由于 AcceptSocket，Thread.Abort 似乎没有抛出 ThreadAbortException

Question

我在以下线程上调用ChannelServer.ListeningThread.Abort，但似乎没有发生任何事情。我想更具体一些，但我想不出更多。似乎没有抛出ThreadAbortException，并且无论阻塞监听器如何都应该抛出这个异常（它在阻塞接收的线程上完美运行）。

重要编辑：使用 ManualResetEvent.WaitOne 而不是 AcceptSocket，正如 Lyrik 建议的测试一样，它可以完美运行。 AcceptSocket怎么会屏蔽ThreadAbortException？

LINK：这个论坛帖子似乎讨论了同样的问题，虽然我想不通：http://www.tek-tips.com/viewthread.cfm?qid=319436&page=413

ChannelServer.ListeningThread = new Thread(new ThreadStart(delegate()
{
    Log.Inform("Waiting for clients on thread {0}.", Thread.CurrentThread.ManagedThreadId);

    while (true)
    {
        try
        {
            new Thread(new ParameterizedThreadStart(ChannelClientHandler.Initialize)).Start(ChannelServer.Listener.AcceptSocket());
        }
        catch (ThreadAbortException)
        {
            Log.Inform("Aborted client listening thread {0}.", Thread.CurrentThread.ManagedThreadId);
            break;
        }
    }
}));
ChannelServer.ListeningThread.Start();

Answer 1

这里是一个简单的AcceptSocket2 扩展方法（对不起，对于名称缺乏想象力......）。 它的工作原理与原来的 AcceptSocket 方法完全相同。

using System;
using System.Net.Sockets;
using System.Threading;

/// <summary>
/// Extensions to TcpListener
/// </summary>
public static class TcpListenerExtensions
{
    /// <summary>
    /// Accepts a pending connection request.
    /// </summary>
    /// <param name="tcpListener">The TCP listener.</param>
    /// <returns>
    /// A <see cref="T:System.Net.Sockets.Socket" /> used to send and receive data.
    /// </returns>
    /// <exception cref="T:System.InvalidOperationException">The listener has not been started with a call to <see cref="M:System.Net.Sockets.TcpListener.Start" />.</exception>
    /// <PermissionSet><IPermission class="System.Security.Permissions.EnvironmentPermission, mscorlib, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Unrestricted="true" /><IPermission class="System.Security.Permissions.FileIOPermission, mscorlib, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Unrestricted="true" /><IPermission class="System.Security.Permissions.SecurityPermission, mscorlib, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Flags="UnmanagedCode, ControlEvidence" /><IPermission class="System.Diagnostics.PerformanceCounterPermission, System, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" version="1" Unrestricted="true" /></PermissionSet>
    public static Socket AcceptSocket2(this TcpListener tcpListener)
    {
        Socket socket = null;
        var clientConnected = new ManualResetEvent(false);
        clientConnected.Reset();
        tcpListener.BeginAcceptSocket(delegate(IAsyncResult asyncResult)
        {
            try
            {
                socket = tcpListener.EndAcceptSocket(asyncResult);
            }
            catch (ObjectDisposedException)
            { }
            clientConnected.Set();
        }, null);
        clientConnected.WaitOne();
        return socket;
    }
}

Answer 2

这行得通，但它非常草率和浪费线程。谁能给我指出一种抛出“AcceptSocket”不会自动捕获的异常的方法？

ChannelServer.ListeningThread = new Thread(new ThreadStart(delegate()
{
    Log.Inform("Waiting for clients on thread {0}.", Thread.CurrentThread.ManagedThreadId);

    while (true)
    {
        try
        {
            ChannelServer.ClientConnected.Reset();
            ChannelServer.Listener.BeginAcceptSocket(new AsyncCallback(ChannelClientHandler.EndAcceptSocket), ChannelServer.Listener);
            ChannelServer.ClientConnected.WaitOne();
        }
        catch (ThreadInterruptedException)
        {
            Log.Inform("Interrupted client listening thread {0}.", Thread.CurrentThread.ManagedThreadId);
            break;
        }
    }
}));
ChannelServer.ListeningThread.Start();

Answer 3

我不确定您为什么会收到该错误，但这是一个有效的简单示例：

ManualResetEvent mrse = new ManualResetEvent(false);
Thread test = new Thread(() =>
    {
        while (true)
        {
            try
            {
                mrse.WaitOne();
            }
            catch (ThreadAbortException)
            {
                Console.WriteLine("No problem here...");
            }
        }
    });

test.IsBackground = true;
test.Start();

Thread.Sleep(1000);
test.Abort();
Console.ReadKey();

所以它对我有用...我假设你已经通过调试器并且你在 catch 语句中的断点没有被命中，对吗？

注意：调用Abort 是不好的做法，您应该调用Interrupt 并处理ThreadInterruptedException...这样更安全。