opt: use accept4 where available (#535)

* opt: use accept4 where available

* ci: update GitHub Actions

.github/workflows/test.yml

@@ -37,18 +37,19 @@ jobs:
     name: Run golangci-lint
     runs-on: ${{ matrix.os }}
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
           go-version: '^1.17'
-
-      - name: Checkout repository
-        uses: actions/checkout@v4
+          cache: false
 
       - name: Setup and run golangci-lint
-        uses: golangci/golangci-lint-action@v3
+        uses: golangci/golangci-lint-action@v4
         with:
-          version: v1.55.2
+          version: v1.56.2
           args: -v -E gofumpt -E gocritic -E misspell -E revive -E godot --timeout 5m
   test:
     needs: lint
@@ -86,19 +87,6 @@ jobs:
           echo "SHORT_SHA=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
           echo "GO_CACHE=$(go env GOCACHE)" >> $GITHUB_OUTPUT
 
-      - name: Cache go modules
-        uses: actions/cache@v4
-        with:
-          path: |
-            ${{ steps.go-env.outputs.GO_CACHE }}
-            ~/go/pkg/mod
-            ~/.cache/go-build
-            ~/Library/Caches/go-build
-            ~\AppData\Local\go-build
-          key: ${{ runner.os }}-${{ matrix.go }}-go-ci-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-${{ matrix.go }}-go-ci-
-
       - name: Run unit tests for packages
         run: go test $(go list ./... | tail -n +2)
 

.github/workflows/test_gc_opt.yml

@@ -37,18 +37,19 @@ jobs:
     name: Run golangci-lint
     runs-on: ${{ matrix.os }}
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
           go-version: '^1.17'
-
-      - name: Checkout repository
-        uses: actions/checkout@v4
+          cache: false
 
       - name: Setup and run golangci-lint
-        uses: golangci/golangci-lint-action@v3
+        uses: golangci/golangci-lint-action@v4
         with:
-          version: v1.55.2
+          version: v1.56.2
           args: -v -E gofumpt -E gocritic -E misspell -E revive -E godot --timeout 5m
   test:
     needs: lint
@@ -86,19 +87,6 @@ jobs:
           echo "SHORT_SHA=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
           echo "GO_CACHE=$(go env GOCACHE)" >> $GITHUB_OUTPUT
 
-      - name: Cache go modules
-        uses: actions/cache@v4
-        with:
-          path: |
-            ${{ steps.go-env.outputs.GO_CACHE }}
-            ~/go/pkg/mod
-            ~/.cache/go-build
-            ~/Library/Caches/go-build
-            ~\AppData\Local\go-build
-          key: ${{ runner.os }}-${{ matrix.go }}-go-ci-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-${{ matrix.go }}-go-ci-
-
       - name: Run unit tests for packages
         run: go test $(go list ./... | tail -n +2)
 

.github/workflows/test_poll_opt.yml

@@ -36,18 +36,19 @@ jobs:
     name: Run golangci-lint
     runs-on: ${{ matrix.os }}
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
           go-version: '^1.17'
-
-      - name: Checkout repository
-        uses: actions/checkout@v4
+          cache: false
 
       - name: Setup and run golangci-lint
-        uses: golangci/golangci-lint-action@v3
+        uses: golangci/golangci-lint-action@v4
         with:
-          version: v1.55.2
+          version: v1.56.2
           args: -v -E gofumpt -E gocritic -E misspell -E revive -E godot
   test:
     needs: lint
@@ -82,19 +83,6 @@ jobs:
           echo "SHORT_SHA=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
           echo "GO_CACHE=$(go env GOCACHE)" >> $GITHUB_OUTPUT
 
-      - name: Cache go modules
-        uses: actions/cache@v4
-        with:
-          path: |
-            ${{ steps.go-env.outputs.GO_CACHE }}
-            ~/go/pkg/mod
-            ~/.cache/go-build
-            ~/Library/Caches/go-build
-            ~\AppData\Local\go-build
-          key: ${{ runner.os }}-${{ matrix.go }}-go-ci-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-${{ matrix.go }}-go-ci-
-
       - name: Run unit tests for packages
         run: go test $(go list ./... | tail -n +2)
 

.github/workflows/test_poll_opt_gc_opt.yml

@@ -36,18 +36,19 @@ jobs:
     name: Run golangci-lint
     runs-on: ${{ matrix.os }}
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
           go-version: '^1.17'
-
-      - name: Checkout repository
-        uses: actions/checkout@v4
+          cache: false
 
