opt: support TCP_NODELAY socket option

Fixed #161

connection_unix.go

@@ -26,7 +26,6 @@ package gnet
 import (
 	"net"
 	"os"
-	"time"
 
 	"github.com/panjf2000/gnet/internal/netpoll"
 	"github.com/panjf2000/gnet/pool/bytebuffer"
@@ -61,11 +60,19 @@ func newTCPConn(fd int, el *eventloop, sa unix.Sockaddr, remoteAddr net.Addr) (c
 	}
 	c.localAddr = el.ln.lnaddr
 	c.remoteAddr = remoteAddr
-	if el.svr.opts.TCPKeepAlive > 0 {
-		if proto := el.ln.network; proto == "tcp" || proto == "unix" {
-			_ = netpoll.SetKeepAlive(fd, int(el.svr.opts.TCPKeepAlive/time.Second))
-		}
+
+	if el.svr.ln.network != "tcp" {
+		return
+	}
+
+	var noDelay bool
+	switch el.svr.opts.TCPNoDelay {
+	case TCPNoDelay:
+		noDelay = true
+	case TCPDelay:
 	}
+	_ = netpoll.SetNoDelay(fd, noDelay)
+	_ = netpoll.SetKeepAlive(fd, el.svr.opts.TCPKeepAlive)
 	return
 }
 

connection_windows.go

@@ -81,11 +81,24 @@ func newTCPConn(conn net.Conn, el *eventloop) (c *stdConn) {
 	}
 	c.localAddr = el.svr.ln.lnaddr
 	c.remoteAddr = c.conn.RemoteAddr()
+
+	var (
+		ok bool
+		tc *net.TCPConn
+	)
+	if tc, ok = conn.(*net.TCPConn); !ok {
+		return
+	}
+	var noDelay bool
+	switch el.svr.opts.TCPNoDelay {
+	case TCPNoDelay:
+		noDelay = true
+	case TCPDelay:
+	}
+	_ = tc.SetNoDelay(noDelay)
 	if el.svr.opts.TCPKeepAlive > 0 {
-		if tc, ok := conn.(*net.TCPConn); ok {
-			_ = tc.SetKeepAlive(true)
-			_ = tc.SetKeepAlivePeriod(el.svr.opts.TCPKeepAlive)
-		}
+		_ = tc.SetKeepAlive(true)
+		_ = tc.SetKeepAlivePeriod(el.svr.opts.TCPKeepAlive)
 	}
 	return
 }

gnet_test.go

@@ -532,7 +532,7 @@ func testServe(network, addr string, reuseport, multicore, async bool, nclients
 		workerPool: goroutine.Default(),
 	}
 	must(Serve(ts, network+"://"+addr, WithLockOSThread(async), WithMulticore(multicore), WithReusePort(reuseport), WithTicker(true),
-		WithTCPKeepAlive(time.Minute*1), WithLoadBalancing(lb)))
+		WithTCPKeepAlive(time.Minute*1), WithTCPNoDelay(TCPDelay), WithLoadBalancing(lb)))
 }
 
 func startClient(network, addr string, multicore, async bool) {

internal/netpoll/netpoll_darwin.go

@@ -22,13 +22,20 @@
 package netpoll
 
 import (
+	"errors"
 	"os"
+	"time"
 
 	"golang.org/x/sys/unix"
 )
 
-// SetKeepAlive sets the keepalive for the connection.
-func SetKeepAlive(fd, secs int) error {
+// SetKeepAlive sets whether the operating system should send
+// keep-alive messages on the connection and sets period between keep-alive's.
+func SetKeepAlive(fd int, d time.Duration) error {
+	if d <= 0 {
+		return errors.New("invalid time duration")
+	}
+	secs := int(d / time.Second)
 	if err := os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)); err != nil {
 		return err
 	}

internal/netpoll/netpoll_posix.go

@@ -0,0 +1,42 @@
+// Copyright (c) 2019 Andy Pan
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+// +build linux freebsd dragonfly darwin
+
+package netpoll
+
+import (
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+// SetNoDelay controls whether the operating system should delay
+// packet transmission in hopes of sending fewer packets (Nagle's algorithm).
+//
+// The default is true (no delay), meaning that data is
+// sent as soon as possible after a Write.
+func SetNoDelay(fd int, noDelay bool) error {
+	var arg int
+	if noDelay {
+		arg = 1
+	}
+	return os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_NODELAY, arg))
+}

internal/netpoll/netpoll_unix.go

@@ -24,13 +24,20 @@
 package netpoll
 
 import (
+	"errors"
 	"os"
+	"time"
 
 	"golang.org/x/sys/unix"
 )
 
-// SetKeepAlive sets the keepalive for the connection.
-func SetKeepAlive(fd, secs int) error {
+// SetKeepAlive sets whether the operating system should send
+// keep-alive messages on the connection and sets period between keep-alive's.
+func SetKeepAlive(fd int, d time.Duration) error {
+	if d <= 0 {
+		return errors.New("invalid time duration")
+	}
+	secs := int(d / time.Second)
 	if err := os.NewSyscallError("setsockopt", unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)); err != nil {
 		return err
 	}

options.go

@@ -37,6 +37,15 @@ func loadOptions(options ...Option) *Options {
 	return opts
 }
 
+// TCPSocketOpt is the type of TCP socket options.
+type TCPSocketOpt int
+
+// Available TCP socket options.
+const (
+	TCPNoDelay TCPSocketOpt = iota
+	TCPDelay
+)
+
 // Options are set when the client opens.
 type Options struct {
 	// Multicore indicates whether the server will be effectively created with multi-cores, if so,
@@ -67,6 +76,13 @@ type Options struct {
 	// TCPKeepAlive sets up a duration for (SO_KEEPALIVE) socket option.
 	TCPKeepAlive time.Duration
 
+	// TCPNoDelay controls whether the operating system should delay
+	// packet transmission in hopes of sending fewer packets (Nagle's algorithm).
+	//
+	// The default is true (no delay), meaning that data is sent
+	// as soon as possible after a Write.
+	TCPNoDelay TCPSocketOpt
+
 	// ICodec encodes and decodes TCP stream.
 	Codec ICodec
 
@@ -117,13 +133,20 @@ func WithReusePort(reusePort bool) Option {
 	}
 }
 
-// WithTCPKeepAlive sets up SO_KEEPALIVE socket option.
+// WithTCPKeepAlive sets up the SO_KEEPALIVE socket option with duration.
 func WithTCPKeepAlive(tcpKeepAlive time.Duration) Option {
 	return func(opts *Options) {
 		opts.TCPKeepAlive = tcpKeepAlive
 	}
 }
 
+// WithTCPNoDelay enable/disable the TCP_NODELAY socket option.
+func WithTCPNoDelay(tcpNoDelay TCPSocketOpt) Option {
+	return func(opts *Options) {
+		opts.TCPNoDelay = tcpNoDelay
+	}
+}
+
 // WithTicker indicates that a ticker is set.
 func WithTicker(ticker bool) Option {
 	return func(opts *Options) {