Output(2, string(b))
-}
-
-func (g *loggerT) Info(args ...any) {
-	g.output(infoLog, fmt.Sprint(args...))
-}
-
-func (g *loggerT) Infoln(args ...any) {
-	g.output(infoLog, fmt.Sprintln(args...))
-}
-
-func (g *loggerT) Infof(format string, args ...any) {
-	g.output(infoLog, fmt.Sprintf(format, args...))
-}
-
-func (g *loggerT) Warning(args ...any) {
-	g.output(warningLog, fmt.Sprint(args...))
-}
-
-func (g *loggerT) Warningln(args ...any) {
-	g.output(warningLog, fmt.Sprintln(args...))
-}
-
-func (g *loggerT) Warningf(format string, args ...any) {
-	g.output(warningLog, fmt.Sprintf(format, args...))
-}
-
-func (g *loggerT) Error(args ...any) {
-	g.output(errorLog, fmt.Sprint(args...))
-}
-
-func (g *loggerT) Errorln(args ...any) {
-	g.output(errorLog, fmt.Sprintln(args...))
-}
-
-func (g *loggerT) Errorf(format string, args ...any) {
-	g.output(errorLog, fmt.Sprintf(format, args...))
-}
-
-func (g *loggerT) Fatal(args ...any) {
-	g.output(fatalLog, fmt.Sprint(args...))
-	os.Exit(1)
-}
-
-func (g *loggerT) Fatalln(args ...any) {
-	g.output(fatalLog, fmt.Sprintln(args...))
-	os.Exit(1)
-}
-
-func (g *loggerT) Fatalf(format string, args ...any) {
-	g.output(fatalLog, fmt.Sprintf(format, args...))
-	os.Exit(1)
-}
-
-func (g *loggerT) V(l int) bool {
-	return l <= g.v
-}
-
 // DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
 // DepthLoggerV2, the below functions will be called with the appropriate stack
 // depth set for trivial functions the logger may ignore.
@@ -245,14 +94,4 @@ func (g *loggerT) V(l int) bool {
 //
 // Notice: This type is EXPERIMENTAL and may be changed or removed in a
 // later release.
-type DepthLoggerV2 interface {
-	LoggerV2
-	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	InfoDepth(depth int, args ...any)
-	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	WarningDepth(depth int, args ...any)
-	// ErrorDepth logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	ErrorDepth(depth int, args ...any)
-	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	FatalDepth(depth int, args ...any)
-}
+type DepthLoggerV2 internal.DepthLoggerV2

vendor/google.golang.org/grpc/health/grpc_health_v1/health.pb.go

@@ -17,8 +17,8 @@
 
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.32.0
-// 	protoc        v4.25.2
+// 	protoc-gen-go v1.36.5
+// 	protoc        v5.27.1
 // source: grpc/health/v1/health.proto
 
 package grpc_health_v1
@@ -28,6 +28,7 @@ import (
 	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
 	reflect "reflect"
 	sync "sync"
+	unsafe "unsafe"
 )
 
 const (
@@ -90,20 +91,17 @@ func (HealthCheckResponse_ServingStatus) EnumDescriptor() ([]byte, []int) {
 }
 
 type HealthCheckRequest struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Service       string                 `protobuf:"bytes,1,opt,name=service,proto3" json:"service,omitempty"`
 	unknownFields protoimpl.UnknownFields
-
-	Service string `protobuf:"bytes,1,opt,name=service,proto3" json:"service,omitempty"`
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *HealthCheckRequest) Reset() {
 	*x = HealthCheckRequest{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_health_v1_health_proto_msgTypes[0]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_health_v1_health_proto_msgTypes[0]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *HealthCheckRequest) String() string {
@@ -114,7 +112,7 @@ func (*HealthCheckRequest) ProtoMessage() {}
 
 func (x *HealthCheckRequest) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_health_v1_health_proto_msgTypes[0]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -137,20 +135,17 @@ func (x *HealthCheckRequest) GetService() string {
 }
 
 type HealthCheckResponse struct {
-	state         protoimpl.MessageState
-	sizeCache     protoimpl.SizeCache
+	state         protoimpl.MessageState            `protogen:"open.v1"`
+	Status        HealthCheckResponse_ServingStatus `protobuf:"varint,1,opt,name=status,proto3,enum=grpc.health.v1.HealthCheckResponse_ServingStatus" json:"status,omitempty"`
 	unknownFields protoimpl.UnknownFields
-
-	Status HealthCheckResponse_ServingStatus `protobuf:"varint,1,opt,name=status,proto3,enum=grpc.health.v1.HealthCheckResponse_ServingStatus" json:"status,omitempty"`
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *HealthCheckResponse) Reset() {
 	*x = HealthCheckResponse{}
-	if protoimpl.UnsafeEnabled {
-		mi := &file_grpc_health_v1_health_proto_msgTypes[1]
-		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
-		ms.StoreMessageInfo(mi)
-	}
+	mi := &file_grpc_health_v1_health_proto_msgTypes[1]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
 }
 
 func (x *HealthCheckResponse) String() string {
@@ -161,7 +156,7 @@ func (*HealthCheckResponse) ProtoMessage() {}
 
 func (x *HealthCheckResponse) ProtoReflect() protoreflect.Message {
 	mi := &file_grpc_health_v1_health_proto_msgTypes[1]
-	if protoimpl.UnsafeEnabled && x != nil {
+	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
 			ms.StoreMessageInfo(mi)
@@ -183,9 +178,90 @@ func (x *HealthCheckResponse) GetStatus() HealthCheckResponse_ServingStatus {
 	return HealthCheckResponse_UNKNOWN
 }
 
+type HealthListRequest struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *HealthListRequest) Reset() {
+	*x = HealthListRequest{}
+	mi := &file_grpc_health_v1_health_proto_msgTypes[2]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *HealthListRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*HealthListRequest) ProtoMessage() {}
+
+func (x *HealthListRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_grpc_health_v1_health_proto_msgTypes[2]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use HealthListRequest.ProtoReflect.Descriptor instead.
+func (*HealthListRequest) Descriptor() ([]byte, []int) {
+	return file_grpc_health_v1_health_proto_rawDescGZIP(), []int{2}
+}
+
+type HealthListResponse struct {
+	state protoimpl.MessageState `protogen:"open.v1"`
+	// statuses contains all the services and their respective status.
+	Statuses      map[string]*HealthCheckResponse `protobuf:"bytes,1,rep,name=statuses,proto3" json:"statuses,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *HealthListResponse) Reset() {
+	*x = HealthListResponse{}
+	mi := &file_grpc_health_v1_health_proto_msgTypes[3]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *HealthListResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*HealthListResponse) ProtoMessage() {}
+
+func (x *HealthListResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_grpc_health_v1_health_proto_msgTypes[3]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use HealthListResponse.ProtoReflect.Descriptor instead.
+func (*HealthListResponse) Descriptor() ([]byte, []int) {
+	return file_grpc_health_v1_health_proto_rawDescGZIP(), []int{3}
+}
+
+func (x *HealthListResponse) GetStatuses() map[string]*HealthCheckResponse {
+	if x != nil {
+		return x.Statuses
+	}
+	return nil
+}
+
 var File_grpc_health_v1_health_proto protoreflect.FileDescriptor
 
-var file_grpc_health_v1_health_proto_rawDesc = []byte{
+var file_grpc_health_v1_health_proto_rawDesc = string([]byte{
 	0x0a, 0x1b, 0x67, 0x72, 0x70, 0x63, 0x2f, 0x68, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x2f, 0x76, 0x31,
 	0x2f, 0x68, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x0e, 0x67,
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@@ -203,56 +279,83 @@ var file_grpc_health_v1_health_proto_rawDesc = []byte{
 	0x0a, 0x07, 0x53, 0x45, 0x52, 0x56, 0x49, 0x4e, 0x47, 0x10, 0x01, 0x12, 0x0f, 0x0a, 0x0b, 0x4e,
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-}
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+	0x2e, 0x76, 0x31, 0x2e, 0x48, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x4c, 0x69, 0x73, 0x74, 0x52, 0x65,
+	0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x22, 0x2e, 0x67, 0x72, 0x70, 0x63, 0x2e, 0x68, 0x65, 0x61,
+	0x6c, 0x74, 0x68, 0x2e, 0x76, 0x31, 0x2e, 0x48, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x4c, 0x69, 0x73,
+	0x74, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x12, 0x52, 0x0a, 0x05, 0x57, 0x61, 0x74,
+	0x63, 0x68, 0x12, 0x22, 0x2e, 0x67, 0x72, 0x70, 0x63, 0x2e, 0x68, 0x65, 0x61, 0x6c, 0x74, 0x68,
+	0x2e, 0x76, 0x31, 0x2e, 0x48, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x43, 0x68, 0x65, 0x63, 0x6b, 0x52,
+	0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x23, 0x2e, 0x67, 0x72, 0x70, 0x63, 0x2e, 0x68, 0x65,
+	0x61, 0x6c, 0x74, 0x68, 0x2e, 0x76, 0x31, 0x2e, 0x48, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x43, 0x68,
+	0x65, 0x63, 0x6b, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x30, 0x01, 0x42, 0x70, 0x0a,
+	0x11, 0x69, 0x6f, 0x2e, 0x67, 0x72, 0x70, 0x63, 0x2e, 0x68, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x2e,
+	0x76, 0x31, 0x42, 0x0b, 0x48, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x50, 0x72, 0x6f, 0x74, 0x6f, 0x50,
+	0x01, 0x5a, 0x2c, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2e, 0x67, 0x6f, 0x6c, 0x61, 0x6e, 0x67,
+	0x2e, 0x6f, 0x72, 0x67, 0x2f, 0x67, 0x72, 0x70, 0x63, 0x2f, 0x68, 0x65, 0x61, 0x6c, 0x74, 0x68,
+	0x2f, 0x67, 0x72, 0x70, 0x63, 0x5f, 0x68, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x5f, 0x76, 0x31, 0xa2,
+	0x02, 0x0c, 0x47, 0x72, 0x70, 0x63, 0x48, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x56, 0x31, 0xaa, 0x02,
+	0x0e, 0x47, 0x72, 0x70, 0x63, 0x2e, 0x48, 0x65, 0x61, 0x6c, 0x74, 0x68, 0x2e, 0x56, 0x31, 0x62,
+	0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+})
 
 var (
 	file_grpc_health_v1_health_proto_rawDescOnce sync.Once
-	file_grpc_health_v1_health_proto_rawDescData = file_grpc_health_v1_health_proto_rawDesc
+	file_grpc_health_v1_health_proto_rawDescData []byte
 )
 
 func file_grpc_health_v1_health_proto_rawDescGZIP() []byte {
 	file_grpc_health_v1_health_proto_rawDescOnce.Do(func() {
-		file_grpc_health_v1_health_proto_rawDescData = protoimpl.X.CompressGZIP(file_grpc_health_v1_health_proto_rawDescData)
+		file_grpc_health_v1_health_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_grpc_health_v1_health_proto_rawDesc), len(file_grpc_health_v1_health_proto_rawDesc)))
 	})
 	return file_grpc_health_v1_health_proto_rawDescData
 }
 
 var file_grpc_health_v1_health_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
-var file_grpc_health_v1_health_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
-var file_grpc_health_v1_health_proto_goTypes = []interface{}{
+var file_grpc_health_v1_health_proto_msgTypes = make([]protoimpl.MessageInfo, 5)
+var file_grpc_health_v1_health_proto_goTypes = []any{
 	(HealthCheckResponse_ServingStatus)(0), // 0: grpc.health.v1.HealthCheckResponse.ServingStatus
 	(*HealthCheckRequest)(nil),             // 1: grpc.health.v1.HealthCheckRequest
 	(*HealthCheckResponse)(nil),            // 2: grpc.health.v1.HealthCheckResponse
+	(*HealthListRequest)(nil),              // 3: grpc.health.v1.HealthListRequest
+	(*HealthListResponse)(nil),             // 4: grpc.health.v1.HealthListResponse
+	nil,                                    // 5: grpc.health.v1.HealthListResponse.StatusesEntry
 }
 var file_grpc_health_v1_health_proto_depIdxs = []int32{
 	0, // 0: grpc.health.v1.HealthCheckResponse.status:type_name -> grpc.health.v1.HealthCheckResponse.ServingStatus
-	1, // 1: grpc.health.v1.Health.Check:input_type -> grpc.health.v1.HealthCheckRequest
-	1, // 2: grpc.health.v1.Health.Watch:input_type -> grpc.health.v1.HealthCheckRequest
-	2, // 3: grpc.health.v1.Health.Check:output_type -> grpc.health.v1.HealthCheckResponse
-	2, // 4: grpc.health.v1.Health.Watch:output_type -> grpc.health.v1.HealthCheckResponse
-	3, // [3:5] is the sub-list for method output_type
-	1, // [1:3] is the sub-list for method input_type
-	1, // [1:1] is the sub-list for extension type_name
-	1, // [1:1] is the sub-list for extension extendee
-	0, // [0:1] is the sub-list for field type_name
+	5, // 1: grpc.health.v1.HealthListResponse.statuses:type_name -> grpc.health.v1.HealthListResponse.StatusesEntry
+	2, // 2: grpc.health.v1.HealthListResponse.StatusesEntry.value:type_name -> grpc.health.v1.HealthCheckResponse
+	1, // 3: grpc.health.v1.Health.Check:input_type -> grpc.health.v1.HealthCheckRequest
+	3, // 4: grpc.health.v1.Health.List:input_type -> grpc.health.v1.HealthListRequest
+	1, // 5: grpc.health.v1.Health.Watch:input_type -> grpc.health.v1.HealthCheckRequest
+	2, // 6: grpc.health.v1.Health.Check:output_type -> grpc.health.v1.HealthCheckResponse
+	4, // 7: grpc.health.v1.Health.List:output_type -> grpc.health.v1.HealthListResponse
+	2, // 8: grpc.health.v1.Health.Watch:output_type -> grpc.health.v1.HealthCheckResponse
+	6, // [6:9] is the sub-list for method output_type
+	3, // [3:6] is the sub-list for method input_type
+	3, // [3:3] is the sub-list for extension type_name
+	3, // [3:3] is the sub-list for extension extendee
+	0, // [0:3] is the sub-list for field type_name
 }
 
 func init() { file_grpc_health_v1_health_proto_init() }
@@ -260,39 +363,13 @@ func file_grpc_health_v1_health_proto_init() {
 	if File_grpc_health_v1_health_proto != nil {
 		return
 	}
-	if !protoimpl.UnsafeEnabled {
-		file_grpc_health_v1_health_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*HealthCheckRequest); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-		file_grpc_health_v1_health_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*HealthCheckResponse); i {
-			case 0:
-				return &v.state
-			case 1:
-				return &v.sizeCache
-			case 2:
-				return &v.unknownFields
-			default:
-				return nil
-			}
-		}
-	}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
-			RawDescriptor: file_grpc_health_v1_health_proto_rawDesc,
+			RawDescriptor: unsafe.Slice(unsafe.StringData(file_grpc_health_v1_health_proto_rawDesc), len(file_grpc_health_v1_health_proto_rawDesc)),
 			NumEnums:      1,
-			NumMessages:   2,
+			NumMessages:   5,
 			NumExtensions: 0,
 			NumServices:   1,
 		},
@@ -302,7 +379,6 @@ func file_grpc_health_v1_health_proto_init() {
 		MessageInfos:      file_grpc_health_v1_health_proto_msgTypes,
 	}.Build()
 	File_grpc_health_v1_health_proto = out.File
-	file_grpc_health_v1_health_proto_rawDesc = nil
 	file_grpc_health_v1_health_proto_goTypes = nil
 	file_grpc_health_v1_health_proto_depIdxs = nil
 }

vendor/google.golang.org/grpc/health/grpc_health_v1/health_grpc.pb.go

@@ -17,8 +17,8 @@
 
 // Code generated by protoc-gen-go-grpc. DO NOT EDIT.
 // versions:
-// - protoc-gen-go-grpc v1.3.0
-// - protoc             v4.25.2
+// - protoc-gen-go-grpc v1.5.1
+// - protoc             v5.27.1
 // source: grpc/health/v1/health.proto
 
 package grpc_health_v1
@@ -32,17 +32,22 @@ import (
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-// Requires gRPC-Go v1.32.0 or later.
-const _ = grpc.SupportPackageIsVersion7
+// Requires gRPC-Go v1.64.0 or later.
+const _ = grpc.SupportPackageIsVersion9
 
 const (
 	Health_Check_FullMethodName = "/grpc.health.v1.Health/Check"
+	Health_List_FullMethodName  = "/grpc.health.v1.Health/List"
 	Health_Watch_FullMethodName = "/grpc.health.v1.Health/Watch"
 )
 
 // HealthClient is the client API for Health service.
 //
 // For semantics around ctx use and closing/ending streaming RPCs, please refer to https://pkg.go.dev/google.golang.org/grpc/?tab=doc#ClientConn.NewStream.
+//
+// Health is gRPC's mechanism for checking whether a server is able to handle
+// RPCs. Its semantics are documented in
+// https://github.com/grpc/grpc/blob/master/doc/health-checking.md.
 type HealthClient interface {
 	// Check gets the health of the specified service. If the requested service
 	// is unknown, the call will fail with status NOT_FOUND. If the caller does
@@ -51,9 +56,19 @@ type HealthClient interface {
 	//
 	// Clients should set a deadline when calling Check, and can declare the
 	// server unhealthy if they do not receive a timely response.
-	//
-	// Check implementations should be idempotent and side effect free.
 	Check(ctx context.Context, in *HealthCheckRequest, opts ...grpc.CallOption) (*HealthCheckResponse, error)
+	// List provides a non-atomic snapshot of the health of all the available
+	// services.
+	//
+	// The server may respond with a RESOURCE_EXHAUSTED error if too many services
+	// exist.
+	//
+	// Clients should set a deadline when calling List, and can declare the server
+	// unhealthy if they do not receive a timely response.
+	//
+	// Clients should keep in mind that the list of health services exposed by an
+	// application can change over the lifetime of the process.
+	List(ctx context.Context, in *HealthListRequest, opts ...grpc.CallOption) (*HealthListResponse, error)
 	// Performs a watch for the serving status of the requested service.
 	// The server will immediately send back a message indicating the current
 	// serving status.  It will then subsequently send a new message whenever
@@ -69,7 +84,7 @@ type HealthClient interface {
 	// should assume this method is not supported and should not retry the
 	// call.  If the call terminates with any other status (including OK),
 	// clients should retry the call with appropriate exponential backoff.
-	Watch(ctx context.Context, in *HealthCheckRequest, opts ...grpc.CallOption) (Health_WatchClient, error)
+	Watch(ctx context.Context, in *HealthCheckRequest, opts ...grpc.CallOption) (grpc.ServerStreamingClient[HealthCheckResponse], error)
 }
 
 type healthClient struct {
@@ -81,20 +96,32 @@ func NewHealthClient(cc grpc.ClientConnInterface) HealthClient {
 }
 
 func (c *healthClient) Check(ctx context.Context, in *HealthCheckRequest, opts ...grpc.CallOption) (*HealthCheckResponse, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
 	out := new(HealthCheckResponse)
-	err := c.cc.Invoke(ctx, Health_Check_FullMethodName, in, out, opts...)
+	err := c.cc.Invoke(ctx, Health_Check_FullMethodName, in, out, cOpts...)
 	if err != nil {
 		return nil, err
 	}
 	return out, nil
 }
 
-func (c *healthClient) Watch(ctx context.Context, in *HealthCheckRequest, opts ...grpc.CallOption) (Health_WatchClient, error) {
-	stream, err := c.cc.NewStream(ctx, &Health_ServiceDesc.Streams[0], Health_Watch_FullMethodName, opts...)
+func (c *healthClient) List(ctx context.Context, in *HealthListRequest, opts ...grpc.CallOption) (*HealthListResponse, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(HealthListResponse)
+	err := c.cc.Invoke(ctx, Health_List_FullMethodName, in, out, cOpts...)
 	if err != nil {
 		return nil, err
 	}
-	x := &healthWatchClient{stream}
+	return out, nil
+}
+
+func (c *healthClient) Watch(ctx context.Context, in *HealthCheckRequest, opts ...grpc.CallOption) (grpc.ServerStreamingClient[HealthCheckResponse], error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	stream, err := c.cc.NewStream(ctx, &Health_ServiceDesc.Streams[0], Health_Watch_FullMethodName, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &grpc.GenericClientStream[HealthCheckRequest, HealthCheckResponse]{ClientStream: stream}
 	if err := x.ClientStream.SendMsg(in); err != nil {
 		return nil, err
 	}
@@ -104,26 +131,16 @@ func (c *healthClient) Watch(ctx context.Context, in *HealthCheckRequest, opts .
 	return x, nil
 }
 
-type Health_WatchClient interface {
-	Recv() (*HealthCheckResponse, error)
-	grpc.ClientStream
-}
-
-type healthWatchClient struct {
-	grpc.ClientStream
-}
-
-func (x *healthWatchClient) Recv() (*HealthCheckResponse, error) {
-	m := new(HealthCheckResponse)
-	if err := x.ClientStream.RecvMsg(m); err != nil {
-		return nil, err
-	}
-	return m, nil
-}
+// This type alias is provided for backwards compatibility with existing code that references the prior non-generic stream type by name.
+type Health_WatchClient = grpc.ServerStreamingClient[HealthCheckResponse]
 
 // HealthServer is the server API for Health service.
 // All implementations should embed UnimplementedHealthServer
-// for forward compatibility
+// for forward compatibility.
+//
+// Health is gRPC's mechanism for checking whether a server is able to handle
+// RPCs. Its semantics are documented in
+// https://github.com/grpc/grpc/blob/master/doc/health-checking.md.
 type HealthServer interface {
 	// Check gets the health of the specified service. If the requested service
 	// is unknown, the call will fail with status NOT_FOUND. If the caller does
@@ -132,9 +149,19 @@ type HealthServer interface {
 	//
 	// Clients should set a deadline when calling Check, and can declare the
 	// server unhealthy if they do not receive a timely response.
-	//
-	// Check implementations should be idempotent and side effect free.
 	Check(context.Context, *HealthCheckRequest) (*HealthCheckResponse, error)
+	// List provides a non-atomic snapshot of the health of all the available
+	// services.
+	//
+	// The server may respond with a RESOURCE_EXHAUSTED error if too many services
+	// exist.
+	//
+	// Clients should set a deadline when calling List, and can declare the server
+	// unhealthy if they do not receive a timely response.
+	//
+	// Clients should keep in mind that the list of health services exposed by an
+	// application can change over the lifetime of the process.
+	List(context.Context, *HealthListRequest) (*HealthListResponse, error)
 	// Performs a watch for the serving status of the requested service.
 	// The server will immediately send back a message indicating the current
 	// serving status.  It will then subsequently send a new message whenever
@@ -150,19 +177,26 @@ type HealthServer interface {
 	// should assume this method is not supported and should not retry the
 	// call.  If the call terminates with any other status (including OK),
 	// clients should retry the call with appropriate exponential backoff.
-	Watch(*HealthCheckRequest, Health_WatchServer) error
+	Watch(*HealthCheckRequest, grpc.ServerStreamingServer[HealthCheckResponse]) error
 }
 
-// UnimplementedHealthServer should be embedded to have forward compatible implementations.
-type UnimplementedHealthServer struct {
-}
+// UnimplementedHealthServer should be embedded to have
+// forward compatible implementations.
+//
+// NOTE: this should be embedded by value instead of pointer to avoid a nil
+// pointer dereference when methods are called.
+type UnimplementedHealthServer struct{}
 
 func (UnimplementedHealthServer) Check(context.Context, *HealthCheckRequest) (*HealthCheckResponse, error) {
 	return nil, status.Errorf(codes.Unimplemented, "method Check not implemented")
 }
-func (UnimplementedHealthServer) Watch(*HealthCheckRequest, Health_WatchServer) error {
+func (UnimplementedHealthServer) List(context.Context, *HealthListRequest) (*HealthListResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method List not implemented")
+}
+func (UnimplementedHealthServer) Watch(*HealthCheckRequest, grpc.ServerStreamingServer[HealthCheckResponse]) error {
 	return status.Errorf(codes.Unimplemented, "method Watch not implemented")
 }
+func (UnimplementedHealthServer) testEmbeddedByValue() {}
 
 // UnsafeHealthServer may be embedded to opt out of forward compatibility for this service.
 // Use of this interface is not recommended, as added methods to HealthServer will
@@ -172,6 +206,13 @@ type UnsafeHealthServer interface {
 }
 
 func RegisterHealthServer(s grpc.ServiceRegistrar, srv HealthServer) {
+	// If the following call panics, it indicates UnimplementedHealthServer was
+	// embedded by pointer and is nil.  This will cause panics if an
+	// unimplemented method is ever invoked, so we test this at initialization
+	// time to prevent it from happening at runtime later due to I/O.
+	if t, ok := srv.(interface{ testEmbeddedByValue() }); ok {
+		t.testEmbeddedByValue()
+	}
 	s.RegisterService(&Health_ServiceDesc, srv)
 }
 
@@ -193,26 +234,34 @@ func _Health_Check_Handler(srv interface{}, ctx context.Context, dec func(interf
 	return interceptor(ctx, in, info, handler)
 }
 
+func _Health_List_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(HealthListRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(HealthServer).List(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: Health_List_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(HealthServer).List(ctx, req.(*HealthListRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 func _Health_Watch_Handler(srv interface{}, stream grpc.ServerStream) error {
 	m := new(HealthCheckRequest)
 	if err := stream.RecvMsg(m); err != nil {
 		return err
 	}
-	return srv.(HealthServer).Watch(m, &healthWatchServer{stream})
+	return srv.(HealthServer).Watch(m, &grpc.GenericServerStream[HealthCheckRequest, HealthCheckResponse]{ServerStream: stream})
 }
 
-type Health_WatchServer interface {
-	Send(*HealthCheckResponse) error
-	grpc.ServerStream
-}
-
-type healthWatchServer struct {
-	grpc.ServerStream
-}
-
-func (x *healthWatchServer) Send(m *HealthCheckResponse) error {
-	return x.ServerStream.SendMsg(m)
-}
+// This type alias is provided for backwards compatibility with existing code that references the prior non-generic stream type by name.
+type Health_WatchServer = grpc.ServerStreamingServer[HealthCheckResponse]
 
 // Health_ServiceDesc is the grpc.ServiceDesc for Health service.
 // It's only intended for direct use with grpc.RegisterService,
@@ -225,6 +274,10 @@ var Health_ServiceDesc = grpc.ServiceDesc{
 			MethodName: "Check",
 			Handler:    _Health_Check_Handler,
 		},
+		{
+			MethodName: "List",
+			Handler:    _Health_List_Handler,
+		},
 	},
 	Streams: []grpc.StreamDesc{
 		{

vendor/google.golang.org/grpc/internal/backoff/backoff.go

@@ -25,10 +25,10 @@ package backoff
 import (
 	"context"
 	"errors"
+	rand "math/rand/v2"
 	"time"
 
 	grpcbackoff "google.golang.org/grpc/backoff"
-	"google.golang.org/grpc/internal/grpcrand"
 )
 
 // Strategy defines the methodology for backing off after a grpc connection
@@ -67,7 +67,7 @@ func (bc Exponential) Backoff(retries int) time.Duration {
 	}
 	// Randomize backoff delays so that if a cluster of requests start at
 	// the same time, they won't operate in lockstep.
-	backoff *= 1 + bc.Config.Jitter*(grpcrand.Float64()*2-1)
+	backoff *= 1 + bc.Config.Jitter*(rand.Float64()*2-1)
 	if backoff < 0 {
 		return 0
 	}

vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/config.go

@@ -33,6 +33,8 @@ type lbConfig struct {
 	childConfig  serviceconfig.LoadBalancingConfig
 }
 
+// ChildName returns the name of the child balancer of the gracefulswitch
+// Balancer.
 func ChildName(l serviceconfig.LoadBalancingConfig) string {
 	return l.(*lbConfig).childBuilder.Name()
 }
@@ -75,7 +77,6 @@ func ParseConfig(cfg json.RawMessage) (serviceconfig.LoadBalancingConfig, error)
 		if err != nil {
 			return nil, fmt.Errorf("error parsing config for policy %q: %v", name, err)
 		}
-
 		return &lbConfig{childBuilder: builder, childConfig: cfg}, nil
 	}
 

vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/gracefulswitch.go

@@ -109,8 +109,9 @@ func (gsb *Balancer) switchTo(builder balancer.Builder) (*balancerWrapper, error
 		return nil, errBalancerClosed
 	}
 	bw := &balancerWrapper{
-		builder: builder,
-		gsb:     gsb,
+		ClientConn: gsb.cc,
+		builder:    builder,
+		gsb:        gsb,
 		lastState: balancer.State{
 			ConnectivityState: connectivity.Connecting,
 			Picker:            base.NewErrPicker(balancer.ErrNoSubConnAvailable),
@@ -169,7 +170,6 @@ func (gsb *Balancer) latestBalancer() *balancerWrapper {
 func (gsb *Balancer) UpdateClientConnState(state balancer.ClientConnState) error {
 	// The resolver data is only relevant to the most recent LB Policy.
 	balToUpdate := gsb.latestBalancer()
-
 	gsbCfg, ok := state.BalancerConfig.(*lbConfig)
 	if ok {
 		// Switch to the child in the config unless it is already active.
@@ -294,6 +294,7 @@ func (gsb *Balancer) Close() {
 // State updates from the wrapped balancer can result in invocation of the
 // graceful switch logic.
 type balancerWrapper struct {
+	balancer.ClientConn
 	balancer.Balancer
 	gsb     *Balancer
 	builder balancer.Builder
@@ -414,7 +415,3 @@ func (bw *balancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver
 	bw.gsb.mu.Unlock()
 	bw.gsb.cc.UpdateAddresses(sc, addrs)
 }
-
-func (bw *balancerWrapper) Target() string {
-	return bw.gsb.cc.Target()
-}

vendor/google.golang.org/grpc/internal/binarylog/method_logger.go

@@ -65,7 +65,7 @@ type TruncatingMethodLogger struct {
 	callID          uint64
 	idWithinCallGen *callIDGenerator
 
-	sink Sink // TODO(blog): make this plugable.
+	sink Sink // TODO(blog): make this pluggable.
 }
 
 // NewTruncatingMethodLogger returns a new truncating method logger.
@@ -80,7 +80,7 @@ func NewTruncatingMethodLogger(h, m uint64) *TruncatingMethodLogger {
 		callID:          idGen.next(),
 		idWithinCallGen: &callIDGenerator{},
 
-		sink: DefaultSink, // TODO(blog): make it plugable.
+		sink: DefaultSink, // TODO(blog): make it pluggable.
 	}
 }
 
@@ -106,7 +106,7 @@ func (ml *TruncatingMethodLogger) Build(c LogEntryConfig) *binlogpb.GrpcLogEntry
 }
 
 // Log creates a proto binary log entry, and logs it to the sink.
-func (ml *TruncatingMethodLogger) Log(ctx context.Context, c LogEntryConfig) {
+func (ml *TruncatingMethodLogger) Log(_ context.Context, c LogEntryConfig) {
 	ml.sink.Write(ml.Build(c))
 }
 
@@ -397,7 +397,7 @@ func metadataKeyOmit(key string) bool {
 	switch key {
 	case "lb-token", ":path", ":authority", "content-encoding", "content-type", "user-agent", "te":
 		return true
-	case "grpc-trace-bin": // grpc-trace-bin is special because it's visiable to users.
+	case "grpc-trace-bin": // grpc-trace-bin is special because it's visible to users.
 		return false
 	}
 	return strings.HasPrefix(key, "grpc-")

vendor/google.golang.org/grpc/internal/channelz/channel.go

@@ -43,6 +43,8 @@ type Channel struct {
 	// Non-zero traceRefCount means the trace of this channel cannot be deleted.
 	traceRefCount int32
 
+	// ChannelMetrics holds connectivity state, target and call metrics for the
+	// channel within channelz.
 	ChannelMetrics ChannelMetrics
 }
 
@@ -50,6 +52,8 @@ type Channel struct {
 // nesting.
 func (c *Channel) channelzIdentifier() {}
 
+// String returns a string representation of the Channel, including its parent
+// entity and ID.
 func (c *Channel) String() string {
 	if c.Parent == nil {
 		return fmt.Sprintf("Channel #%d", c.ID)
@@ -61,24 +65,31 @@ func (c *Channel) id() int64 {
 	return c.ID
 }
 
+// SubChans returns a copy of the map of sub-channels associated with the
+// Channel.
 func (c *Channel) SubChans() map[int64]string {
 	db.mu.RLock()
 	defer db.mu.RUnlock()
 	return copyMap(c.subChans)
 }
 
+// NestedChans returns a copy of the map of nested channels associated with the
+// Channel.
 func (c *Channel) NestedChans() map[int64]string {
 	db.mu.RLock()
 	defer db.mu.RUnlock()
 	return copyMap(c.nestedChans)
 }
 
+// Trace returns a copy of the Channel's trace data.
 func (c *Channel) Trace() *ChannelTrace {
 	db.mu.RLock()
 	defer db.mu.RUnlock()
 	return c.trace.copy()
 }
 
+// ChannelMetrics holds connectivity state, target and call metrics for the
+// channel within channelz.
 type ChannelMetrics struct {
 	// The current connectivity state of the channel.
 	State atomic.Pointer[connectivity.State]
@@ -136,12 +147,16 @@ func strFromPointer(s *string) string {
 	return *s
 }
 
+// String returns a string representation of the ChannelMetrics, including its
+// state, target, and call metrics.
 func (c *ChannelMetrics) String() string {
 	return fmt.Sprintf("State: %v, Target: %s, CallsStarted: %v, CallsSucceeded: %v, CallsFailed: %v, LastCallStartedTimestamp: %v",
 		c.State.Load(), strFromPointer(c.Target.Load()), c.CallsStarted.Load(), c.CallsSucceeded.Load(), c.CallsFailed.Load(), c.LastCallStartedTimestamp.Load(),
 	)
 }
 
+// NewChannelMetricForTesting creates a new instance of ChannelMetrics with
+// specified initial values for testing purposes.
 func NewChannelMetricForTesting(state connectivity.State, target string, started, succeeded, failed, timestamp int64) *ChannelMetrics {
 	c := &ChannelMetrics{}
 	c.State.Store(&state)

vendor/google.golang.org/grpc/internal/channelz/channelmap.go

@@ -46,7 +46,7 @@ type entry interface {
 
 // channelMap is the storage data structure for channelz.
 //
-// Methods of channelMap can be divided in two two categories with respect to
+// Methods of channelMap can be divided into two categories with respect to
 // locking.
 //
 // 1. Methods acquire the global lock.
@@ -234,13 +234,6 @@ func copyMap(m map[int64]string) map[int64]string {
 	return n
 }
 
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 func (c *channelMap) getTopChannels(id int64, maxResults int) ([]*Channel, bool) {
 	if maxResults <= 0 {
 		maxResults = EntriesPerPage

vendor/google.golang.org/grpc/internal/channelz/funcs.go

@@ -33,7 +33,7 @@ var (
 	// outside this package except by tests.
 	IDGen IDGenerator
 
-	db *channelMap = newChannelMap()
+	db = newChannelMap()
 	// EntriesPerPage defines the number of channelz entries to be shown on a web page.
 	EntriesPerPage = 50
 	curState       int32

vendor/google.golang.org/grpc/internal/channelz/server.go

@@ -59,6 +59,8 @@ func NewServerMetricsForTesting(started, succeeded, failed, timestamp int64) *Se
 	return sm
 }
 
+// CopyFrom copies the metrics data from the provided ServerMetrics
+// instance into the current instance.
 func (sm *ServerMetrics) CopyFrom(o *ServerMetrics) {
 	sm.CallsStarted.Store(o.CallsStarted.Load())
 	sm.CallsSucceeded.Store(o.CallsSucceeded.Load())

vendor/google.golang.org/grpc/internal/channelz/socket.go

@@ -70,13 +70,18 @@ type EphemeralSocketMetrics struct {
 	RemoteFlowControlWindow int64
 }
 
+// SocketType represents the type of socket.
 type SocketType string
 
+// SocketType can be one of these.
 const (
 	SocketTypeNormal = "NormalSocket"
 	SocketTypeListen = "ListenSocket"
 )
 
+// Socket represents a socket within channelz which includes socket
+// metrics and data related to socket activity and provides methods
+// for managing and interacting with sockets.
 type Socket struct {
 	Entity
 	SocketType       SocketType
@@ -100,6 +105,8 @@ type Socket struct {
 	Security credentials.ChannelzSecurityValue
 }
 
+// String returns a string representation of the Socket, including its parent
+// entity, socket type, and ID.
 func (ls *Socket) String() string {
 	return fmt.Sprintf("%s %s #%d", ls.Parent, ls.SocketType, ls.ID)
 }

vendor/google.golang.org/grpc/internal/channelz/subchannel.go

@@ -47,12 +47,14 @@ func (sc *SubChannel) id() int64 {
 	return sc.ID
 }
 
+// Sockets returns a copy of the sockets map associated with the SubChannel.
 func (sc *SubChannel) Sockets() map[int64]string {
 	db.mu.RLock()
 	defer db.mu.RUnlock()
 	return copyMap(sc.sockets)
 }
 
+// Trace returns a copy of the ChannelTrace associated with the SubChannel.
 func (sc *SubChannel) Trace() *ChannelTrace {
 	db.mu.RLock()
 	defer db.mu.RUnlock()

vendor/google.golang.org/grpc/internal/channelz/syscall_nonlinux.go

@@ -35,13 +35,13 @@ type SocketOptionData struct {
 // Getsockopt defines the function to get socket options requested by channelz.
 // It is to be passed to syscall.RawConn.Control().
 // Windows OS doesn't support Socket Option
-func (s *SocketOptionData) Getsockopt(fd uintptr) {
+func (s *SocketOptionData) Getsockopt(uintptr) {
 	once.Do(func() {
 		logger.Warning("Channelz: socket options are not supported on non-linux environments")
 	})
 }
 
 // GetSocketOption gets the socket option info of the conn.
-func GetSocketOption(c any) *SocketOptionData {
+func GetSocketOption(any) *SocketOptionData {
 	return nil
 }

vendor/google.golang.org/grpc/internal/channelz/trace.go

@@ -79,13 +79,21 @@ type TraceEvent struct {
 	Parent   *TraceEvent
 }
 
+// ChannelTrace provides tracing information for a channel.
+// It tracks various events and metadata related to the channel's lifecycle
+// and operations.
 type ChannelTrace struct {
-	cm           *channelMap
-	clearCalled  bool
+	cm          *channelMap
+	clearCalled bool
+	// The time when the trace was created.
 	CreationTime time.Time
-	EventNum     int64
-	mu           sync.Mutex
-	Events       []*traceEvent
+	// A counter for the number of events recorded in the
+	// trace.
+	EventNum int64
+	mu       sync.Mutex
+	// A slice of traceEvent pointers representing the events recorded for
+	// this channel.
+	Events []*traceEvent
 }
 
 func (c *ChannelTrace) copy() *ChannelTrace {
@@ -175,6 +183,7 @@ var refChannelTypeToString = map[RefChannelType]string{
 	RefNormalSocket: "NormalSocket",
 }
 
+// String returns a string representation of the RefChannelType
 func (r RefChannelType) String() string {
 	return refChannelTypeToString[r]
 }

vendor/google.golang.org/grpc/internal/envconfig/envconfig.go

@@ -28,9 +28,6 @@ import (
 var (
 	// TXTErrIgnore is set if TXT errors should be ignored ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
 	TXTErrIgnore = boolFromEnv("GRPC_GO_IGNORE_TXT_ERRORS", true)
-	// AdvertiseCompressors is set if registered compressor should be advertised
-	// ("GRPC_GO_ADVERTISE_COMPRESSORS" is not "false").
-	AdvertiseCompressors = boolFromEnv("GRPC_GO_ADVERTISE_COMPRESSORS", true)
 	// RingHashCap indicates the maximum ring size which defaults to 4096
 	// entries but may be overridden by setting the environment variable
 	// "GRPC_RING_HASH_CAP".  This does not override the default bounds
@@ -43,6 +40,35 @@ var (
 	// ALTSMaxConcurrentHandshakes is the maximum number of concurrent ALTS
 	// handshakes that can be performed.
 	ALTSMaxConcurrentHandshakes = uint64FromEnv("GRPC_ALTS_MAX_CONCURRENT_HANDSHAKES", 100, 1, 100)
+	// EnforceALPNEnabled is set if TLS connections to servers with ALPN disabled
+	// should be rejected. The HTTP/2 protocol requires ALPN to be enabled, this
+	// option is present for backward compatibility. This option may be overridden
+	// by setting the environment variable "GRPC_ENFORCE_ALPN_ENABLED" to "true"
+	// or "false".
+	EnforceALPNEnabled = boolFromEnv("GRPC_ENFORCE_ALPN_ENABLED", true)
+	// XDSFallbackSupport is the env variable that controls whether support for
+	// xDS fallback is turned on. If this is unset or is false, only the first
+	// xDS server in the list of server configs will be used.
+	XDSFallbackSupport = boolFromEnv("GRPC_EXPERIMENTAL_XDS_FALLBACK", true)
+	// NewPickFirstEnabled is set if the new pickfirst leaf policy is to be used
+	// instead of the exiting pickfirst implementation. This can be disabled by
+	// setting the environment variable "GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST"
+	// to "false".
+	NewPickFirstEnabled = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST", true)
+
+	// XDSEndpointHashKeyBackwardCompat controls the parsing of the endpoint hash
+	// key from EDS LbEndpoint metadata. Endpoint hash keys can be disabled by
+	// setting "GRPC_XDS_ENDPOINT_HASH_KEY_BACKWARD_COMPAT" to "true". When the
+	// implementation of A76 is stable, we will flip the default value to false
+	// in a subsequent release. A final release will remove this environment
+	// variable, enabling the new behavior unconditionally.
+	XDSEndpointHashKeyBackwardCompat = boolFromEnv("GRPC_XDS_ENDPOINT_HASH_KEY_BACKWARD_COMPAT", true)
+
+	// RingHashSetRequestHashKey is set if the ring hash balancer can get the
+	// request hash header by setting the "requestHashHeader" field, according
+	// to gRFC A76. It can be enabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_RING_HASH_SET_REQUEST_HASH_KEY" to "true".
+	RingHashSetRequestHashKey = boolFromEnv("GRPC_EXPERIMENTAL_RING_HASH_SET_REQUEST_HASH_KEY", false)
 )
 
 func boolFromEnv(envVar string, def bool) bool {

vendor/google.golang.org/grpc/internal/envconfig/xds.go

@@ -53,4 +53,14 @@ var (
 
 	// C2PResolverTestOnlyTrafficDirectorURI is the TD URI for testing.
 	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv("GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI")
+
+	// XDSDualstackEndpointsEnabled is true if gRPC should read the
+	// "additional addresses" in the xDS endpoint resource.
+	XDSDualstackEndpointsEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_DUALSTACK_ENDPOINTS", true)
+
+	// XDSSystemRootCertsEnabled is true when xDS enabled gRPC clients can use
+	// the system's default root certificates for TLS certificate validation.
+	// For more details, see:
+	// https://github.com/grpc/proposal/blob/master/A82-xds-system-root-certs.md.
+	XDSSystemRootCertsEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_SYSTEM_ROOT_CERTS", false)
 )

vendor/google.golang.org/grpc/internal/experimental.go

@@ -18,11 +18,11 @@
 package internal
 
 var (
-	// WithRecvBufferPool is implemented by the grpc package and returns a dial
+	// WithBufferPool is implemented by the grpc package and returns a dial
 	// option to configure a shared buffer pool for a grpc.ClientConn.
-	WithRecvBufferPool any // func (grpc.SharedBufferPool) grpc.DialOption
+	WithBufferPool any // func (grpc.SharedBufferPool) grpc.DialOption
 
-	// RecvBufferPool is implemented by the grpc package and returns a server
+	// BufferPool is implemented by the grpc package and returns a server
 	// option to configure a shared buffer pool for a grpc.Server.
-	RecvBufferPool any // func (grpc.SharedBufferPool) grpc.ServerOption
+	BufferPool any // func (grpc.SharedBufferPool) grpc.ServerOption
 )

vendor/google.golang.org/grpc/internal/grpclog/grpclog.go

@@ -1,126 +0,0 @@
-/*
- *
- * Copyright 2020 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// Package grpclog (internal) defines depth logging for grpc.
-package grpclog
-
-import (
-	"os"
-)
-
-// Logger is the logger used for the non-depth log functions.
-var Logger LoggerV2
-
-// DepthLogger is the logger used for the depth log functions.
-var DepthLogger DepthLoggerV2
-
-// InfoDepth logs to the INFO log at the specified depth.
-func InfoDepth(depth int, args ...any) {
-	if DepthLogger != nil {
-		DepthLogger.InfoDepth(depth, args...)
-	} else {
-		Logger.Infoln(args...)
-	}
-}
-
-// WarningDepth logs to the WARNING log at the specified depth.
-func WarningDepth(depth int, args ...any) {
-	if DepthLogger != nil {
-		DepthLogger.WarningDepth(depth, args...)
-	} else {
-		Logger.Warningln(args...)
-	}
-}
-
-// ErrorDepth logs to the ERROR log at the specified depth.
-func ErrorDepth(depth int, args ...any) {
-	if DepthLogger != nil {
-		DepthLogger.ErrorDepth(depth, args...)
-	} else {
-		Logger.Errorln(args...)
-	}
-}
-
-// FatalDepth logs to the FATAL log at the specified depth.
-func FatalDepth(depth int, args ...any) {
-	if DepthLogger != nil {
-		DepthLogger.FatalDepth(depth, args...)
-	} else {
-		Logger.Fatalln(args...)
-	}
-	os.Exit(1)
-}
-
-// LoggerV2 does underlying logging work for grpclog.
-// This is a copy of the LoggerV2 defined in the external grpclog package. It
-// is defined here to avoid a circular dependency.
-type LoggerV2 interface {
-	// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
-	Info(args ...any)
-	// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
-	Infoln(args ...any)
-	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
-	Infof(format string, args ...any)
-	// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
-	Warning(args ...any)
-	// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
-	Warningln(args ...any)
-	// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
-	Warningf(format string, args ...any)
-	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
-	Error(args ...any)
-	// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
-	Errorln(args ...any)
-	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
-	Errorf(format string, args ...any)
-	// Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Print.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatal(args ...any)
-	// Fatalln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatalln(args ...any)
-	// Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatalf(format string, args ...any)
-	// V reports whether verbosity level l is at least the requested verbose level.
-	V(l int) bool
-}
-
-// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
-// DepthLoggerV2, the below functions will be called with the appropriate stack
-// depth set for trivial functions the logger may ignore.
-// This is a copy of the DepthLoggerV2 defined in the external grpclog package.
-// It is defined here to avoid a circular dependency.
-//
-// # Experimental
-//
-// Notice: This type is EXPERIMENTAL and may be changed or removed in a
-// later release.
-type DepthLoggerV2 interface {
-	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	InfoDepth(depth int, args ...any)
-	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	WarningDepth(depth int, args ...any)
-	// ErrorDepth logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	ErrorDepth(depth int, args ...any)
-	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	FatalDepth(depth int, args ...any)
-}

vendor/google.golang.org/grpc/internal/grpclog/prefix_logger.go

@@ -16,17 +16,21 @@
  *
  */
 
+// Package grpclog provides logging functionality for internal gRPC packages,
+// outside of the functionality provided by the external `grpclog` package.
 package grpclog
 
 import (
 	"fmt"
+
+	"google.golang.org/grpc/grpclog"
 )
 
 // PrefixLogger does logging with a prefix.
 //
 // Logging method on a nil logs without any prefix.
 type PrefixLogger struct {
-	logger DepthLoggerV2
+	logger grpclog.DepthLoggerV2
 	prefix string
 }
 
@@ -38,7 +42,7 @@ func (pl *PrefixLogger) Infof(format string, args ...any) {
 		pl.logger.InfoDepth(1, fmt.Sprintf(format, args...))
 		return
 	}
-	InfoDepth(1, fmt.Sprintf(format, args...))
+	grpclog.InfoDepth(1, fmt.Sprintf(format, args...))
 }
 
 // Warningf does warning logging.
@@ -48,7 +52,7 @@ func (pl *PrefixLogger) Warningf(format string, args ...any) {
 		pl.logger.WarningDepth(1, fmt.Sprintf(format, args...))
 		return
 	}
-	WarningDepth(1, fmt.Sprintf(format, args...))
+	grpclog.WarningDepth(1, fmt.Sprintf(format, args...))
 }
 
 // Errorf does error logging.
@@ -58,36 +62,18 @@ func (pl *PrefixLogger) Errorf(format string, args ...any) {
 		pl.logger.ErrorDepth(1, fmt.Sprintf(format, args...))
 		return
 	}
-	ErrorDepth(1, fmt.Sprintf(format, args...))
-}
-
-// Debugf does info logging at verbose level 2.
-func (pl *PrefixLogger) Debugf(format string, args ...any) {
-	// TODO(6044): Refactor interfaces LoggerV2 and DepthLogger, and maybe
-	// rewrite PrefixLogger a little to ensure that we don't use the global
-	// `Logger` here, and instead use the `logger` field.
-	if !Logger.V(2) {
-		return
-	}
-	if pl != nil {
-		// Handle nil, so the tests can pass in a nil logger.
-		format = pl.prefix + format
-		pl.logger.InfoDepth(1, fmt.Sprintf(format, args...))
-		return
-	}
-	InfoDepth(1, fmt.Sprintf(format, args...))
-
+	grpclog.ErrorDepth(1, fmt.Sprintf(format, args...))
 }
 
 // V reports whether verbosity level l is at least the requested verbose level.
 func (pl *PrefixLogger) V(l int) bool {
-	// TODO(6044): Refactor interfaces LoggerV2 and DepthLogger, and maybe
-	// rewrite PrefixLogger a little to ensure that we don't use the global
-	// `Logger` here, and instead use the `logger` field.
-	return Logger.V(l)
+	if pl != nil {
+		return pl.logger.V(l)
+	}
+	return true
 }
 
 // NewPrefixLogger creates a prefix logger with the given prefix.
-func NewPrefixLogger(logger DepthLoggerV2, prefix string) *PrefixLogger {
+func NewPrefixLogger(logger grpclog.DepthLoggerV2, prefix string) *PrefixLogger {
 	return &PrefixLogger{logger: logger, prefix: prefix}
 }

vendor/google.golang.org/grpc/internal/grpcrand/grpcrand.go

@@ -1,100 +0,0 @@
-//go:build !go1.21
-
-// TODO: when this file is deleted (after Go 1.20 support is dropped), delete
-// all of grpcrand and call the rand package directly.
-
-/*
- *
- * Copyright 2018 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// Package grpcrand implements math/rand functions in a concurrent-safe way
-// with a global random source, independent of math/rand's global source.
-package grpcrand
-
-import (
-	"math/rand"
-	"sync"
-	"time"
-)
-
-var (
-	r  = rand.New(rand.NewSource(time.Now().UnixNano()))
-	mu sync.Mutex
-)
-
-// Int implements rand.Int on the grpcrand global source.
-func Int() int {
-	mu.Lock()
-	defer mu.Unlock()
-	return r.Int()
-}
-
-// Int63n implements rand.Int63n on the grpcrand global source.
-func Int63n(n int64) int64 {
-	mu.Lock()
-	defer mu.Unlock()
-	return r.Int63n(n)
-}
-
-// Intn implements rand.Intn on the grpcrand global source.
-func Intn(n int) int {
-	mu.Lock()
-	defer mu.Unlock()
-	return r.Intn(n)
-}
-
-// Int31n implements rand.Int31n on the grpcrand global source.
-func Int31n(n int32) int32 {
-	mu.Lock()
-	defer mu.Unlock()
-	return r.Int31n(n)
-}
-
-// Float64 implements rand.Float64 on the grpcrand global source.
-func Float64() float64 {
-	mu.Lock()
-	defer mu.Unlock()
-	return r.Float64()
-}
-
-// Uint64 implements rand.Uint64 on the grpcrand global source.
-func Uint64() uint64 {
-	mu.Lock()
-	defer mu.Unlock()
-	return r.Uint64()
-}
-
-// Uint32 implements rand.Uint32 on the grpcrand global source.
-func Uint32() uint32 {
-	mu.Lock()
-	defer mu.Unlock()
-	return r.Uint32()
-}
-
-// ExpFloat64 implements rand.ExpFloat64 on the grpcrand global source.
-func ExpFloat64() float64 {
-	mu.Lock()
-	defer mu.Unlock()
-	return r.ExpFloat64()
-}
-
-// Shuffle implements rand.Shuffle on the grpcrand global source.
-var Shuffle = func(n int, f func(int, int)) {
-	mu.Lock()
-	defer mu.Unlock()
-	r.Shuffle(n, f)
-}

vendor/google.golang.org/grpc/internal/grpcrand/grpcrand_go1.21.go

@@ -1,73 +0,0 @@
-//go:build go1.21
-
-/*
- *
- * Copyright 2024 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// Package grpcrand implements math/rand functions in a concurrent-safe way
-// with a global random source, independent of math/rand's global source.
-package grpcrand
-
-import "math/rand"
-
-// This implementation will be used for Go version 1.21 or newer.
-// For older versions, the original implementation with mutex will be used.
-
-// Int implements rand.Int on the grpcrand global source.
-func Int() int {
-	return rand.Int()
-}
-
-// Int63n implements rand.Int63n on the grpcrand global source.
-func Int63n(n int64) int64 {
-	return rand.Int63n(n)
-}
-
-// Intn implements rand.Intn on the grpcrand global source.
-func Intn(n int) int {
-	return rand.Intn(n)
-}
-
-// Int31n implements rand.Int31n on the grpcrand global source.
-func Int31n(n int32) int32 {
-	return rand.Int31n(n)
-}
-
-// Float64 implements rand.Float64 on the grpcrand global source.
-func Float64() float64 {
-	return rand.Float64()
-}
-
-// Uint64 implements rand.Uint64 on the grpcrand global source.
-func Uint64() uint64 {
-	return rand.Uint64()
-}
-
-// Uint32 implements rand.Uint32 on the grpcrand global source.
-func Uint32() uint32 {
-	return rand.Uint32()
-}
-
-// ExpFloat64 implements rand.ExpFloat64 on the grpcrand global source.
-func ExpFloat64() float64 {
-	return rand.ExpFloat64()
-}
-
-// Shuffle implements rand.Shuffle on the grpcrand global source.
-var Shuffle = func(n int, f func(int, int)) {
-	rand.Shuffle(n, f)
-}

vendor/google.golang.org/grpc/internal/grpcsync/callback_serializer.go

@@ -53,16 +53,28 @@ func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
 	return cs
 }
 
-// Schedule adds a callback to be scheduled after existing callbacks are run.
+// TrySchedule tries to schedule the provided callback function f to be
+// executed in the order it was added. This is a best-effort operation. If the
+// context passed to NewCallbackSerializer was canceled before this method is
+// called, the callback will not be scheduled.
 //
 // Callbacks are expected to honor the context when performing any blocking
 // operations, and should return early when the context is canceled.
+func (cs *CallbackSerializer) TrySchedule(f func(ctx context.Context)) {
+	cs.callbacks.Put(f)
+}
+
+// ScheduleOr schedules the provided callback function f to be executed in the
+// order it was added. If the context passed to NewCallbackSerializer has been
+// canceled before this method is called, the onFailure callback will be
+// executed inline instead.
 //
-// Return value indicates if the callback was successfully added to the list of
-// callbacks to be executed by the serializer. It is not possible to add
-// callbacks once the context passed to NewCallbackSerializer is cancelled.
-func (cs *CallbackSerializer) Schedule(f func(ctx context.Context)) bool {
-	return cs.callbacks.Put(f) == nil
+// Callbacks are expected to honor the context when performing any blocking
+// operations, and should return early when the context is canceled.
+func (cs *CallbackSerializer) ScheduleOr(f func(ctx context.Context), onFailure func()) {
+	if cs.callbacks.Put(f) != nil {
+		onFailure()
+	}
 }
 
 func (cs *CallbackSerializer) run(ctx context.Context) {

vendor/google.golang.org/grpc/internal/grpcsync/pubsub.go

@@ -77,7 +77,7 @@ func (ps *PubSub) Subscribe(sub Subscriber) (cancel func()) {
 
 	if ps.msg != nil {
 		msg := ps.msg
-		ps.cs.Schedule(func(context.Context) {
+		ps.cs.TrySchedule(func(context.Context) {
 			ps.mu.Lock()
 			defer ps.mu.Unlock()
 			if !ps.subscribers[sub] {
@@ -103,7 +103,7 @@ func (ps *PubSub) Publish(msg any) {
 	ps.msg = msg
 	for sub := range ps.subscribers {
 		s := sub
-		ps.cs.Schedule(func(context.Context) {
+		ps.cs.TrySchedule(func(context.Context) {
 			ps.mu.Lock()
 			defer ps.mu.Unlock()
 			if !ps.subscribers[s] {

vendor/google.golang.org/grpc/internal/grpcutil/compressor.go

@@ -20,8 +20,6 @@ package grpcutil
 
 import (
 	"strings"
-
-	"google.golang.org/grpc/internal/envconfig"
 )
 
 // RegisteredCompressorNames holds names of the registered compressors.
@@ -40,8 +38,5 @@ func IsCompressorNameRegistered(name string) bool {
 // RegisteredCompressors returns a string of registered compressor names
 // separated by comma.
 func RegisteredCompressors() string {
-	if !envconfig.AdvertiseCompressors {
-		return ""
-	}
 	return strings.Join(RegisteredCompressorNames, ",")
 }

vendor/google.golang.org/grpc/internal/grpcutil/method.go

@@ -39,7 +39,7 @@ func ParseMethod(methodName string) (service, method string, _ error) {
 }
 
 // baseContentType is the base content-type for gRPC.  This is a valid
-// content-type on it's own, but can also include a content-subtype such as
+// content-type on its own, but can also include a content-subtype such as
 // "proto" as a suffix after "+" or ";".  See
 // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
 // for more details.

vendor/google.golang.org/grpc/internal/idle/idle.go

@@ -182,6 +182,7 @@ func (m *Manager) tryEnterIdleMode() bool {
 	return true
 }
 
+// EnterIdleModeForTesting instructs the channel to enter idle mode.
 func (m *Manager) EnterIdleModeForTesting() {
 	m.tryEnterIdleMode()
 }
@@ -225,7 +226,7 @@ func (m *Manager) ExitIdleMode() error {
 		//   came in and OnCallBegin() noticed that the calls count is negative.
 		// - Channel is in idle mode, and multiple new RPCs come in at the same
 		//   time, all of them notice a negative calls count in OnCallBegin and get
-		//   here. The first one to get the lock would got the channel to exit idle.
+		//   here. The first one to get the lock would get the channel to exit idle.
 		// - Channel is not in idle mode, and the user calls Connect which calls
 		//   m.ExitIdleMode.
 		//
@@ -266,6 +267,7 @@ func (m *Manager) isClosed() bool {
 	return atomic.LoadInt32(&m.closed) == 1
 }
 
+// Close stops the timer associated with the Manager, if it exists.
 func (m *Manager) Close() {
 	atomic.StoreInt32(&m.closed, 1)
 

vendor/google.golang.org/grpc/internal/internal.go

@@ -29,10 +29,12 @@ import (
 )
 
 var (
-	// WithHealthCheckFunc is set by dialoptions.go
-	WithHealthCheckFunc any // func (HealthChecker) DialOption
 	// HealthCheckFunc is used to provide client-side LB channel health checking
 	HealthCheckFunc HealthChecker
+	// RegisterClientHealthCheckListener is used to provide a listener for
+	// updates from the client-side health checking service. It returns a
+	// function that can be called to stop the health producer.
+	RegisterClientHealthCheckListener any // func(ctx context.Context, sc balancer.SubConn, serviceName string, listener func(balancer.SubConnState)) func()
 	// BalancerUnregister is exported by package balancer to unregister a balancer.
 	BalancerUnregister func(name string)
 	// KeepaliveMinPingTime is the minimum ping interval.  This must be 10s by
@@ -62,6 +64,9 @@ var (
 	// gRPC server. An xDS-enabled server needs to know what type of credentials
 	// is configured on the underlying gRPC server. This is set by server.go.
 	GetServerCredentials any // func (*grpc.Server) credentials.TransportCredentials
+	// MetricsRecorderForServer returns the MetricsRecorderList derived from a
+	// server's stats handlers.
+	MetricsRecorderForServer any // func (*grpc.Server) estats.MetricsRecorder
 	// CanonicalString returns the canonical string of the code defined here:
 	// https://github.com/grpc/grpc/blob/master/doc/statuscodes.md.
 	//
@@ -106,6 +111,14 @@ var (
 	// This is used in the 1.0 release of gcp/observability, and thus must not be
 	// deleted or changed.
 	ClearGlobalDialOptions func()
+
+	// AddGlobalPerTargetDialOptions adds a PerTargetDialOption that will be
+	// configured for newly created ClientConns.
+	AddGlobalPerTargetDialOptions any // func (opt any)
+	// ClearGlobalPerTargetDialOptions clears the slice of global late apply
+	// dial options.
+	ClearGlobalPerTargetDialOptions func()
+
 	// JoinDialOptions combines the dial options passed as arguments into a
 	// single dial option.
 	JoinDialOptions any // func(...grpc.DialOption) grpc.DialOption
@@ -126,7 +139,8 @@ var (
 	// deleted or changed.
 	BinaryLogger any // func(binarylog.Logger) grpc.ServerOption
 
-	// SubscribeToConnectivityStateChanges adds a grpcsync.Subscriber to a provided grpc.ClientConn
+	// SubscribeToConnectivityStateChanges adds a grpcsync.Subscriber to a
+	// provided grpc.ClientConn.
 	SubscribeToConnectivityStateChanges any // func(*grpc.ClientConn, grpcsync.Subscriber)
 
 	// NewXDSResolverWithConfigForTesting creates a new xds resolver builder using
@@ -140,6 +154,34 @@ var (
 	// other features, including the CSDS service.
 	NewXDSResolverWithConfigForTesting any // func([]byte) (resolver.Builder, error)
 
+	// NewXDSResolverWithPoolForTesting creates a new xDS resolver builder
+	// using the provided xDS pool instead of creating a new one using the
+	// bootstrap configuration specified by the supported environment variables.
+	// The resolver.Builder is meant to be used in conjunction with the
+	// grpc.WithResolvers DialOption. The resolver.Builder does not take
+	// ownership of the provided xDS client and it is the responsibility of the
+	// caller to close the client when no longer required.
+	//
+	// Testing Only
+	//
+	// This function should ONLY be used for testing and may not work with some
+	// other features, including the CSDS service.
+	NewXDSResolverWithPoolForTesting any // func(*xdsclient.Pool) (resolver.Builder, error)
+
+	// NewXDSResolverWithClientForTesting creates a new xDS resolver builder
+	// using the provided xDS client instead of creating a new one using the
+	// bootstrap configuration specified by the supported environment variables.
+	// The resolver.Builder is meant to be used in conjunction with the
+	// grpc.WithResolvers DialOption. The resolver.Builder does not take
+	// ownership of the provided xDS client and it is the responsibility of the
+	// caller to close the client when no longer required.
+	//
+	// Testing Only
+	//
+	// This function should ONLY be used for testing and may not work with some
+	// other features, including the CSDS service.
+	NewXDSResolverWithClientForTesting any // func(xdsclient.XDSClient) (resolver.Builder, error)
+
 	// RegisterRLSClusterSpecifierPluginForTesting registers the RLS Cluster
 	// Specifier Plugin for testing purposes, regardless of the XDSRLS environment
 	// variable.
@@ -174,7 +216,7 @@ var (
 
 	// GRPCResolverSchemeExtraMetadata determines when gRPC will add extra
 	// metadata to RPCs.
-	GRPCResolverSchemeExtraMetadata string = "xds"
+	GRPCResolverSchemeExtraMetadata = "xds"
 
 	// EnterIdleModeForTesting gets the ClientConn to enter IDLE mode.
 	EnterIdleModeForTesting any // func(*grpc.ClientConn)
@@ -182,31 +224,56 @@ var (
 	// ExitIdleModeForTesting gets the ClientConn to exit IDLE mode.
 	ExitIdleModeForTesting any // func(*grpc.ClientConn) error
 
+	// ChannelzTurnOffForTesting disables the Channelz service for testing
+	// purposes.
 	ChannelzTurnOffForTesting func()
 
-	// TriggerXDSResourceNameNotFoundForTesting triggers the resource-not-found
-	// error for a given resource type and name. This is usually triggered when
-	// the associated watch timer fires. For testing purposes, having this
-	// function makes events more predictable than relying on timer events.
-	TriggerXDSResourceNameNotFoundForTesting any // func(func(xdsresource.Type, string), string, string) error
+	// TriggerXDSResourceNotFoundForTesting causes the provided xDS Client to
+	// invoke resource-not-found error for the given resource type and name.
+	TriggerXDSResourceNotFoundForTesting any // func(xdsclient.XDSClient, xdsresource.Type, string) error
 
-	// TriggerXDSResourceNameNotFoundClient invokes the testing xDS Client
-	// singleton to invoke resource not found for a resource type name and
-	// resource name.
-	TriggerXDSResourceNameNotFoundClient any // func(string, string) error
-
-	// FromOutgoingContextRaw returns the un-merged, intermediary contents of metadata.rawMD.
+	// FromOutgoingContextRaw returns the un-merged, intermediary contents of
+	// metadata.rawMD.
 	FromOutgoingContextRaw any // func(context.Context) (metadata.MD, [][]string, bool)
 
-	// UserSetDefaultScheme is set to true if the user has overridden the default resolver scheme.
-	UserSetDefaultScheme bool = false
+	// UserSetDefaultScheme is set to true if the user has overridden the
+	// default resolver scheme.
+	UserSetDefaultScheme = false
+
+	// ConnectedAddress returns the connected address for a SubConnState. The
+	// address is only valid if the state is READY.
+	ConnectedAddress any // func (scs SubConnState) resolver.Address
+
+	// SetConnectedAddress sets the connected address for a SubConnState.
+	SetConnectedAddress any // func(scs *SubConnState, addr resolver.Address)
+
+	// SnapshotMetricRegistryForTesting snapshots the global data of the metric
+	// registry. Returns a cleanup function that sets the metric registry to its
+	// original state. Only called in testing functions.
+	SnapshotMetricRegistryForTesting func() func()
+
+	// SetDefaultBufferPoolForTesting updates the default buffer pool, for
+	// testing purposes.
+	SetDefaultBufferPoolForTesting any // func(mem.BufferPool)
+
+	// SetBufferPoolingThresholdForTesting updates the buffer pooling threshold, for
+	// testing purposes.
+	SetBufferPoolingThresholdForTesting any // func(int)
+
+	// TimeAfterFunc is used to create timers. During tests the function is
+	// replaced to track allocated timers and fail the test if a timer isn't
+	// cancelled.
+	TimeAfterFunc = func(d time.Duration, f func()) Timer {
+		return time.AfterFunc(d, f)
+	}
 )
 