       - name: Setup and run golangci-lint
-        uses: golangci/golangci-lint-action@v3
+        uses: golangci/golangci-lint-action@v4
         with:
-          version: v1.55.2
+          version: v1.56.2
           args: -v -E gofumpt -E gocritic -E misspell -E revive -E godot
   test:
     needs: lint
@@ -82,19 +83,6 @@ jobs:
           echo "SHORT_SHA=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
           echo "GO_CACHE=$(go env GOCACHE)" >> $GITHUB_OUTPUT
 
-      - name: Cache go modules
-        uses: actions/cache@v4
-        with:
-          path: |
-            ${{ steps.go-env.outputs.GO_CACHE }}
-            ~/go/pkg/mod
-            ~/.cache/go-build
-            ~/Library/Caches/go-build
-            ~\AppData\Local\go-build
-          key: ${{ runner.os }}-${{ matrix.go }}-go-ci-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-${{ matrix.go }}-go-ci-
-
       - name: Run unit tests for packages
         run: go test $(go list ./... | tail -n +2)
 

acceptor_bsd.go

@@ -26,10 +26,3 @@ func (eng *engine) accept(fd int, filter netpoll.IOEvent, flags netpoll.IOFlags)
 func (el *eventloop) accept(fd int, filter netpoll.IOEvent, flags netpoll.IOFlags) error {
 	return el.accept1(fd, filter, flags)
 }
-
-// The canonical BSD sockets implementation will inherit file status flags
-// from the listening socket, so we don't need to set the non-blocking flag
-// for the accepted sockets explicitly.
-func setNonBlock(_ int, _ bool) error {
-	return nil
-}

acceptor_linux.go

@@ -17,11 +17,7 @@
 
 package gnet
 
-import (
-	"golang.org/x/sys/unix"
-
-	"github.com/panjf2000/gnet/v2/internal/netpoll"
-)
+import "github.com/panjf2000/gnet/v2/internal/netpoll"
 
 func (eng *engine) accept(fd int, ev netpoll.IOEvent) error {
 	return eng.accept1(fd, ev, 0)
@@ -30,7 +26,3 @@ func (eng *engine) accept(fd int, ev netpoll.IOEvent) error {
 func (el *eventloop) accept(fd int, ev netpoll.IOEvent) error {
 	return el.accept1(fd, ev, 0)
 }
-
-func setNonBlock(fd int, nonBlocking bool) error {
-	return unix.SetNonblock(fd, nonBlocking)
-}

acceptor_unix.go

@@ -18,7 +18,6 @@
 package gnet
 
 import (
-	"os"
 	"time"
 
 	"golang.org/x/sys/unix"
@@ -30,7 +29,7 @@ import (
 )
 
 func (eng *engine) accept1(fd int, _ netpoll.IOEvent, _ netpoll.IOFlags) error {
-	nfd, sa, err := unix.Accept(fd)
+	nfd, sa, err := socket.Accept(fd)
 	if err != nil {
 		switch err {
 		case unix.EINTR, unix.EAGAIN, unix.ECONNABORTED:
@@ -44,9 +43,6 @@ func (eng *engine) accept1(fd int, _ netpoll.IOEvent, _ netpoll.IOFlags) error {
 		}
 	}
 
-	if err = os.NewSyscallError("fcntl nonblock", setNonBlock(nfd, true)); err != nil {
-		return err
-	}
 	remoteAddr := socket.SockaddrToTCPOrUnixAddr(sa)
 	if eng.opts.TCPKeepAlive > 0 && eng.ln.network == "tcp" {
 		err = socket.SetKeepAlivePeriod(nfd, int(eng.opts.TCPKeepAlive.Seconds()))
@@ -69,7 +65,7 @@ func (el *eventloop) accept1(fd int, ev netpoll.IOEvent, flags netpoll.IOFlags)
 		return el.readUDP1(fd, ev, flags)
 	}
 
-	nfd, sa, err := unix.Accept(el.ln.fd)
+	nfd, sa, err := socket.Accept(el.ln.fd)
 	if err != nil {
 		switch err {
 		case unix.EINTR, unix.EAGAIN, unix.ECONNABORTED:
@@ -83,9 +79,6 @@ func (el *eventloop) accept1(fd int, ev netpoll.IOEvent, flags netpoll.IOFlags)
 		}
 	}
 
