Question

我只是想知道C＃中套接字的以下行为。通常，TCP负责运输，包括在请求时终止连接。所以我不明白，为什么这个示例代码有这些结果我期望如果s2关闭到s3的连接，s3将无法发送更多数据。但是s3.send（...） - 调用没有产生任何错误（如下所示）此外，我希望server / client-role对此行为没有影响，因为关闭套接字应该发送FIN并返回FIN / ACK，因此两个套接字都应该知道已关闭的连接。

所以请看一下这个示例代码：

    void MyMethod()
    {
        IPAddress localIP = IPAddress.Loopback;

        Socket s1 = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        Socket s2 = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

        s1.Bind(new IPEndPoint(localIP, 20003));
        s1.Listen(1);
        s2.Bind(new IPEndPoint(localIP, 20004));
        s2.ConnectAsync(new SocketAsyncEventArgs { RemoteEndPoint = new IPEndPoint(localIP, 20003) });
        Socket s3 = s1.Accept();

        Console.WriteLine($"Accepted Connection: {s3.LocalEndPoint} -> {s3.RemoteEndPoint}");

        s1.Close();

        Console.WriteLine($"S2: Connected: {s2.Connected} @ {s2.LocalEndPoint} -> {s2.RemoteEndPoint}");
        Console.WriteLine($"S3: Connected: {s3.Connected} @ {s3.LocalEndPoint} -> {s3.RemoteEndPoint}");
        s2.Shutdown(SocketShutdown.Both);
        s2.Close();

        SocketError error;
        s3.Send(new byte[] {1, 2, 3}, 0, 3, SocketFlags.None, out error);
        Console.WriteLine($"Transmission SocketError: {error}");
        Console.WriteLine($"S2: Connected: {s2.Connected}");
        Console.WriteLine($"S3: Connected: {s3.Connected} @ {s3.LocalEndPoint} -> {s3.RemoteEndPoint}");

        s3.Close();
    }

此代码生成此输出：

Accepted Connection: 127.0.0.1:20003 -> 127.0.0.1:20004
S2: Connected: True @ 127.0.0.1:20004 -> 127.0.0.1:20003
S3: Connected: True @ 127.0.0.1:20003 -> 127.0.0.1:20004
Transmission SocketError: Success
S2: Connected: False
S3: Connected: True @ 127.0.0.1:20003 -> 127.0.0.1:20004

C＃套接字连接混乱

0 个答案: