关闭在NamedPipeServer＃WaitForConnection上阻塞的线程的好方法是什么？

Question

我启动了我的应用程序，它生成了许多线程，每个线程创建一个NamedPipeServer（.net 3.5为命名管道IPC添加了托管类型）并等待客户端连接（块）。代码按预期运行。

private void StartNamedPipeServer()
  {
    using (NamedPipeServerStream pipeStream =
                    new NamedPipeServerStream(m_sPipeName, PipeDirection.InOut, m_iMaxInstancesToCreate, PipeTransmissionMode.Message, PipeOptions.None))
    {
      m_pipeServers.Add(pipeStream);
      while (!m_bShutdownRequested)
      {
        pipeStream.WaitForConnection();
        Console.WriteLine("Client connection received by {0}", Thread.CurrentThread.Name);
        ....  

现在我还需要一种Shutdown方法来干净地完成这个过程。我尝试了通常的bool标志isShutdownRequested技巧。但是管道流在WaitForConnection（）调用中保持阻塞，并且线程不会死亡。

public void Stop()
{
   m_bShutdownRequested = true;
   for (int i = 0; i < m_iMaxInstancesToCreate; i++)
   {
     Thread t = m_serverThreads[i];
     NamedPipeServerStream pipeStream = m_pipeServers[i];
     if (pipeStream != null)
     {
       if (pipeStream.IsConnected)
          pipeStream.Disconnect();
       pipeStream.Close();
       pipeStream.Dispose();
     }

     Console.Write("Shutting down {0} ...", t.Name);
     t.Join();
     Console.WriteLine(" done!");
   }
} 

加入永不回归。

我没有尝试但可能有效的选项是调用Thread.Abort并吃掉异常。但它感觉不对..任何建议

更新2009-12-22
很抱歉没有提前发布..这是我收到的Kim Hamilton（BCL团队）的回复

  

“正确”做一个可中断的方式   WaitForConnection是要调用的   BeginWaitForConnection，处理新的   回调中的连接，并关闭   管道流停止等待   连接。如果管道关闭，   EndWaitForConnection会抛出   ObjectDisposedException中的哪个   回调线程可以捕获，清理   任何松散的结束，并干净利落地退出。

     

我们意识到这一定是常见的   问题，所以我的团队中有人   计划很快发布博客。

Answer 1

切换到异步版本： BeginWaitForConnection 。

如果它完成了，你需要一个标志，这样完成处理程序只需调用 EndWaitForConnection 吸收任何异常并退出（调用End ...以确保能够清除任何资源）向上）。

Answer 2

这很俗气，但这是我开始工作的唯一方法。创建一个'假'客户端并连接到您的命名管道以移过WaitForConnection。每次都有效。

另外，即使是Thread.Abort（）也没有为我解决这个问题。

---

_pipeserver.Dispose();
_pipeserver = null;

using (NamedPipeClientStream npcs = new NamedPipeClientStream("pipename")) 
{
    npcs.Connect(100);
}

Answer 3

您可以使用以下扩展方法。请注意包含'ManualResetEvent cancelEvent' - 您可以从另一个线程设置此事件，以表示等待连接方法现在应该中止并关闭管道。设置m_bShutdownRequested时包括cancelEvent.Set（），关闭应该相对优雅。

    public static void WaitForConnectionEx(this NamedPipeServerStream stream, ManualResetEvent cancelEvent)
    {
        Exception e = null;
        AutoResetEvent connectEvent = new AutoResetEvent(false);
        stream.BeginWaitForConnection(ar =>
        {
            try
            {
                stream.EndWaitForConnection(ar);
            }
            catch (Exception er)
            {
                e = er;
            }
            connectEvent.Set();
        }, null);
        if (WaitHandle.WaitAny(new WaitHandle[] { connectEvent, cancelEvent }) == 1)
            stream.Close();
        if (e != null)
            throw e; // rethrow exception
    }

Answer 4

我写了这个扩展方法来解决这个问题：

public static void WaitForConnectionEx(this NamedPipeServerStream stream)
{
    var evt = new AutoResetEvent(false);
    Exception e = null;
    stream.BeginWaitForConnection(ar => 
    {
        try
        {
            stream.EndWaitForConnection(ar);
        }
        catch (Exception er)
        {
            e = er;
        }
        evt.Set();
    }, null);
    evt.WaitOne();
    if (e != null)
        throw e; // rethrow exception
}