-	if err = os.NewSyscallError("fcntl nonblock", setNonBlock(nfd, true)); err != nil {
-		return err
-	}
 	remoteAddr := socket.SockaddrToTCPOrUnixAddr(sa)
 	if el.engine.opts.TCPKeepAlive > 0 && el.ln.network == "tcp" {
 		err = socket.SetKeepAlivePeriod(nfd, int(el.engine.opts.TCPKeepAlive/time.Second))

engine_unix.go

@@ -66,14 +66,14 @@ func (eng *engine) shutdown(err error) {
 }
 
 func (eng *engine) startEventLoops() {
-	eng.eventLoops.iterate(func(i int, el *eventloop) bool {
+	eng.eventLoops.iterate(func(_ int, el *eventloop) bool {
 		eng.workerPool.Go(el.run)
 		return true
 	})
 }
 
 func (eng *engine) closeEventLoops() {
-	eng.eventLoops.iterate(func(i int, el *eventloop) bool {
+	eng.eventLoops.iterate(func(_ int, el *eventloop) bool {
 		el.ln.close()
 		_ = el.poller.Close()
 		return true
@@ -88,7 +88,7 @@ func (eng *engine) closeEventLoops() {
 }
 
 func (eng *engine) startSubReactors() {
-	eng.eventLoops.iterate(func(i int, el *eventloop) bool {
+	eng.eventLoops.iterate(func(_ int, el *eventloop) bool {
 		eng.workerPool.Go(el.activateSubReactor)
 		return true
 	})
@@ -202,7 +202,7 @@ func (eng *engine) stop(s Engine) {
 	eng.eventHandler.OnShutdown(s)
 
 	// Notify all event-loops to exit.
-	eng.eventLoops.iterate(func(i int, el *eventloop) bool {
+	eng.eventLoops.iterate(func(_ int, el *eventloop) bool {
 		err := el.poller.UrgentTrigger(func(_ interface{}) error { return errors.ErrEngineShutdown }, nil)
 		if err != nil {
 			eng.opts.Logger.Errorf("failed to call UrgentTrigger on sub event-loop when stopping engine: %v", err)

gnet.go

@@ -65,7 +65,7 @@ func (e Engine) CountConnections() (count int) {
 		return -1
 	}
 
-	e.eng.eventLoops.iterate(func(i int, el *eventloop) bool {
+	e.eng.eventLoops.iterate(func(_ int, el *eventloop) bool {
 		count += int(el.countConn())
 		return true
 	})

gnet_test.go

@@ -886,7 +886,7 @@ func (t *testCloseConnectionServer) OnTraffic(c Conn) (action Action) {
 	_, _ = c.Discard(-1)
 	go func() {
 		time.Sleep(time.Second)
-		_ = c.CloseWithCallback(func(c Conn, err error) error {
+		_ = c.CloseWithCallback(func(_ Conn, err error) error {
 			assert.ErrorIsf(t.tester, err, errorx.ErrEngineShutdown, "should be engine shutdown error")
 			return nil
 		})

internal/socket/sock_cloexec.go

@@ -22,3 +22,7 @@ import "golang.org/x/sys/unix"
 func sysSocket(family, sotype, proto int) (int, error) {
 	return unix.Socket(family, sotype|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, proto)
 }
+
+func sysAccept(fd int) (nfd int, sa unix.Sockaddr, err error) {
+	return unix.Accept4(fd, unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC)
+}

internal/socket/socket.go

@@ -22,6 +22,8 @@ package socket
 
 import (
 	"net"
+
+	"golang.org/x/sys/unix"
 )
 
 // Option is used for setting an option on socket.
@@ -44,3 +46,9 @@ func UDPSocket(proto, addr string, connect bool, sockOpts ...Option) (int, net.A
 func UnixSocket(proto, addr string, passive bool, sockOpts ...Option) (int, net.Addr, error) {
 	return udsSocket(proto, addr, passive, sockOpts...)
 }
+
+// Accept accepts the next incoming socket along with setting
+// O_NONBLOCK and O_CLOEXEC flags on it.
+func Accept(fd int) (int, unix.Sockaddr, error) {
+	return sysAccept(fd)
+}

internal/socket/sys_cloexec.go

@@ -29,14 +29,26 @@ func sysSocket(family, sotype, proto int) (fd int, err error) {
 		unix.CloseOnExec(fd)
 	}
 	syscall.ForkLock.RUnlock()
-
 	if err != nil {
 		return
 	}
-
 	if err = unix.SetNonblock(fd, true); err != nil {
 		_ = unix.Close(fd)
 	}
+	return
+}
 
+func sysAccept(fd int) (nfd int, sa unix.Sockaddr, err error) {
+	syscall.ForkLock.RLock()
+	if nfd, sa, err = unix.Accept(fd); err == nil {
+		unix.CloseOnExec(nfd)
+	}
+	syscall.ForkLock.RUnlock()
+	if err != nil {
+		return
+	}
+	if err = unix.SetNonblock(nfd, true); err != nil {
+		_ = unix.Close(nfd)
+	}
 	return
 }