我正在开发一个服务器应用程序,它将接收消息并做出响应。没有什么新东西。所以,实际上我正在关注 this answerthis post ,但我无法使用 AcceptAsync() 方法来触发 Completed 事件。在互联网上到处搜索,尝试了类似问题的解决方案,但似乎对我没有任何作用。

我也尝试从 server.Start() 调用 Task.Run() ,但没​​有成功。我知道服务器正在监听,因为我可以在 netstat -an 上看到它,如果我在 Listen() 之后中断,我也可以使用 telnet 进行连接。

据我所知,如果 AcceptAsync() 方法返回 true,它将引发 SocketAsyncEventArgs.Completed 事件,该事件又会再次调用 StartAccept() 方法并循环直到我强制退出。
SocketAsyncEventArgs.Completed 也是正确的: http://prntscr.com/8l3x8p ,但仍然不起作用。

这是我的一段代码:

public class TTSServer
{
    private Socket m_serverSocket;
    private IPEndPoint m_serverEndPoint;

    [DefaultValue(39454)]
    public int Port { get; set; }
    [DefaultValue(100)]
    public int IncommingQueueSize { get; set; }
    [DefaultValue(512)]
    public int BufferSize { get; set; }

    //Listeners to hold event when something happens.

    public static void Main(string[] args)
    {
        TTSServer server = new TTSServer(39454, 100, 512);
        server.Start();
    }

    public TTSServer(int port, int queueSize, int bufferSize)
    {
        Port = port;
        IncommingQueueSize = queueSize;
        BufferSize = bufferSize;
    }


    public void Start()
    {
        Console.WriteLine("Starting TTS Server (Port: {0}, QueueSize: {1}, BufferSize: {2})", Port, IncommingQueueSize, BufferSize);
        m_serverEndPoint = new IPEndPoint(IPAddress.Any, Port);
        m_serverSocket = new Socket(m_serverEndPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
        Console.WriteLine("Binding ({0})", m_serverEndPoint.ToString());
        m_serverSocket.Bind(m_serverEndPoint);
        Console.WriteLine("Listening");
        m_serverSocket.Listen(IncommingQueueSize);

        StartAccept(null);
    }

    public void Stop()
    {

    }

    /// <summary>
    /// Receive a incomming connection attemp in an asynchronous way.
    /// </summary>
    /// <param name="socketEvent">If is null, a new object is created, else, it'll be used for cache friendly reason.</param>
    private void StartAccept(SocketAsyncEventArgs socketEvent)
    {
        //If received reference points to null, let's create a new object.
        if (socketEvent == null)
        {
            Console.WriteLine("Accepting new connections...");
            socketEvent = new SocketAsyncEventArgs();
            socketEvent.Completed += AcceptCompleted; //Add a callback on completed accept incomming connections attemp.
        }
        else
        {
            //Clear current incomming connection socket, so object may be reused.
            socketEvent.AcceptSocket = null;
        }

        //If there is an incomming connection pending(pooled), this method will receive the connection in a async way (witch returns true)
        //and will call SocketAsyncEventArgs.Completed callback when done.
        //Else, it waits for a new connection, returns false, and don't won't SocketAsyncEventArgs.Completed callback when done, so we have to
        //call it manually.
        bool async = true;

        //When I debug this code, async receive true from AcceptAsync.
        async = m_serverSocket.AcceptAsync(socketEvent);

        if (!async)
        {
            AcceptCompleted(this, socketEvent);
        }
    }

    /// <summary>
    /// Handles a incomming connection after it's fully received. This function will do the business logic for incomming connections and prepare
    /// to receive data.
    /// </summary>
    /// <param name="sender">Object who posted this function</param>
    /// <param name="socketEvent">Information of the incomming connection</param>
    private void AcceptCompleted(object sender, SocketAsyncEventArgs socketEvent)
    {
        Connection connection = new Connection(this, socketEvent.AcceptSocket, BufferSize);

        SocketAsyncEventArgs connectedSocketEvent = new SocketAsyncEventArgs();
        connectedSocketEvent.UserToken = connection;

        //Add a receive callback, to be called whenever the Receive function is finished.
        connectedSocketEvent.Completed += FlushBuffer;
        ReceiveData(connectedSocketEvent);

        //Accept next incomming connection.
        StartAccept(socketEvent);
    }

不知道为什么, AcceptCompleted 永远不会被触发,即使 AcceptAsync() 方法返回 true

最佳答案

似乎根本原因是默认缓冲:



假设不需要缓冲,禁用缓冲 seems to be a solution :

SocketAsyncEventArgs args = ...;
args.SetBuffer(null, 0, 0);

关于c# - 为什么 Socket.AcceptAsync 不触发 SocketAsyncEventArgs Completed 事件?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/32810722/

10-11 06:47