C#UDP数据包丢失，尽管所有数据包都到达(WireShark)

Question

正如标题所说，我在C#中遇到UDP问题。我正试图为游戏DayZ的rcon协议建立一个库。

我的问题是我没有收到我应该收到的每一包。发送命令后，服务器将使用拆分的答案进行回复。数据包标头包含总数据包计数和当前数据包的索引。现在，如果我应该得到17个数据包，我的应用程序中只得到8-15个数据包。

在使用WireShark进行测试后，我现在知道所有的软件包都到达了我的电脑上。他们只是没有得到我的申请或类似的东西的认可。

我的实际问题是：有可能防止我的网卡和应用程序之间的包丢失吗？或为什么会发生这种情况？

这是我当前的代码。它很脏，因为我在没有按预期工作后把它拆开了：

    private Socket _udpClient;
    private Thread _receiverThread;
    private Thread _workerThread;
    private Queue<byte[]> _packetQueue;
    private PacketBuffer[] MessageBuffer;
    private byte SenderSequence = 0;
    private IPEndPoint connection;
    public RCon(IPAddress ip, int port)
    {
        connection = new IPEndPoint(ip, port);
        _udpClient = new Socket(connection.Address.AddressFamily, SocketType.Dgram, ProtocolType.Udp);
        _udpClient.Connect(connection);
        MessageBuffer = new PacketBuffer[256];
        _packetQueue = new Queue<byte[]>();
        _receiverThread = new Thread(new ThreadStart(ReceiveCallback));
        _receiverThread.IsBackground = true;
        _receiverThread.Priority = ThreadPriority.AboveNormal;
        _receiverThread.Start();
        _workerThread = new Thread(new ThreadStart(WorkerCallback));
        _workerThread.IsBackground = true;
        _workerThread.Start();
    }
    public void Login(string password)
    {
        LoginPacket packet = new LoginPacket(password);
        _udpClient.Send(packet.Bytes);
    }
    public void SendCommand(string command)
    {
        CommandPacket packet = new CommandPacket(SenderSequence, command);
        SenderSequence++;
        _udpClient.Send(packet.Bytes);
    }
    private void ReceiveCallback()
    {
        while (true)
        {
                byte[] buffer = new byte[1036];
                if (_udpClient.Receive(buffer) > 0)
                    _packetQueue.Enqueue(buffer);
        }
    }
    private void WorkerCallback()
    {
        while (true)
        {
            if (_packetQueue.Count > 0)
            {
                byte[] buffer = _packetQueue.Dequeue();
                if (buffer != null)
                {
                    try
                    {
                        Packet receivedPacket = Packet.ParseIncoming(buffer);
                        OnPacketReceived(new PacketReceivedEventArgs(receivedPacket));
                        switch (receivedPacket.Type)
                        {
                            case PacketType.Message:
                                OnMessageReceived(new MessageReceivedEventArgs(receivedPacket.Content));
                                MessageCallbackPacket packet = new MessageCallbackPacket(receivedPacket.SequenceNumber);
                                _udpClient.Send(packet.Bytes);
                                break;
                            case PacketType.CommandCallback:
                                if (MessageBuffer[receivedPacket.SequenceNumber] == null)
                                    MessageBuffer[receivedPacket.SequenceNumber] = new PacketBuffer(receivedPacket);
                                else
                                    MessageBuffer[receivedPacket.SequenceNumber].AddPacket(receivedPacket);
                                if (MessageBuffer[receivedPacket.SequenceNumber].IsComplete)
                                    OnCommandCallback(new CommandCallbackEventArgs(MessageBuffer[receivedPacket.SequenceNumber].GetContent()));
                                break;
                        }
                    }
                    catch (ArgumentException) { }
                    catch (OverflowException) { }
                    catch (FormatException) { }
                }
            }
        }
    }

Answer 1

这通常是因为您消耗数据报的速度不够快，所以内核套接字缓冲区已满，网络堆栈开始丢弃新到达的数据包。一些要点：

• 增加套接字上的接收缓冲区
• 不要在每次迭代中都获取锁——尽可能多地读取，然后将数据放入队列
• 考虑非阻塞方法而不是线程