receiver.go

package main

import (
	"fmt"
	"net"
	"os"
	"syscall"
	"time"
)

func main() {
	var err error
	finish := make(chan bool, 1)

	pipe := make([]*os.File, 2)

	pipe[0], pipe[1], err = os.Pipe()
	if err != nil {
		panic(err.Error())
	}

	go func() {
		fmt.Println("listen...")
		ln, err := net.Listen("tcp", ":8080")
		if err != nil {
			panic(err.Error())
		}
		conn, err := ln.Accept()
		if err != nil {
			panic(err.Error())
		}
		fmt.Println("accepted!")

		fmt.Println("splicing... buffer size:", 4096)
		connFile, err := conn.(*net.TCPConn).File()
		if err != nil {
			panic(err.Error())
		}
		n, err := syscall.Splice(int(connFile.Fd()), nil, int(pipe[1].Fd()), nil, 4096, 0)
		if err != nil {
			panic(err.Error())
		}

		b := make([]byte, 4096)
		_, err = pipe[0].Read(b)
		if err != nil {
			panic(err.Error())
		}

		fmt.Printf("recv: %scount: %d\n", string(b), n)
		finish <- true
	}()

	select {
	case <-finish:
		fmt.Println("finish")
	case <-time.After(10 * time.Second):
		fmt.Println("time out")
	}
}

sender.go

package main

import (
	"fmt"
	"net"
	"time"
)

func main() {
	conn, err := net.Dial("tcp", ":8080")
	if err != nil {
		panic(err.Error())
	}

	for i := 0; i < 10; i++ {
		b := fmt.Sprintf("hello %d", i)
		conn.Write([]byte(b))
		<-time.After(1 * time.Second)
	}
	conn.Close()
	fmt.Println("done")
}