Answer 5

可行的一种方法是在WaitForConnection之后立即检查m_bShutdownRequested。

在关机过程中设置bool。之后，将虚拟消息发送到所有现有管道，以便打开连接并检查bool并干净地关闭。

Answer 6

最简单的解决方案是创建虚拟客户端并与服务器建立连接。

NamedPipeServerStream pServer;
bool exit_flg=false;
    public void PipeServerWaiter()
{

    NamedPipeServerStream  pipeServer = new NamedPipeServerStream("DphPipe", PipeDirection.InOut, NamedPipeServerStream.MaxAllowedServerInstances);
    pServer = pipeServer;
    pipeServer.WaitForConnection();


    if (exit_flg) return;
    thread = new Thread(PipeServerWaiter);
    thread.Start();

}
public void Dispose()
{
    try
    {
        exit_flg = true;
        NamedPipeClientStream clt = new NamedPipeClientStream(".", "DphPipe");
        clt.Connect();
        clt.Close();

        pServer.Close();
        pServer.Dispose();


    }

Answer 7

using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Pipes;
using System.Threading;
using System.Windows;
using System.Windows.Controls;

namespace PIPESERVER
{
    public partial class PWIN : UserControl
   {
    public string msg = "", cmd = "", text = "";
    public NamedPipeServerStream pipe;
    public NamedPipeClientStream dummyclient;
    public string PipeName = "PIPE1";
    public static string status = "";
    private static int numThreads = 2;
    int threadId;
    int i;
    string[] word;
    char[] buffer;
    public StreamString ss;

    public bool ConnectDummyClient()
    {
        new Thread(() =>
        {
            dummyclient = new NamedPipeClientStream(".", "PIPE1");
            try
            {
                dummyclient.Connect(5000); // 5 second timeout
            }
            catch (Exception e)
            {
                Act.m.md.AMsg(e.Message); // Display error msg
                Act.m.console.PipeButton.IsChecked = false;
            }
        }).Start();
        return true;
    }

    public bool RaisePipe()
    {
        TextBlock tb = Act.m.tb;
        try
        {
            pipe = new NamedPipeServerStream("PIPE1", PipeDirection.InOut, numThreads);
            threadId = Thread.CurrentThread.ManagedThreadId;
            pipe.WaitForConnection();
            Act.m.md.Msg("Pipe Raised");
            return true;
        }
        catch (Exception e)
        {
            string err = e.Message;
            tb.Inlines.Add(new Run("Pipe Failed to Init on Server Side"));
            tb.Inlines.Add(new LineBreak());
            return false;
        }
    }

    public void ServerWaitForMessages()
    {
        new Thread(() =>
        {
            cmd = "";
            ss = new StreamString(pipe);
            while (cmd != "CLOSE")
            {
                try
                {
                    buffer = new char[256];
                    text = "";
                    msg = ss.ReadString().ToUpper();
                    word = msg.Split(' ');
                    cmd = word[0].ToUpper();
                    for (i = 1; i < word.Length; i++) text += word[i] + " ";
                    switch (cmd)
                    {
                        case "AUTHENTICATE": ss.WriteString("I am PIPE1 server"); break;
                        case "SOMEPIPEREQUEST":ss.WriteString(doSomePipeRequestReturningString()):break;
                        case "CLOSE": ss.WriteString("CLOSE");// reply to client
                            Thread.Sleep(1000);// wait for client to pick-up shutdown message
                            pipe.Close();
                            Act.m.md.Msg("Server Shutdown ok"); // Server side message
                            break;
                    }
                }
                catch (IOException iox)
                {
                    string error = iox.Message;
                    Act.m.md.Msg(error);
                    break;
                }
            }
        }).Start();
    }

    public void DummyClientCloseServerRequest()
    {
        StreamString ss = new StreamString(dummyclient);
        ss.WriteString("CLOSE");
        ss.ReadString();
    }

//用法，将ToggleButtons放在StackPanel中，然后将它们放回代码中：

private void PipeButton_Checked(object sender, RoutedEventArgs e)
    {
        Act.m.pwin.ConnectDummyClient();
        Act.m.pwin.RaisePipe();
    }
private void PipeButton_Unchecked(object sender, RoutedEventArgs e)
    {
        Act.m.pwin.DummyClientCloseServerRequest();
        Act.m.console.WaitButton.IsChecked = false;
        Keyboard.Focus(Act.m.md.tb1);
    }
private void WaitButton_Checked(object sender, RoutedEventArgs e)
    {
        Act.m.pwin.Wait();
    }
private void WaitButton_Unchecked(object sender, RoutedEventArgs e)
    {
    }

//对我来说就像一个魅力。恭敬地，zzzbc     }