-// HealthChecker defines the signature of the client-side LB channel health checking function.
+// HealthChecker defines the signature of the client-side LB channel health
+// checking function.
 //
 // The implementation is expected to create a health checking RPC stream by
 // calling newStream(), watch for the health status of serviceName, and report
-// it's health back by calling setConnectivityState().
+// its health back by calling setConnectivityState().
 //
 // The health checking protocol is defined at:
 // https://github.com/grpc/grpc/blob/master/doc/health-checking.md
@@ -228,3 +295,21 @@ const (
 // It currently has an experimental suffix which would be removed once
 // end-to-end testing of the policy is completed.
 const RLSLoadBalancingPolicyName = "rls_experimental"
+
+// EnforceSubConnEmbedding is used to enforce proper SubConn implementation
+// embedding.
+type EnforceSubConnEmbedding interface {
+	enforceSubConnEmbedding()
+}
+
+// EnforceClientConnEmbedding is used to enforce proper ClientConn implementation
+// embedding.
+type EnforceClientConnEmbedding interface {
+	enforceClientConnEmbedding()
+}
+
+// Timer is an interface to allow injecting different time.Timer implementations
+// during tests.
+type Timer interface {
+	Stop() bool
+}

vendor/google.golang.org/grpc/internal/metadata/metadata.go

@@ -97,13 +97,11 @@ func hasNotPrintable(msg string) bool {
 	return false
 }
 
-// ValidatePair validate a key-value pair with the following rules (the pseudo-header will be skipped) :
-//
-// - key must contain one or more characters.
-// - the characters in the key must be contained in [0-9 a-z _ - .].
-// - if the key ends with a "-bin" suffix, no validation of the corresponding value is performed.
-// - the characters in the every value must be printable (in [%x20-%x7E]).
-func ValidatePair(key string, vals ...string) error {
+// ValidateKey validates a key with the following rules (pseudo-headers are
+// skipped):
+// - the key must contain one or more characters.
+// - the characters in the key must be in [0-9 a-z _ - .].
+func ValidateKey(key string) error {
 	// key should not be empty
 	if key == "" {
 		return fmt.Errorf("there is an empty key in the header")
@@ -119,6 +117,20 @@ func ValidatePair(key string, vals ...string) error {
 			return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", key)
 		}
 	}
+	return nil
+}
+
+// ValidatePair validates a key-value pair with the following rules
+// (pseudo-header are skipped):
+//   - the key must contain one or more characters.
+//   - the characters in the key must be in [0-9 a-z _ - .].
+//   - if the key ends with a "-bin" suffix, no validation of the corresponding
+//     value is performed.
+//   - the characters in every value must be printable (in [%x20-%x7E]).
+func ValidatePair(key string, vals ...string) error {
+	if err := ValidateKey(key); err != nil {
+		return err
+	}
 	if strings.HasSuffix(key, "-bin") {
 		return nil
 	}

vendor/google.golang.org/grpc/internal/proxyattributes/proxyattributes.go

@@ -0,0 +1,54 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package proxyattributes contains functions for getting and setting proxy
+// attributes like the CONNECT address and user info.
+package proxyattributes
+
+import (
+	"net/url"
+
+	"google.golang.org/grpc/resolver"
+)
+
+type keyType string
+
+const proxyOptionsKey = keyType("grpc.resolver.delegatingresolver.proxyOptions")
+
+// Options holds the proxy connection details needed during the CONNECT
+// handshake.
+type Options struct {
+	User        *url.Userinfo
+	ConnectAddr string
+}
+
+// Set returns a copy of addr with opts set in its attributes.
+func Set(addr resolver.Address, opts Options) resolver.Address {
+	addr.Attributes = addr.Attributes.WithValue(proxyOptionsKey, opts)
+	return addr
+}
+
+// Get returns the Options for the proxy [resolver.Address] and a boolean
+// value representing if the attribute is present or not. The returned data
+// should not be mutated.
+func Get(addr resolver.Address) (Options, bool) {
+	if a := addr.Attributes.Value(proxyOptionsKey); a != nil {
+		return a.(Options), true
+	}
+	return Options{}, false
+}

vendor/google.golang.org/grpc/internal/resolver/delegatingresolver/delegatingresolver.go

@@ -0,0 +1,427 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package delegatingresolver implements a resolver capable of resolving both
+// target URIs and proxy addresses.
+package delegatingresolver
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"sync"
+
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/proxyattributes"
+	"google.golang.org/grpc/internal/transport"
+	"google.golang.org/grpc/internal/transport/networktype"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+var (
+	logger = grpclog.Component("delegating-resolver")
+	// HTTPSProxyFromEnvironment will be overwritten in the tests
+	HTTPSProxyFromEnvironment = http.ProxyFromEnvironment
+)
+
+// delegatingResolver manages both target URI and proxy address resolution by
+// delegating these tasks to separate child resolvers. Essentially, it acts as
+// an intermediary between the gRPC ClientConn and the child resolvers.
+//
+// It implements the [resolver.Resolver] interface.
+type delegatingResolver struct {
+	target   resolver.Target     // parsed target URI to be resolved
+	cc       resolver.ClientConn // gRPC ClientConn
+	proxyURL *url.URL            // proxy URL, derived from proxy environment and target
+
+	// We do not hold both mu and childMu in the same goroutine. Avoid holding
+	// both locks when calling into the child, as the child resolver may
+	// synchronously callback into the channel.
+	mu                  sync.Mutex         // protects all the fields below
+	targetResolverState *resolver.State    // state of the target resolver
+	proxyAddrs          []resolver.Address // resolved proxy addresses; empty if no proxy is configured
+
+	// childMu serializes calls into child resolvers. It also protects access to
+	// the following fields.
+	childMu        sync.Mutex
+	targetResolver resolver.Resolver // resolver for the target URI, based on its scheme
+	proxyResolver  resolver.Resolver // resolver for the proxy URI; nil if no proxy is configured
+}
+
+// nopResolver is a resolver that does nothing.
+type nopResolver struct{}
+
+func (nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (nopResolver) Close() {}
+
+// proxyURLForTarget determines the proxy URL for the given address based on the
+// environment. It can return the following:
+//   - nil URL, nil error: No proxy is configured or the address is excluded
+//     using the `NO_PROXY` environment variable or if req.URL.Host is
+//     "localhost" (with or without // a port number)
+//   - nil URL, non-nil error: An error occurred while retrieving the proxy URL.
+//   - non-nil URL, nil error: A proxy is configured, and the proxy URL was
+//     retrieved successfully without any errors.
+func proxyURLForTarget(address string) (*url.URL, error) {
+	req := &http.Request{URL: &url.URL{
+		Scheme: "https",
+		Host:   address,
+	}}
+	return HTTPSProxyFromEnvironment(req)
+}
+
+// New creates a new delegating resolver that can create up to two child
+// resolvers:
+//   - one to resolve the proxy address specified using the supported
+//     environment variables. This uses the registered resolver for the "dns"
+//     scheme. It is lazily built when a target resolver update contains at least
+//     one TCP address.
+//   - one to resolve the target URI using the resolver specified by the scheme
+//     in the target URI or specified by the user using the WithResolvers dial
+//     option. As a special case, if the target URI's scheme is "dns" and a
+//     proxy is specified using the supported environment variables, the target
+//     URI's path portion is used as the resolved address unless target
+//     resolution is enabled using the dial option.
+func New(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions, targetResolverBuilder resolver.Builder, targetResolutionEnabled bool) (resolver.Resolver, error) {
+	r := &delegatingResolver{
+		target:         target,
+		cc:             cc,
+		proxyResolver:  nopResolver{},
+		targetResolver: nopResolver{},
+	}
+
+	var err error
+	r.proxyURL, err = proxyURLForTarget(target.Endpoint())
+	if err != nil {
+		return nil, fmt.Errorf("delegating_resolver: failed to determine proxy URL for target %s: %v", target, err)
+	}
+
+	// proxy is not configured or proxy address excluded using `NO_PROXY` env
+	// var, so only target resolver is used.
+	if r.proxyURL == nil {
+		return targetResolverBuilder.Build(target, cc, opts)
+	}
+
+	if logger.V(2) {
+		logger.Infof("Proxy URL detected : %s", r.proxyURL)
+	}
+
+	// Resolver updates from one child may trigger calls into the other. Block
+	// updates until the children are initialized.
+	r.childMu.Lock()
+	defer r.childMu.Unlock()
+	// When the scheme is 'dns' and target resolution on client is not enabled,
+	// resolution should be handled by the proxy, not the client. Therefore, we
+	// bypass the target resolver and store the unresolved target address.
+	if target.URL.Scheme == "dns" && !targetResolutionEnabled {
+		r.targetResolverState = &resolver.State{
+			Addresses: []resolver.Address{{Addr: target.Endpoint()}},
+			Endpoints: []resolver.Endpoint{{Addresses: []resolver.Address{{Addr: target.Endpoint()}}}},
+		}
+		r.updateTargetResolverState(*r.targetResolverState)
+		return r, nil
+	}
+	wcc := &wrappingClientConn{
+		stateListener: r.updateTargetResolverState,
+		parent:        r,
+	}
+	if r.targetResolver, err = targetResolverBuilder.Build(target, wcc, opts); err != nil {
+		return nil, fmt.Errorf("delegating_resolver: unable to build the resolver for target %s: %v", target, err)
+	}
+	return r, nil
+}
+
+// proxyURIResolver creates a resolver for resolving proxy URIs using the "dns"
+// scheme. It adjusts the proxyURL to conform to the "dns:///" format and builds
+// a resolver with a wrappingClientConn to capture resolved addresses.
+func (r *delegatingResolver) proxyURIResolver(opts resolver.BuildOptions) (resolver.Resolver, error) {
+	proxyBuilder := resolver.Get("dns")
+	if proxyBuilder == nil {
+		panic("delegating_resolver: resolver for proxy not found for scheme dns")
+	}
+	url := *r.proxyURL
+	url.Scheme = "dns"
+	url.Path = "/" + r.proxyURL.Host
+	url.Host = "" // Clear the Host field to conform to the "dns:///" format
+
+	proxyTarget := resolver.Target{URL: url}
+	wcc := &wrappingClientConn{
+		stateListener: r.updateProxyResolverState,
+		parent:        r,
+	}
+	return proxyBuilder.Build(proxyTarget, wcc, opts)
+}
+
+func (r *delegatingResolver) ResolveNow(o resolver.ResolveNowOptions) {
+	r.childMu.Lock()
+	defer r.childMu.Unlock()
+	r.targetResolver.ResolveNow(o)
+	r.proxyResolver.ResolveNow(o)
+}
+
+func (r *delegatingResolver) Close() {
+	r.childMu.Lock()
+	defer r.childMu.Unlock()
+	r.targetResolver.Close()
+	r.targetResolver = nil
+
+	r.proxyResolver.Close()
+	r.proxyResolver = nil
+}
+
+func needsProxyResolver(state *resolver.State) bool {
+	for _, addr := range state.Addresses {
+		if !skipProxy(addr) {
+			return true
+		}
+	}
+	for _, endpoint := range state.Endpoints {
+		for _, addr := range endpoint.Addresses {
+			if !skipProxy(addr) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func skipProxy(address resolver.Address) bool {
+	// Avoid proxy when network is not tcp.
+	networkType, ok := networktype.Get(address)
+	if !ok {
+		networkType, _ = transport.ParseDialTarget(address.Addr)
+	}
+	if networkType != "tcp" {
+		return true
+	}
+
+	req := &http.Request{URL: &url.URL{
+		Scheme: "https",
+		Host:   address.Addr,
+	}}
+	// Avoid proxy when address included in `NO_PROXY` environment variable or
+	// fails to get the proxy address.
+	url, err := HTTPSProxyFromEnvironment(req)
+	if err != nil || url == nil {
+		return true
+	}
+	return false
+}
+
+// updateClientConnStateLocked constructs a combined list of addresses by
+// pairing each proxy address with every target address of type TCP. For each
+// pair, it creates a new [resolver.Address] using the proxy address and
+// attaches the corresponding target address and user info as attributes. Target
+// addresses that are not of type TCP are appended to the list as-is. The
+// function returns nil if either resolver has not yet provided an update, and
+// returns the result of ClientConn.UpdateState once both resolvers have
+// provided at least one update.
+func (r *delegatingResolver) updateClientConnStateLocked() error {
+	if r.targetResolverState == nil || r.proxyAddrs == nil {
+		return nil
+	}
+
+	// If multiple resolved proxy addresses are present, we send only the
+	// unresolved proxy host and let net.Dial handle the proxy host name
+	// resolution when creating the transport. Sending all resolved addresses
+	// would increase the number of addresses passed to the ClientConn and
+	// subsequently to load balancing (LB) policies like Round Robin, leading
+	// to additional TCP connections. However, if there's only one resolved
+	// proxy address, we send it directly, as it doesn't affect the address
+	// count returned by the target resolver and the address count sent to the
+	// ClientConn.
+	var proxyAddr resolver.Address
+	if len(r.proxyAddrs) == 1 {
+		proxyAddr = r.proxyAddrs[0]
+	} else {
+		proxyAddr = resolver.Address{Addr: r.proxyURL.Host}
+	}
+	var addresses []resolver.Address
+	for _, targetAddr := range (*r.targetResolverState).Addresses {
+		if skipProxy(targetAddr) {
+			addresses = append(addresses, targetAddr)
+			continue
+		}
+		addresses = append(addresses, proxyattributes.Set(proxyAddr, proxyattributes.Options{
+			User:        r.proxyURL.User,
+			ConnectAddr: targetAddr.Addr,
+		}))
+	}
+
+	// For each target endpoint, construct a new [resolver.Endpoint] that
+	// includes all addresses from all proxy endpoints and the addresses from
+	// that target endpoint, preserving the number of target endpoints.
+	var endpoints []resolver.Endpoint
+	for _, endpt := range (*r.targetResolverState).Endpoints {
+		var addrs []resolver.Address
+		for _, targetAddr := range endpt.Addresses {
+			// Avoid proxy when network is not tcp.
+			if skipProxy(targetAddr) {
+				addrs = append(addrs, targetAddr)
+				continue
+			}
+			for _, proxyAddr := range r.proxyAddrs {
+				addrs = append(addrs, proxyattributes.Set(proxyAddr, proxyattributes.Options{
+					User:        r.proxyURL.User,
+					ConnectAddr: targetAddr.Addr,
+				}))
+			}
+		}
+		endpoints = append(endpoints, resolver.Endpoint{Addresses: addrs})
+	}
+	// Use the targetResolverState for its service config and attributes
+	// contents. The state update is only sent after both the target and proxy
+	// resolvers have sent their updates, and curState has been updated with the
+	// combined addresses.
+	curState := *r.targetResolverState
+	curState.Addresses = addresses
+	curState.Endpoints = endpoints
+	return r.cc.UpdateState(curState)
+}
+
+// updateProxyResolverState updates the proxy resolver state by storing proxy
+// addresses and endpoints, marking the resolver as ready, and triggering a
+// state update if both proxy and target resolvers are ready. If the ClientConn
+// returns a non-nil error, it calls `ResolveNow()` on the target resolver.  It
+// is a StateListener function of wrappingClientConn passed to the proxy
+// resolver.
+func (r *delegatingResolver) updateProxyResolverState(state resolver.State) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if logger.V(2) {
+		logger.Infof("Addresses received from proxy resolver: %s", state.Addresses)
+	}
+	if len(state.Endpoints) > 0 {
+		// We expect exactly one address per endpoint because the proxy resolver
+		// uses "dns" resolution.
+		r.proxyAddrs = make([]resolver.Address, 0, len(state.Endpoints))
+		for _, endpoint := range state.Endpoints {
+			r.proxyAddrs = append(r.proxyAddrs, endpoint.Addresses...)
+		}
+	} else if state.Addresses != nil {
+		r.proxyAddrs = state.Addresses
+	} else {
+		r.proxyAddrs = []resolver.Address{} // ensure proxyAddrs is non-nil to indicate an update has been received
+	}
+	err := r.updateClientConnStateLocked()
+	// Another possible approach was to block until updates are received from
+	// both resolvers. But this is not used because calling `New()` triggers
+	// `Build()` for the first resolver, which calls `UpdateState()`. And the
+	// second resolver hasn't sent an update yet, so it would cause `New()` to
+	// block indefinitely.
+	if err != nil {
+		go func() {
+			r.childMu.Lock()
+			defer r.childMu.Unlock()
+			if r.targetResolver != nil {
+				r.targetResolver.ResolveNow(resolver.ResolveNowOptions{})
+			}
+		}()
+	}
+	return err
+}
+
+// updateTargetResolverState is the StateListener function provided to the
+// target resolver via wrappingClientConn. It updates the resolver state and
+// marks the target resolver as ready. If the update includes at least one TCP
+// address and the proxy resolver has not yet been constructed, it initializes
+// the proxy resolver. A combined state update is triggered once both resolvers
+// are ready. If all addresses are non-TCP, it proceeds without waiting for the
+// proxy resolver. If ClientConn.UpdateState returns a non-nil error,
+// ResolveNow() is called on the proxy resolver.
+func (r *delegatingResolver) updateTargetResolverState(state resolver.State) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if logger.V(2) {
+		logger.Infof("Addresses received from target resolver: %v", state.Addresses)
+	}
+	r.targetResolverState = &state
+	// If all addresses returned by the target resolver have a non-TCP network
+	// type, or are listed in the `NO_PROXY` environment variable, do not wait
+	// for proxy update.
+	if !needsProxyResolver(r.targetResolverState) {
+		return r.cc.UpdateState(*r.targetResolverState)
+	}
+
+	// The proxy resolver may be rebuilt multiple times, specifically each time
+	// the target resolver sends an update, even if the target resolver is built
+	// successfully but building the proxy resolver fails.
+	if len(r.proxyAddrs) == 0 {
+		go func() {
+			r.childMu.Lock()
+			defer r.childMu.Unlock()
+			if _, ok := r.proxyResolver.(nopResolver); !ok {
+				return
+			}
+			proxyResolver, err := r.proxyURIResolver(resolver.BuildOptions{})
+			if err != nil {
+				r.cc.ReportError(fmt.Errorf("delegating_resolver: unable to build the proxy resolver: %v", err))
+				return
+			}
+			r.proxyResolver = proxyResolver
+		}()
+	}
+
+	err := r.updateClientConnStateLocked()
+	if err != nil {
+		go func() {
+			r.childMu.Lock()
+			defer r.childMu.Unlock()
+			if r.proxyResolver != nil {
+				r.proxyResolver.ResolveNow(resolver.ResolveNowOptions{})
+			}
+		}()
+	}
+	return nil
+}
+
+// wrappingClientConn serves as an intermediary between the parent ClientConn
+// and the child resolvers created here. It implements the resolver.ClientConn
+// interface and is passed in that capacity to the child resolvers.
+type wrappingClientConn struct {
+	// Callback to deliver resolver state updates
+	stateListener func(state resolver.State) error
+	parent        *delegatingResolver
+}
+
+// UpdateState receives resolver state updates and forwards them to the
+// appropriate listener function (either for the proxy or target resolver).
+func (wcc *wrappingClientConn) UpdateState(state resolver.State) error {
+	return wcc.stateListener(state)
+}
+
+// ReportError intercepts errors from the child resolvers and passes them to
+// ClientConn.
+func (wcc *wrappingClientConn) ReportError(err error) {
+	wcc.parent.cc.ReportError(err)
+}
+
+// NewAddress intercepts the new resolved address from the child resolvers and
+// passes them to ClientConn.
+func (wcc *wrappingClientConn) NewAddress(addrs []resolver.Address) {
+	wcc.UpdateState(resolver.State{Addresses: addrs})
+}
+
+// ParseServiceConfig parses the provided service config and returns an object
+// that provides the parsed config.
+func (wcc *wrappingClientConn) ParseServiceConfig(serviceConfigJSON string) *serviceconfig.ParseResult {
+	return wcc.parent.cc.ParseServiceConfig(serviceConfigJSON)
+}

vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go

@@ -24,7 +24,9 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	rand "math/rand/v2"
 	"net"
+	"net/netip"
 	"os"
 	"strconv"
 	"strings"
@@ -35,28 +37,35 @@ import (
 	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/internal/backoff"
 	"google.golang.org/grpc/internal/envconfig"
-	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/internal/resolver/dns/internal"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/serviceconfig"
 )
 
-// EnableSRVLookups controls whether the DNS resolver attempts to fetch gRPCLB
-// addresses from SRV records.  Must not be changed after init time.
-var EnableSRVLookups = false
+var (
+	// EnableSRVLookups controls whether the DNS resolver attempts to fetch gRPCLB
+	// addresses from SRV records.  Must not be changed after init time.
+	EnableSRVLookups = false
 
-// ResolvingTimeout specifies the maximum duration for a DNS resolution request.
-// If the timeout expires before a response is received, the request will be canceled.
-//
-// It is recommended to set this value at application startup. Avoid modifying this variable
-// after initialization as it's not thread-safe for concurrent modification.
-var ResolvingTimeout = 30 * time.Second
+	// MinResolutionInterval is the minimum interval at which re-resolutions are
+	// allowed. This helps to prevent excessive re-resolution.
+	MinResolutionInterval = 30 * time.Second
 
-var logger = grpclog.Component("dns")
+	// ResolvingTimeout specifies the maximum duration for a DNS resolution request.
+	// If the timeout expires before a response is received, the request will be canceled.
+	//
+	// It is recommended to set this value at application startup. Avoid modifying this variable
+	// after initialization as it's not thread-safe for concurrent modification.
+	ResolvingTimeout = 30 * time.Second
+
+	logger = grpclog.Component("dns")
+)
 
 func init() {
 	resolver.Register(NewBuilder())
 	internal.TimeAfterFunc = time.After
+	internal.TimeNowFunc = time.Now
+	internal.TimeUntilFunc = time.Until
 	internal.NewNetResolver = newNetResolver
 	internal.AddressDialer = addressDialer
 }
@@ -114,7 +123,7 @@ func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts
 	}
 
 	// IP address.
-	if ipAddr, ok := formatIP(host); ok {
+	if ipAddr, err := formatIP(host); err == nil {
 		addr := []resolver.Address{{Addr: ipAddr + ":" + port}}
 		cc.UpdateState(resolver.State{Addresses: addr})
 		return deadResolver{}, nil
@@ -169,7 +178,7 @@ type dnsResolver struct {
 	// finished. Otherwise, data race will be possible. [Race Example] in
 	// dns_resolver_test we replace the real lookup functions with mocked ones to
 	// facilitate testing. If Close() doesn't wait for watcher() goroutine
-	// finishes, race detector sometimes will warns lookup (READ the lookup
+	// finishes, race detector sometimes will warn lookup (READ the lookup
 	// function pointers) inside watcher() goroutine has data race with
 	// replaceNetFunc (WRITE the lookup function pointers).
 	wg                   sync.WaitGroup
@@ -203,12 +212,12 @@ func (d *dnsResolver) watcher() {
 			err = d.cc.UpdateState(*state)
 		}
 
-		var waitTime time.Duration
+		var nextResolutionTime time.Time
 		if err == nil {
 			// Success resolving, wait for the next ResolveNow. However, also wait 30
 			// seconds at the very least to prevent constantly re-resolving.
 			backoffIndex = 1
-			waitTime = internal.MinResolutionRate
+			nextResolutionTime = internal.TimeNowFunc().Add(MinResolutionInterval)
 			select {
 			case <-d.ctx.Done():
 				return
@@ -217,19 +226,21 @@ func (d *dnsResolver) watcher() {
 		} else {
 			// Poll on an error found in DNS Resolver or an error received from
 			// ClientConn.
-			waitTime = backoff.DefaultExponential.Backoff(backoffIndex)
+			nextResolutionTime = internal.TimeNowFunc().Add(backoff.DefaultExponential.Backoff(backoffIndex))
 			backoffIndex++
 		}
 		select {
 		case <-d.ctx.Done():
 			return
-		case <-internal.TimeAfterFunc(waitTime):
+		case <-internal.TimeAfterFunc(internal.TimeUntilFunc(nextResolutionTime)):
 		}
 	}
 }
 
 func (d *dnsResolver) lookupSRV(ctx context.Context) ([]resolver.Address, error) {
-	if !EnableSRVLookups {
+	// Skip this particular host to avoid timeouts with some versions of
+	// systemd-resolved.
+	if !EnableSRVLookups || d.host == "metadata.google.internal." {
 		return nil, nil
 	}
 	var newAddrs []resolver.Address
@@ -250,9 +261,9 @@ func (d *dnsResolver) lookupSRV(ctx context.Context) ([]resolver.Address, error)
 			return nil, err
 		}
 		for _, a := range lbAddrs {
-			ip, ok := formatIP(a)
-			if !ok {
-				return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+			ip, err := formatIP(a)
+			if err != nil {
+				return nil, fmt.Errorf("dns: error parsing A record IP address %v: %v", a, err)
 			}
 			addr := ip + ":" + strconv.Itoa(int(s.Port))
 			newAddrs = append(newAddrs, resolver.Address{Addr: addr, ServerName: s.Target})
@@ -312,9 +323,9 @@ func (d *dnsResolver) lookupHost(ctx context.Context) ([]resolver.Address, error
 	}
 	newAddrs := make([]resolver.Address, 0, len(addrs))
 	for _, a := range addrs {
-		ip, ok := formatIP(a)
-		if !ok {
-			return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+		ip, err := formatIP(a)
+		if err != nil {
+			return nil, fmt.Errorf("dns: error parsing A record IP address %v: %v", a, err)
 		}
 		addr := ip + ":" + d.port
 		newAddrs = append(newAddrs, resolver.Address{Addr: addr})
@@ -341,19 +352,19 @@ func (d *dnsResolver) lookup() (*resolver.State, error) {
 	return &state, nil
 }
 
-// formatIP returns ok = false if addr is not a valid textual representation of
-// an IP address. If addr is an IPv4 address, return the addr and ok = true.
+// formatIP returns an error if addr is not a valid textual representation of
+// an IP address. If addr is an IPv4 address, return the addr and error = nil.
 // If addr is an IPv6 address, return the addr enclosed in square brackets and
-// ok = true.
-func formatIP(addr string) (addrIP string, ok bool) {
-	ip := net.ParseIP(addr)
-	if ip == nil {
-		return "", false
+// error = nil.
+func formatIP(addr string) (string, error) {
+	ip, err := netip.ParseAddr(addr)
+	if err != nil {
+		return "", err
 	}
-	if ip.To4() != nil {
-		return addr, true
+	if ip.Is4() {
+		return addr, nil
 	}
-	return "[" + addr + "]", true
+	return "[" + addr + "]", nil
 }
 
 // parseTarget takes the user input target string and default port, returns
@@ -369,7 +380,7 @@ func parseTarget(target, defaultPort string) (host, port string, err error) {
 	if target == "" {
 		return "", "", internal.ErrMissingAddr
 	}
-	if ip := net.ParseIP(target); ip != nil {
+	if _, err := netip.ParseAddr(target); err == nil {
 		// target is an IPv4 or IPv6(without brackets) address
 		return target, defaultPort, nil
 	}
@@ -417,7 +428,7 @@ func chosenByPercentage(a *int) bool {
 	if a == nil {
 		return true
 	}
-	return grpcrand.Intn(100)+1 <= *a
+	return rand.IntN(100)+1 <= *a
 }
 
 func canaryingSC(js string) string {

vendor/google.golang.org/grpc/internal/resolver/dns/internal/internal.go

@@ -28,7 +28,7 @@ import (
 
 // NetResolver groups the methods on net.Resolver that are used by the DNS
 // resolver implementation. This allows the default net.Resolver instance to be
-// overidden from tests.
+// overridden from tests.
 type NetResolver interface {
 	LookupHost(ctx context.Context, host string) (addrs []string, err error)
 	LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error)
@@ -50,16 +50,23 @@ var (
 
 // The following vars are overridden from tests.
 var (
-	// MinResolutionRate is the minimum rate at which re-resolutions are
-	// allowed. This helps to prevent excessive re-resolution.
-	MinResolutionRate = 30 * time.Second
-
 	// TimeAfterFunc is used by the DNS resolver to wait for the given duration
-	// to elapse. In non-test code, this is implemented by time.After.  In test
+	// to elapse. In non-test code, this is implemented by time.After. In test
 	// code, this can be used to control the amount of time the resolver is
 	// blocked waiting for the duration to elapse.
 	TimeAfterFunc func(time.Duration) <-chan time.Time
 
+	// TimeNowFunc is used by the DNS resolver to get the current time.
+	// In non-test code, this is implemented by time.Now. In test code,
+	// this can be used to control the current time for the resolver.
+	TimeNowFunc func() time.Time
+
+	// TimeUntilFunc is used by the DNS resolver to calculate the remaining
+	// wait time for re-resolution. In non-test code, this is implemented by
+	// time.Until. In test code, this can be used to control the remaining
+	// time for resolver to wait for re-resolution.
+	TimeUntilFunc func(time.Time) time.Duration
+
 	// NewNetResolver returns the net.Resolver instance for the given target.
 	NewNetResolver func(string) (NetResolver, error)
 

vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go

@@ -55,7 +55,7 @@ func (r *passthroughResolver) start() {
 	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint()}}})
 }
 
-func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOptions) {}
+func (*passthroughResolver) ResolveNow(resolver.ResolveNowOptions) {}
 
 func (*passthroughResolver) Close() {}
 

vendor/google.golang.org/grpc/internal/stats/labels.go

@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package stats provides internal stats related functionality.
+package stats
+
+import "context"
+
+// Labels are the labels for metrics.
+type Labels struct {
+	// TelemetryLabels are the telemetry labels to record.
+	TelemetryLabels map[string]string
+}
+
+type labelsKey struct{}
+
+// GetLabels returns the Labels stored in the context, or nil if there is one.
+func GetLabels(ctx context.Context) *Labels {
+	labels, _ := ctx.Value(labelsKey{}).(*Labels)
+	return labels
+}
+
+// SetLabels sets the Labels in the context.
+func SetLabels(ctx context.Context, labels *Labels) context.Context {
+	// could also append
+	return context.WithValue(ctx, labelsKey{}, labels)
+}

vendor/google.golang.org/grpc/internal/stats/metrics_recorder_list.go

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package stats
+
+import (
+	"fmt"
+
+	estats "google.golang.org/grpc/experimental/stats"
+	"google.golang.org/grpc/stats"
+)
+
+// MetricsRecorderList forwards Record calls to all of its metricsRecorders.
+//
+// It eats any record calls where the label values provided do not match the
+// number of label keys.
+type MetricsRecorderList struct {
+	// metricsRecorders are the metrics recorders this list will forward to.
+	metricsRecorders []estats.MetricsRecorder
+}
+
+// NewMetricsRecorderList creates a new metric recorder list with all the stats
+// handlers provided which implement the MetricsRecorder interface.
+// If no stats handlers provided implement the MetricsRecorder interface,
+// the MetricsRecorder list returned is a no-op.
+func NewMetricsRecorderList(shs []stats.Handler) *MetricsRecorderList {
+	var mrs []estats.MetricsRecorder
+	for _, sh := range shs {
+		if mr, ok := sh.(estats.MetricsRecorder); ok {
+			mrs = append(mrs, mr)
+		}
+	}
+	return &MetricsRecorderList{
+		metricsRecorders: mrs,
+	}
+}
+
+func verifyLabels(desc *estats.MetricDescriptor, labelsRecv ...string) {
+	if got, want := len(labelsRecv), len(desc.Labels)+len(desc.OptionalLabels); got != want {
+		panic(fmt.Sprintf("Received %d labels in call to record metric %q, but expected %d.", got, desc.Name, want))
+	}
+}
+
+// RecordInt64Count records the measurement alongside labels on the int
+// count associated with the provided handle.
+func (l *MetricsRecorderList) RecordInt64Count(handle *estats.Int64CountHandle, incr int64, labels ...string) {
+	verifyLabels(handle.Descriptor(), labels...)
+
+	for _, metricRecorder := range l.metricsRecorders {
+		metricRecorder.RecordInt64Count(handle, incr, labels...)
+	}
+}
+
+// RecordFloat64Count records the measurement alongside labels on the float
+// count associated with the provided handle.
+func (l *MetricsRecorderList) RecordFloat64Count(handle *estats.Float64CountHandle, incr float64, labels ...string) {
+	verifyLabels(handle.Descriptor(), labels...)
+
+	for _, metricRecorder := range l.metricsRecorders {
+		metricRecorder.RecordFloat64Count(handle, incr, labels...)
+	}
+}
+
+// RecordInt64Histo records the measurement alongside labels on the int
+// histo associated with the provided handle.
+func (l *MetricsRecorderList) RecordInt64Histo(handle *estats.Int64HistoHandle, incr int64, labels ...string) {
+	verifyLabels(handle.Descriptor(), labels...)
+
+	for _, metricRecorder := range l.metricsRecorders {
+		metricRecorder.RecordInt64Histo(handle, incr, labels...)
+	}
+}
+
+// RecordFloat64Histo records the measurement alongside labels on the float
+// histo associated with the provided handle.
+func (l *MetricsRecorderList) RecordFloat64Histo(handle *estats.Float64HistoHandle, incr float64, labels ...string) {
+	verifyLabels(handle.Descriptor(), labels...)
+
+	for _, metricRecorder := range l.metricsRecorders {
+		metricRecorder.RecordFloat64Histo(handle, incr, labels...)
+	}
+}
+
+// RecordInt64Gauge records the measurement alongside labels on the int
+// gauge associated with the provided handle.
+func (l *MetricsRecorderList) RecordInt64Gauge(handle *estats.Int64GaugeHandle, incr int64, labels ...string) {
+	verifyLabels(handle.Descriptor(), labels...)
+
+	for _, metricRecorder := range l.metricsRecorders {
+		metricRecorder.RecordInt64Gauge(handle, incr, labels...)
+	}
+}

vendor/google.golang.org/grpc/internal/status/status.go

@@ -138,17 +138,19 @@ func (s *Status) WithDetails(details ...protoadapt.MessageV1) (*Status, error) {
 	// s.Code() != OK implies that s.Proto() != nil.
 	p := s.Proto()
 	for _, detail := range details {
-		any, err := anypb.New(protoadapt.MessageV2Of(detail))
+		m, err := anypb.New(protoadapt.MessageV2Of(detail))
 		if err != nil {
 			return nil, err
 		}
-		p.Details = append(p.Details, any)
+		p.Details = append(p.Details, m)
 	}
 	return &Status{s: p}, nil
 }
 
 // Details returns a slice of details messages attached to the status.
 // If a detail cannot be decoded, the error is returned in place of the detail.
+// If the detail can be decoded, the proto message returned is of the same
+// type that was given to WithDetails().
 func (s *Status) Details() []any {
 	if s == nil || s.s == nil {
 		return nil
@@ -160,7 +162,38 @@ func (s *Status) Details() []any {
 			details = append(details, err)
 			continue
 		}
-		details = append(details, detail)
+		// The call to MessageV1Of is required to unwrap the proto message if
+		// it implemented only the MessageV1 API. The proto message would have
+		// been wrapped in a V2 wrapper in Status.WithDetails. V2 messages are
+		// added to a global registry used by any.UnmarshalNew().
+		// MessageV1Of has the following behaviour:
+		// 1. If the given message is a wrapped MessageV1, it returns the
+		//   unwrapped value.
+		// 2. If the given message already implements MessageV1, it returns it
+		//   as is.
+		// 3. Else, it wraps the MessageV2 in a MessageV1 wrapper.
+		//
+		// Since the Status.WithDetails() API only accepts MessageV1, calling
+		// MessageV1Of ensures we return the same type that was given to
+		// WithDetails:
+		// * If the give type implemented only MessageV1, the unwrapping from
+		//   point 1 above will restore the type.
+		// * If the given type implemented both MessageV1 and MessageV2, point 2
+		//   above will ensure no wrapping is performed.
+		// * If the given type implemented only MessageV2 and was wrapped using
+		//   MessageV1Of before passing to WithDetails(), it would be unwrapped
+		//   in WithDetails by calling MessageV2Of(). Point 3 above will ensure
+		//   that the type is wrapped in a MessageV1 wrapper again before
+		//   returning. Note that protoc-gen-go doesn't generate code which
+		//   implements ONLY MessageV2 at the time of writing.
+		//
+		// NOTE: Status details can also be added using the FromProto method.
+		// This could theoretically allow passing a Detail message that only
+		// implements the V2 API. In such a case the message will be wrapped in
+		// a MessageV1 wrapper when fetched using Details().
+		// Since protoc-gen-go generates only code that implements both V1 and
+		// V2 APIs for backward compatibility, this is not a concern.
+		details = append(details, protoadapt.MessageV1Of(detail))
 	}
 	return details
 }

vendor/google.golang.org/grpc/internal/syscall/syscall_nonlinux.go

@@ -58,20 +58,20 @@ func GetRusage() *Rusage {
 
 // CPUTimeDiff returns the differences of user CPU time and system CPU time used
 // between two Rusage structs. It a no-op function for non-linux environments.
-func CPUTimeDiff(first *Rusage, latest *Rusage) (float64, float64) {
+func CPUTimeDiff(*Rusage, *Rusage) (float64, float64) {
 	log()
 	return 0, 0
 }
 
 // SetTCPUserTimeout is a no-op function under non-linux environments.
-func SetTCPUserTimeout(conn net.Conn, timeout time.Duration) error {
+func SetTCPUserTimeout(net.Conn, time.Duration) error {
 	log()
 	return nil
 }
 
 // GetTCPUserTimeout is a no-op function under non-linux environments.
 // A negative return value indicates the operation is not supported
-func GetTCPUserTimeout(conn net.Conn) (int, error) {
+func GetTCPUserTimeout(net.Conn) (int, error) {
 	log()
 	return -1, nil
 }

vendor/google.golang.org/grpc/internal/tcp_keepalive_unix.go

@@ -44,7 +44,7 @@ func NetDialerWithTCPKeepalive() *net.Dialer {
 		// combination of unconditionally enabling TCP keepalives here, and
 		// disabling the overriding of TCP keepalive parameters by setting the
 		// KeepAlive field to a negative value above, results in OS defaults for
-		// the TCP keealive interval and time parameters.
+		// the TCP keepalive interval and time parameters.
 		Control: func(_, _ string, c syscall.RawConn) error {
 			return c.Control(func(fd uintptr) {
 				unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)

vendor/google.golang.org/grpc/internal/tcp_keepalive_windows.go

@@ -44,7 +44,7 @@ func NetDialerWithTCPKeepalive() *net.Dialer {
 		// combination of unconditionally enabling TCP keepalives here, and
 		// disabling the overriding of TCP keepalive parameters by setting the
 		// KeepAlive field to a negative value above, results in OS defaults for
-		// the TCP keealive interval and time parameters.
+		// the TCP keepalive interval and time parameters.
 		Control: func(_, _ string, c syscall.RawConn) error {
 			return c.Control(func(fd uintptr) {
 				windows.SetsockoptInt(windows.Handle(fd), windows.SOL_SOCKET, windows.SO_KEEPALIVE, 1)

vendor/google.golang.org/grpc/internal/transport/client_stream.go

@@ -0,0 +1,144 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"sync/atomic"
+
+	"golang.org/x/net/http2"
+	"google.golang.org/grpc/mem"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+// ClientStream implements streaming functionality for a gRPC client.
+type ClientStream struct {
+	*Stream // Embed for common stream functionality.
+
+	ct       *http2Client
+	done     chan struct{} // closed at the end of stream to unblock writers.
+	doneFunc func()        // invoked at the end of stream.
+
+	headerChan       chan struct{} // closed to indicate the end of header metadata.
+	headerChanClosed uint32        // set when headerChan is closed. Used to avoid closing headerChan multiple times.
+	// headerValid indicates whether a valid header was received.  Only
+	// meaningful after headerChan is closed (always call waitOnHeader() before
+	// reading its value).
+	headerValid bool
+	header      metadata.MD // the received header metadata
+	noHeaders   bool        // set if the client never received headers (set only after the stream is done).
+
+	bytesReceived atomic.Bool // indicates whether any bytes have been received on this stream
+	unprocessed   atomic.Bool // set if the server sends a refused stream or GOAWAY including this stream
+
+	status *status.Status // the status error received from the server
+}
+
+// Read reads an n byte message from the input stream.
+func (s *ClientStream) Read(n int) (mem.BufferSlice, error) {
+	b, err := s.Stream.read(n)
+	if err == nil {
+		s.ct.incrMsgRecv()
+	}
+	return b, err
+}
+
+// Close closes the stream and propagates err to any readers.
+func (s *ClientStream) Close(err error) {
+	var (
+		rst     bool
+		rstCode http2.ErrCode
+	)
+	if err != nil {
+		rst = true
+		rstCode = http2.ErrCodeCancel
+	}
+	s.ct.closeStream(s, err, rst, rstCode, status.Convert(err), nil, false)
+}
+
+// Write writes the hdr and data bytes to the output stream.
+func (s *ClientStream) Write(hdr []byte, data mem.BufferSlice, opts *WriteOptions) error {
+	return s.ct.write(s, hdr, data, opts)
+}
+
+// BytesReceived indicates whether any bytes have been received on this stream.
+func (s *ClientStream) BytesReceived() bool {
+	return s.bytesReceived.Load()
+}
+
+// Unprocessed indicates whether the server did not process this stream --
+// i.e. it sent a refused stream or GOAWAY including this stream ID.
+func (s *ClientStream) Unprocessed() bool {
+	return s.unprocessed.Load()
+}
+
+func (s *ClientStream) waitOnHeader() {
+	select {
+	case <-s.ctx.Done():
+		// Close the stream to prevent headers/trailers from changing after
+		// this function returns.
+		s.Close(ContextErr(s.ctx.Err()))
+		// headerChan could possibly not be closed yet if closeStream raced
+		// with operateHeaders; wait until it is closed explicitly here.
+		<-s.headerChan
+	case <-s.headerChan:
+	}
+}
+
+// RecvCompress returns the compression algorithm applied to the inbound
+// message. It is empty string if there is no compression applied.
+func (s *ClientStream) RecvCompress() string {
+	s.waitOnHeader()
+	return s.recvCompress
+}
+
+// Done returns a channel which is closed when it receives the final status
+// from the server.
+func (s *ClientStream) Done() <-chan struct{} {
+	return s.done
+}
+
+// Header returns the header metadata of the stream. Acquires the key-value
+// pairs of header metadata once it is available. It blocks until i) the
+// metadata is ready or ii) there is no header metadata or iii) the stream is
+// canceled/expired.
+func (s *ClientStream) Header() (metadata.MD, error) {
+	s.waitOnHeader()
+
+	if !s.headerValid || s.noHeaders {
+		return nil, s.status.Err()
+	}
+
+	return s.header.Copy(), nil
+}
+
+// TrailersOnly blocks until a header or trailers-only frame is received and
+// then returns true if the stream was trailers-only.  If the stream ends
+// before headers are received, returns true, nil.
+func (s *ClientStream) TrailersOnly() bool {
+	s.waitOnHeader()
+	return s.noHeaders
+}
+
+// Status returns the status received from the server.
+// Status can be read safely only after the stream has ended,
+// that is, after Done() is closed.
+func (s *ClientStream) Status() *status.Status {
+	return s.status
+}

vendor/google.golang.org/grpc/internal/transport/controlbuf.go

@@ -32,6 +32,7 @@ import (
 	"golang.org/x/net/http2/hpack"
 	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/grpc/status"
 )
 
@@ -148,9 +149,9 @@ type dataFrame struct {
 	streamID  uint32
 	endStream bool
 	h         []byte
-	d         []byte
+	reader    mem.Reader
 	// onEachWrite is called every time
-	// a part of d is written out.
+	// a part of data is written out.
 	onEachWrite func()
 }
 
@@ -193,7 +194,7 @@ type goAway struct {
 	code      http2.ErrCode
 	debugData []byte
 	headsUp   bool
-	closeConn error // if set, loopyWriter will exit, resulting in conn closure
+	closeConn error // if set, loopyWriter will exit with this error
 }
 
 func (*goAway) isTransportResponseFrame() bool { return false }
@@ -289,18 +290,22 @@ func (l *outStreamList) dequeue() *outStream {
 }
 
 // controlBuffer is a way to pass information to loopy.
-// Information is passed as specific struct types called control frames.
-// A control frame not only represents data, messages or headers to be sent out
-// but can also be used to instruct loopy to update its internal state.
-// It shouldn't be confused with an HTTP2 frame, although some of the control frames
-// like dataFrame and headerFrame do go out on wire as HTTP2 frames.
+//
+// Information is passed as specific struct types called control frames. A
+// control frame not only represents data, messages or headers to be sent out
+// but can also be used to instruct loopy to update its internal state. It
+// shouldn't be confused with an HTTP2 frame, although some of the control
+// frames like dataFrame and headerFrame do go out on wire as HTTP2 frames.
 type controlBuffer struct {
-	ch              chan struct{}
-	done            <-chan struct{}
+	wakeupCh chan struct{}   // Unblocks readers waiting for something to read.
+	done     <-chan struct{} // Closed when the transport is done.
+
+	// Mutex guards all the fields below, except trfChan which can be read
+	// atomically without holding mu.
 	mu              sync.Mutex
-	consumerWaiting bool
-	list            *itemList
-	err             error
+	consumerWaiting bool      // True when readers are blocked waiting for new data.
+	closed          bool      // True when the controlbuf is finished.
+	list            *itemList // List of queued control frames.
 
 	// transportResponseFrames counts the number of queued items that represent
 	// the response of an action initiated by the peer.  trfChan is created
@@ -308,47 +313,59 @@ type controlBuffer struct {
 	// closed and nilled when transportResponseFrames drops below the
 	// threshold.  Both fields are protected by mu.
 	transportResponseFrames int
-	trfChan                 atomic.Value // chan struct{}
+	trfChan                 atomic.Pointer[chan struct{}]
 }
 
 func newControlBuffer(done <-chan struct{}) *controlBuffer {
 	return &controlBuffer{
-		ch:   make(chan struct{}, 1),
-		list: &itemList{},
-		done: done,
+		wakeupCh: make(chan struct{}, 1),
+		list:     &itemList{},
+		done:     done,
 	}
 }
 
-// throttle blocks if there are too many incomingSettings/cleanupStreams in the
-// controlbuf.
+// throttle blocks if there are too many frames in the control buf that
+// represent the response of an action initiated by the peer, like
+// incomingSettings cleanupStreams etc.
 func (c *controlBuffer) throttle() {
-	ch, _ := c.trfChan.Load().(chan struct{})
-	if ch != nil {
+	if ch := c.trfChan.Load(); ch != nil {
 		select {
-		case <-ch:
+		case <-(*ch):
 		case <-c.done:
 		}
 	}
 }
 
+// put adds an item to the controlbuf.
 func (c *controlBuffer) put(it cbItem) error {
 	_, err := c.executeAndPut(nil, it)
 	return err
 }
 
-func (c *controlBuffer) executeAndPut(f func(it any) bool, it cbItem) (bool, error) {
-	var wakeUp bool
+// executeAndPut runs f, and if the return value is true, adds the given item to
+// the controlbuf. The item could be nil, in which case, this method simply
+// executes f and does not add the item to the controlbuf.
+//
+// The first return value indicates whether the item was successfully added to
+// the control buffer. A non-nil error, specifically ErrConnClosing, is returned
+// if the control buffer is already closed.
+func (c *controlBuffer) executeAndPut(f func() bool, it cbItem) (bool, error) {
 	c.mu.Lock()
-	if c.err != nil {
-		c.mu.Unlock()
-		return false, c.err
+	defer c.mu.Unlock()
+
+	if c.closed {
+		return false, ErrConnClosing
 	}
 	if f != nil {
-		if !f(it) { // f wasn't successful
-			c.mu.Unlock()
+		if !f() { // f wasn't successful
 			return false, nil
 		}
 	}
+	if it == nil {
+		return true, nil
+	}
+
+	var wakeUp bool
 	if c.consumerWaiting {
 		wakeUp = true
 		c.consumerWaiting = false
@@ -359,98 +376,102 @@ func (c *controlBuffer) executeAndPut(f func(it any) bool, it cbItem) (bool, err
 		if c.transportResponseFrames == maxQueuedTransportResponseFrames {
 			// We are adding the frame that puts us over the threshold; create
 			// a throttling channel.
-			c.trfChan.Store(make(chan struct{}))
+			ch := make(chan struct{})
+			c.trfChan.Store(&ch)
 		}
 	}
-	c.mu.Unlock()
 	if wakeUp {
 		select {
-		case c.ch <- struct{}{}:
+		case c.wakeupCh <- struct{}{}:
 		default:
 		}
 	}
 	return true, nil
 }
 
-// Note argument f should never be nil.
-func (c *controlBuffer) execute(f func(it any) bool, it any) (bool, error) {
-	c.mu.Lock()
-	if c.err != nil {
-		c.mu.Unlock()
-		return false, c.err
-	}
-	if !f(it) { // f wasn't successful
-		c.mu.Unlock()
-		return false, nil
-	}
-	c.mu.Unlock()
-	return true, nil
-}
-
+// get returns the next control frame from the control buffer. If block is true
+// **and** there are no control frames in the control buffer, the call blocks
+// until one of the conditions is met: there is a frame to return or the
+// transport is closed.
 func (c *controlBuffer) get(block bool) (any, error) {
 	for {
 		c.mu.Lock()
-		if c.err != nil {
+		frame, err := c.getOnceLocked()
+		if frame != nil || err != nil || !block {
+			// If we read a frame or an error, we can return to the caller. The
+			// call to getOnceLocked() returns a nil frame and a nil error if
+			// there is nothing to read, and in that case, if the caller asked
+			// us not to block, we can return now as well.
 			c.mu.Unlock()
-			return nil, c.err
-		}
-		if !c.list.isEmpty() {
-			h := c.list.dequeue().(cbItem)
-			if h.isTransportResponseFrame() {
-				if c.transportResponseFrames == maxQueuedTransportResponseFrames {
-					// We are removing the frame that put us over the
-					// threshold; close and clear the throttling channel.
-					ch := c.trfChan.Load().(chan struct{})
-					close(ch)
-					c.trfChan.Store((chan struct{})(nil))
-				}
-				c.transportResponseFrames--
-			}
-			c.mu.Unlock()
-			return h, nil
-		}
-		if !block {
-			c.mu.Unlock()
-			return nil, nil
+			return frame, err
 		}
 		c.consumerWaiting = true
 		c.mu.Unlock()
+
+		// Release the lock above and wait to be woken up.
 		select {
-		case <-c.ch:
+		case <-c.wakeupCh:
 		case <-c.done:
 			return nil, errors.New("transport closed by client")
 		}
 	}
 }
 
+// Callers must not use this method, but should instead use get().
+//
+// Caller must hold c.mu.
+func (c *controlBuffer) getOnceLocked() (any, error) {
+	if c.closed {
+		return false, ErrConnClosing
+	}
+	if c.list.isEmpty() {
+		return nil, nil
+	}
+	h := c.list.dequeue().(cbItem)
+	if h.isTransportResponseFrame() {
+		if c.transportResponseFrames == maxQueuedTransportResponseFrames {
+			// We are removing the frame that put us over the
+			// threshold; close and clear the throttling channel.
+			ch := c.trfChan.Swap(nil)
+			close(*ch)
+		}
+		c.transportResponseFrames--
+	}
+	return h, nil
+}
+
+// finish closes the control buffer, cleaning up any streams that have queued
+// header frames. Once this method returns, no more frames can be added to the
+// control buffer, and attempts to do so will return ErrConnClosing.
 func (c *controlBuffer) finish() {
 	c.mu.Lock()
-	if c.err != nil {
-		c.mu.Unlock()
+	defer c.mu.Unlock()
+
+	if c.closed {
 		return
 	}
-	c.err = ErrConnClosing
+	c.closed = true
 	// There may be headers for streams in the control buffer.
 	// These streams need to be cleaned out since the transport
 	// is still not aware of these yet.
 	for head := c.list.dequeueAll(); head != nil; head = head.next {
-		hdr, ok := head.it.(*headerFrame)
-		if !ok {
-			continue
-		}
-		if hdr.onOrphaned != nil { // It will be nil on the server-side.
-			hdr.onOrphaned(ErrConnClosing)
+		switch v := head.it.(type) {
+		case *headerFrame:
+			if v.onOrphaned != nil { // It will be nil on the server-side.
+				v.onOrphaned(ErrConnClosing)
+			}
+		case *dataFrame:
+			_ = v.reader.Close()
 		}
 	}
+
 	// In case throttle() is currently in flight, it needs to be unblocked.
 	// Otherwise, the transport may not close, since the transport is closed by
 	// the reader encountering the connection error.
-	ch, _ := c.trfChan.Load().(chan struct{})
+	ch := c.trfChan.Swap(nil)
 	if ch != nil {
-		close(ch)
+		close(*ch)
 	}
-	c.trfChan.Store((chan struct{})(nil))
-	c.mu.Unlock()
 }
 
 type side int
@@ -466,7 +487,7 @@ const (
 // stream maintains a queue of data frames; as loopy receives data frames
 // it gets added to the queue of the relevant stream.
 // Loopy goes over this list of active streams by processing one node every iteration,
-// thereby closely resemebling to a round-robin scheduling over all streams. While
+// thereby closely resembling a round-robin scheduling over all streams. While
 // processing a stream, loopy writes out data bytes from this stream capped by the min
 // of http2MaxFrameLen, connection-level flow control and stream-level flow control.
 type loopyWriter struct {
@@ -490,26 +511,29 @@ type loopyWriter struct {
 	draining      bool
 	conn          net.Conn
 	logger        *grpclog.PrefixLogger
+	bufferPool    mem.BufferPool
 
 	// Side-specific handlers
 	ssGoAwayHandler func(*goAway) (bool, error)
 }
 
-func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimator, conn net.Conn, logger *grpclog.PrefixLogger) *loopyWriter {
+func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimator, conn net.Conn, logger *grpclog.PrefixLogger, goAwayHandler func(*goAway) (bool, error), bufferPool mem.BufferPool) *loopyWriter {
 	var buf bytes.Buffer
 	l := &loopyWriter{
-		side:          s,
-		cbuf:          cbuf,
-		sendQuota:     defaultWindowSize,
-		oiws:          defaultWindowSize,
-		estdStreams:   make(map[uint32]*outStream),
-		activeStreams: newOutStreamList(),
-		framer:        fr,
-		hBuf:          &buf,
-		hEnc:          hpack.NewEncoder(&buf),
-		bdpEst:        bdpEst,
-		conn:          conn,
-		logger:        logger,
+		side:            s,
+		cbuf:            cbuf,
+		sendQuota:       defaultWindowSize,
+		oiws:            defaultWindowSize,
+		estdStreams:     make(map[uint32]*outStream),
+		activeStreams:   newOutStreamList(),
+		framer:          fr,
+		hBuf:            &buf,
+		hEnc:            hpack.NewEncoder(&buf),
+		bdpEst:          bdpEst,
+		conn:            conn,
+		logger:          logger,
+		ssGoAwayHandler: goAwayHandler,
+		bufferPool:      bufferPool,
 	}
 	return l
 }
@@ -767,6 +791,11 @@ func (l *loopyWriter) cleanupStreamHandler(c *cleanupStream) error {
 		// not be established yet.
 		delete(l.estdStreams, c.streamID)
 		str.deleteSelf()
+		for head := str.itl.dequeueAll(); head != nil; head = head.next {
+			if df, ok := head.it.(*dataFrame); ok {
+				_ = df.reader.Close()
+			}
+		}
 	}
 	if c.rst { // If RST_STREAM needs to be sent.
 		if err := l.framer.fr.WriteRSTStream(c.streamID, c.rstCode); err != nil {
@@ -902,16 +931,18 @@ func (l *loopyWriter) processData() (bool, error) {
 	dataItem := str.itl.peek().(*dataFrame) // Peek at the first data item this stream.
 	// A data item is represented by a dataFrame, since it later translates into
 	// multiple HTTP2 data frames.
-	// Every dataFrame has two buffers; h that keeps grpc-message header and d that is actual data.
-	// As an optimization to keep wire traffic low, data from d is copied to h to make as big as the
-	// maximum possible HTTP2 frame size.
+	// Every dataFrame has two buffers; h that keeps grpc-message header and data
+	// that is the actual message. As an optimization to keep wire traffic low, data
+	// from data is copied to h to make as big as the maximum possible HTTP2 frame
+	// size.
 
-	if len(dataItem.h) == 0 && len(dataItem.d) == 0 { // Empty data frame
+	if len(dataItem.h) == 0 && dataItem.reader.Remaining() == 0 { // Empty data frame
 		// Client sends out empty data frame with endStream = true
 		if err := l.framer.fr.WriteData(dataItem.streamID, dataItem.endStream, nil); err != nil {
 			return false, err
 		}
 		str.itl.dequeue() // remove the empty data item from stream
+		_ = dataItem.reader.Close()
 		if str.itl.isEmpty() {
 			str.state = empty
 		} else if trailer, ok := str.itl.peek().(*headerFrame); ok { // the next item is trailers.
@@ -926,9 +957,7 @@ func (l *loopyWriter) processData() (bool, error) {
 		}
 		return false, nil
 	}
-	var (
-		buf []byte
-	)
+
 	// Figure out the maximum size we can send
 	maxSize := http2MaxFrameLen
 	if strQuota := int(l.oiws) - str.bytesOutStanding; strQuota <= 0 { // stream-level flow control.
@@ -942,43 +971,50 @@ func (l *loopyWriter) processData() (bool, error) {
 	}
 	// Compute how much of the header and data we can send within quota and max frame length
 	hSize := min(maxSize, len(dataItem.h))
-	dSize := min(maxSize-hSize, len(dataItem.d))
-	if hSize != 0 {
-		if dSize == 0 {
-			buf = dataItem.h
-		} else {
-			// We can add some data to grpc message header to distribute bytes more equally across frames.
-			// Copy on the stack to avoid generating garbage
-			var localBuf [http2MaxFrameLen]byte
-			copy(localBuf[:hSize], dataItem.h)
-			copy(localBuf[hSize:], dataItem.d[:dSize])
-			buf = localBuf[:hSize+dSize]
-		}
-	} else {
-		buf = dataItem.d
-	}
-
+	dSize := min(maxSize-hSize, dataItem.reader.Remaining())
+	remainingBytes := len(dataItem.h) + dataItem.reader.Remaining() - hSize - dSize
 	size := hSize + dSize
 
+	var buf *[]byte
+
+	if hSize != 0 && dSize == 0 {
+		buf = &dataItem.h
+	} else {
+		// Note: this is only necessary because the http2.Framer does not support
+		// partially writing a frame, so the sequence must be materialized into a buffer.
+		// TODO: Revisit once https://github.com/golang/go/issues/66655 is addressed.
+		pool := l.bufferPool
+		if pool == nil {
+			// Note that this is only supposed to be nil in tests. Otherwise, stream is
+			// always initialized with a BufferPool.
+			pool = mem.DefaultBufferPool()
+		}
+		buf = pool.Get(size)
+		defer pool.Put(buf)
+
+		copy((*buf)[:hSize], dataItem.h)
+		_, _ = dataItem.reader.Read((*buf)[hSize:])
+	}
+
 	// Now that outgoing flow controls are checked we can replenish str's write quota
 	str.wq.replenish(size)
 	var endStream bool
 	// If this is the last data message on this stream and all of it can be written in this iteration.
-	if dataItem.endStream && len(dataItem.h)+len(dataItem.d) <= size {
+	if dataItem.endStream && remainingBytes == 0 {
 		endStream = true
 	}
 	if dataItem.onEachWrite != nil {
 		dataItem.onEachWrite()
 	}
-	if err := l.framer.fr.WriteData(dataItem.streamID, endStream, buf[:size]); err != nil {
+	if err := l.framer.fr.WriteData(dataItem.streamID, endStream, (*buf)[:size]); err != nil {
 		return false, err
 	}
 	str.bytesOutStanding += size
 	l.sendQuota -= uint32(size)
 	dataItem.h = dataItem.h[hSize:]
-	dataItem.d = dataItem.d[dSize:]
 
-	if len(dataItem.h) == 0 && len(dataItem.d) == 0 { // All the data from that message was written out.
+	if remainingBytes == 0 { // All the data from that message was written out.
+		_ = dataItem.reader.Close()
 		str.itl.dequeue()
 	}
 	if str.itl.isEmpty() {
@@ -997,10 +1033,3 @@ func (l *loopyWriter) processData() (bool, error) {
 	}
 	return false, nil
 }
-
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}

vendor/google.golang.org/grpc/internal/transport/flowcontrol.go

@@ -92,14 +92,11 @@ func (f *trInFlow) newLimit(n uint32) uint32 {
 
 func (f *trInFlow) onData(n uint32) uint32 {
 	f.unacked += n
-	if f.unacked >= f.limit/4 {
-		w := f.unacked
-		f.unacked = 0
+	if f.unacked < f.limit/4 {
 		f.updateEffectiveWindowSize()
-		return w
+		return 0
 	}
-	f.updateEffectiveWindowSize()
-	return 0
+	return f.reset()
 }
 
 func (f *trInFlow) reset() uint32 {

vendor/google.golang.org/grpc/internal/transport/handler_server.go

@@ -24,7 +24,6 @@
 package transport
 
 import (
-	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -40,6 +39,7 @@ import (
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
 	"google.golang.org/grpc/stats"
@@ -50,7 +50,7 @@ import (
 // NewServerHandlerTransport returns a ServerTransport handling gRPC from
 // inside an http.Handler, or writes an HTTP error to w and returns an error.
 // It requires that the http Server supports HTTP/2.
-func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats []stats.Handler) (ServerTransport, error) {
+func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats []stats.Handler, bufferPool mem.BufferPool) (ServerTransport, error) {
 	if r.Method != http.MethodPost {
 		w.Header().Set("Allow", http.MethodPost)
 		msg := fmt.Sprintf("invalid gRPC request method %q", r.Method)
@@ -98,6 +98,7 @@ func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats []s
 		contentType:    contentType,
 		contentSubtype: contentSubtype,
 		stats:          stats,
+		bufferPool:     bufferPool,
 	}
 	st.logger = prefixLoggerForServerHandlerTransport(st)
 
@@ -171,6 +172,8 @@ type serverHandlerTransport struct {
 
 	stats  []stats.Handler
 	logger *grpclog.PrefixLogger
+
+	bufferPool mem.BufferPool
 }
 
 func (ht *serverHandlerTransport) Close(err error) {
@@ -222,7 +225,7 @@ func (ht *serverHandlerTransport) do(fn func()) error {
 	}
 }
 
-func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) error {
+func (ht *serverHandlerTransport) writeStatus(s *ServerStream, st *status.Status) error {
 	ht.writeStatusMu.Lock()
 	defer ht.writeStatusMu.Unlock()
 
@@ -244,6 +247,7 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 		}
 
 		s.hdrMu.Lock()
+		defer s.hdrMu.Unlock()
 		if p := st.Proto(); p != nil && len(p.Details) > 0 {
 			delete(s.trailer, grpcStatusDetailsBinHeader)
 			stBytes, err := proto.Marshal(p)
@@ -268,7 +272,6 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 				}
 			}
 		}
-		s.hdrMu.Unlock()
 	})
 
 	if err == nil { // transport has not been closed
@@ -286,14 +289,14 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 
 // writePendingHeaders sets common and custom headers on the first
 // write call (Write, WriteHeader, or WriteStatus)
-func (ht *serverHandlerTransport) writePendingHeaders(s *Stream) {
+func (ht *serverHandlerTransport) writePendingHeaders(s *ServerStream) {
 	ht.writeCommonHeaders(s)
 	ht.writeCustomHeaders(s)
 }
 
 // writeCommonHeaders sets common headers on the first write
 // call (Write, WriteHeader, or WriteStatus).
-func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
+func (ht *serverHandlerTransport) writeCommonHeaders(s *ServerStream) {
 	h := ht.rw.Header()
 	h["Date"] = nil // suppress Date to make tests happy; TODO: restore
 	h.Set("Content-Type", ht.contentType)
@@ -314,7 +317,7 @@ func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
 
 // writeCustomHeaders sets custom headers set on the stream via SetHeader
 // on the first write call (Write, WriteHeader, or WriteStatus)
-func (ht *serverHandlerTransport) writeCustomHeaders(s *Stream) {
+func (ht *serverHandlerTransport) writeCustomHeaders(s *ServerStream) {
 	h := ht.rw.Header()
 
 	s.hdrMu.Lock()
@@ -330,19 +333,31 @@ func (ht *serverHandlerTransport) writeCustomHeaders(s *Stream) {
 	s.hdrMu.Unlock()
 }
 
-func (ht *serverHandlerTransport) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
+func (ht *serverHandlerTransport) write(s *ServerStream, hdr []byte, data mem.BufferSlice, _ *WriteOptions) error {
+	// Always take a reference because otherwise there is no guarantee the data will
+	// be available after this function returns. This is what callers to Write
+	// expect.
+	data.Ref()
 	headersWritten := s.updateHeaderSent()
-	return ht.do(func() {
+	err := ht.do(func() {
+		defer data.Free()
 		if !headersWritten {
 			ht.writePendingHeaders(s)
 		}
 		ht.rw.Write(hdr)
-		ht.rw.Write(data)
+		for _, b := range data {
+			_, _ = ht.rw.Write(b.ReadOnlyData())
+		}
 		ht.rw.(http.Flusher).Flush()
 	})
+	if err != nil {
+		data.Free()
+		return err
+	}
+	return nil
 }
 
-func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error {
+func (ht *serverHandlerTransport) writeHeader(s *ServerStream, md metadata.MD) error {
 	if err := s.SetHeader(md); err != nil {
 		return err
 	}
@@ -370,7 +385,7 @@ func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error {
 	return err
 }
 
-func (ht *serverHandlerTransport) HandleStreams(ctx context.Context, startStream func(*Stream)) {
+func (ht *serverHandlerTransport) HandleStreams(ctx context.Context, startStream func(*ServerStream)) {
 	// With this transport type there will be exactly 1 stream: this HTTP request.
 	var cancel context.CancelFunc
 	if ht.timeoutSet {
@@ -393,20 +408,22 @@ func (ht *serverHandlerTransport) HandleStreams(ctx context.Context, startStream
 
 	ctx = metadata.NewIncomingContext(ctx, ht.headerMD)
 	req := ht.req
-	s := &Stream{
-		id:               0, // irrelevant
-		ctx:              ctx,
-		requestRead:      func(int) {},
+	s := &ServerStream{
+		Stream: &Stream{
+			id:             0, // irrelevant
+			ctx:            ctx,
+			requestRead:    func(int) {},
+			buf:            newRecvBuffer(),
+			method:         req.URL.Path,
+			recvCompress:   req.Header.Get("grpc-encoding"),
+			contentSubtype: ht.contentSubtype,
+		},
 		cancel:           cancel,
-		buf:              newRecvBuffer(),
 		st:               ht,
-		method:           req.URL.Path,
-		recvCompress:     req.Header.Get("grpc-encoding"),
-		contentSubtype:   ht.contentSubtype,
 		headerWireLength: 0, // won't have access to header wire length until golang/go#18997.
 	}
 	s.trReader = &transportReader{
-		reader:        &recvBufferReader{ctx: s.ctx, ctxDone: s.ctx.Done(), recv: s.buf, freeBuffer: func(*bytes.Buffer) {}},
+		reader:        &recvBufferReader{ctx: s.ctx, ctxDone: s.ctx.Done(), recv: s.buf},
 		windowHandler: func(int) {},
 	}
 
@@ -415,21 +432,19 @@ func (ht *serverHandlerTransport) HandleStreams(ctx context.Context, startStream
 	go func() {
 		defer close(readerDone)
 
-		// TODO: minimize garbage, optimize recvBuffer code/ownership
-		const readSize = 8196
-		for buf := make([]byte, readSize); ; {
-			n, err := req.Body.Read(buf)
+		for {
+			buf := ht.bufferPool.Get(http2MaxFrameLen)
+			n, err := req.Body.Read(*buf)
 			if n > 0 {
-				s.buf.put(recvMsg{buffer: bytes.NewBuffer(buf[:n:n])})
-				buf = buf[n:]
+				*buf = (*buf)[:n]
+				s.buf.put(recvMsg{buffer: mem.NewBuffer(buf, ht.bufferPool)})
+			} else {
+				ht.bufferPool.Put(buf)
 			}
 			if err != nil {
 				s.buf.put(recvMsg{err: mapRecvMsgError(err)})
 				return
 			}
-			if len(buf) == 0 {
-				buf = make([]byte, readSize)
-			}
 		}
 	}()
 
@@ -458,11 +473,9 @@ func (ht *serverHandlerTransport) runStream() {
 	}
 }
 
-func (ht *serverHandlerTransport) IncrMsgSent() {}
+func (ht *serverHandlerTransport) incrMsgRecv() {}
 
-func (ht *serverHandlerTransport) IncrMsgRecv() {}
-
-func (ht *serverHandlerTransport) Drain(debugData string) {
+func (ht *serverHandlerTransport) Drain(string) {
 	panic("Drain() is not implemented")
 }
 
