PHP与Go基于Unix域套接字的进程间通信：连接管理与常见陷阱

package main

import (
    "net"
    "fmt"
    "log"
    "os"
    "time" // 导入time包以使用time.Now()
)

const socket_addr = "/tmp/odc_ws.sock"

func echoServer(c net.Conn){
    // 注意：此处缺少连接关闭操作
    buf := make([]byte, 512)
    size, err := c.Read(buf)
    if err != nil {
        log.Println("Read error: ", err) // 使用Println而非Fatal，避免子goroutine退出主程序
        return
    }
    data := buf[0:size]     
    fmt.Println("Server received: ", string(data))

    t := time.Now()
    retMsg := fmt.Sprintf("OK+ at %s", t)
    _, err = fmt.Fprintln(c, retMsg) // 使用fmt.Fprintln确保发送换行符

    if err == nil{
        fmt.Println("Wrote this many bytes: ", len(retMsg))
    } else {
        log.Println("Write error: ", err) // 使用Println
    }
}

func main(){
    // 确保在启动前移除旧的socket文件，避免绑定失败
    if err := os.RemoveAll(socket_addr); err != nil {
        log.Fatal("Failed to remove old socket file:", err)
    }

    l, err := net.Listen("unix", socket_addr)
    if err != nil{
        log.Fatalf("Failed to listen on Unix socket: %v", err) // 使用Fatalf输出错误并退出
    }
    defer l.Close() // 确保监听器关闭

    fmt.Printf("Listening on Unix socket: %s\n", socket_addr)
    for{
        fd, err := l.Accept()
        if err != nil{
            log.Println("Accept error:", err) // 使用Println
            continue // 继续监听下一个连接
        }
        go echoServer(fd) // 为每个连接启动一个goroutine处理
    }
}

<?php
ob_implicit_flush(); // 开启隐式刷新，确保输出立即发送
$socket_file = "/tmp/odc_ws.sock";

// 创建Unix域套接字
if (($socket = socket_create(AF_UNIX, SOCK_STREAM, 0)) === false) {
    echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "<br>";
    exit(); // 错误时退出
}

// 连接到Go服务端
if (socket_connect($socket, $socket_file) === false) {
    echo "socket_connect() failed: reason: " . socket_strerror(socket_last_error($socket)) . "<br>";
    socket_close($socket); // 连接失败也需关闭套接字
    exit();
}

// 构造并发送消息
$msg = 'PHP sent Go a message at ' . date('H:i:s');
$msg_len = strlen($msg);
$write_res = socket_write($socket, $msg, $msg_len);
if($write_res === false || $write_res != $msg_len){
    echo '<div>Socket write error: ' . socket_strerror( socket_last_error($socket) ) . '</div>';
    socket_close($socket);
    exit();
}

// 循环读取服务端响应
while($read = socket_read($socket, 512, PHP_NORMAL_READ)){
    echo "<div>Server says: $read</div>";
    // 如果服务器没有关闭连接，此循环将无限等待
}

// 关闭套接字
socket_close($socket);
echo "<div>Connection closed by PHP client.</div>"; // 添加确认信息
?>

func echoServer(c net.Conn){
    defer c.Close() // 确保在函数退出时关闭客户端连接

    buf := make([]byte, 512)
    size, err := c.Read(buf)
    if err != nil {
        log.Println("Read error: ", err)
        return
    }
    data := buf[0:size]     
    fmt.Println("Server received: ", string(data))

    t := time.Now()
    retMsg := fmt.Sprintf("OK+ at %s", t)
    _, err = fmt.Fprintln(c, retMsg)

    if err == nil{
        fmt.Println("Wrote this many bytes: ", len(retMsg))
    } else {
        log.Println("Write error: ", err)
    }
    // 函数结束，defer c.Close() 将被执行，关闭连接
}

package main

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

const socket_addr = "/tmp/odc_ws.sock"

func echoServer(c net.Conn){
    defer c.Close() // 关键：确保在函数退出时关闭客户端连接

    buf := make([]byte, 512)
    size, err := c.Read(buf)
    if err != nil {
        log.Println("Read error: ", err)
        return
    }
    data := buf[0:size]     
    fmt.Println("Server received: ", string(data))

    t := time.Now()
    retMsg := fmt.Sprintf("OK+ at %s", t)
    _, err = fmt.Fprintln(c, retMsg) // 使用fmt.Fprintln确保发送换行符

    if err == nil{
        fmt.Println("Wrote this many bytes: ", len(retMsg))
    } else {
        log.Println("Write error: ", err)
    }
}

func main(){
    // 确保在启动前移除旧的socket文件，避免绑定失败
    if err := os.RemoveAll(socket_addr); err != nil {
        log.Fatal("Failed to remove old socket file:", err)
    }

    l, err := net.Listen("unix", socket_addr)
    if err != nil{
        log.Fatalf("Failed to listen on Unix socket: %v", err)
    }
    defer l.Close() // 确保监听器关闭

    fmt.Printf("Listening on Unix socket: %s\n", socket_addr)
    for{
        fd, err := l.Accept()
        if err != nil{
            log.Println("Accept error:", err)
            continue
        }
        go echoServer(fd)
    }
}