我正在研究接受来自不同客户端的多个 tcp 连接的 ac# 应用程序(.net 4)。有一个接受套接字的 tcp 侦听器。双工通信 b/w 节点。使用 Networkstream.Write 方法发送数据并使用 Networkstream.read 方法读取数据。对于每个 tcp 连接,都会创建一个单独的线程。
问题是,几天前我们注意到其中一个客户端停止读取数据(由于错误)达 20 分钟。由于连接没有断开,服务器上没有(IO)异常。但是,我们注意到其他客户端的数据也没有传输。20 分钟后,该客户端再次开始接收数据,很快其他客户端也开始接收数据。
我知道网络流的写入方法是一种阻塞方法,我们没有使用任何超时。所以有一个潜在的写被阻止(描述here)。但据我了解,每个 tcp 连接都必须有一个单独的写入缓冲区,或者还有更多的东西在起作用。tcp 连接的发送阻塞会影响同一应用程序中的其他 tcp 连接吗?
这是写操作的伪代码。对于每个连接,都有一个单独的线程单独的传出队列进程。
public class TCPServerListener : baseConnection
{
private readonly int _Port;
private TcpListener _tcpListener;
private Thread _thread;
private List<TcpClientData> _tcpClientDataList = new List<TcpClientData>();
private long _messageDiscardTimeout;
private bool LoopForClientConnection = true;
public TCPServerListener(int port, ThreadPriority threadPriority)
{
try
{
// init property
}
catch (Exception ex)
{
// log
}
}
public void SendMessageToAll(int type)
{
base.EnqueueMessageToSend(type, _tcpClientDataList);
}
public void SendMessageToList(int type, IList<TcpClient> tcpClientList)
{
base.EnqueueMessageToSend(type, tcpClientList);
}
public void SendMessage(int type, TcpClient tcpClient)
{
base.EnqueueMessageToSend(type, tcpClient);
}
private void AcceptClientConnections()
{
while (LoopForClientConnection)
{
try
{
Socket socket = _tcpListener.AcceptSocket();
TcpClientData tcpClientData = new TcpClientData();
tcpClientData.tcpClientThread = new Thread(new ParameterizedThreadStart(StartAsync));
tcpClientData.tcpClientThread.Priority = _threadPriority;
tcpClientData.tcpClientThread.IsBackground = true;
tcpClientData.tcpClientThread.Name = "CD" + tcpClientData.tcpClientThread.ManagedThreadId;
tcpClientData.tcpClient = new TcpClient();
tcpClientData.tcpClient.Client = socket;
_tcpClientDataList.Add(tcpClientData);
tcpClientData.tcpClientThread.Start(tcpClientData.tcpClient);
}
catch (ThreadAbortException ex)
{
//log
}
catch (Exception ex)
{
//log
}
}
}
public override void Start()
{
base.Start();
_tcpListener = new TcpListener(System.Net.IPAddress.Any, _Port);
_thread = new Thread(AcceptClientConnections);
_thread.Priority = _threadPriority;
_thread.IsBackground = true;
_tcpListener.Start();
_thread.Start();
}
public override void Stop()
{
// stop listener and terminate threads
}
}
public class baseConnection
{
private Thread _InCommingThread;
private Thread _OutGoingThread;
protected ThreadPriority _threadPriority;
protected BlockingCollection<MessageReceived> _InComingMessageQueue = new BlockingCollection<MessageReceived>();
protected BlockingCollection<MessageToSend> _OutgoingMessageQueue = new BlockingCollection<MessageToSend>();
public void StartAsync(Object oTcpClient)
{
TcpClient tcpClient = oTcpClient as TcpClient;
if (tcpClient == null)
return;
using (tcpClient)
{
using (NetworkStream stream = tcpClient.GetStream())
{
stream.ReadTimeout = Timeout.Infinite;
stream.WriteTimeout = Timeout.Infinite;
BinaryReader bodyReader = new BinaryReader(stream);
while (tcpClient.Connected)
{
try
{
int messageType = bodyReader.ReadInt32();
// checks to verify messages
// enqueue message in incoming queue
_InComingMessageQueue.Add(new MessageReceived(messageType, tcpClient));
}
catch (EndOfStreamException ex)
{
// log
break;
}
catch (Exception ex)
{
// log
Thread.Sleep(100);
}
}
//RaiseDisconnected(tcpClient);
}
}
}
public virtual void Start()
{
_InCommingThread = new Thread(HandleInCommingMessnge);
_InCommingThread.Priority = _threadPriority;
_InCommingThread.IsBackground = true;
_InCommingThread.Start();
_OutGoingThread = new Thread(HandleOutgoingQueue);
_OutGoingThread.Priority = _threadPriority;
_OutGoingThread.IsBackground = true;
_OutGoingThread.Start();
}
public virtual void Stop()
{
// stop the threads and free up resources
}
protected void EnqueueMessageToSend(int type, List<TcpClientData> tcpClientDataList)
{
tcpClientDataList.ForEach(x => _OutgoingMessageQueue.Add(new MessageToSend(type, x.tcpClient)));
}
protected void EnqueueMessageToSend(int type, IList<TcpClient> tcpClientList)
{
foreach (TcpClient tcpClient in tcpClientList)
{
_OutgoingMessageQueue.Add(new MessageToSend(type, tcpClient));
}
}
protected void EnqueueMessageToSend(int type, TcpClient tcpClient)
{
_OutgoingMessageQueue.Add(new MessageToSend(type, tcpClient));
}
private void HandleOutgoingQueue()
{
while (true)
{
try
{
MessageToSend message = _OutgoingMessageQueue.Take();
if (message.tcpClient.Connected)
{
BinaryWriter writer = new BinaryWriter(message.tcpClient.GetStream());
writer.Write(message.type);
}
}
catch (ThreadAbortException ex)
{
// log
return;
}
catch (Exception ex)
{
//_logger.Error(ex.Message, ex);
}
}
}
private void HandleInCommingMessnge()
{
while (true)
{
try
{
MessageReceived messageReceived = _InComingMessageQueue.Take();
// handle message
}
catch (ThreadAbortException ex)
{
// log
return;
}
catch (Exception ex)
{
// log
//_logger.Error(ex.Message, ex);
}
}
}
public class MessageReceived
{
public MessageReceived(int type, TcpClient tcpClient)
{
this.tcpClient = tcpClient;
this.type = type;
}
public int type;
public TcpClient tcpClient;
}
public class MessageToSend
{
public MessageToSend(int type, TcpClient tcpClient)
{
this.tcpClient = tcpClient;
this.type = type;
}
public int type;
public TcpClient tcpClient;
}
public class TcpClientData
{
public Thread tcpClientThread;
public TcpClient tcpClient;
}
}