@@ -485,5 +498,5 @@ func mapRecvMsgError(err error) error {
 	if strings.Contains(err.Error(), "body closed by handler") {
 		return status.Error(codes.Canceled, err.Error())
 	}
-	return connectionErrorf(true, err, err.Error())
+	return connectionErrorf(true, err, "%s", err.Error())
 }

vendor/google.golang.org/grpc/internal/transport/http2_client.go

@@ -43,10 +43,12 @@ import (
 	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/internal/grpcutil"
 	imetadata "google.golang.org/grpc/internal/metadata"
+	"google.golang.org/grpc/internal/proxyattributes"
 	istatus "google.golang.org/grpc/internal/status"
 	isyscall "google.golang.org/grpc/internal/syscall"
 	"google.golang.org/grpc/internal/transport/networktype"
 	"google.golang.org/grpc/keepalive"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
 	"google.golang.org/grpc/resolver"
@@ -59,6 +61,8 @@ import (
 // atomically.
 var clientConnectionCounter uint64
 
+var goAwayLoopyWriterTimeout = 5 * time.Second
+
 var metadataFromOutgoingContextRaw = internal.FromOutgoingContextRaw.(func(context.Context) (metadata.MD, [][]string, bool))
 
 // http2Client implements the ClientTransport interface with HTTP2.
@@ -83,9 +87,9 @@ type http2Client struct {
 	writerDone chan struct{} // sync point to enable testing.
 	// goAway is closed to notify the upper layer (i.e., addrConn.transportMonitor)
 	// that the server sent GoAway on this transport.
-	goAway chan struct{}
-
-	framer *framer
+	goAway        chan struct{}
+	keepaliveDone chan struct{} // Closed when the keepalive goroutine exits.
+	framer        *framer
 	// controlBuf delivers all the control related tasks (e.g., window
 	// updates, reset streams, and various settings) to the controller.
 	// Do not access controlBuf with mu held.
@@ -114,13 +118,13 @@ type http2Client struct {
 	streamQuota           int64
 	streamsQuotaAvailable chan struct{}
 	waitingStreams        uint32
-	nextID                uint32
 	registeredCompressors string
 
 	// Do not access controlBuf with mu held.
 	mu            sync.Mutex // guard the following variables
+	nextID        uint32
 	state         transportState
-	activeStreams map[uint32]*Stream
+	activeStreams map[uint32]*ClientStream
 	// prevGoAway ID records the Last-Stream-ID in the previous GOAway frame.
 	prevGoAwayID uint32
 	// goAwayReason records the http2.ErrCode and debug data received with the
@@ -144,13 +148,13 @@ type http2Client struct {
 
 	onClose func(GoAwayReason)
 
-	bufferPool *bufferPool
+	bufferPool mem.BufferPool
 
 	connectionID uint64
 	logger       *grpclog.PrefixLogger
 }
 
-func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr resolver.Address, useProxy bool, grpcUA string) (net.Conn, error) {
+func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr resolver.Address, grpcUA string) (net.Conn, error) {
 	address := addr.Addr
 	networkType, ok := networktype.Get(addr)
 	if fn != nil {
@@ -172,10 +176,10 @@ func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error
 		return fn(ctx, address)
 	}
 	if !ok {
-		networkType, address = parseDialTarget(address)
+		networkType, address = ParseDialTarget(address)
 	}
-	if networkType == "tcp" && useProxy {
-		return proxyDial(ctx, address, grpcUA)
+	if opts, present := proxyattributes.Get(addr); present {
+		return proxyDial(ctx, addr, grpcUA, opts)
 	}
 	return internal.NetDialerWithTCPKeepalive().DialContext(ctx, networkType, address)
 }
@@ -196,10 +200,10 @@ func isTemporary(err error) bool {
 	return true
 }
 
-// newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
+// NewHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
 // and starts to receive messages on it. Non-nil error returns if construction
 // fails.
-func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (_ *http2Client, err error) {
+func NewHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (_ ClientTransport, err error) {
 	scheme := "http"
 	ctx, cancel := context.WithCancel(ctx)
 	defer func() {
@@ -214,7 +218,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 	// address specific arbitrary data to reach custom dialers and credential handshakers.
 	connectCtx = icredentials.NewClientHandshakeInfoContext(connectCtx, credentials.ClientHandshakeInfo{Attributes: addr.Attributes})
 
-	conn, err := dial(connectCtx, opts.Dialer, addr, opts.UseProxy, opts.UserAgent)
+	conn, err := dial(connectCtx, opts.Dialer, addr, opts.UserAgent)
 	if err != nil {
 		if opts.FailOnNonTempDialError {
 			return nil, connectionErrorf(isTemporary(err), err, "transport: error while dialing: %v", err)
@@ -229,7 +233,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		}
 	}(conn)
 
-	// The following defer and goroutine monitor the connectCtx for cancelation
+	// The following defer and goroutine monitor the connectCtx for cancellation
 	// and deadline.  On context expiration, the connection is hard closed and
 	// this function will naturally fail as a result.  Otherwise, the defer
 	// waits for the goroutine to exit to prevent the context from being
@@ -332,10 +336,11 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		readerDone:            make(chan struct{}),
 		writerDone:            make(chan struct{}),
 		goAway:                make(chan struct{}),
+		keepaliveDone:         make(chan struct{}),
 		framer:                newFramer(conn, writeBufSize, readBufSize, opts.SharedWriteBuffer, maxHeaderListSize),
 		fc:                    &trInFlow{limit: uint32(icwz)},
 		scheme:                scheme,
-		activeStreams:         make(map[uint32]*Stream),
+		activeStreams:         make(map[uint32]*ClientStream),
 		isSecure:              isSecure,
 		perRPCCreds:           perRPCCreds,
 		kp:                    kp,
@@ -346,7 +351,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		streamQuota:           defaultMaxStreamsClient,
 		streamsQuotaAvailable: make(chan struct{}, 1),
 		keepaliveEnabled:      keepaliveEnabled,
-		bufferPool:            newBufferPool(),
+		bufferPool:            opts.BufferPool,
 		onClose:               onClose,
 	}
 	var czSecurity credentials.ChannelzSecurityValue
@@ -408,10 +413,10 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 	readerErrCh := make(chan error, 1)
 	go t.reader(readerErrCh)
 	defer func() {
-		if err == nil {
-			err = <-readerErrCh
-		}
 		if err != nil {
+			// writerDone should be closed since the loopy goroutine
+			// wouldn't have started in the case this function returns an error.
+			close(t.writerDone)
 			t.Close(err)
 		}
 	}()
@@ -458,8 +463,12 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 	if err := t.framer.writer.Flush(); err != nil {
 		return nil, err
 	}
+	// Block until the server preface is received successfully or an error occurs.
+	if err = <-readerErrCh; err != nil {
+		return nil, err
+	}
 	go func() {
-		t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger)
+		t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger, t.outgoingGoAwayHandler, t.bufferPool)
 		if err := t.loopy.run(); !isIOError(err) {
 			// Immediately close the connection, as the loopy writer returns
 			// when there are no more active streams and we were draining (the
@@ -472,17 +481,19 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 	return t, nil
 }
 
-func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream {
+func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *ClientStream {
 	// TODO(zhaoq): Handle uint32 overflow of Stream.id.
-	s := &Stream{
-		ct:             t,
-		done:           make(chan struct{}),
-		method:         callHdr.Method,
-		sendCompress:   callHdr.SendCompress,
-		buf:            newRecvBuffer(),
-		headerChan:     make(chan struct{}),
-		contentSubtype: callHdr.ContentSubtype,
-		doneFunc:       callHdr.DoneFunc,
+	s := &ClientStream{
+		Stream: &Stream{
+			method:         callHdr.Method,
+			sendCompress:   callHdr.SendCompress,
+			buf:            newRecvBuffer(),
+			contentSubtype: callHdr.ContentSubtype,
+		},
+		ct:         t,
+		done:       make(chan struct{}),
+		headerChan: make(chan struct{}),
+		doneFunc:   callHdr.DoneFunc,
 	}
 	s.wq = newWriteQuota(defaultWriteQuota, s.done)
 	s.requestRead = func(n int) {
@@ -498,9 +509,8 @@ func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream {
 			ctxDone: s.ctx.Done(),
 			recv:    s.buf,
 			closeStream: func(err error) {
-				t.CloseStream(s, err)
+				s.Close(err)
 			},
-			freeBuffer: t.bufferPool.put,
 		},
 		windowHandler: func(n int) {
 			t.updateWindow(s, uint32(n))
@@ -517,6 +527,18 @@ func (t *http2Client) getPeer() *peer.Peer {
 	}
 }
 
+// OutgoingGoAwayHandler writes a GOAWAY to the connection.  Always returns (false, err) as we want the GoAway
+// to be the last frame loopy writes to the transport.
+func (t *http2Client) outgoingGoAwayHandler(g *goAway) (bool, error) {
+	t.mu.Lock()
+	maxStreamID := t.nextID - 2
+	t.mu.Unlock()
+	if err := t.framer.fr.WriteGoAway(maxStreamID, http2.ErrCodeNo, g.debugData); err != nil {
+		return false, err
+	}
+	return false, g.closeConn
+}
+
 func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr) ([]hpack.HeaderField, error) {
 	aud := t.createAudience(callHdr)
 	ri := credentials.RequestInfo{
@@ -578,12 +600,6 @@ func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr)
 	for k, v := range callAuthData {
 		headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
 	}
-	if b := stats.OutgoingTags(ctx); b != nil {
-		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-tags-bin", Value: encodeBinHeader(b)})
-	}
-	if b := stats.OutgoingTrace(ctx); b != nil {
-		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-trace-bin", Value: encodeBinHeader(b)})
-	}
 
 	if md, added, ok := metadataFromOutgoingContextRaw(ctx); ok {
 		var k string
@@ -719,7 +735,7 @@ func (e NewStreamError) Error() string {
 
 // NewStream creates a stream and registers it into the transport as "active"
 // streams.  All non-nil errors returned will be *NewStreamError.
-func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error) {
+func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*ClientStream, error) {
 	ctx = peer.NewContext(ctx, t.getPeer())
 
 	// ServerName field of the resolver returned address takes precedence over
@@ -744,7 +760,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 			return
 		}
 		// The stream was unprocessed by the server.
-		atomic.StoreUint32(&s.unprocessed, 1)
+		s.unprocessed.Store(true)
 		s.write(recvMsg{err: err})
 		close(s.done)
 		// If headerChan isn't closed, then close it.
@@ -755,7 +771,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 	hdr := &headerFrame{
 		hf:        headerFields,
 		endStream: false,
-		initStream: func(id uint32) error {
+		initStream: func(uint32) error {
 			t.mu.Lock()
 			// TODO: handle transport closure in loopy instead and remove this
 			// initStream is never called when transport is draining.
@@ -781,7 +797,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 	firstTry := true
 	var ch chan struct{}
 	transportDrainRequired := false
-	checkForStreamQuota := func(it any) bool {
+	checkForStreamQuota := func() bool {
 		if t.streamQuota <= 0 { // Can go negative if server decreases it.
 			if firstTry {
 				t.waitingStreams++
@@ -793,23 +809,24 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 			t.waitingStreams--
 		}
 		t.streamQuota--
-		h := it.(*headerFrame)
-		h.streamID = t.nextID
-		t.nextID += 2
 
-		// Drain client transport if nextID > MaxStreamID which signals gRPC that
-		// the connection is closed and a new one must be created for subsequent RPCs.
-		transportDrainRequired = t.nextID > MaxStreamID
-
-		s.id = h.streamID
-		s.fc = &inFlow{limit: uint32(t.initialWindowSize)}
 		t.mu.Lock()
 		if t.state == draining || t.activeStreams == nil { // Can be niled from Close().
 			t.mu.Unlock()
 			return false // Don't create a stream if the transport is already closed.
 		}
+
+		hdr.streamID = t.nextID
+		t.nextID += 2
+		// Drain client transport if nextID > MaxStreamID which signals gRPC that
+		// the connection is closed and a new one must be created for subsequent RPCs.
+		transportDrainRequired = t.nextID > MaxStreamID
+
+		s.id = hdr.streamID
+		s.fc = &inFlow{limit: uint32(t.initialWindowSize)}
 		t.activeStreams[s.id] = s
 		t.mu.Unlock()
+
 		if t.streamQuota > 0 && t.waitingStreams > 0 {
 			select {
 			case t.streamsQuotaAvailable <- struct{}{}:
@@ -819,13 +836,12 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 		return true
 	}
 	var hdrListSizeErr error
-	checkForHeaderListSize := func(it any) bool {
+	checkForHeaderListSize := func() bool {
 		if t.maxSendHeaderListSize == nil {
 			return true
 		}
-		hdrFrame := it.(*headerFrame)
 		var sz int64
-		for _, f := range hdrFrame.hf {
+		for _, f := range hdr.hf {
 			if sz += int64(f.Size()); sz > int64(*t.maxSendHeaderListSize) {
 				hdrListSizeErr = status.Errorf(codes.Internal, "header list size to send violates the maximum size (%d bytes) set by server", *t.maxSendHeaderListSize)
 				return false
@@ -834,8 +850,8 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 		return true
 	}
 	for {
-		success, err := t.controlBuf.executeAndPut(func(it any) bool {
-			return checkForHeaderListSize(it) && checkForStreamQuota(it)
+		success, err := t.controlBuf.executeAndPut(func() bool {
+			return checkForHeaderListSize() && checkForStreamQuota()
 		}, hdr)
 		if err != nil {
 			// Connection closed.
@@ -889,21 +905,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 	return s, nil
 }
 
-// CloseStream clears the footprint of a stream when the stream is not needed any more.
-// This must not be executed in reader's goroutine.
-func (t *http2Client) CloseStream(s *Stream, err error) {
-	var (
-		rst     bool
-		rstCode http2.ErrCode
-	)
-	if err != nil {
-		rst = true
-		rstCode = http2.ErrCodeCancel
-	}
-	t.closeStream(s, err, rst, rstCode, status.Convert(err), nil, false)
-}
-
-func (t *http2Client) closeStream(s *Stream, err error, rst bool, rstCode http2.ErrCode, st *status.Status, mdata map[string][]string, eosReceived bool) {
+func (t *http2Client) closeStream(s *ClientStream, err error, rst bool, rstCode http2.ErrCode, st *status.Status, mdata map[string][]string, eosReceived bool) {
 	// Set stream status to done.
 	if s.swapState(streamDone) == streamDone {
 		// If it was already done, return.  If multiple closeStream calls
@@ -946,7 +948,7 @@ func (t *http2Client) closeStream(s *Stream, err error, rst bool, rstCode http2.
 		rst:     rst,
 		rstCode: rstCode,
 	}
-	addBackStreamQuota := func(any) bool {
+	addBackStreamQuota := func() bool {
 		t.streamQuota++
 		if t.streamQuota > 0 && t.waitingStreams > 0 {
 			select {
@@ -966,8 +968,9 @@ func (t *http2Client) closeStream(s *Stream, err error, rst bool, rstCode http2.
 
 // Close kicks off the shutdown process of the transport. This should be called
 // only once on a transport. Once it is called, the transport should not be
-// accessed any more.
+// accessed anymore.
 func (t *http2Client) Close(err error) {
+	t.conn.SetWriteDeadline(time.Now().Add(time.Second * 10))
 	t.mu.Lock()
 	// Make sure we only close once.
 	if t.state == closing {
@@ -990,15 +993,33 @@ func (t *http2Client) Close(err error) {
 		// should unblock it so that the goroutine eventually exits.
 		t.kpDormancyCond.Signal()
 	}
-	t.mu.Unlock()
-	t.controlBuf.finish()
-	t.cancel()
-	t.conn.Close()
-	channelz.RemoveEntry(t.channelz.ID)
 	// Append info about previous goaways if there were any, since this may be important
 	// for understanding the root cause for this connection to be closed.
-	_, goAwayDebugMessage := t.GetGoAwayReason()
+	goAwayDebugMessage := t.goAwayDebugMessage
+	t.mu.Unlock()
 
+	// Per HTTP/2 spec, a GOAWAY frame must be sent before closing the
+	// connection. See https://httpwg.org/specs/rfc7540.html#GOAWAY. It
+	// also waits for loopyWriter to be closed with a timer to avoid the
+	// long blocking in case the connection is blackholed, i.e. TCP is
+	// just stuck.
+	t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte("client transport shutdown"), closeConn: err})
+	timer := time.NewTimer(goAwayLoopyWriterTimeout)
+	defer timer.Stop()
+	select {
+	case <-t.writerDone: // success
+	case <-timer.C:
+		t.logger.Infof("Failed to write a GOAWAY frame as part of connection close after %s. Giving up and closing the transport.", goAwayLoopyWriterTimeout)
+	}
+	t.cancel()
+	t.conn.Close()
+	// Waits for the reader and keepalive goroutines to exit before returning to
+	// ensure all resources are cleaned up before Close can return.
+	<-t.readerDone
+	if t.keepaliveEnabled {
+		<-t.keepaliveDone
+	}
+	channelz.RemoveEntry(t.channelz.ID)
 	var st *status.Status
 	if len(goAwayDebugMessage) > 0 {
 		st = status.Newf(codes.Unavailable, "closing transport due to: %v, received prior goaway: %v", err, goAwayDebugMessage)
@@ -1047,30 +1068,40 @@ func (t *http2Client) GracefulClose() {
 
 // Write formats the data into HTTP2 data frame(s) and sends it out. The caller
 // should proceed only if Write returns nil.
-func (t *http2Client) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
+func (t *http2Client) write(s *ClientStream, hdr []byte, data mem.BufferSlice, opts *WriteOptions) error {
+	reader := data.Reader()
+
 	if opts.Last {
 		// If it's the last message, update stream state.
 		if !s.compareAndSwapState(streamActive, streamWriteDone) {
+			_ = reader.Close()
 			return errStreamDone
 		}
 	} else if s.getState() != streamActive {
+		_ = reader.Close()
 		return errStreamDone
 	}
 	df := &dataFrame{
 		streamID:  s.id,
 		endStream: opts.Last,
 		h:         hdr,
-		d:         data,
+		reader:    reader,
 	}
-	if hdr != nil || data != nil { // If it's not an empty data frame, check quota.
-		if err := s.wq.get(int32(len(hdr) + len(data))); err != nil {
+	if hdr != nil || df.reader.Remaining() != 0 { // If it's not an empty data frame, check quota.
+		if err := s.wq.get(int32(len(hdr) + df.reader.Remaining())); err != nil {
+			_ = reader.Close()
 			return err
 		}
 	}
-	return t.controlBuf.put(df)
+	if err := t.controlBuf.put(df); err != nil {
+		_ = reader.Close()
+		return err
+	}
+	t.incrMsgSent()
+	return nil
 }
 
-func (t *http2Client) getStream(f http2.Frame) *Stream {
+func (t *http2Client) getStream(f http2.Frame) *ClientStream {
 	t.mu.Lock()
 	s := t.activeStreams[f.Header().StreamID]
 	t.mu.Unlock()
@@ -1080,7 +1111,7 @@ func (t *http2Client) getStream(f http2.Frame) *Stream {
 // adjustWindow sends out extra window update over the initial window size
 // of stream if the application is requesting data larger in size than
 // the window.
-func (t *http2Client) adjustWindow(s *Stream, n uint32) {
+func (t *http2Client) adjustWindow(s *ClientStream, n uint32) {
 	if w := s.fc.maybeAdjust(n); w > 0 {
 		t.controlBuf.put(&outgoingWindowUpdate{streamID: s.id, increment: w})
 	}
@@ -1089,7 +1120,7 @@ func (t *http2Client) adjustWindow(s *Stream, n uint32) {
 // updateWindow adjusts the inbound quota for the stream.
 // Window updates will be sent out when the cumulative quota
 // exceeds the corresponding threshold.
-func (t *http2Client) updateWindow(s *Stream, n uint32) {
+func (t *http2Client) updateWindow(s *ClientStream, n uint32) {
 	if w := s.fc.onRead(n); w > 0 {
 		t.controlBuf.put(&outgoingWindowUpdate{streamID: s.id, increment: w})
 	}
@@ -1099,7 +1130,7 @@ func (t *http2Client) updateWindow(s *Stream, n uint32) {
 // for the transport and the stream based on the current bdp
 // estimation.
 func (t *http2Client) updateFlowControl(n uint32) {
-	updateIWS := func(any) bool {
+	updateIWS := func() bool {
 		t.initialWindowSize = int32(n)
 		t.mu.Lock()
 		for _, s := range t.activeStreams {
@@ -1172,10 +1203,13 @@ func (t *http2Client) handleData(f *http2.DataFrame) {
 		// guarantee f.Data() is consumed before the arrival of next frame.
 		// Can this copy be eliminated?
 		if len(f.Data()) > 0 {
-			buffer := t.bufferPool.get()
-			buffer.Reset()
-			buffer.Write(f.Data())
-			s.write(recvMsg{buffer: buffer})
+			pool := t.bufferPool
+			if pool == nil {
+				// Note that this is only supposed to be nil in tests. Otherwise, stream is
+				// always initialized with a BufferPool.
+				pool = mem.DefaultBufferPool()
+			}
+			s.write(recvMsg{buffer: mem.Copy(f.Data(), pool)})
 		}
 	}
 	// The server has closed the stream without sending trailers.  Record that
@@ -1192,7 +1226,7 @@ func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
 	}
 	if f.ErrCode == http2.ErrCodeRefusedStream {
 		// The stream was unprocessed by the server.
-		atomic.StoreUint32(&s.unprocessed, 1)
+		s.unprocessed.Store(true)
 	}
 	statusCode, ok := http2ErrConvTab[f.ErrCode]
 	if !ok {
@@ -1204,11 +1238,12 @@ func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
 	if statusCode == codes.Canceled {
 		if d, ok := s.ctx.Deadline(); ok && !d.After(time.Now()) {
 			// Our deadline was already exceeded, and that was likely the cause
-			// of this cancelation.  Alter the status code accordingly.
+			// of this cancellation.  Alter the status code accordingly.
 			statusCode = codes.DeadlineExceeded
 		}
 	}
-	t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %v", f.ErrCode), nil, false)
+	st := status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %v", f.ErrCode)
+	t.closeStream(s, st.Err(), false, http2.ErrCodeNo, st, nil, false)
 }
 
 func (t *http2Client) handleSettings(f *http2.SettingsFrame, isFirst bool) {
@@ -1252,7 +1287,7 @@ func (t *http2Client) handleSettings(f *http2.SettingsFrame, isFirst bool) {
 		}
 		updateFuncs = append(updateFuncs, updateStreamQuota)
 	}
-	t.controlBuf.executeAndPut(func(any) bool {
+	t.controlBuf.executeAndPut(func() bool {
 		for _, f := range updateFuncs {
 			f()
 		}
@@ -1273,11 +1308,11 @@ func (t *http2Client) handlePing(f *http2.PingFrame) {
 	t.controlBuf.put(pingAck)
 }
 
-func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
+func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) error {
 	t.mu.Lock()
 	if t.state == closing {
 		t.mu.Unlock()
-		return
+		return nil
 	}
 	if f.ErrCode == http2.ErrCodeEnhanceYourCalm && string(f.DebugData()) == "too_many_pings" {
 		// When a client receives a GOAWAY with error code ENHANCE_YOUR_CALM and debug
@@ -1289,8 +1324,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 	id := f.LastStreamID
 	if id > 0 && id%2 == 0 {
 		t.mu.Unlock()
-		t.Close(connectionErrorf(true, nil, "received goaway with non-zero even-numbered numbered stream id: %v", id))
-		return
+		return connectionErrorf(true, nil, "received goaway with non-zero even-numbered stream id: %v", id)
 	}
 	// A client can receive multiple GoAways from the server (see
 	// https://github.com/grpc/grpc-go/issues/1387).  The idea is that the first
@@ -1307,8 +1341,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 		// If there are multiple GoAways the first one should always have an ID greater than the following ones.
 		if id > t.prevGoAwayID {
 			t.mu.Unlock()
-			t.Close(connectionErrorf(true, nil, "received goaway with stream id: %v, which exceeds stream id of previous goaway: %v", id, t.prevGoAwayID))
-			return
+			return connectionErrorf(true, nil, "received goaway with stream id: %v, which exceeds stream id of previous goaway: %v", id, t.prevGoAwayID)
 		}
 	default:
 		t.setGoAwayReason(f)
@@ -1332,15 +1365,14 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 	t.prevGoAwayID = id
 	if len(t.activeStreams) == 0 {
 		t.mu.Unlock()
-		t.Close(connectionErrorf(true, nil, "received goaway and there are no active streams"))
-		return
+		return connectionErrorf(true, nil, "received goaway and there are no active streams")
 	}
 
-	streamsToClose := make([]*Stream, 0)
+	streamsToClose := make([]*ClientStream, 0)
 	for streamID, stream := range t.activeStreams {
 		if streamID > id && streamID <= upperLimit {
 			// The stream was unprocessed by the server.
-			atomic.StoreUint32(&stream.unprocessed, 1)
+			stream.unprocessed.Store(true)
 			streamsToClose = append(streamsToClose, stream)
 		}
 	}
@@ -1350,6 +1382,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 	for _, stream := range streamsToClose {
 		t.closeStream(stream, errStreamDrain, false, http2.ErrCodeNo, statusGoAway, nil, false)
 	}
+	return nil
 }
 
 // setGoAwayReason sets the value of t.goAwayReason based
@@ -1358,8 +1391,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 // the caller.
 func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
 	t.goAwayReason = GoAwayNoReason
-	switch f.ErrCode {
-	case http2.ErrCodeEnhanceYourCalm:
+	if f.ErrCode == http2.ErrCodeEnhanceYourCalm {
 		if string(f.DebugData()) == "too_many_pings" {
 			t.goAwayReason = GoAwayTooManyPings
 		}
@@ -1391,7 +1423,7 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		return
 	}
 	endStream := frame.StreamEnded()
-	atomic.StoreUint32(&s.bytesReceived, 1)
+	s.bytesReceived.Store(true)
 	initialHeader := atomic.LoadUint32(&s.headerChanClosed) == 0
 
 	if !initialHeader && !endStream {
@@ -1585,7 +1617,13 @@ func (t *http2Client) readServerPreface() error {
 // network connection.  If the server preface is not read successfully, an
 // error is pushed to errCh; otherwise errCh is closed with no error.
 func (t *http2Client) reader(errCh chan<- error) {
-	defer close(t.readerDone)
+	var errClose error
+	defer func() {
+		close(t.readerDone)
+		if errClose != nil {
+			t.Close(errClose)
+		}
+	}()
 
 	if err := t.readServerPreface(); err != nil {
 		errCh <- err
@@ -1624,11 +1662,10 @@ func (t *http2Client) reader(errCh chan<- error) {
 					t.closeStream(s, status.Error(code, msg), true, http2.ErrCodeProtocol, status.New(code, msg), nil, false)
 				}
 				continue
-			} else {
-				// Transport error.
-				t.Close(connectionErrorf(true, err, "error reading from server: %v", err))
-				return
 			}
+			// Transport error.
+			errClose = connectionErrorf(true, err, "error reading from server: %v", err)
+			return
 		}
 		switch frame := frame.(type) {
 		case *http2.MetaHeadersFrame:
@@ -1642,7 +1679,7 @@ func (t *http2Client) reader(errCh chan<- error) {
 		case *http2.PingFrame:
 			t.handlePing(frame)
 		case *http2.GoAwayFrame:
-			t.handleGoAway(frame)
+			errClose = t.handleGoAway(frame)
 		case *http2.WindowUpdateFrame:
 			t.handleWindowUpdate(frame)
 		default:
@@ -1653,15 +1690,15 @@ func (t *http2Client) reader(errCh chan<- error) {
 	}
 }
 
-func minTime(a, b time.Duration) time.Duration {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 // keepalive running in a separate goroutine makes sure the connection is alive by sending pings.
 func (t *http2Client) keepalive() {
+	var err error
+	defer func() {
+		close(t.keepaliveDone)
+		if err != nil {
+			t.Close(err)
+		}
+	}()
 	p := &ping{data: [8]byte{}}
 	// True iff a ping has been sent, and no data has been received since then.
 	outstandingPing := false
@@ -1685,7 +1722,7 @@ func (t *http2Client) keepalive() {
 				continue
 			}
 			if outstandingPing && timeoutLeft <= 0 {
-				t.Close(connectionErrorf(true, nil, "keepalive ping failed to receive ACK within timeout"))
+				err = connectionErrorf(true, nil, "keepalive ping failed to receive ACK within timeout")
 				return
 			}
 			t.mu.Lock()
@@ -1727,7 +1764,7 @@ func (t *http2Client) keepalive() {
 			// timeoutLeft. This will ensure that we wait only for kp.Time
 			// before sending out the next ping (for cases where the ping is
 			// acked).
-			sleepDuration := minTime(t.kp.Time, timeoutLeft)
+			sleepDuration := min(t.kp.Time, timeoutLeft)
 			timeoutLeft -= sleepDuration
 			timer.Reset(sleepDuration)
 		case <-t.ctx.Done():
@@ -1756,14 +1793,18 @@ func (t *http2Client) socketMetrics() *channelz.EphemeralSocketMetrics {
 
 func (t *http2Client) RemoteAddr() net.Addr { return t.remoteAddr }
 
-func (t *http2Client) IncrMsgSent() {
-	t.channelz.SocketMetrics.MessagesSent.Add(1)
-	t.channelz.SocketMetrics.LastMessageSentTimestamp.Store(time.Now().UnixNano())
+func (t *http2Client) incrMsgSent() {
+	if channelz.IsOn() {
+		t.channelz.SocketMetrics.MessagesSent.Add(1)
+		t.channelz.SocketMetrics.LastMessageSentTimestamp.Store(time.Now().UnixNano())
+	}
 }
 
-func (t *http2Client) IncrMsgRecv() {
-	t.channelz.SocketMetrics.MessagesReceived.Add(1)
-	t.channelz.SocketMetrics.LastMessageReceivedTimestamp.Store(time.Now().UnixNano())
+func (t *http2Client) incrMsgRecv() {
+	if channelz.IsOn() {
+		t.channelz.SocketMetrics.MessagesReceived.Add(1)
+		t.channelz.SocketMetrics.LastMessageReceivedTimestamp.Store(time.Now().UnixNano())
+	}
 }
 
 func (t *http2Client) getOutFlowWindow() int64 {

vendor/google.golang.org/grpc/internal/transport/http2_server.go

@@ -25,6 +25,7 @@ import (
 	"fmt"
 	"io"
 	"math"
+	rand "math/rand/v2"
 	"net"
 	"net/http"
 	"strconv"
@@ -34,16 +35,17 @@ import (
 
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
 	"google.golang.org/grpc/internal/pretty"
 	"google.golang.org/grpc/internal/syscall"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/protobuf/proto"
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal/channelz"
-	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
@@ -110,7 +112,7 @@ type http2Server struct {
 	// already initialized since draining is already underway.
 	drainEvent    *grpcsync.Event
 	state         transportState
-	activeStreams map[uint32]*Stream
+	activeStreams map[uint32]*ServerStream
 	// idle is the time instant when the connection went idle.
 	// This is either the beginning of the connection or when the number of
 	// RPCs go down to 0.
@@ -119,7 +121,7 @@ type http2Server struct {
 
 	// Fields below are for channelz metric collection.
 	channelz   *channelz.Socket
-	bufferPool *bufferPool
+	bufferPool mem.BufferPool
 
 	connectionID uint64
 
@@ -255,13 +257,13 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 		inTapHandle:       config.InTapHandle,
 		fc:                &trInFlow{limit: uint32(icwz)},
 		state:             reachable,
-		activeStreams:     make(map[uint32]*Stream),
+		activeStreams:     make(map[uint32]*ServerStream),
 		stats:             config.StatsHandlers,
 		kp:                kp,
 		idle:              time.Now(),
 		kep:               kep,
 		initialWindowSize: iwz,
-		bufferPool:        newBufferPool(),
+		bufferPool:        config.BufferPool,
 	}
 	var czSecurity credentials.ChannelzSecurityValue
 	if au, ok := authInfo.(credentials.ChannelzSecurityInfo); ok {
@@ -330,8 +332,7 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	t.handleSettings(sf)
 
 	go func() {
-		t.loopy = newLoopyWriter(serverSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger)
-		t.loopy.ssGoAwayHandler = t.outgoingGoAwayHandler
+		t.loopy = newLoopyWriter(serverSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger, t.outgoingGoAwayHandler, t.bufferPool)
 		err := t.loopy.run()
 		close(t.loopyWriterDone)
 		if !isIOError(err) {
@@ -359,7 +360,7 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 
 // operateHeaders takes action on the decoded headers. Returns an error if fatal
 // error encountered and transport needs to close, otherwise returns nil.
-func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeadersFrame, handle func(*Stream)) error {
+func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeadersFrame, handle func(*ServerStream)) error {
 	// Acquire max stream ID lock for entire duration
 	t.maxStreamMu.Lock()
 	defer t.maxStreamMu.Unlock()
@@ -385,11 +386,13 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 	t.maxStreamID = streamID
 
 	buf := newRecvBuffer()
-	s := &Stream{
-		id:               streamID,
+	s := &ServerStream{
+		Stream: &Stream{
+			id:  streamID,
+			buf: buf,
+			fc:  &inFlow{limit: uint32(t.initialWindowSize)},
+		},
 		st:               t,
-		buf:              buf,
-		fc:               &inFlow{limit: uint32(t.initialWindowSize)},
 		headerWireLength: int(frame.Header().Length),
 	}
 	var (
@@ -537,12 +540,6 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 	// Attach the received metadata to the context.
 	if len(mdata) > 0 {
 		s.ctx = metadata.NewIncomingContext(s.ctx, mdata)
-		if statsTags := mdata["grpc-tags-bin"]; len(statsTags) > 0 {
-			s.ctx = stats.SetIncomingTags(s.ctx, []byte(statsTags[len(statsTags)-1]))
-		}
-		if statsTrace := mdata["grpc-trace-bin"]; len(statsTrace) > 0 {
-			s.ctx = stats.SetIncomingTrace(s.ctx, []byte(statsTrace[len(statsTrace)-1]))
-		}
 	}
 	t.mu.Lock()
 	if t.state != reachable {
@@ -568,7 +565,7 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 			t.logger.Infof("Aborting the stream early: %v", errMsg)
 		}
 		t.controlBuf.put(&earlyAbortStream{
-			httpStatus:     405,
+			httpStatus:     http.StatusMethodNotAllowed,
 			streamID:       streamID,
 			contentSubtype: s.contentSubtype,
 			status:         status.New(codes.Internal, errMsg),
@@ -589,7 +586,7 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 				stat = status.New(codes.PermissionDenied, err.Error())
 			}
 			t.controlBuf.put(&earlyAbortStream{
-				httpStatus:     200,
+				httpStatus:     http.StatusOK,
 				streamID:       s.id,
 				contentSubtype: s.contentSubtype,
 				status:         stat,
@@ -602,6 +599,22 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 	if len(t.activeStreams) == 1 {
 		t.idle = time.Time{}
 	}
+	// Start a timer to close the stream on reaching the deadline.
+	if timeoutSet {
+		// We need to wait for s.cancel to be updated before calling
+		// t.closeStream to avoid data races.
+		cancelUpdated := make(chan struct{})
+		timer := internal.TimeAfterFunc(timeout, func() {
+			<-cancelUpdated
+			t.closeStream(s, true, http2.ErrCodeCancel, false)
+		})
+		oldCancel := s.cancel
+		s.cancel = func() {
+			oldCancel()
+			timer.Stop()
+		}
+		close(cancelUpdated)
+	}
 	t.mu.Unlock()
 	if channelz.IsOn() {
 		t.channelz.SocketMetrics.StreamsStarted.Add(1)
@@ -614,10 +627,9 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 	s.wq = newWriteQuota(defaultWriteQuota, s.ctxDone)
 	s.trReader = &transportReader{
 		reader: &recvBufferReader{
-			ctx:        s.ctx,
-			ctxDone:    s.ctxDone,
-			recv:       s.buf,
-			freeBuffer: t.bufferPool.put,
+			ctx:     s.ctx,
+			ctxDone: s.ctxDone,
+			recv:    s.buf,
 		},
 		windowHandler: func(n int) {
 			t.updateWindow(s, uint32(n))
@@ -635,7 +647,7 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 // HandleStreams receives incoming streams using the given handler. This is
 // typically run in a separate goroutine.
 // traceCtx attaches trace to ctx and returns the new context.
-func (t *http2Server) HandleStreams(ctx context.Context, handle func(*Stream)) {
+func (t *http2Server) HandleStreams(ctx context.Context, handle func(*ServerStream)) {
 	defer func() {
 		close(t.readerDone)
 		<-t.loopyWriterDone
@@ -699,7 +711,7 @@ func (t *http2Server) HandleStreams(ctx context.Context, handle func(*Stream)) {
 	}
 }
 
-func (t *http2Server) getStream(f http2.Frame) (*Stream, bool) {
+func (t *http2Server) getStream(f http2.Frame) (*ServerStream, bool) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	if t.activeStreams == nil {
@@ -717,7 +729,7 @@ func (t *http2Server) getStream(f http2.Frame) (*Stream, bool) {
 // adjustWindow sends out extra window update over the initial window size
 // of stream if the application is requesting data larger in size than
 // the window.
-func (t *http2Server) adjustWindow(s *Stream, n uint32) {
+func (t *http2Server) adjustWindow(s *ServerStream, n uint32) {
 	if w := s.fc.maybeAdjust(n); w > 0 {
 		t.controlBuf.put(&outgoingWindowUpdate{streamID: s.id, increment: w})
 	}
@@ -727,7 +739,7 @@ func (t *http2Server) adjustWindow(s *Stream, n uint32) {
 // updateWindow adjusts the inbound quota for the stream and the transport.
 // Window updates will deliver to the controller for sending when
 // the cumulative quota exceeds the corresponding threshold.
-func (t *http2Server) updateWindow(s *Stream, n uint32) {
+func (t *http2Server) updateWindow(s *ServerStream, n uint32) {
 	if w := s.fc.onRead(n); w > 0 {
 		t.controlBuf.put(&outgoingWindowUpdate{streamID: s.id,
 			increment: w,
@@ -814,10 +826,13 @@ func (t *http2Server) handleData(f *http2.DataFrame) {
 		// guarantee f.Data() is consumed before the arrival of next frame.
 		// Can this copy be eliminated?
 		if len(f.Data()) > 0 {
-			buffer := t.bufferPool.get()
-			buffer.Reset()
-			buffer.Write(f.Data())
-			s.write(recvMsg{buffer: buffer})
+			pool := t.bufferPool
+			if pool == nil {
+				// Note that this is only supposed to be nil in tests. Otherwise, stream is
+				// always initialized with a BufferPool.
+				pool = mem.DefaultBufferPool()
+			}
+			s.write(recvMsg{buffer: mem.Copy(f.Data(), pool)})
 		}
 	}
 	if f.StreamEnded() {
@@ -860,7 +875,7 @@ func (t *http2Server) handleSettings(f *http2.SettingsFrame) {
 		}
 		return nil
 	})
-	t.controlBuf.executeAndPut(func(any) bool {
+	t.controlBuf.executeAndPut(func() bool {
 		for _, f := range updateFuncs {
 			f()
 		}
@@ -961,7 +976,7 @@ func (t *http2Server) checkForHeaderListSize(it any) bool {
 	return true
 }
 
-func (t *http2Server) streamContextErr(s *Stream) error {
+func (t *http2Server) streamContextErr(s *ServerStream) error {
 	select {
 	case <-t.done:
 		return ErrConnClosing
@@ -971,7 +986,7 @@ func (t *http2Server) streamContextErr(s *Stream) error {
 }
 
 // WriteHeader sends the header metadata md back to the client.
-func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
+func (t *http2Server) writeHeader(s *ServerStream, md metadata.MD) error {
 	s.hdrMu.Lock()
 	defer s.hdrMu.Unlock()
 	if s.getState() == streamDone {
@@ -1004,7 +1019,7 @@ func (t *http2Server) setResetPingStrikes() {
 	atomic.StoreUint32(&t.resetPingStrikes, 1)
 }
 
-func (t *http2Server) writeHeaderLocked(s *Stream) error {
+func (t *http2Server) writeHeaderLocked(s *ServerStream) error {
 	// TODO(mmukhi): Benchmark if the performance gets better if count the metadata and other header fields
 	// first and create a slice of that exact size.
 	headerFields := make([]hpack.HeaderField, 0, 2) // at least :status, content-type will be there if none else.
@@ -1014,12 +1029,13 @@ func (t *http2Server) writeHeaderLocked(s *Stream) error {
 		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-encoding", Value: s.sendCompress})
 	}
 	headerFields = appendHeaderFieldsFromMD(headerFields, s.header)
-	success, err := t.controlBuf.executeAndPut(t.checkForHeaderListSize, &headerFrame{
+	hf := &headerFrame{
 		streamID:  s.id,
 		hf:        headerFields,
 		endStream: false,
 		onWrite:   t.setResetPingStrikes,
-	})
+	}
+	success, err := t.controlBuf.executeAndPut(func() bool { return t.checkForHeaderListSize(hf) }, hf)
 	if !success {
 		if err != nil {
 			return err
@@ -1043,7 +1059,7 @@ func (t *http2Server) writeHeaderLocked(s *Stream) error {
 // There is no further I/O operations being able to perform on this stream.
 // TODO(zhaoq): Now it indicates the end of entire stream. Revisit if early
 // OK is adopted.
-func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
+func (t *http2Server) writeStatus(s *ServerStream, st *status.Status) error {
 	s.hdrMu.Lock()
 	defer s.hdrMu.Unlock()
 
@@ -1089,7 +1105,9 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 		onWrite:   t.setResetPingStrikes,
 	}
 
-	success, err := t.controlBuf.execute(t.checkForHeaderListSize, trailingHeader)
+	success, err := t.controlBuf.executeAndPut(func() bool {
+		return t.checkForHeaderListSize(trailingHeader)
+	}, nil)
 	if !success {
 		if err != nil {
 			return err
@@ -1112,27 +1130,38 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 
 // Write converts the data into HTTP2 data frame and sends it out. Non-nil error
 // is returns if it fails (e.g., framing error, transport error).
-func (t *http2Server) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
+func (t *http2Server) write(s *ServerStream, hdr []byte, data mem.BufferSlice, _ *WriteOptions) error {
+	reader := data.Reader()
+
 	if !s.isHeaderSent() { // Headers haven't been written yet.
-		if err := t.WriteHeader(s, nil); err != nil {
+		if err := t.writeHeader(s, nil); err != nil {
+			_ = reader.Close()
 			return err
 		}
 	} else {
 		// Writing headers checks for this condition.
 		if s.getState() == streamDone {
+			_ = reader.Close()
 			return t.streamContextErr(s)
 		}
 	}
+
 	df := &dataFrame{
 		streamID:    s.id,
 		h:           hdr,
-		d:           data,
+		reader:      reader,
 		onEachWrite: t.setResetPingStrikes,
 	}
-	if err := s.wq.get(int32(len(hdr) + len(data))); err != nil {
+	if err := s.wq.get(int32(len(hdr) + df.reader.Remaining())); err != nil {
+		_ = reader.Close()
 		return t.streamContextErr(s)
 	}
-	return t.controlBuf.put(df)
+	if err := t.controlBuf.put(df); err != nil {
+		_ = reader.Close()
+		return err
+	}
+	t.incrMsgSent()
+	return nil
 }
 
 // keepalive running in a separate goroutine does the following:
@@ -1208,7 +1237,7 @@ func (t *http2Server) keepalive() {
 				continue
 			}
 			if outstandingPing && kpTimeoutLeft <= 0 {
-				t.Close(fmt.Errorf("keepalive ping not acked within timeout %s", t.kp.Time))
+				t.Close(fmt.Errorf("keepalive ping not acked within timeout %s", t.kp.Timeout))
 				return
 			}
 			if !outstandingPing {
@@ -1223,7 +1252,7 @@ func (t *http2Server) keepalive() {
 			// timeoutLeft. This will ensure that we wait only for kp.Time
 			// before sending out the next ping (for cases where the ping is
 			// acked).
-			sleepDuration := minTime(t.kp.Time, kpTimeoutLeft)
+			sleepDuration := min(t.kp.Time, kpTimeoutLeft)
 			kpTimeoutLeft -= sleepDuration
 			kpTimer.Reset(sleepDuration)
 		case <-t.done:
@@ -1261,8 +1290,7 @@ func (t *http2Server) Close(err error) {
 }
 
 // deleteStream deletes the stream s from transport's active streams.
-func (t *http2Server) deleteStream(s *Stream, eosReceived bool) {
-
+func (t *http2Server) deleteStream(s *ServerStream, eosReceived bool) {
 	t.mu.Lock()
 	if _, ok := t.activeStreams[s.id]; ok {
 		delete(t.activeStreams, s.id)
@@ -1282,7 +1310,7 @@ func (t *http2Server) deleteStream(s *Stream, eosReceived bool) {
 }
 
 // finishStream closes the stream and puts the trailing headerFrame into controlbuf.
-func (t *http2Server) finishStream(s *Stream, rst bool, rstCode http2.ErrCode, hdr *headerFrame, eosReceived bool) {
+func (t *http2Server) finishStream(s *ServerStream, rst bool, rstCode http2.ErrCode, hdr *headerFrame, eosReceived bool) {
 	// In case stream sending and receiving are invoked in separate
 	// goroutines (e.g., bi-directional streaming), cancel needs to be
 	// called to interrupt the potential blocking on other goroutines.
@@ -1306,13 +1334,16 @@ func (t *http2Server) finishStream(s *Stream, rst bool, rstCode http2.ErrCode, h
 }
 
 // closeStream clears the footprint of a stream when the stream is not needed any more.
-func (t *http2Server) closeStream(s *Stream, rst bool, rstCode http2.ErrCode, eosReceived bool) {
+func (t *http2Server) closeStream(s *ServerStream, rst bool, rstCode http2.ErrCode, eosReceived bool) {
 	// In case stream sending and receiving are invoked in separate
 	// goroutines (e.g., bi-directional streaming), cancel needs to be
 	// called to interrupt the potential blocking on other goroutines.
 	s.cancel()
 
-	s.swapState(streamDone)
+	oldState := s.swapState(streamDone)
+	if oldState == streamDone {
+		return
+	}
 	t.deleteStream(s, eosReceived)
 
 	t.controlBuf.put(&cleanupStream{
@@ -1400,14 +1431,18 @@ func (t *http2Server) socketMetrics() *channelz.EphemeralSocketMetrics {
 	}
 }
 
-func (t *http2Server) IncrMsgSent() {
-	t.channelz.SocketMetrics.MessagesSent.Add(1)
-	t.channelz.SocketMetrics.LastMessageSentTimestamp.Add(1)
+func (t *http2Server) incrMsgSent() {
+	if channelz.IsOn() {
+		t.channelz.SocketMetrics.MessagesSent.Add(1)
+		t.channelz.SocketMetrics.LastMessageSentTimestamp.Add(1)
+	}
 }
 
-func (t *http2Server) IncrMsgRecv() {
-	t.channelz.SocketMetrics.MessagesReceived.Add(1)
-	t.channelz.SocketMetrics.LastMessageReceivedTimestamp.Add(1)
+func (t *http2Server) incrMsgRecv() {
+	if channelz.IsOn() {
+		t.channelz.SocketMetrics.MessagesReceived.Add(1)
+		t.channelz.SocketMetrics.LastMessageReceivedTimestamp.Add(1)
+	}
 }
 
 func (t *http2Server) getOutFlowWindow() int64 {
@@ -1440,7 +1475,7 @@ func getJitter(v time.Duration) time.Duration {
 	}
 	// Generate a jitter between +/- 10% of the value.
 	r := int64(v / 10)
-	j := grpcrand.Int63n(2*r) - r
+	j := rand.Int64N(2*r) - r
 	return time.Duration(j)
 }
 

vendor/google.golang.org/grpc/internal/transport/http_util.go

@@ -317,28 +317,32 @@ func newBufWriter(conn net.Conn, batchSize int, pool *sync.Pool) *bufWriter {
 	return w
 }
 
-func (w *bufWriter) Write(b []byte) (n int, err error) {
+func (w *bufWriter) Write(b []byte) (int, error) {
 	if w.err != nil {
 		return 0, w.err
 	}
 	if w.batchSize == 0 { // Buffer has been disabled.
-		n, err = w.conn.Write(b)
+		n, err := w.conn.Write(b)
 		return n, toIOError(err)
 	}
 	if w.buf == nil {
 		b := w.pool.Get().(*[]byte)
 		w.buf = *b
 	}
+	written := 0
 	for len(b) > 0 {
-		nn := copy(w.buf[w.offset:], b)
-		b = b[nn:]
-		w.offset += nn
-		n += nn
-		if w.offset >= w.batchSize {
-			err = w.flushKeepBuffer()
+		copied := copy(w.buf[w.offset:], b)
+		b = b[copied:]
+		written += copied
+		w.offset += copied
+		if w.offset < w.batchSize {
+			continue
+		}
+		if err := w.flushKeepBuffer(); err != nil {
+			return written, err
 		}
 	}
-	return n, err
+	return written, nil
 }
 
 func (w *bufWriter) Flush() error {
@@ -389,7 +393,7 @@ type framer struct {
 	fr     *http2.Framer
 }
 
-var writeBufferPoolMap map[int]*sync.Pool = make(map[int]*sync.Pool)
+var writeBufferPoolMap = make(map[int]*sync.Pool)
 var writeBufferMutex sync.Mutex
 
 func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, sharedWriteBuffer bool, maxHeaderListSize uint32) *framer {
@@ -435,8 +439,8 @@ func getWriteBufferPool(size int) *sync.Pool {
 	return pool
 }
 
-// parseDialTarget returns the network and address to pass to dialer.
-func parseDialTarget(target string) (string, string) {
+// ParseDialTarget returns the network and address to pass to dialer.
+func ParseDialTarget(target string) (string, string) {
 	net := "tcp"
 	m1 := strings.Index(target, ":")
 	m2 := strings.Index(target, ":/")

vendor/google.golang.org/grpc/internal/transport/proxy.go

@@ -30,34 +30,16 @@ import (
 	"net/url"
 
 	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/internal/proxyattributes"
+	"google.golang.org/grpc/resolver"
 )
 
 const proxyAuthHeaderKey = "Proxy-Authorization"
 
-var (
-	// The following variable will be overwritten in the tests.
-	httpProxyFromEnvironment = http.ProxyFromEnvironment
-)
-
-func mapAddress(address string) (*url.URL, error) {
-	req := &http.Request{
-		URL: &url.URL{
-			Scheme: "https",
-			Host:   address,
-		},
-	}
-	url, err := httpProxyFromEnvironment(req)
-	if err != nil {
-		return nil, err
-	}
-	return url, nil
-}
-
 // To read a response from a net.Conn, http.ReadResponse() takes a bufio.Reader.
-// It's possible that this reader reads more than what's need for the response and stores
-// those bytes in the buffer.
-// bufConn wraps the original net.Conn and the bufio.Reader to make sure we don't lose the
-// bytes in the buffer.
+// It's possible that this reader reads more than what's need for the response
+// and stores those bytes in the buffer. bufConn wraps the original net.Conn
+// and the bufio.Reader to make sure we don't lose the bytes in the buffer.
 type bufConn struct {
 	net.Conn
 	r io.Reader
@@ -72,7 +54,7 @@ func basicAuth(username, password string) string {
 	return base64.StdEncoding.EncodeToString([]byte(auth))
 }
 
-func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, backendAddr string, proxyURL *url.URL, grpcUA string) (_ net.Conn, err error) {
+func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, grpcUA string, opts proxyattributes.Options) (_ net.Conn, err error) {
 	defer func() {
 		if err != nil {
 			conn.Close()
@@ -81,15 +63,14 @@ func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, backendAddr stri
 
 	req := &http.Request{
 		Method: http.MethodConnect,
-		URL:    &url.URL{Host: backendAddr},
+		URL:    &url.URL{Host: opts.ConnectAddr},
 		Header: map[string][]string{"User-Agent": {grpcUA}},
 	}
-	if t := proxyURL.User; t != nil {
-		u := t.Username()
-		p, _ := t.Password()
+	if user := opts.User; user != nil {
+		u := user.Username()
+		p, _ := user.Password()
 		req.Header.Add(proxyAuthHeaderKey, "Basic "+basicAuth(u, p))
 	}
-
 	if err := sendHTTPRequest(ctx, req, conn); err != nil {
 		return nil, fmt.Errorf("failed to write the HTTP request: %v", err)
 	}
@@ -107,32 +88,23 @@ func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, backendAddr stri
 		}
 		return nil, fmt.Errorf("failed to do connect handshake, response: %q", dump)
 	}
-
-	return &bufConn{Conn: conn, r: r}, nil
+	// The buffer could contain extra bytes from the target server, so we can't
+	// discard it. However, in many cases where the server waits for the client
+	// to send the first message (e.g. when TLS is being used), the buffer will
+	// be empty, so we can avoid the overhead of reading through this buffer.
+	if r.Buffered() != 0 {
+		return &bufConn{Conn: conn, r: r}, nil
+	}
+	return conn, nil
 }
 
-// proxyDial dials, connecting to a proxy first if necessary. Checks if a proxy
-// is necessary, dials, does the HTTP CONNECT handshake, and returns the
-// connection.
-func proxyDial(ctx context.Context, addr string, grpcUA string) (net.Conn, error) {
-	newAddr := addr
-	proxyURL, err := mapAddress(addr)
+// proxyDial establishes a TCP connection to the specified address and performs an HTTP CONNECT handshake.
+func proxyDial(ctx context.Context, addr resolver.Address, grpcUA string, opts proxyattributes.Options) (net.Conn, error) {
+	conn, err := internal.NetDialerWithTCPKeepalive().DialContext(ctx, "tcp", addr.Addr)
 	if err != nil {
 		return nil, err
 	}
-	if proxyURL != nil {
-		newAddr = proxyURL.Host
-	}
-
-	conn, err := internal.NetDialerWithTCPKeepalive().DialContext(ctx, "tcp", newAddr)
-	if err != nil {
-		return nil, err
-	}
-	if proxyURL == nil {
-		// proxy is disabled if proxyURL is nil.
-		return conn, err
-	}
-	return doHTTPConnectHandshake(ctx, conn, addr, proxyURL, grpcUA)
+	return doHTTPConnectHandshake(ctx, conn, grpcUA, opts)
 }
 
 func sendHTTPRequest(ctx context.Context, req *http.Request, conn net.Conn) error {

vendor/google.golang.org/grpc/internal/transport/server_stream.go

@@ -0,0 +1,180 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"sync"
+	"sync/atomic"
+
+	"google.golang.org/grpc/mem"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+// ServerStream implements streaming functionality for a gRPC server.
+type ServerStream struct {
+	*Stream // Embed for common stream functionality.
+
+	st      internalServerTransport
+	ctxDone <-chan struct{} // closed at the end of stream.  Cache of ctx.Done() (for performance)
+	// cancel is invoked at the end of stream to cancel ctx. It also stops the
+	// timer for monitoring the rpc deadline if configured.
+	cancel func()
+
+	// Holds compressor names passed in grpc-accept-encoding metadata from the
+	// client.
+	clientAdvertisedCompressors string
+	headerWireLength            int
+
+	// hdrMu protects outgoing header and trailer metadata.
+	hdrMu      sync.Mutex
+	header     metadata.MD // the outgoing header metadata.  Updated by WriteHeader.
+	headerSent atomic.Bool // atomically set when the headers are sent out.
+}
+
+// Read reads an n byte message from the input stream.
+func (s *ServerStream) Read(n int) (mem.BufferSlice, error) {
+	b, err := s.Stream.read(n)
+	if err == nil {
+		s.st.incrMsgRecv()
+	}
+	return b, err
+}
+
+// SendHeader sends the header metadata for the given stream.
+func (s *ServerStream) SendHeader(md metadata.MD) error {
+	return s.st.writeHeader(s, md)
+}
+
+// Write writes the hdr and data bytes to the output stream.
+func (s *ServerStream) Write(hdr []byte, data mem.BufferSlice, opts *WriteOptions) error {
+	return s.st.write(s, hdr, data, opts)
+}
+
+// WriteStatus sends the status of a stream to the client.  WriteStatus is
+// the final call made on a stream and always occurs.
+func (s *ServerStream) WriteStatus(st *status.Status) error {
+	return s.st.writeStatus(s, st)
+}
+
+// isHeaderSent indicates whether headers have been sent.
+func (s *ServerStream) isHeaderSent() bool {
+	return s.headerSent.Load()
+}
+
+// updateHeaderSent updates headerSent and returns true
+// if it was already set.
+func (s *ServerStream) updateHeaderSent() bool {
+	return s.headerSent.Swap(true)
+}
+
+// RecvCompress returns the compression algorithm applied to the inbound
+// message. It is empty string if there is no compression applied.
+func (s *ServerStream) RecvCompress() string {
+	return s.recvCompress
+}
+
+// SendCompress returns the send compressor name.
+func (s *ServerStream) SendCompress() string {
+	return s.sendCompress
+}
+
+// ContentSubtype returns the content-subtype for a request. For example, a
+// content-subtype of "proto" will result in a content-type of
+// "application/grpc+proto". This will always be lowercase.  See
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
+// more details.
+func (s *ServerStream) ContentSubtype() string {
+	return s.contentSubtype
+}
+
+// SetSendCompress sets the compression algorithm to the stream.
+func (s *ServerStream) SetSendCompress(name string) error {
+	if s.isHeaderSent() || s.getState() == streamDone {
+		return errors.New("transport: set send compressor called after headers sent or stream done")
+	}
+
+	s.sendCompress = name
+	return nil
+}
+
+// SetContext sets the context of the stream. This will be deleted once the
+// stats handler callouts all move to gRPC layer.
+func (s *ServerStream) SetContext(ctx context.Context) {
+	s.ctx = ctx
+}
+
+// ClientAdvertisedCompressors returns the compressor names advertised by the
+// client via grpc-accept-encoding header.
+func (s *ServerStream) ClientAdvertisedCompressors() []string {
+	values := strings.Split(s.clientAdvertisedCompressors, ",")
+	for i, v := range values {
+		values[i] = strings.TrimSpace(v)
+	}
+	return values
+}
+
+// Header returns the header metadata of the stream.  It returns the out header
+// after t.WriteHeader is called.  It does not block and must not be called
+// until after WriteHeader.
+func (s *ServerStream) Header() (metadata.MD, error) {
+	// Return the header in stream. It will be the out
+	// header after t.WriteHeader is called.
+	return s.header.Copy(), nil
+}
+
+// HeaderWireLength returns the size of the headers of the stream as received
+// from the wire.
+func (s *ServerStream) HeaderWireLength() int {
+	return s.headerWireLength
+}
+
+// SetHeader sets the header metadata. This can be called multiple times.
+// This should not be called in parallel to other data writes.
+func (s *ServerStream) SetHeader(md metadata.MD) error {
+	if md.Len() == 0 {
+		return nil
+	}
+	if s.isHeaderSent() || s.getState() == streamDone {
+		return ErrIllegalHeaderWrite
+	}
+	s.hdrMu.Lock()
+	s.header = metadata.Join(s.header, md)
+	s.hdrMu.Unlock()
+	return nil
+}
+
+// SetTrailer sets the trailer metadata which will be sent with the RPC status
+// by the server. This can be called multiple times.
+// This should not be called parallel to other data writes.
+func (s *ServerStream) SetTrailer(md metadata.MD) error {
+	if md.Len() == 0 {
+		return nil
+	}
+	if s.getState() == streamDone {
+		return ErrIllegalHeaderWrite
+	}
+	s.hdrMu.Lock()
+	s.trailer = metadata.Join(s.trailer, md)
+	s.hdrMu.Unlock()
+	return nil
+}

vendor/google.golang.org/grpc/internal/transport/transport.go

@@ -22,13 +22,11 @@
 package transport
 
 import (
-	"bytes"
 	"context"
 	"errors"
 	"fmt"
 	"io"
 	"net"
-	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -37,9 +35,9 @@ import (
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/keepalive"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
-	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/stats"
 	"google.golang.org/grpc/status"
 	"google.golang.org/grpc/tap"
@@ -47,32 +45,10 @@ import (
 
 const logLevel = 2
 
-type bufferPool struct {
-	pool sync.Pool
-}
-
-func newBufferPool() *bufferPool {
-	return &bufferPool{
-		pool: sync.Pool{
-			New: func() any {
-				return new(bytes.Buffer)
-			},
-		},
-	}
-}
-
-func (p *bufferPool) get() *bytes.Buffer {
-	return p.pool.Get().(*bytes.Buffer)
-}
-
-func (p *bufferPool) put(b *bytes.Buffer) {
-	p.pool.Put(b)
-}
-
 // recvMsg represents the received msg from the transport. All transport
 // protocol specific info has been removed.
 type recvMsg struct {
-	buffer *bytes.Buffer
+	buffer mem.Buffer
 	// nil: received some data
 	// io.EOF: stream is completed. data is nil.
 	// other non-nil error: transport failure. data is nil.
@@ -102,6 +78,9 @@ func newRecvBuffer() *recvBuffer {
 func (b *recvBuffer) put(r recvMsg) {
 	b.mu.Lock()
 	if b.err != nil {
+		// drop the buffer on the floor. Since b.err is not nil, any subsequent reads
+		// will always return an error, making this buffer inaccessible.
+		r.buffer.Free()
 		b.mu.Unlock()
 		// An error had occurred earlier, don't accept more
 		// data or errors.
@@ -148,45 +127,70 @@ type recvBufferReader struct {
 	ctx         context.Context
 	ctxDone     <-chan struct{} // cache of ctx.Done() (for performance).
 	recv        *recvBuffer
-	last        *bytes.Buffer // Stores the remaining data in the previous calls.
+	last        mem.Buffer // Stores the remaining data in the previous calls.
 	err         error
-	freeBuffer  func(*bytes.Buffer)
 }
 
-// Read reads the next len(p) bytes from last. If last is drained, it tries to
-// read additional data from recv. It blocks if there no additional data available
-// in recv. If Read returns any non-nil error, it will continue to return that error.
-func (r *recvBufferReader) Read(p []byte) (n int, err error) {
+func (r *recvBufferReader) ReadMessageHeader(header []byte) (n int, err error) {
 	if r.err != nil {
 		return 0, r.err
 	}
 	if r.last != nil {
-		// Read remaining data left in last call.
-		copied, _ := r.last.Read(p)
-		if r.last.Len() == 0 {
-			r.freeBuffer(r.last)
-			r.last = nil
-		}
-		return copied, nil
+		n, r.last = mem.ReadUnsafe(header, r.last)
+		return n, nil
 	}
 	if r.closeStream != nil {
-		n, r.err = r.readClient(p)
+		n, r.err = r.readMessageHeaderClient(header)
 	} else {
-		n, r.err = r.read(p)
+		n, r.err = r.readMessageHeader(header)
 	}
 	return n, r.err
 }
 
-func (r *recvBufferReader) read(p []byte) (n int, err error) {
+// Read reads the next n bytes from last. If last is drained, it tries to read
+// additional data from recv. It blocks if there no additional data available in
+// recv. If Read returns any non-nil error, it will continue to return that
+// error.
+func (r *recvBufferReader) Read(n int) (buf mem.Buffer, err error) {
+	if r.err != nil {
+		return nil, r.err
+	}
+	if r.last != nil {
+		buf = r.last
+		if r.last.Len() > n {
+			buf, r.last = mem.SplitUnsafe(buf, n)
+		} else {
+			r.last = nil
+		}
+		return buf, nil
+	}
+	if r.closeStream != nil {
+		buf, r.err = r.readClient(n)
+	} else {
+		buf, r.err = r.read(n)
+	}
+	return buf, r.err
+}
+
+func (r *recvBufferReader) readMessageHeader(header []byte) (n int, err error) {
 	select {
 	case <-r.ctxDone:
 		return 0, ContextErr(r.ctx.Err())
 	case m := <-r.recv.get():
-		return r.readAdditional(m, p)
+		return r.readMessageHeaderAdditional(m, header)
 	}
 }
 
-func (r *recvBufferReader) readClient(p []byte) (n int, err error) {
+func (r *recvBufferReader) read(n int) (buf mem.Buffer, err error) {
+	select {
+	case <-r.ctxDone:
+		return nil, ContextErr(r.ctx.Err())
+	case m := <-r.recv.get():
+		return r.readAdditional(m, n)
+	}
+}
+
+func (r *recvBufferReader) readMessageHeaderClient(header []byte) (n int, err error) {
 	// If the context is canceled, then closes the stream with nil metadata.
 	// closeStream writes its error parameter to r.recv as a recvMsg.
 	// r.readAdditional acts on that message and returns the necessary error.
@@ -207,25 +211,67 @@ func (r *recvBufferReader) readClient(p []byte) (n int, err error) {
 		// faster.
 		r.closeStream(ContextErr(r.ctx.Err()))
 		m := <-r.recv.get()
-		return r.readAdditional(m, p)
+		return r.readMessageHeaderAdditional(m, header)
 	case m := <-r.recv.get():
-		return r.readAdditional(m, p)
+		return r.readMessageHeaderAdditional(m, header)
 	}
 }
 
-func (r *recvBufferReader) readAdditional(m recvMsg, p []byte) (n int, err error) {
+func (r *recvBufferReader) readClient(n int) (buf mem.Buffer, err error) {
+	// If the context is canceled, then closes the stream with nil metadata.
+	// closeStream writes its error parameter to r.recv as a recvMsg.
+	// r.readAdditional acts on that message and returns the necessary error.
+	select {
+	case <-r.ctxDone:
+		// Note that this adds the ctx error to the end of recv buffer, and
+		// reads from the head. This will delay the error until recv buffer is
+		// empty, thus will delay ctx cancellation in Recv().
+		//
+		// It's done this way to fix a race between ctx cancel and trailer. The
+		// race was, stream.Recv() may return ctx error if ctxDone wins the
+		// race, but stream.Trailer() may return a non-nil md because the stream
+		// was not marked as done when trailer is received. This closeStream
+		// call will mark stream as done, thus fix the race.
+		//
+		// TODO: delaying ctx error seems like a unnecessary side effect. What
+		// we really want is to mark the stream as done, and return ctx error
+		// faster.
+		r.closeStream(ContextErr(r.ctx.Err()))
+		m := <-r.recv.get()
+		return r.readAdditional(m, n)
+	case m := <-r.recv.get():
+		return r.readAdditional(m, n)
+	}
+}
+
+func (r *recvBufferReader) readMessageHeaderAdditional(m recvMsg, header []byte) (n int, err error) {
 	r.recv.load()
 	if m.err != nil {
+		if m.buffer != nil {
+			m.buffer.Free()
+		}
 		return 0, m.err
 	}
-	copied, _ := m.buffer.Read(p)
-	if m.buffer.Len() == 0 {
-		r.freeBuffer(m.buffer)
-		r.last = nil
-	} else {
-		r.last = m.buffer
+
+	n, r.last = mem.ReadUnsafe(header, m.buffer)
+
+	return n, nil
+}
+
+func (r *recvBufferReader) readAdditional(m recvMsg, n int) (b mem.Buffer, err error) {
+	r.recv.load()
+	if m.err != nil {
+		if m.buffer != nil {
+			m.buffer.Free()
+		}
+		return nil, m.err
 	}
-	return copied, nil
+
+	if m.buffer.Len() > n {
+		m.buffer, r.last = mem.SplitUnsafe(m.buffer, n)
+	}
+
+	return m.buffer, nil
 }
 
 type streamState uint32
@@ -240,73 +286,26 @@ const (
 // Stream represents an RPC in the transport layer.
 type Stream struct {
 	id           uint32
-	st           ServerTransport    // nil for client side Stream
-	ct           *http2Client       // nil for server side Stream
-	ctx          context.Context    // the associated context of the stream
-	cancel       context.CancelFunc // always nil for client side Stream
-	done         chan struct{}      // closed at the end of stream to unblock writers. On the client side.
-	doneFunc     func()             // invoked at the end of stream on client side.
-	ctxDone      <-chan struct{}    // same as done chan but for server side. Cache of ctx.Done() (for performance)
-	method       string             // the associated RPC method of the stream
+	ctx          context.Context // the associated context of the stream
+	method       string          // the associated RPC method of the stream
 	recvCompress string
 	sendCompress string
 	buf          *recvBuffer
-	trReader     io.Reader
+	trReader     *transportReader
 	fc           *inFlow
 	wq           *writeQuota
 
-	// Holds compressor names passed in grpc-accept-encoding metadata from the
-	// client. This is empty for the client side stream.
-	clientAdvertisedCompressors string
 	// Callback to state application's intentions to read data. This
 	// is used to adjust flow control, if needed.
 	requestRead func(int)
 
-	headerChan       chan struct{} // closed to indicate the end of header metadata.
-	headerChanClosed uint32        // set when headerChan is closed. Used to avoid closing headerChan multiple times.
-	// headerValid indicates whether a valid header was received.  Only
-	// meaningful after headerChan is closed (always call waitOnHeader() before
-	// reading its value).  Not valid on server side.
-	headerValid      bool
-	headerWireLength int // Only set on server side.
-
-	// hdrMu protects header and trailer metadata on the server-side.
-	hdrMu sync.Mutex
-	// On client side, header keeps the received header metadata.
-	//
-	// On server side, header keeps the header set by SetHeader(). The complete
-	// header will merged into this after t.WriteHeader() is called.
-	header  metadata.MD
-	trailer metadata.MD // the key-value map of trailer metadata.
-
-	noHeaders bool // set if the client never received headers (set only after the stream is done).
-
-	// On the server-side, headerSent is atomically set to 1 when the headers are sent out.
-	headerSent uint32
-
 	state streamState
 
-	// On client-side it is the status error received from the server.
-	// On server-side it is unused.
-	status *status.Status
-
-	bytesReceived uint32 // indicates whether any bytes have been received on this stream
-	unprocessed   uint32 // set if the server sends a refused stream or GOAWAY including this stream
-
 	// contentSubtype is the content-subtype for requests.
 	// this must be lowercase or the behavior is undefined.
 	contentSubtype string
-}
 
-// isHeaderSent is only valid on the server-side.
-func (s *Stream) isHeaderSent() bool {
-	return atomic.LoadUint32(&s.headerSent) == 1
-}
-
-// updateHeaderSent updates headerSent and returns true
-// if it was alreay set. It is valid only on server-side.
-func (s *Stream) updateHeaderSent() bool {
-	return atomic.SwapUint32(&s.headerSent, 1) == 1
+	trailer metadata.MD // the key-value map of trailer metadata.
 }
 
 func (s *Stream) swapState(st streamState) streamState {
@@ -321,110 +320,12 @@ func (s *Stream) getState() streamState {
 	return streamState(atomic.LoadUint32((*uint32)(&s.state)))
 }
 
-func (s *Stream) waitOnHeader() {
-	if s.headerChan == nil {
-		// On the server headerChan is always nil since a stream originates
-		// only after having received headers.
-		return
-	}
-	select {
-	case <-s.ctx.Done():
-		// Close the stream to prevent headers/trailers from changing after
-		// this function returns.
-		s.ct.CloseStream(s, ContextErr(s.ctx.Err()))
-		// headerChan could possibly not be closed yet if closeStream raced
-		// with operateHeaders; wait until it is closed explicitly here.
-		<-s.headerChan
-	case <-s.headerChan:
-	}
-}
-
-// RecvCompress returns the compression algorithm applied to the inbound
-// message. It is empty string if there is no compression applied.
-func (s *Stream) RecvCompress() string {
-	s.waitOnHeader()
-	return s.recvCompress
-}
-
-// SetSendCompress sets the compression algorithm to the stream.
-func (s *Stream) SetSendCompress(name string) error {
-	if s.isHeaderSent() || s.getState() == streamDone {
-		return errors.New("transport: set send compressor called after headers sent or stream done")
-	}
-
-	s.sendCompress = name
-	return nil
-}
-
-// SendCompress returns the send compressor name.
-func (s *Stream) SendCompress() string {
-	return s.sendCompress
-}
-
-// ClientAdvertisedCompressors returns the compressor names advertised by the
-// client via grpc-accept-encoding header.
-func (s *Stream) ClientAdvertisedCompressors() []string {
-	values := strings.Split(s.clientAdvertisedCompressors, ",")
-	for i, v := range values {
-		values[i] = strings.TrimSpace(v)
-	}
-	return values
-}
-
-// Done returns a channel which is closed when it receives the final status
-// from the server.
-func (s *Stream) Done() <-chan struct{} {
-	return s.done
-}
-
-// Header returns the header metadata of the stream.
-//
-// On client side, it acquires the key-value pairs of header metadata once it is
-// available. It blocks until i) the metadata is ready or ii) there is no header
-// metadata or iii) the stream is canceled/expired.
-//
-// On server side, it returns the out header after t.WriteHeader is called.  It
-// does not block and must not be called until after WriteHeader.
-func (s *Stream) Header() (metadata.MD, error) {
-	if s.headerChan == nil {
-		// On server side, return the header in stream. It will be the out
-		// header after t.WriteHeader is called.
-		return s.header.Copy(), nil
-	}
-	s.waitOnHeader()
-
-	if !s.headerValid || s.noHeaders {
-		return nil, s.status.Err()
-	}
-
-	return s.header.Copy(), nil
-}
-
-// TrailersOnly blocks until a header or trailers-only frame is received and
-// then returns true if the stream was trailers-only.  If the stream ends
-// before headers are received, returns true, nil.  Client-side only.
-func (s *Stream) TrailersOnly() bool {
-	s.waitOnHeader()
-	return s.noHeaders
-}
-
-// Trailer returns the cached trailer metedata. Note that if it is not called
-// after the entire stream is done, it could return an empty MD. Client
-// side only.
+// Trailer returns the cached trailer metadata. Note that if it is not called
+// after the entire stream is done, it could return an empty MD.
 // It can be safely read only after stream has ended that is either read
 // or write have returned io.EOF.
 func (s *Stream) Trailer() metadata.MD {
-	c := s.trailer.Copy()
-	return c
-}
-
-// ContentSubtype returns the content-subtype for a request. For example, a
-// content-subtype of "proto" will result in a content-type of
-// "application/grpc+proto". This will always be lowercase.  See
-// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
-// more details.
-func (s *Stream) ContentSubtype() string {
-	return s.contentSubtype
+	return s.trailer.Copy()
 }
 
 // Context returns the context of the stream.
@@ -432,114 +333,104 @@ func (s *Stream) Context() context.Context {
 	return s.ctx
 }
 
-// SetContext sets the context of the stream. This will be deleted once the
-// stats handler callouts all move to gRPC layer.
-func (s *Stream) SetContext(ctx context.Context) {
-	s.ctx = ctx
-}
-
 // Method returns the method for the stream.
 func (s *Stream) Method() string {
 	return s.method
 }
 
-// Status returns the status received from the server.
-// Status can be read safely only after the stream has ended,
-// that is, after Done() is closed.
-func (s *Stream) Status() *status.Status {
-	return s.status
-}
-
-// HeaderWireLength returns the size of the headers of the stream as received
-// from the wire. Valid only on the server.
-func (s *Stream) HeaderWireLength() int {
-	return s.headerWireLength
-}
-
-// SetHeader sets the header metadata. This can be called multiple times.
-// Server side only.
-// This should not be called in parallel to other data writes.
-func (s *Stream) SetHeader(md metadata.MD) error {
-	if md.Len() == 0 {
-		return nil
-	}
-	if s.isHeaderSent() || s.getState() == streamDone {
-		return ErrIllegalHeaderWrite
-	}
-	s.hdrMu.Lock()
-	s.header = metadata.Join(s.header, md)
-	s.hdrMu.Unlock()
-	return nil
-}
-
-// SendHeader sends the given header metadata. The given metadata is
-// combined with any metadata set by previous calls to SetHeader and
-// then written to the transport stream.
-func (s *Stream) SendHeader(md metadata.MD) error {
-	return s.st.WriteHeader(s, md)
-}
-
-// SetTrailer sets the trailer metadata which will be sent with the RPC status
-// by the server. This can be called multiple times. Server side only.
-// This should not be called parallel to other data writes.
-func (s *Stream) SetTrailer(md metadata.MD) error {
-	if md.Len() == 0 {
-		return nil
-	}
-	if s.getState() == streamDone {
-		return ErrIllegalHeaderWrite
-	}
-	s.hdrMu.Lock()
-	s.trailer = metadata.Join(s.trailer, md)
-	s.hdrMu.Unlock()
-	return nil
-}
-
 func (s *Stream) write(m recvMsg) {
 	s.buf.put(m)
 }
 
-// Read reads all p bytes from the wire for this stream.
-func (s *Stream) Read(p []byte) (n int, err error) {
+// ReadMessageHeader reads data into the provided header slice from the stream.
+// It first checks if there was an error during a previous read operation and
+// returns it if present. It then requests a read operation for the length of
+// the header. It continues to read from the stream until the entire header
+// slice is filled or an error occurs. If an `io.EOF` error is encountered with
+// partially read data, it is converted to `io.ErrUnexpectedEOF` to indicate an
+// unexpected end of the stream. The method returns any error encountered during
+// the read process or nil if the header was successfully read.
+func (s *Stream) ReadMessageHeader(header []byte) (err error) {
 	// Don't request a read if there was an error earlier
-	if er := s.trReader.(*transportReader).er; er != nil {
-		return 0, er
+	if er := s.trReader.er; er != nil {
+		return er
 	}
-	s.requestRead(len(p))
-	return io.ReadFull(s.trReader, p)
+	s.requestRead(len(header))
+	for len(header) != 0 {
+		n, err := s.trReader.ReadMessageHeader(header)
+		header = header[n:]
+		if len(header) == 0 {
+			err = nil
+		}
+		if err != nil {
+			if n > 0 && err == io.EOF {
+				err = io.ErrUnexpectedEOF
+			}
+			return err
+		}
+	}
+	return nil
 }
 
-// tranportReader reads all the data available for this Stream from the transport and
+// Read reads n bytes from the wire for this stream.
+func (s *Stream) read(n int) (data mem.BufferSlice, err error) {
+	// Don't request a read if there was an error earlier
+	if er := s.trReader.er; er != nil {
+		return nil, er
+	}
+	s.requestRead(n)
+	for n != 0 {
+		buf, err := s.trReader.Read(n)
+		var bufLen int
+		if buf != nil {
+			bufLen = buf.Len()
+		}
+		n -= bufLen
+		if n == 0 {
+			err = nil
+		}
+		if err != nil {
+			if bufLen > 0 && err == io.EOF {
+				err = io.ErrUnexpectedEOF
+			}
+			data.Free()
+			return nil, err
+		}
+		data = append(data, buf)
+	}
+	return data, nil
+}
+
+// transportReader reads all the data available for this Stream from the transport and
 // passes them into the decoder, which converts them into a gRPC message stream.
 // The error is io.EOF when the stream is done or another non-nil error if
 // the stream broke.
 type transportReader struct {
-	reader io.Reader
+	reader *recvBufferReader
 	// The handler to control the window update procedure for both this
 	// particular stream and the associated transport.
 	windowHandler func(int)
 	er            error
 }
 
-func (t *transportReader) Read(p []byte) (n int, err error) {
-	n, err = t.reader.Read(p)
+func (t *transportReader) ReadMessageHeader(header []byte) (int, error) {
+	n, err := t.reader.ReadMessageHeader(header)
 	if err != nil {
 		t.er = err
-		return
+		return 0, err
 	}
 	t.windowHandler(n)
-	return
+	return n, nil
 }
 
-// BytesReceived indicates whether any bytes have been received on this stream.
-func (s *Stream) BytesReceived() bool {
-	return atomic.LoadUint32(&s.bytesReceived) == 1
-}
-
-// Unprocessed indicates whether the server did not process this stream --
-// i.e. it sent a refused stream or GOAWAY including this stream ID.
-func (s *Stream) Unprocessed() bool {
-	return atomic.LoadUint32(&s.unprocessed) == 1
+func (t *transportReader) Read(n int) (mem.Buffer, error) {
+	buf, err := t.reader.Read(n)
+	if err != nil {
+		t.er = err
+		return buf, err
+	}
+	t.windowHandler(buf.Len())
+	return buf, nil
 }
 
 // GoString is implemented by Stream so context.String() won't
@@ -574,6 +465,7 @@ type ServerConfig struct {
 	ChannelzParent        *channelz.Server
 	MaxHeaderListSize     *uint32
 	HeaderTableSize       *uint32
+	BufferPool            mem.BufferPool
 }
 
 // ConnectOptions covers all relevant options for communicating with the server.
@@ -610,19 +502,13 @@ type ConnectOptions struct {
 	ChannelzParent *channelz.SubChannel
 	// MaxHeaderListSize sets the max (uncompressed) size of header list that is prepared to be received.
 	MaxHeaderListSize *uint32
-	// UseProxy specifies if a proxy should be used.
-	UseProxy bool
+	// The mem.BufferPool to use when reading/writing to the wire.
+	BufferPool mem.BufferPool
 }
 
-// NewClientTransport establishes the transport with the required ConnectOptions
-// and returns it to the caller.
-func NewClientTransport(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (ClientTransport, error) {
-	return newHTTP2Client(connectCtx, ctx, addr, opts, onClose)
-}
-
-// Options provides additional hints and information for message
+// WriteOptions provides additional hints and information for message
 // transmission.
-type Options struct {
+type WriteOptions struct {
 	// Last indicates whether this write is the last piece for
 	// this stream.
 	Last bool
@@ -671,18 +557,8 @@ type ClientTransport interface {
 	// It does not block.
 	GracefulClose()
 
-	// Write sends the data for the given stream. A nil stream indicates
-	// the write is to be performed on the transport as a whole.
-	Write(s *Stream, hdr []byte, data []byte, opts *Options) error
-
 	// NewStream creates a Stream for an RPC.
-	NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error)
-
-	// CloseStream clears the footprint of a stream when the stream is
-	// not needed any more. The err indicates the error incurred when
-	// CloseStream is called. Must be called when a stream is finished
-	// unless the associated transport is closing.
-	CloseStream(stream *Stream, err error)
+	NewStream(ctx context.Context, callHdr *CallHdr) (*ClientStream, error)
 
 	// Error returns a channel that is closed when some I/O error
 	// happens. Typically the caller should have a goroutine to monitor
@@ -702,12 +578,6 @@ type ClientTransport interface {
 
 	// RemoteAddr returns the remote network address.
 	RemoteAddr() net.Addr
-
-	// IncrMsgSent increments the number of message sent through this transport.
-	IncrMsgSent()
-
-	// IncrMsgRecv increments the number of message received through this transport.
-	IncrMsgRecv()
 }
 
 // ServerTransport is the common interface for all gRPC server-side transport
@@ -717,19 +587,7 @@ type ClientTransport interface {
 // Write methods for a given Stream will be called serially.
 type ServerTransport interface {
 	// HandleStreams receives incoming streams using the given handler.
-	HandleStreams(context.Context, func(*Stream))
-
-	// WriteHeader sends the header metadata for the given stream.
-	// WriteHeader may not be called on all streams.
-	WriteHeader(s *Stream, md metadata.MD) error
-
-	// Write sends the data for the given stream.
-	// Write may not be called on all streams.
-	Write(s *Stream, hdr []byte, data []byte, opts *Options) error
-
-	// WriteStatus sends the status of a stream to the client.  WriteStatus is
-	// the final call made on a stream and always occurs.
-	WriteStatus(s *Stream, st *status.Status) error
+	HandleStreams(context.Context, func(*ServerStream))
 
 	// Close tears down the transport. Once it is called, the transport
 	// should not be accessed any more. All the pending streams and their
@@ -741,12 +599,14 @@ type ServerTransport interface {
 
 	// Drain notifies the client this ServerTransport stops accepting new RPCs.
 	Drain(debugData string)
+}
 
-	// IncrMsgSent increments the number of message sent through this transport.
-	IncrMsgSent()
-
-	// IncrMsgRecv increments the number of message received through this transport.
-	IncrMsgRecv()
+type internalServerTransport interface {
+	ServerTransport
+	writeHeader(s *ServerStream, md metadata.MD) error
+	write(s *ServerStream, hdr []byte, data mem.BufferSlice, opts *WriteOptions) error
+	writeStatus(s *ServerStream, st *status.Status) error
+	incrMsgRecv()
 }
 
 // connectionErrorf creates an ConnectionError with the specified error description.
@@ -798,7 +658,7 @@ var (
 	// connection is draining. This could be caused by goaway or balancer
 	// removing the address.
 	errStreamDrain = status.Error(codes.Unavailable, "the connection is draining")
-	// errStreamDone is returned from write at the client side to indiacte application
+	// errStreamDone is returned from write at the client side to indicate application
 	// layer of an error.
 	errStreamDone = errors.New("the stream is done")
 	// StatusGoAway indicates that the server sent a GOAWAY that included this

vendor/google.golang.org/grpc/keepalive/keepalive.go

@@ -34,15 +34,29 @@ type ClientParameters struct {
 	// After a duration of this time if the client doesn't see any activity it
 	// pings the server to see if the transport is still alive.
 	// If set below 10s, a minimum value of 10s will be used instead.
-	Time time.Duration // The current default value is infinity.
+	//
+	// Note that gRPC servers have a default EnforcementPolicy.MinTime of 5
+	// minutes (which means the client shouldn't ping more frequently than every
+	// 5 minutes).
+	//
+	// Though not ideal, it's not a strong requirement for Time to be less than
+	// EnforcementPolicy.MinTime.  Time will automatically double if the server
+	// disconnects due to its enforcement policy.
+	//
+	// For more details, see
+	// https://github.com/grpc/proposal/blob/master/A8-client-side-keepalive.md
+	Time time.Duration
 	// After having pinged for keepalive check, the client waits for a duration
 	// of Timeout and if no activity is seen even after that the connection is
 	// closed.
-	Timeout time.Duration // The current default value is 20 seconds.
+	//
+	// If keepalive is enabled, and this value is not explicitly set, the default
+	// is 20 seconds.
+	Timeout time.Duration
 	// If true, client sends keepalive pings even with no active RPCs. If false,
 	// when there are no active RPCs, Time and Timeout will be ignored and no
 	// keepalive pings will be sent.
-	PermitWithoutStream bool // false by default.
+	PermitWithoutStream bool
 }
 
 // ServerParameters is used to set keepalive and max-age parameters on the

vendor/google.golang.org/grpc/mem/buffer_pool.go

@@ -0,0 +1,194 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package mem
+
+import (
+	"sort"
+	"sync"
+
+	"google.golang.org/grpc/internal"
+)
+
+// BufferPool is a pool of buffers that can be shared and reused, resulting in
+// decreased memory allocation.
+type BufferPool interface {
+	// Get returns a buffer with specified length from the pool.
+	Get(length int) *[]byte
+
+	// Put returns a buffer to the pool.
+	Put(*[]byte)
+}
+
+var defaultBufferPoolSizes = []int{
+	256,
+	4 << 10,  // 4KB (go page size)
+	16 << 10, // 16KB (max HTTP/2 frame size used by gRPC)
+	32 << 10, // 32KB (default buffer size for io.Copy)
+	1 << 20,  // 1MB
+}
+
+var defaultBufferPool BufferPool
+
+func init() {
+	defaultBufferPool = NewTieredBufferPool(defaultBufferPoolSizes...)
+
+	internal.SetDefaultBufferPoolForTesting = func(pool BufferPool) {
+		defaultBufferPool = pool
+	}
+
+	internal.SetBufferPoolingThresholdForTesting = func(threshold int) {
+		bufferPoolingThreshold = threshold
+	}
+}
+
+// DefaultBufferPool returns the current default buffer pool. It is a BufferPool
+// created with NewBufferPool that uses a set of default sizes optimized for
+// expected workflows.
+func DefaultBufferPool() BufferPool {
+	return defaultBufferPool
+}
+
+// NewTieredBufferPool returns a BufferPool implementation that uses multiple
+// underlying pools of the given pool sizes.
+func NewTieredBufferPool(poolSizes ...int) BufferPool {
+	sort.Ints(poolSizes)
+	pools := make([]*sizedBufferPool, len(poolSizes))
+	for i, s := range poolSizes {
+		pools[i] = newSizedBufferPool(s)
+	}
+	return &tieredBufferPool{
+		sizedPools: pools,
+	}
+}
+
+// tieredBufferPool implements the BufferPool interface with multiple tiers of
+// buffer pools for different sizes of buffers.
+type tieredBufferPool struct {
+	sizedPools   []*sizedBufferPool
+	fallbackPool simpleBufferPool
+}
+
+func (p *tieredBufferPool) Get(size int) *[]byte {
+	return p.getPool(size).Get(size)
+}
+
+func (p *tieredBufferPool) Put(buf *[]byte) {
+	p.getPool(cap(*buf)).Put(buf)
+}
+
+func (p *tieredBufferPool) getPool(size int) BufferPool {
+	poolIdx := sort.Search(len(p.sizedPools), func(i int) bool {
+		return p.sizedPools[i].defaultSize >= size
+	})
+
+	if poolIdx == len(p.sizedPools) {
+		return &p.fallbackPool
+	}
+
+	return p.sizedPools[poolIdx]
+}
+
+// sizedBufferPool is a BufferPool implementation that is optimized for specific
+// buffer sizes. For example, HTTP/2 frames within gRPC have a default max size
+// of 16kb and a sizedBufferPool can be configured to only return buffers with a
+// capacity of 16kb. Note that however it does not support returning larger
+// buffers and in fact panics if such a buffer is requested. Because of this,
+// this BufferPool implementation is not meant to be used on its own and rather
+// is intended to be embedded in a tieredBufferPool such that Get is only
+// invoked when the required size is smaller than or equal to defaultSize.
+type sizedBufferPool struct {
+	pool        sync.Pool
+	defaultSize int
+}
+
+func (p *sizedBufferPool) Get(size int) *[]byte {
+	buf := p.pool.Get().(*[]byte)
+	b := *buf
+	clear(b[:cap(b)])
+	*buf = b[:size]
+	return buf
+}
+
+func (p *sizedBufferPool) Put(buf *[]byte) {
+	if cap(*buf) < p.defaultSize {
+		// Ignore buffers that are too small to fit in the pool. Otherwise, when
+		// Get is called it will panic as it tries to index outside the bounds
+		// of the buffer.
+		return
+	}
+	p.pool.Put(buf)
+}
+
+func newSizedBufferPool(size int) *sizedBufferPool {
+	return &sizedBufferPool{
+		pool: sync.Pool{
+			New: func() any {
+				buf := make([]byte, size)
+				return &buf
+			},
+		},
+		defaultSize: size,
+	}
+}
+
+var _ BufferPool = (*simpleBufferPool)(nil)
+
+// simpleBufferPool is an implementation of the BufferPool interface that
+// attempts to pool buffers with a sync.Pool. When Get is invoked, it tries to
+// acquire a buffer from the pool but if that buffer is too small, it returns it
+// to the pool and creates a new one.
+type simpleBufferPool struct {
+	pool sync.Pool
+}
+
+func (p *simpleBufferPool) Get(size int) *[]byte {
+	bs, ok := p.pool.Get().(*[]byte)
+	if ok && cap(*bs) >= size {
+		*bs = (*bs)[:size]
+		return bs
+	}
+
+	// A buffer was pulled from the pool, but it is too small. Put it back in
+	// the pool and create one large enough.
+	if ok {
+		p.pool.Put(bs)
+	}
+
+	b := make([]byte, size)
+	return &b
+}
+
+func (p *simpleBufferPool) Put(buf *[]byte) {
+	p.pool.Put(buf)
+}
+
+var _ BufferPool = NopBufferPool{}
+
+// NopBufferPool is a buffer pool that returns new buffers without pooling.
+type NopBufferPool struct{}
+
+// Get returns a buffer with specified length from the pool.
+func (NopBufferPool) Get(length int) *[]byte {
+	b := make([]byte, length)
+	return &b
+}
+
+// Put returns a buffer to the pool.
+func (NopBufferPool) Put(*[]byte) {
+}

vendor/google.golang.org/grpc/mem/buffer_slice.go

@@ -0,0 +1,281 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package mem
+
+import (
+	"io"
+)
+
+const (
+	// 32 KiB is what io.Copy uses.
+	readAllBufSize = 32 * 1024
+)
+
+// BufferSlice offers a means to represent data that spans one or more Buffer
+// instances. A BufferSlice is meant to be immutable after creation, and methods
+// like Ref create and return copies of the slice. This is why all methods have
+// value receivers rather than pointer receivers.
+//
+// Note that any of the methods that read the underlying buffers such as Ref,
+// Len or CopyTo etc., will panic if any underlying buffers have already been
+// freed. It is recommended to not directly interact with any of the underlying
+// buffers directly, rather such interactions should be mediated through the
+// various methods on this type.
+//
+// By convention, any APIs that return (mem.BufferSlice, error) should reduce
+// the burden on the caller by never returning a mem.BufferSlice that needs to
+// be freed if the error is non-nil, unless explicitly stated.
+type BufferSlice []Buffer
+
+// Len returns the sum of the length of all the Buffers in this slice.
+//
+// # Warning
+//
+// Invoking the built-in len on a BufferSlice will return the number of buffers
+// in the slice, and *not* the value returned by this function.
+func (s BufferSlice) Len() int {
+	var length int
+	for _, b := range s {
+		length += b.Len()
+	}
+	return length
+}
+
+// Ref invokes Ref on each buffer in the slice.
+func (s BufferSlice) Ref() {
+	for _, b := range s {
+		b.Ref()
+	}
+}
+
+// Free invokes Buffer.Free() on each Buffer in the slice.
+func (s BufferSlice) Free() {
+	for _, b := range s {
+		b.Free()
+	}
+}
+
+// CopyTo copies each of the underlying Buffer's data into the given buffer,
+// returning the number of bytes copied. Has the same semantics as the copy
+// builtin in that it will copy as many bytes as it can, stopping when either dst
+// is full or s runs out of data, returning the minimum of s.Len() and len(dst).
+func (s BufferSlice) CopyTo(dst []byte) int {
+	off := 0
+	for _, b := range s {
+		off += copy(dst[off:], b.ReadOnlyData())
+	}
+	return off
+}
+
+// Materialize concatenates all the underlying Buffer's data into a single
+// contiguous buffer using CopyTo.
+func (s BufferSlice) Materialize() []byte {
+	l := s.Len()
+	if l == 0 {
+		return nil
+	}
+	out := make([]byte, l)
+	s.CopyTo(out)
+	return out
+}
+
+// MaterializeToBuffer functions like Materialize except that it writes the data
+// to a single Buffer pulled from the given BufferPool.
+//
+// As a special case, if the input BufferSlice only actually has one Buffer, this
+// function simply increases the refcount before returning said Buffer. Freeing this
+// buffer won't release it until the BufferSlice is itself released.
+func (s BufferSlice) MaterializeToBuffer(pool BufferPool) Buffer {
+	if len(s) == 1 {
+		s[0].Ref()
+		return s[0]
+	}
+	sLen := s.Len()
+	if sLen == 0 {
+		return emptyBuffer{}
+	}
+	buf := pool.Get(sLen)
+	s.CopyTo(*buf)
+	return NewBuffer(buf, pool)
+}
+
+// Reader returns a new Reader for the input slice after taking references to
+// each underlying buffer.
+func (s BufferSlice) Reader() Reader {
+	s.Ref()
+	return &sliceReader{
+		data: s,
+		len:  s.Len(),
+	}
+}
+
+// Reader exposes a BufferSlice's data as an io.Reader, allowing it to interface
+// with other parts systems. It also provides an additional convenience method
+// Remaining(), which returns the number of unread bytes remaining in the slice.
+// Buffers will be freed as they are read.
+type Reader interface {
+	io.Reader
+	io.ByteReader
+	// Close frees the underlying BufferSlice and never returns an error. Subsequent
+	// calls to Read will return (0, io.EOF).
+	Close() error
+	// Remaining returns the number of unread bytes remaining in the slice.
+	Remaining() int
+}
+
+type sliceReader struct {
+	data BufferSlice
+	len  int
+	// The index into data[0].ReadOnlyData().
+	bufferIdx int
+}
+
+func (r *sliceReader) Remaining() int {
+	return r.len
+}
+
+func (r *sliceReader) Close() error {
+	r.data.Free()
+	r.data = nil
+	r.len = 0
+	return nil
+}
+
+func (r *sliceReader) freeFirstBufferIfEmpty() bool {
+	if len(r.data) == 0 || r.bufferIdx != len(r.data[0].ReadOnlyData()) {
+		return false
+	}
+
+	r.data[0].Free()
+	r.data = r.data[1:]
+	r.bufferIdx = 0
+	return true
+}
+
+func (r *sliceReader) Read(buf []byte) (n int, _ error) {
+	if r.len == 0 {
+		return 0, io.EOF
+	}
+
+	for len(buf) != 0 && r.len != 0 {
+		// Copy as much as possible from the first Buffer in the slice into the
+		// given byte slice.
+		data := r.data[0].ReadOnlyData()
+		copied := copy(buf, data[r.bufferIdx:])
+		r.len -= copied       // Reduce len by the number of bytes copied.
+		r.bufferIdx += copied // Increment the buffer index.
+		n += copied           // Increment the total number of bytes read.
+		buf = buf[copied:]    // Shrink the given byte slice.
+
+		// If we have copied all the data from the first Buffer, free it and advance to
+		// the next in the slice.
+		r.freeFirstBufferIfEmpty()
+	}
+
+	return n, nil
+}
+
+func (r *sliceReader) ReadByte() (byte, error) {
+	if r.len == 0 {
+		return 0, io.EOF
+	}
+
+	// There may be any number of empty buffers in the slice, clear them all until a
+	// non-empty buffer is reached. This is guaranteed to exit since r.len is not 0.
+	for r.freeFirstBufferIfEmpty() {
+	}
+
+	b := r.data[0].ReadOnlyData()[r.bufferIdx]
+	r.len--
+	r.bufferIdx++
+	// Free the first buffer in the slice if the last byte was read
+	r.freeFirstBufferIfEmpty()
+	return b, nil
+}
+
+var _ io.Writer = (*writer)(nil)
+
+type writer struct {
+	buffers *BufferSlice
+	pool    BufferPool
+}
+
+func (w *writer) Write(p []byte) (n int, err error) {
+	b := Copy(p, w.pool)
+	*w.buffers = append(*w.buffers, b)
+	return b.Len(), nil
+}
+
+// NewWriter wraps the given BufferSlice and BufferPool to implement the
+// io.Writer interface. Every call to Write copies the contents of the given
+// buffer into a new Buffer pulled from the given pool and the Buffer is
+// added to the given BufferSlice.
+func NewWriter(buffers *BufferSlice, pool BufferPool) io.Writer {
+	return &writer{buffers: buffers, pool: pool}
+}
+
+// ReadAll reads from r until an error or EOF and returns the data it read.
+// A successful call returns err == nil, not err == EOF. Because ReadAll is
+// defined to read from src until EOF, it does not treat an EOF from Read
+// as an error to be reported.
+//
+// Important: A failed call returns a non-nil error and may also return
+// partially read buffers. It is the responsibility of the caller to free the
+// BufferSlice returned, or its memory will not be reused.
+func ReadAll(r io.Reader, pool BufferPool) (BufferSlice, error) {
+	var result BufferSlice
+	if wt, ok := r.(io.WriterTo); ok {
+		// This is more optimal since wt knows the size of chunks it wants to
+		// write and, hence, we can allocate buffers of an optimal size to fit
+		// them. E.g. might be a single big chunk, and we wouldn't chop it
+		// into pieces.
+		w := NewWriter(&result, pool)
+		_, err := wt.WriteTo(w)
+		return result, err
+	}
+nextBuffer:
+	for {
+		buf := pool.Get(readAllBufSize)
+		// We asked for 32KiB but may have been given a bigger buffer.
+		// Use all of it if that's the case.
+		*buf = (*buf)[:cap(*buf)]
+		usedCap := 0
+		for {
+			n, err := r.Read((*buf)[usedCap:])
+			usedCap += n
+			if err != nil {
+				if usedCap == 0 {
+					// Nothing in this buf, put it back
+					pool.Put(buf)
+				} else {
+					*buf = (*buf)[:usedCap]
+					result = append(result, NewBuffer(buf, pool))
+				}
+				if err == io.EOF {
+					err = nil
+				}
+				return result, err
+			}
+			if len(*buf) == usedCap {
+				result = append(result, NewBuffer(buf, pool))
+				continue nextBuffer
+			}
+		}
+	}
+}

