Question

所以我在这里有两件事。一个iPad应用程序与在Linux服务器上运行的python脚本交谈。 python脚本将大约〜1K字节的iPad应用程序数据文件发送到~10K字节。我偶尔会发生一个非常奇怪的事件（比如可能每100或200次尝试一次）。

I modeled my Asynchronous Client Socket from this example。在我在下面发布的ReceiveCallback函数中，我将数据接收到我的缓冲区中，如下所示：

string stuffWeReceived = Encoding.ASCII.GetString(state.buffer,0,bytesRead);

但我的问题是，有时我会收到无序的数据。我有时会强调这个词。在我的测试中，我有5台iPad并排运行我的应用程序，并且正在向所有5个ipad发送相同的确切数据。 99.9％的时间他们正确地按正确的顺序接收数据，但有一半的时间，iPad将无法接收数据。

I was told in this post, that Data should never come out of order... Any ideas as to what I'm doing wrong to trigger this?

以下是数据的控制台输出示例，其顺序正确无误：

enter image description here Link to above picture

我知道发送数据的服务器上的python脚本正在正确发送数据，因为正如我上面提到的，在我的测试中，我有5台运行应用程序的iPad，只有1台iPad会出现这个问题（这个问题只会发生）一小部分时间......）

我正在后台线程中查看我的异步客户端套接字，如下所示：

    AsyncClient_Thread = new Thread(() => AsyncClient.StartClient());
    AsyncClient_Thread.IsBackground = true;
    AsyncClient_Thread.Start();


    public void StartClient()
    {
        // Connect to a remote device.
        try {
            // Establish the remote endpoint for the socket.                

            string ipAddress = appDel.wallInteractionScreen.Host_WallServer;
            IPEndPoint remoteEP = new IPEndPoint(IPAddress.Parse(ipAddress), port);

            // Create a TCP/IP socket.
            ClientSocket = new Socket(AddressFamily.InterNetwork,
                SocketType.Stream, ProtocolType.Tcp);

            // Connect to the remote endpoint.
            ClientSocket.BeginConnect( remoteEP, 
                new AsyncCallback(ConnectCallback), ClientSocket);
            connectDone.WaitOne();

            Receive(ClientSocket);
            receiveDone.WaitOne();
        } 
        catch (Exception e) {
            Console.WriteLine("Error in AsyncClient StartClient: ");
            Console.WriteLine(e.Message);
            Console.WriteLine(e.StackTrace);
        }

        //          Console.WriteLine("Finished StartClient");
    }

这是我的ReceiveCallback功能

    private static void ReceiveCallback( IAsyncResult ar )
    {
        AppDelegate appDel = (AppDelegate)UIApplication.SharedApplication.Delegate;

        // I added this InvokeOnMainThread to see if it would solve the "data out of order problem", but it didn't
        appDel.InvokeOnMainThread (delegate{
            Console.WriteLine("ReceiveCallback IsMainThread = " + NSThread.IsMain);

            try {
                // Retrieve the state object and the client socket 
                // from the asynchronous state object.
                StateObject state = (StateObject) ar.AsyncState;
                Socket client = state.workSocket;

                // Read data from the remote device.
                int bytesRead = client.EndReceive(ar);

                if (bytesRead > 0) {
                    // There might be more data, so store the data received so far.
                    string stuffWeReceived = Encoding.ASCII.GetString(state.buffer,0,bytesRead);

                    string debugString = "~~ReceiveCallback~~ len = " + stuffWeReceived.Length + " bytesRead = " + bytesRead + ": " + stuffWeReceived;
                    if ( appDel.diagnosticsScreen.DebugAsyncReceiveBuffer_Switch.On )
                    {
                        appDel.diagnosticsScreen.AppendToDebugLog(debugString);
                    }
                    Console.WriteLine(debugString);


                    // Send this data to be received
                    appDel.wallInteractionScreen.ChitterChatter.ReceiveSomeData(stuffWeReceived);

                    // Get the rest of the data.
                    client.BeginReceive(state.buffer,0,StateObject.BufferSize,0,
                        new AsyncCallback(ReceiveCallback), state);
                } else {
                    // Signal that all bytes have been received.
                    receiveDone.Set();
                }
            } 
            catch (Exception e) {
                Console.WriteLine("Error in AsyncClient ReceiveCallback: ");
                Console.WriteLine(e.Message);
                Console.WriteLine(e.StackTrace);
            }
        });

    }

Answer 1

这最终成为我在C＃端的代码中的线程/锁定问题。我从头开始重写了我的锁定机制，现在有100％的时间都能正常工作。感谢所有帮助我看到这一切的人！

异步客户端套接字，无序接收缓冲区数据

1 个答案: