fix: too many conn in parallel

go.mod

@@ -1,17 +1,17 @@
 module github.com/fumiama/dnskip
 
-go 1.22
+go 1.24.0
 
 require (
-	github.com/FloatTech/ttl v0.0.0-20250224045156-012b1463287d
 	github.com/fumiama/orbyte v0.0.0-20251002065953-3bb358367eb5
 	github.com/fumiama/terasu v1.0.2
-	github.com/sirupsen/logrus v1.9.3
+	github.com/sirupsen/logrus v1.9.4
 )
 
 require (
+	github.com/FloatTech/ttl v0.0.0-20250224045156-012b1463287d // indirect
 	github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7 // indirect
-	golang.org/x/net v0.28.0 // indirect
+	golang.org/x/net v0.49.0 // indirect
-	golang.org/x/sys v0.23.0 // indirect
+	golang.org/x/sys v0.40.0 // indirect
-	golang.org/x/text v0.17.0 // indirect
+	golang.org/x/text v0.33.0 // indirect
 )

go.sum

@@ -2,7 +2,6 @@ github.com/FloatTech/ttl v0.0.0-20250224045156-012b1463287d h1:mUQ/c3wXKsUGa4Sg9
 github.com/FloatTech/ttl v0.0.0-20250224045156-012b1463287d/go.mod h1:fHZFWGquNXuHttu9dUYoKuNbm3dzLETnIOnm1muSfDs=
 github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7 h1:S/ferNiehVjNaBMNNBxUjLtVmP/YWD6Yh79RfPv4ehU=
 github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7/go.mod h1:vD7Ra3Q9onRtojoY5sMCLQ7JBgjUsrXDnDKyFxqpf9w=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fumiama/orbyte v0.0.0-20251002065953-3bb358367eb5 h1:j9o0XVvdAeLwrBYMnh0SerrMc9CgNU6AGszbsvFzoc0=
@@ -11,20 +10,15 @@ github.com/fumiama/terasu v1.0.2 h1:Dxj2vPIgLHyeMlBd61xYHx5Jg8v7k24yg7taNLlK8/8=
 github.com/fumiama/terasu v1.0.2/go.mod h1:1eHzpL/GJVcOnqEkh1vUbKu2zo6gojSuueUNJ9yHJE0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.4 h1:TsZE7l11zFCLZnZ+teH4Umoq5BhEIfIzfRDZ1Uzql2w=
-github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/sirupsen/logrus v1.9.4/go.mod h1:ftWc9WdOfJ0a92nsE2jF5u5ZwH8Bv2zdeOC42RjbV2g=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
-github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
-golang.org/x/net v0.28.0 h1:a9JDOJc5GMUJ0+UDqmLT86WiEy7iWyIhz8gz8E4e5hE=
+golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
-golang.org/x/net v0.28.0/go.mod h1:yqtgsTWOOnlGLG9GFRrK3++bGOUEkNBoHZc8MEDWPNg=
+golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
-golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
-golang.org/x/sys v0.23.0 h1:YfKFowiIMvtgl1UERQoTPPToxltDeZfbj4H7dVUCwmM=
+golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
-golang.org/x/sys v0.23.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.17.0 h1:XtiM5bkSOt+ewxlOE/aE/AKEHibwj/6gvWMl9Rsh0Qc=
-golang.org/x/text v0.17.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"crypto/tls"
 	"encoding/binary"
 	"errors"
 	"flag"
@@ -9,11 +10,12 @@ import (
 	"math"
 	"net"
 	"net/netip"
+	"runtime"
+	"sync"
 	"sync/atomic"
 	"time"
 	"unsafe"
 
-	"github.com/FloatTech/ttl"
 	"github.com/fumiama/orbyte/pbuf"
 	"github.com/fumiama/terasu"
 	"github.com/fumiama/terasu/dns"
@@ -22,14 +24,6 @@ import (
 )
 
 var (
-	freeconn     = uintptr(0)
-	tlsconnCache = ttl.NewCacheOn(
-		5*time.Minute, [4]func(uint8, net.Conn){
-			nil, nil, func(_ uint8, c net.Conn) {
-				logrus.Warnln("Close idle/error tls conn to", c.RemoteAddr())
-				_ = c.Close()
-			}, nil,
-		})
 	fallback *net.UDPAddr
 	forcefb  bool
 	timeout  uint
@@ -103,7 +97,8 @@ RECONN:
 func response(cnt uint8, conn *net.UDPConn, addr *net.UDPAddr, payload pbuf.Bytes) {
 	var (
 		err     error
-		tlsconn net.Conn
+		cl      func()
+		tlsconn *tls.Conn
 		loopcnt = 0
 		ctx     context.Context
 		cancel  context.CancelFunc
@@ -114,12 +109,12 @@ func response(cnt uint8, conn *net.UDPConn, addr *net.UDPAddr, payload pbuf.Byte
 	}
 
 	defer releasefree(cnt)
-	logrus.Debugln(addr, "Run on lock", cnt)
+	logrus.Debugln(addr, "Run thread", cnt)
 