vendor/google.golang.org/grpc/mem/buffers.go

@@ -0,0 +1,268 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package mem provides utilities that facilitate memory reuse in byte slices
+// that are used as buffers.
+//
+// # Experimental
+//
+// Notice: All APIs in this package are EXPERIMENTAL and may be changed or
+// removed in a later release.
+package mem
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+)
+
+// A Buffer represents a reference counted piece of data (in bytes) that can be
+// acquired by a call to NewBuffer() or Copy(). A reference to a Buffer may be
+// released by calling Free(), which invokes the free function given at creation
+// only after all references are released.
+//
+// Note that a Buffer is not safe for concurrent access and instead each
+// goroutine should use its own reference to the data, which can be acquired via
+// a call to Ref().
+//
+// Attempts to access the underlying data after releasing the reference to the
+// Buffer will panic.
+type Buffer interface {
+	// ReadOnlyData returns the underlying byte slice. Note that it is undefined
+	// behavior to modify the contents of this slice in any way.
+	ReadOnlyData() []byte
+	// Ref increases the reference counter for this Buffer.
+	Ref()
+	// Free decrements this Buffer's reference counter and frees the underlying
+	// byte slice if the counter reaches 0 as a result of this call.
+	Free()
+	// Len returns the Buffer's size.
+	Len() int
+
+	split(n int) (left, right Buffer)
+	read(buf []byte) (int, Buffer)
+}
+
+var (
+	bufferPoolingThreshold = 1 << 10
+
+	bufferObjectPool = sync.Pool{New: func() any { return new(buffer) }}
+	refObjectPool    = sync.Pool{New: func() any { return new(atomic.Int32) }}
+)
+
+// IsBelowBufferPoolingThreshold returns true if the given size is less than or
+// equal to the threshold for buffer pooling. This is used to determine whether
+// to pool buffers or allocate them directly.
+func IsBelowBufferPoolingThreshold(size int) bool {
+	return size <= bufferPoolingThreshold
+}
+
+type buffer struct {
+	origData *[]byte
+	data     []byte
+	refs     *atomic.Int32
+	pool     BufferPool
+}
+
+func newBuffer() *buffer {
+	return bufferObjectPool.Get().(*buffer)
+}
+
+// NewBuffer creates a new Buffer from the given data, initializing the reference
+// counter to 1. The data will then be returned to the given pool when all
+// references to the returned Buffer are released. As a special case to avoid
+// additional allocations, if the given buffer pool is nil, the returned buffer
+// will be a "no-op" Buffer where invoking Buffer.Free() does nothing and the
+// underlying data is never freed.
+//
+// Note that the backing array of the given data is not copied.
+func NewBuffer(data *[]byte, pool BufferPool) Buffer {
+	// Use the buffer's capacity instead of the length, otherwise buffers may
+	// not be reused under certain conditions. For example, if a large buffer
+	// is acquired from the pool, but fewer bytes than the buffering threshold
+	// are written to it, the buffer will not be returned to the pool.
+	if pool == nil || IsBelowBufferPoolingThreshold(cap(*data)) {
+		return (SliceBuffer)(*data)
+	}
+	b := newBuffer()
+	b.origData = data
+	b.data = *data
+	b.pool = pool
+	b.refs = refObjectPool.Get().(*atomic.Int32)
+	b.refs.Add(1)
+	return b
+}
+
+// Copy creates a new Buffer from the given data, initializing the reference
+// counter to 1.
+//
+// It acquires a []byte from the given pool and copies over the backing array
+// of the given data. The []byte acquired from the pool is returned to the
+// pool when all references to the returned Buffer are released.
+func Copy(data []byte, pool BufferPool) Buffer {
+	if IsBelowBufferPoolingThreshold(len(data)) {
+		buf := make(SliceBuffer, len(data))
+		copy(buf, data)
+		return buf
+	}
+
+	buf := pool.Get(len(data))
+	copy(*buf, data)
+	return NewBuffer(buf, pool)
+}
+
+func (b *buffer) ReadOnlyData() []byte {
+	if b.refs == nil {
+		panic("Cannot read freed buffer")
+	}
+	return b.data
+}
+
+func (b *buffer) Ref() {
+	if b.refs == nil {
+		panic("Cannot ref freed buffer")
+	}
+	b.refs.Add(1)
+}
+
+func (b *buffer) Free() {
+	if b.refs == nil {
+		panic("Cannot free freed buffer")
+	}
+
+	refs := b.refs.Add(-1)
+	switch {
+	case refs > 0:
+		return
+	case refs == 0:
+		if b.pool != nil {
+			b.pool.Put(b.origData)
+		}
+
+		refObjectPool.Put(b.refs)
+		b.origData = nil
+		b.data = nil
+		b.refs = nil
+		b.pool = nil
+		bufferObjectPool.Put(b)
+	default:
+		panic("Cannot free freed buffer")
+	}
+}
+
+func (b *buffer) Len() int {
+	return len(b.ReadOnlyData())
+}
+
+func (b *buffer) split(n int) (Buffer, Buffer) {
+	if b.refs == nil {
+		panic("Cannot split freed buffer")
+	}
+
+	b.refs.Add(1)
+	split := newBuffer()
+	split.origData = b.origData
+	split.data = b.data[n:]
+	split.refs = b.refs
+	split.pool = b.pool
+
+	b.data = b.data[:n]
+
+	return b, split
+}
+
+func (b *buffer) read(buf []byte) (int, Buffer) {
+	if b.refs == nil {
+		panic("Cannot read freed buffer")
+	}
+
+	n := copy(buf, b.data)
+	if n == len(b.data) {
+		b.Free()
+		return n, nil
+	}
+
+	b.data = b.data[n:]
+	return n, b
+}
+
+func (b *buffer) String() string {
+	return fmt.Sprintf("mem.Buffer(%p, data: %p, length: %d)", b, b.ReadOnlyData(), len(b.ReadOnlyData()))
+}
+
+// ReadUnsafe reads bytes from the given Buffer into the provided slice.
+// It does not perform safety checks.
+func ReadUnsafe(dst []byte, buf Buffer) (int, Buffer) {
+	return buf.read(dst)
+}
+
+// SplitUnsafe modifies the receiver to point to the first n bytes while it
+// returns a new reference to the remaining bytes. The returned Buffer
+// functions just like a normal reference acquired using Ref().
+func SplitUnsafe(buf Buffer, n int) (left, right Buffer) {
+	return buf.split(n)
+}
+
+type emptyBuffer struct{}
+
+func (e emptyBuffer) ReadOnlyData() []byte {
+	return nil
+}
+
+func (e emptyBuffer) Ref()  {}
+func (e emptyBuffer) Free() {}
+
+func (e emptyBuffer) Len() int {
+	return 0
+}
+
+func (e emptyBuffer) split(int) (left, right Buffer) {
+	return e, e
+}
+
+func (e emptyBuffer) read([]byte) (int, Buffer) {
+	return 0, e
+}
+
+// SliceBuffer is a Buffer implementation that wraps a byte slice. It provides
+// methods for reading, splitting, and managing the byte slice.
+type SliceBuffer []byte
+
+// ReadOnlyData returns the byte slice.
+func (s SliceBuffer) ReadOnlyData() []byte { return s }
+
+// Ref is a noop implementation of Ref.
+func (s SliceBuffer) Ref() {}
+
+// Free is a noop implementation of Free.
+func (s SliceBuffer) Free() {}
+
+// Len is a noop implementation of Len.
+func (s SliceBuffer) Len() int { return len(s) }
+
+func (s SliceBuffer) split(n int) (left, right Buffer) {
+	return s[:n], s[n:]
+}
+
+func (s SliceBuffer) read(buf []byte) (int, Buffer) {
+	n := copy(buf, s)
+	if n == len(s) {
+		return n, nil
+	}
+	return n, s[n:]
+}

vendor/google.golang.org/grpc/metadata/metadata.go

@@ -213,11 +213,6 @@ func FromIncomingContext(ctx context.Context) (MD, bool) {
 // ValueFromIncomingContext returns the metadata value corresponding to the metadata
 // key from the incoming metadata if it exists. Keys are matched in a case insensitive
 // manner.
-//
-// # Experimental
-//
-// Notice: This API is EXPERIMENTAL and may be changed or removed in a
-// later release.
 func ValueFromIncomingContext(ctx context.Context, key string) []string {
 	md, ok := ctx.Value(mdIncomingKey{}).(MD)
 	if !ok {
@@ -228,7 +223,7 @@ func ValueFromIncomingContext(ctx context.Context, key string) []string {
 		return copyOf(v)
 	}
 	for k, v := range md {
-		// Case insenitive comparison: MD is a map, and there's no guarantee
+		// Case insensitive comparison: MD is a map, and there's no guarantee
 		// that the MD attached to the context is created using our helper
 		// functions.
 		if strings.EqualFold(k, key) {

vendor/google.golang.org/grpc/peer/peer.go

@@ -22,7 +22,9 @@ package peer
 
 import (
 	"context"
+	"fmt"
 	"net"
+	"strings"
 
 	"google.golang.org/grpc/credentials"
 )
@@ -39,6 +41,34 @@ type Peer struct {
 	AuthInfo credentials.AuthInfo
 }
 
+// String ensures the Peer types implements the Stringer interface in order to
+// allow to print a context with a peerKey value effectively.
+func (p *Peer) String() string {
+	if p == nil {
+		return "Peer<nil>"
+	}
+	sb := &strings.Builder{}
+	sb.WriteString("Peer{")
+	if p.Addr != nil {
+		fmt.Fprintf(sb, "Addr: '%s', ", p.Addr.String())
+	} else {
+		fmt.Fprintf(sb, "Addr: <nil>, ")
+	}
+	if p.LocalAddr != nil {
+		fmt.Fprintf(sb, "LocalAddr: '%s', ", p.LocalAddr.String())
+	} else {
+		fmt.Fprintf(sb, "LocalAddr: <nil>, ")
+	}
+	if p.AuthInfo != nil {
+		fmt.Fprintf(sb, "AuthInfo: '%s'", p.AuthInfo.AuthType())
+	} else {
+		fmt.Fprintf(sb, "AuthInfo: <nil>")
+	}
+	sb.WriteString("}")
+
+	return sb.String()
+}
+
 type peerKey struct{}
 
 // NewContext creates a new context with peer information attached.

vendor/google.golang.org/grpc/picker_wrapper.go

@@ -20,8 +20,9 @@ package grpc
 
 import (
 	"context"
+	"fmt"
 	"io"
-	"sync"
+	"sync/atomic"
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/codes"
@@ -32,35 +33,43 @@ import (
 	"google.golang.org/grpc/status"
 )
 
+// pickerGeneration stores a picker and a channel used to signal that a picker
+// newer than this one is available.
+type pickerGeneration struct {
+	// picker is the picker produced by the LB policy.  May be nil if a picker
+	// has never been produced.
+	picker balancer.Picker
+	// blockingCh is closed when the picker has been invalidated because there
+	// is a new one available.
+	blockingCh chan struct{}
+}
+
 // pickerWrapper is a wrapper of balancer.Picker. It blocks on certain pick
 // actions and unblock when there's a picker update.
 type pickerWrapper struct {
-	mu            sync.Mutex
-	done          bool
-	blockingCh    chan struct{}
-	picker        balancer.Picker
+	// If pickerGen holds a nil pointer, the pickerWrapper is closed.
+	pickerGen     atomic.Pointer[pickerGeneration]
 	statsHandlers []stats.Handler // to record blocking picker calls
 }
 
 func newPickerWrapper(statsHandlers []stats.Handler) *pickerWrapper {
-	return &pickerWrapper{
-		blockingCh:    make(chan struct{}),
+	pw := &pickerWrapper{
 		statsHandlers: statsHandlers,
 	}
+	pw.pickerGen.Store(&pickerGeneration{
+		blockingCh: make(chan struct{}),
+	})
+	return pw
 }
 
-// updatePicker is called by UpdateBalancerState. It unblocks all blocked pick.
+// updatePicker is called by UpdateState calls from the LB policy. It
+// unblocks all blocked pick.
 func (pw *pickerWrapper) updatePicker(p balancer.Picker) {
-	pw.mu.Lock()
-	if pw.done {
-		pw.mu.Unlock()
-		return
-	}
-	pw.picker = p
-	// pw.blockingCh should never be nil.
-	close(pw.blockingCh)
-	pw.blockingCh = make(chan struct{})
-	pw.mu.Unlock()
+	old := pw.pickerGen.Swap(&pickerGeneration{
+		picker:     p,
+		blockingCh: make(chan struct{}),
+	})
+	close(old.blockingCh)
 }
 
 // doneChannelzWrapper performs the following:
@@ -97,27 +106,24 @@ func (pw *pickerWrapper) pick(ctx context.Context, failfast bool, info balancer.
 	var lastPickErr error
 
 	for {
-		pw.mu.Lock()
-		if pw.done {
-			pw.mu.Unlock()
+		pg := pw.pickerGen.Load()
+		if pg == nil {
 			return nil, balancer.PickResult{}, ErrClientConnClosing
 		}
-
-		if pw.picker == nil {
-			ch = pw.blockingCh
+		if pg.picker == nil {
+			ch = pg.blockingCh
 		}
-		if ch == pw.blockingCh {
+		if ch == pg.blockingCh {
 			// This could happen when either:
 			// - pw.picker is nil (the previous if condition), or
-			// - has called pick on the current picker.
-			pw.mu.Unlock()
+			// - we have already called pick on the current picker.
 			select {
 			case <-ctx.Done():
 				var errStr string
 				if lastPickErr != nil {
 					errStr = "latest balancer error: " + lastPickErr.Error()
 				} else {
-					errStr = ctx.Err().Error()
+					errStr = fmt.Sprintf("%v while waiting for connections to become ready", ctx.Err())
 				}
 				switch ctx.Err() {
 				case context.DeadlineExceeded:
@@ -144,9 +150,8 @@ func (pw *pickerWrapper) pick(ctx context.Context, failfast bool, info balancer.
 			}
 		}
 
-		ch = pw.blockingCh
-		p := pw.picker
-		pw.mu.Unlock()
+		ch = pg.blockingCh
+		p := pg.picker
 
 		pickResult, err := p.Pick(info)
 		if err != nil {
@@ -196,24 +201,15 @@ func (pw *pickerWrapper) pick(ctx context.Context, failfast bool, info balancer.
 }
 
 func (pw *pickerWrapper) close() {
-	pw.mu.Lock()
-	defer pw.mu.Unlock()
-	if pw.done {
-		return
-	}
-	pw.done = true
-	close(pw.blockingCh)
+	old := pw.pickerGen.Swap(nil)
+	close(old.blockingCh)
 }
 
 // reset clears the pickerWrapper and prepares it for being used again when idle
 // mode is exited.
 func (pw *pickerWrapper) reset() {
-	pw.mu.Lock()
-	defer pw.mu.Unlock()
-	if pw.done {
-		return
-	}
-	pw.blockingCh = make(chan struct{})
+	old := pw.pickerGen.Swap(&pickerGeneration{blockingCh: make(chan struct{})})
+	close(old.blockingCh)
 }
 
 // dropError is a wrapper error that indicates the LB policy wishes to drop the

vendor/google.golang.org/grpc/preloader.go

@@ -20,6 +20,7 @@ package grpc
 
 import (
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/grpc/status"
 )
 
@@ -31,9 +32,10 @@ import (
 // later release.
 type PreparedMsg struct {
 	// Struct for preparing msg before sending them
-	encodedData []byte
+	encodedData mem.BufferSlice
 	hdr         []byte
-	payload     []byte
+	payload     mem.BufferSlice
+	pf          payloadFormat
 }
 
 // Encode marshalls and compresses the message using the codec and compressor for the stream.
@@ -57,11 +59,27 @@ func (p *PreparedMsg) Encode(s Stream, msg any) error {
 	if err != nil {
 		return err
 	}
-	p.encodedData = data
-	compData, err := compress(data, rpcInfo.preloaderInfo.cp, rpcInfo.preloaderInfo.comp)
+
+	materializedData := data.Materialize()
+	data.Free()
+	p.encodedData = mem.BufferSlice{mem.SliceBuffer(materializedData)}
+
+	// TODO: it should be possible to grab the bufferPool from the underlying
+	//  stream implementation with a type cast to its actual type (such as
+	//  addrConnStream) and accessing the buffer pool directly.
+	var compData mem.BufferSlice
+	compData, p.pf, err = compress(p.encodedData, rpcInfo.preloaderInfo.cp, rpcInfo.preloaderInfo.comp, mem.DefaultBufferPool())
 	if err != nil {
 		return err
 	}
-	p.hdr, p.payload = msgHeader(data, compData)
+
+	if p.pf.isCompressed() {
+		materializedCompData := compData.Materialize()
+		compData.Free()
+		compData = mem.BufferSlice{mem.SliceBuffer(materializedCompData)}
+	}
+
+	p.hdr, p.payload = msgHeader(p.encodedData, compData, p.pf)
+
 	return nil
 }

vendor/google.golang.org/grpc/regenerate.sh

@@ -1,123 +0,0 @@
-#!/bin/bash
-# Copyright 2020 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -eu -o pipefail
-
-WORKDIR=$(mktemp -d)
-
-function finish {
-  rm -rf "$WORKDIR"
-}
-trap finish EXIT
-
-export GOBIN=${WORKDIR}/bin
-export PATH=${GOBIN}:${PATH}
-mkdir -p ${GOBIN}
-
-echo "remove existing generated files"
-# grpc_testing_not_regenerate/*.pb.go is not re-generated,
-# see grpc_testing_not_regenerate/README.md for details.
-rm -f $(find . -name '*.pb.go' | grep -v 'grpc_testing_not_regenerate')
-
-echo "go install google.golang.org/protobuf/cmd/protoc-gen-go"
-(cd test/tools && go install google.golang.org/protobuf/cmd/protoc-gen-go)
-
-echo "go install cmd/protoc-gen-go-grpc"
-(cd cmd/protoc-gen-go-grpc && go install .)
-
-echo "git clone https://github.com/grpc/grpc-proto"
-git clone --quiet https://github.com/grpc/grpc-proto ${WORKDIR}/grpc-proto
-
-echo "git clone https://github.com/protocolbuffers/protobuf"
-git clone --quiet https://github.com/protocolbuffers/protobuf ${WORKDIR}/protobuf
-
-# Pull in code.proto as a proto dependency
-mkdir -p ${WORKDIR}/googleapis/google/rpc
-echo "curl https://raw.githubusercontent.com/googleapis/googleapis/master/google/rpc/code.proto"
-curl --silent https://raw.githubusercontent.com/googleapis/googleapis/master/google/rpc/code.proto > ${WORKDIR}/googleapis/google/rpc/code.proto
-
-mkdir -p ${WORKDIR}/out
-
-# Generates sources without the embed requirement
-LEGACY_SOURCES=(
-  ${WORKDIR}/grpc-proto/grpc/binlog/v1/binarylog.proto
-  ${WORKDIR}/grpc-proto/grpc/channelz/v1/channelz.proto
-  ${WORKDIR}/grpc-proto/grpc/health/v1/health.proto
-  ${WORKDIR}/grpc-proto/grpc/lb/v1/load_balancer.proto
-  profiling/proto/service.proto
-  ${WORKDIR}/grpc-proto/grpc/reflection/v1alpha/reflection.proto
-  ${WORKDIR}/grpc-proto/grpc/reflection/v1/reflection.proto
-)
-
-# Generates only the new gRPC Service symbols
-SOURCES=(
-  $(git ls-files --exclude-standard --cached --others "*.proto" | grep -v '^\(profiling/proto/service.proto\|reflection/grpc_reflection_v1alpha/reflection.proto\)$')
-  ${WORKDIR}/grpc-proto/grpc/gcp/altscontext.proto
-  ${WORKDIR}/grpc-proto/grpc/gcp/handshaker.proto
-  ${WORKDIR}/grpc-proto/grpc/gcp/transport_security_common.proto
-  ${WORKDIR}/grpc-proto/grpc/lookup/v1/rls.proto
-  ${WORKDIR}/grpc-proto/grpc/lookup/v1/rls_config.proto
-  ${WORKDIR}/grpc-proto/grpc/testing/*.proto
-  ${WORKDIR}/grpc-proto/grpc/core/*.proto
-)
-
-# These options of the form 'Mfoo.proto=bar' instruct the codegen to use an
-# import path of 'bar' in the generated code when 'foo.proto' is imported in
-# one of the sources.
-#
-# Note that the protos listed here are all for testing purposes. All protos to
-# be used externally should have a go_package option (and they don't need to be
-# listed here).
-OPTS=Mgrpc/core/stats.proto=google.golang.org/grpc/interop/grpc_testing/core,\
-Mgrpc/testing/benchmark_service.proto=google.golang.org/grpc/interop/grpc_testing,\
-Mgrpc/testing/stats.proto=google.golang.org/grpc/interop/grpc_testing,\
-Mgrpc/testing/report_qps_scenario_service.proto=google.golang.org/grpc/interop/grpc_testing,\
-Mgrpc/testing/messages.proto=google.golang.org/grpc/interop/grpc_testing,\
-Mgrpc/testing/worker_service.proto=google.golang.org/grpc/interop/grpc_testing,\
-Mgrpc/testing/control.proto=google.golang.org/grpc/interop/grpc_testing,\
-Mgrpc/testing/test.proto=google.golang.org/grpc/interop/grpc_testing,\
-Mgrpc/testing/payloads.proto=google.golang.org/grpc/interop/grpc_testing,\
-Mgrpc/testing/empty.proto=google.golang.org/grpc/interop/grpc_testing
-
-for src in ${SOURCES[@]}; do
-  echo "protoc ${src}"
-  protoc --go_out=${OPTS}:${WORKDIR}/out --go-grpc_out=${OPTS}:${WORKDIR}/out \
-    -I"." \
-    -I${WORKDIR}/grpc-proto \
-    -I${WORKDIR}/googleapis \
-    -I${WORKDIR}/protobuf/src \
-    ${src}
-done
-
-for src in ${LEGACY_SOURCES[@]}; do
-  echo "protoc ${src}"
-  protoc --go_out=${OPTS}:${WORKDIR}/out --go-grpc_out=${OPTS},require_unimplemented_servers=false:${WORKDIR}/out \
-    -I"." \
-    -I${WORKDIR}/grpc-proto \
-    -I${WORKDIR}/googleapis \
-    -I${WORKDIR}/protobuf/src \
-    ${src}
-done
-
-# The go_package option in grpc/lookup/v1/rls.proto doesn't match the
-# current location. Move it into the right place.
-mkdir -p ${WORKDIR}/out/google.golang.org/grpc/internal/proto/grpc_lookup_v1
-mv ${WORKDIR}/out/google.golang.org/grpc/lookup/grpc_lookup_v1/* ${WORKDIR}/out/google.golang.org/grpc/internal/proto/grpc_lookup_v1
-
-# grpc_testing_not_regenerate/*.pb.go are not re-generated,
-# see grpc_testing_not_regenerate/README.md for details.
-rm ${WORKDIR}/out/google.golang.org/grpc/reflection/grpc_testing_not_regenerate/*.pb.go
-
-cp -R ${WORKDIR}/out/google.golang.org/grpc/* .

vendor/google.golang.org/grpc/resolver/dns/dns_resolver.go

@@ -18,9 +18,6 @@
 
 // Package dns implements a dns resolver to be installed as the default resolver
 // in grpc.
-//
-// Deprecated: this package is imported by grpc and should not need to be
-// imported directly by users.
 package dns
 
 import (
@@ -52,3 +49,12 @@ func SetResolvingTimeout(timeout time.Duration) {
 func NewBuilder() resolver.Builder {
 	return dns.NewBuilder()
 }
+
+// SetMinResolutionInterval sets the default minimum interval at which DNS
+// re-resolutions are allowed. This helps to prevent excessive re-resolution.
+//
+// It must be called only at application startup, before any gRPC calls are
+// made. Modifying this value after initialization is not thread-safe.
+func SetMinResolutionInterval(d time.Duration) {
+	dns.MinResolutionInterval = d
+}

vendor/google.golang.org/grpc/resolver/map.go

@@ -18,16 +18,28 @@
 
 package resolver
 
-type addressMapEntry struct {
+import (
+	"encoding/base64"
+	"sort"
+	"strings"
+)
+
+type addressMapEntry[T any] struct {
 	addr  Address
-	value any
+	value T
 }
 
-// AddressMap is a map of addresses to arbitrary values taking into account
+// AddressMap is an AddressMapV2[any].  It will be deleted in an upcoming
+// release of grpc-go.
+//
+// Deprecated: use the generic AddressMapV2 type instead.
+type AddressMap = AddressMapV2[any]
+
+// AddressMapV2 is a map of addresses to arbitrary values taking into account
 // Attributes.  BalancerAttributes are ignored, as are Metadata and Type.
 // Multiple accesses may not be performed concurrently.  Must be created via
 // NewAddressMap; do not construct directly.
-type AddressMap struct {
+type AddressMapV2[T any] struct {
 	// The underlying map is keyed by an Address with fields that we don't care
 	// about being set to their zero values. The only fields that we care about
 	// are `Addr`, `ServerName` and `Attributes`. Since we need to be able to
@@ -41,23 +53,30 @@ type AddressMap struct {
 	// The value type of the map contains a slice of addresses which match the key
 	// in their `Addr` and `ServerName` fields and contain the corresponding value
 	// associated with them.
-	m map[Address]addressMapEntryList
+	m map[Address]addressMapEntryList[T]
 }
 
 func toMapKey(addr *Address) Address {
 	return Address{Addr: addr.Addr, ServerName: addr.ServerName}
 }
 
-type addressMapEntryList []*addressMapEntry
+type addressMapEntryList[T any] []*addressMapEntry[T]
 
-// NewAddressMap creates a new AddressMap.
+// NewAddressMap creates a new AddressMapV2[any].
+//
+// Deprecated: use the generic NewAddressMapV2 constructor instead.
 func NewAddressMap() *AddressMap {
-	return &AddressMap{m: make(map[Address]addressMapEntryList)}
+	return NewAddressMapV2[any]()
+}
+
+// NewAddressMapV2 creates a new AddressMapV2.
+func NewAddressMapV2[T any]() *AddressMapV2[T] {
+	return &AddressMapV2[T]{m: make(map[Address]addressMapEntryList[T])}
 }
 
 // find returns the index of addr in the addressMapEntry slice, or -1 if not
 // present.
-func (l addressMapEntryList) find(addr Address) int {
+func (l addressMapEntryList[T]) find(addr Address) int {
 	for i, entry := range l {
 		// Attributes are the only thing to match on here, since `Addr` and
 		// `ServerName` are already equal.
@@ -69,28 +88,28 @@ func (l addressMapEntryList) find(addr Address) int {
 }
 
 // Get returns the value for the address in the map, if present.
-func (a *AddressMap) Get(addr Address) (value any, ok bool) {
+func (a *AddressMapV2[T]) Get(addr Address) (value T, ok bool) {
 	addrKey := toMapKey(&addr)
 	entryList := a.m[addrKey]
 	if entry := entryList.find(addr); entry != -1 {
 		return entryList[entry].value, true
 	}
-	return nil, false
+	return value, false
 }
 
 // Set updates or adds the value to the address in the map.
-func (a *AddressMap) Set(addr Address, value any) {
+func (a *AddressMapV2[T]) Set(addr Address, value T) {
 	addrKey := toMapKey(&addr)
 	entryList := a.m[addrKey]
 	if entry := entryList.find(addr); entry != -1 {
 		entryList[entry].value = value
 		return
 	}
-	a.m[addrKey] = append(entryList, &addressMapEntry{addr: addr, value: value})
+	a.m[addrKey] = append(entryList, &addressMapEntry[T]{addr: addr, value: value})
 }
 
 // Delete removes addr from the map.
-func (a *AddressMap) Delete(addr Address) {
+func (a *AddressMapV2[T]) Delete(addr Address) {
 	addrKey := toMapKey(&addr)
 	entryList := a.m[addrKey]
 	entry := entryList.find(addr)
@@ -107,7 +126,7 @@ func (a *AddressMap) Delete(addr Address) {
 }
 
 // Len returns the number of entries in the map.
-func (a *AddressMap) Len() int {
+func (a *AddressMapV2[T]) Len() int {
 	ret := 0
 	for _, entryList := range a.m {
 		ret += len(entryList)
@@ -116,7 +135,7 @@ func (a *AddressMap) Len() int {
 }
 
 // Keys returns a slice of all current map keys.
-func (a *AddressMap) Keys() []Address {
+func (a *AddressMapV2[T]) Keys() []Address {
 	ret := make([]Address, 0, a.Len())
 	for _, entryList := range a.m {
 		for _, entry := range entryList {
@@ -127,8 +146,8 @@ func (a *AddressMap) Keys() []Address {
 }
 
 // Values returns a slice of all current map values.
-func (a *AddressMap) Values() []any {
-	ret := make([]any, 0, a.Len())
+func (a *AddressMapV2[T]) Values() []T {
+	ret := make([]T, 0, a.Len())
 	for _, entryList := range a.m {
 		for _, entry := range entryList {
 			ret = append(ret, entry.value)
@@ -137,70 +156,65 @@ func (a *AddressMap) Values() []any {
 	return ret
 }
 
-type endpointNode struct {
-	addrs map[string]struct{}
-}
-
-// Equal returns whether the unordered set of addrs are the same between the
-// endpoint nodes.
-func (en *endpointNode) Equal(en2 *endpointNode) bool {
-	if len(en.addrs) != len(en2.addrs) {
-		return false
-	}
-	for addr := range en.addrs {
-		if _, ok := en2.addrs[addr]; !ok {
-			return false
-		}
-	}
-	return true
-}
-
-func toEndpointNode(endpoint Endpoint) endpointNode {
-	en := make(map[string]struct{})
-	for _, addr := range endpoint.Addresses {
-		en[addr.Addr] = struct{}{}
-	}
-	return endpointNode{
-		addrs: en,
-	}
-}
+type endpointMapKey string
 
 // EndpointMap is a map of endpoints to arbitrary values keyed on only the
 // unordered set of address strings within an endpoint. This map is not thread
 // safe, thus it is unsafe to access concurrently. Must be created via
 // NewEndpointMap; do not construct directly.
-type EndpointMap struct {
-	endpoints map[*endpointNode]any
+type EndpointMap[T any] struct {
+	endpoints map[endpointMapKey]endpointData[T]
+}
+
+type endpointData[T any] struct {
+	// decodedKey stores the original key to avoid decoding when iterating on
+	// EndpointMap keys.
+	decodedKey Endpoint
+	value      T
 }
 
 // NewEndpointMap creates a new EndpointMap.
-func NewEndpointMap() *EndpointMap {
-	return &EndpointMap{
-		endpoints: make(map[*endpointNode]any),
+func NewEndpointMap[T any]() *EndpointMap[T] {
+	return &EndpointMap[T]{
+		endpoints: make(map[endpointMapKey]endpointData[T]),
 	}
 }
 
+// encodeEndpoint returns a string that uniquely identifies the unordered set of
+// addresses within an endpoint.
+func encodeEndpoint(e Endpoint) endpointMapKey {
+	addrs := make([]string, 0, len(e.Addresses))
+	// base64 encoding the address strings restricts the characters present
+	// within the strings. This allows us to use a delimiter without the need of
+	// escape characters.
+	for _, addr := range e.Addresses {
+		addrs = append(addrs, base64.StdEncoding.EncodeToString([]byte(addr.Addr)))
+	}
+	sort.Strings(addrs)
+	// " " should not appear in base64 encoded strings.
+	return endpointMapKey(strings.Join(addrs, " "))
+}
+
 // Get returns the value for the address in the map, if present.
-func (em *EndpointMap) Get(e Endpoint) (value any, ok bool) {
-	en := toEndpointNode(e)
-	if endpoint := em.find(en); endpoint != nil {
-		return em.endpoints[endpoint], true
+func (em *EndpointMap[T]) Get(e Endpoint) (value T, ok bool) {
+	val, found := em.endpoints[encodeEndpoint(e)]
+	if found {
+		return val.value, true
 	}
-	return nil, false
+	return value, false
 }
 
 // Set updates or adds the value to the address in the map.
-func (em *EndpointMap) Set(e Endpoint, value any) {
-	en := toEndpointNode(e)
-	if endpoint := em.find(en); endpoint != nil {
-		em.endpoints[endpoint] = value
-		return
+func (em *EndpointMap[T]) Set(e Endpoint, value T) {
+	en := encodeEndpoint(e)
+	em.endpoints[en] = endpointData[T]{
+		decodedKey: Endpoint{Addresses: e.Addresses},
+		value:      value,
 	}
-	em.endpoints[&en] = value
 }
 
 // Len returns the number of entries in the map.
-func (em *EndpointMap) Len() int {
+func (em *EndpointMap[T]) Len() int {
 	return len(em.endpoints)
 }
 
@@ -209,43 +223,25 @@ func (em *EndpointMap) Len() int {
 // the unordered set of addresses. Thus, endpoint information returned is not
 // the full endpoint data (drops duplicated addresses and attributes) but can be
 // used for EndpointMap accesses.
-func (em *EndpointMap) Keys() []Endpoint {
+func (em *EndpointMap[T]) Keys() []Endpoint {
 	ret := make([]Endpoint, 0, len(em.endpoints))
-	for en := range em.endpoints {
-		var endpoint Endpoint
-		for addr := range en.addrs {
-			endpoint.Addresses = append(endpoint.Addresses, Address{Addr: addr})
-		}
-		ret = append(ret, endpoint)
+	for _, en := range em.endpoints {
+		ret = append(ret, en.decodedKey)
 	}
 	return ret
 }
 
 // Values returns a slice of all current map values.
-func (em *EndpointMap) Values() []any {
-	ret := make([]any, 0, len(em.endpoints))
+func (em *EndpointMap[T]) Values() []T {
+	ret := make([]T, 0, len(em.endpoints))
 	for _, val := range em.endpoints {
-		ret = append(ret, val)
+		ret = append(ret, val.value)
 	}
 	return ret
 }
 
-// find returns a pointer to the endpoint node in em if the endpoint node is
-// already present. If not found, nil is returned. The comparisons are done on
-// the unordered set of addresses within an endpoint.
-func (em EndpointMap) find(e endpointNode) *endpointNode {
-	for endpoint := range em.endpoints {
-		if e.Equal(endpoint) {
-			return endpoint
-		}
-	}
-	return nil
-}
-
 // Delete removes the specified endpoint from the map.
-func (em *EndpointMap) Delete(e Endpoint) {
-	en := toEndpointNode(e)
-	if entry := em.find(en); entry != nil {
-		delete(em.endpoints, entry)
-	}
+func (em *EndpointMap[T]) Delete(e Endpoint) {
+	en := encodeEndpoint(e)
+	delete(em.endpoints, en)
 }

vendor/google.golang.org/grpc/resolver/resolver.go

@@ -22,6 +22,7 @@ package resolver
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net"
 	"net/url"
@@ -29,6 +30,7 @@ import (
 
 	"google.golang.org/grpc/attributes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/experimental/stats"
 	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/serviceconfig"
 )
@@ -174,6 +176,8 @@ type BuildOptions struct {
 	// Authority is the effective authority of the clientconn for which the
 	// resolver is built.
 	Authority string
+	// MetricsRecorder is the metrics recorder to do recording.
+	MetricsRecorder stats.MetricsRecorder
 }
 
 // An Endpoint is one network endpoint, or server, which may have multiple
@@ -237,8 +241,8 @@ type ClientConn interface {
 	// UpdateState can be omitted.
 	UpdateState(State) error
 	// ReportError notifies the ClientConn that the Resolver encountered an
-	// error.  The ClientConn will notify the load balancer and begin calling
-	// ResolveNow on the Resolver with exponential backoff.
+	// error. The ClientConn then forwards this error to the load balancing
+	// policy.
 	ReportError(error)
 	// NewAddress is called by resolver to notify ClientConn a new list
 	// of resolved addresses.
@@ -330,3 +334,20 @@ type AuthorityOverrider interface {
 	// typically in line, and must keep it unchanged.
 	OverrideAuthority(Target) string
 }
+
+// ValidateEndpoints validates endpoints from a petiole policy's perspective.
+// Petiole policies should call this before calling into their children. See
+// [gRPC A61](https://github.com/grpc/proposal/blob/master/A61-IPv4-IPv6-dualstack-backends.md)
+// for details.
+func ValidateEndpoints(endpoints []Endpoint) error {
+	if len(endpoints) == 0 {
+		return errors.New("endpoints list is empty")
+	}
+
+	for _, endpoint := range endpoints {
+		for range endpoint.Addresses {
+			return nil
+		}
+	}
+	return errors.New("endpoints list contains no addresses")
+}