在关闭套接字或写入换行符之前，TCPConn Write不会执行任何操作

Question

Calling TCPConn.Write without any newline or null byte delimiter doesn't seem to do anything until the socket or writer is closed.

In this example I'd expect conn.Write to trigger the read on the server as soon as the write is complete, but nothing happens until the socket is closed. If I Write a string with a newline character before writing the ones without it works fine. Is this intended behavior? Are delimiters required? Or am I just missing something here..

Server

package main

import (
    "log"
    "net"
)

func main() {
    addr, _ := net.ResolveTCPAddr("tcp4", ":8080")
    l, err := net.ListenTCP("tcp4", addr)
    if err != nil {
        log.Fatal(err.Error())
    }

    defer l.Close()

    for {
        var conn *net.TCPConn
        if conn, err = l.AcceptTCP(); err != nil {
            log.Println(err.Error())
            continue
        }

        log.Println("client connected")
        go handleConnection(conn)
    }
}

func handleConnection(conn *net.TCPConn) {
    defer conn.Close()

    for {
        var b = make([]byte, 128)
        bytesRead, err := conn.Read(b)
        if err != nil {
            break
        }

        log.Printf("got: %s
", string(b[:bytesRead]))
    }

    log.Println("client disconnected")
}

Client

package main

import (
    "log"
    "net"
    "time"
)

func main() {
    addr, _ := net.ResolveTCPAddr("tcp", "localhost:8080")
    conn, err := net.DialTCP("tcp", nil, addr)
    if err != nil {
        log.Fatal(err.Error())
    }

    // uncommenting the following line will make the following writes work as expected
    //conn.Write([]byte("hello world
"))

    for i := 0; i < 5; i++ {
        conn.Write([]byte("hello"))
        log.Println("wrote hello")
        time.Sleep(time.Second)
    }

    time.Sleep(time.Second)
    conn.Close()
}

Answer 1

Thanks for giving it a go, I ran it on a Ubuntu vm where it worked as expected. So, as of 1.5.1 for Windows, it seems to be a bug.

Edit:

Turns out it's Eset Smart Security's protocol filtering, go isn't the culprit