 REDAIL:
 	ctx, cancel = context.WithTimeout(context.Background(), time.Second*time.Duration(timeout))
 	defer cancel()
-	tlsconn, err = dialtls(cnt, ctx)
+	tlsconn, cl, err = dialtls(cnt, ctx)
 	if err != nil {
 		logrus.Warnln(addr, "Dial DNS server err:", err)
 		return
@@ -127,6 +122,8 @@ REDAIL:
 	logrus.Debugln(addr, "Dial to DNS server", tlsconn.RemoteAddr())
 
 	payload.V(func(b []byte) {
+		defer cl()
+
 		var plen [2]byte
 		binary.BigEndian.PutUint16(plen[:], uint16(len(b)))
 		_, err = io.Copy(tlsconn, &net.Buffers{plen[:], b})
@@ -162,7 +159,10 @@ REDAIL:
 		return
 	}
 	logrus.Warnln(addr, "Proxy to DNS server err:", err)
-	tlsconnCache.Delete(cnt)
+	atomic.StorePointer(
+		(*unsafe.Pointer)(unsafe.Pointer(&remoconn)),
+		unsafe.Pointer(nil),
+	)
 	loopcnt++
 	if loopcnt < 2 {
 		goto REDAIL
@@ -214,17 +214,21 @@ FALLBACK:
 	})
 }
 
+var (
+	freeconn = uint32(0)
+)
+
 // lockfree is spin update
 func lockfree() uint8 {
-	old := atomic.LoadUintptr(&freeconn)
+	old := atomic.LoadUint32(&freeconn)
 	for i := uint8(0); i < uint8(unsafe.Sizeof(uintptr(0)))*8; i++ {
 		for old&(1<<i) == 0 { // is free
-			ok := atomic.CompareAndSwapUintptr(&freeconn, old, old|(1<<i))
+			ok := atomic.CompareAndSwapUint32(&freeconn, old, old|(1<<i))
 			if ok {
 				return i
 			}
 			// update latest
-			old = atomic.LoadUintptr(&freeconn)
+			old = atomic.LoadUint32(&freeconn)
 		}
 	}
 	return math.MaxUint8
@@ -232,29 +236,52 @@ func lockfree() uint8 {
 
 // releasefree is spin update
 func releasefree(i uint8) {
-	old := atomic.LoadUintptr(&freeconn)
+	old := atomic.LoadUint32(&freeconn)
 	for old&(1<<i) != 0 { // is not free
-		ok := atomic.CompareAndSwapUintptr(&freeconn, old, old&^(1<<i))
+		ok := atomic.CompareAndSwapUint32(&freeconn, old, old&^(1<<i))
 		if ok {
 			return
 		}
 		// update latest
-		old = atomic.LoadUintptr(&freeconn)
+		old = atomic.LoadUint32(&freeconn)
 	}
+	logrus.Debugln("Free thread", i)
 }
 
-func dialtls(cnt uint8, ctx context.Context) (net.Conn, error) {
+var (
-	conn := tlsconnCache.Get(cnt)
+	remoconn *tls.Conn
+	connmu   sync.Mutex
+)
+
+func dialtls(cnt uint8, ctx context.Context) (*tls.Conn, func(), error) {
+	conn := (*tls.Conn)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&remoconn))))
 	if conn != nil {
-		logrus.Debugln("Lock", cnt, "get cached tls conn to", conn.RemoteAddr())
+		logrus.Debugln("Thread", cnt, "get cached tls conn to", conn.RemoteAddr())
-		return conn, nil
+		connmu.Lock()
+		return conn, connmu.Unlock, nil
+	}
+	// slow path
+	connmu.Lock()
+	conn = (*tls.Conn)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&remoconn))))
+	if conn != nil {
+		logrus.Debugln("Thread", cnt, "slowly get cached tls conn to", conn.RemoteAddr())
+		return conn, connmu.Unlock, nil
 	}
 	// dummy nw and addr
-	conn, err := dns.DefaultResolver.Dial(ctx, "", "")
+	connintf, err := dns.DefaultResolver.Dial(ctx, "", "")
 	if err != nil {
-		return nil, err
+		connmu.Unlock()
+		return nil, nil, err
 	}
-	tlsconnCache.Set(cnt, conn)
+	conn = connintf.(*tls.Conn)
-	logrus.Debugln("Lock", cnt, "set new tls conn to", conn.RemoteAddr())
+	atomic.StorePointer(
-	return conn, nil
+		(*unsafe.Pointer)(unsafe.Pointer(&remoconn)),
+		unsafe.Pointer(conn),
+	)
+	runtime.SetFinalizer(conn, func(conn *tls.Conn) {
+		logrus.Warnln("Cleanup unused conn to", conn.RemoteAddr())
+		_ = conn.Close()
+	})
+	logrus.Debugln("Thread", cnt, "set new tls conn to", conn.RemoteAddr())
+	return conn, connmu.Unlock, nil
 }