如何正确终止工作线程在C＃ [英] How to terminate a worker thread correctly in c#

问题描述

问题陈述

我有一个工作线程，基本上扫描一个文件夹，进入该文件中，然后睡了而。扫描操作可能需要2-3秒而不是更多。我正在寻找一种方法来阻止优雅这个线程。

I have a worker thread that basically scans a folder, going into the files within it, and then sleeps for a while. The scanning operation might take 2-3 seconds but not much more. I'm looking for a way to stop this thread elegantly.

澄清：我想停止线程，而它的睡觉的，而不是当它的扫描的。然而，问题是，我不知道什么是线程的当前状态。如果它睡觉，我希望它立即退出。如果是扫描，我希望它退出它试图阻止的时刻。

Clarification: I want to stop the thread while it's sleeping, and not while it's scanning. However, the problem is that I do not know what is the current state of the thread. If it's sleeping I want it to exit immediately. If it's scanning, I want it to exit the moment it tries to block.

是在一个解决方案尝试

起初我使用休眠和中断。后来我发现，中断并没有真正中断睡眠 - 它只有当线程试图进入睡眠的作品。

At first I was using Sleep and Interrupt. Then I found out that Interrupt doesn't really interrupt the Sleep - it only works when the threads TRIES to go into sleeping.

所以我切换到监控等待和放大器;脉冲。后来我发现，当我在等待其实是脉冲才起作用。所以现在我有一个线程这看起来像：

So I switched to Monitor Wait&Pulse. Then I found out that the Pulse only works when I'm actually in the Wait. So now I have a thread which looks like that:

while (m_shouldRun)
{
    try
    {
        DoSomethingThatTakesSeveralSeconds();
        lock (this)
        {
            Monitor.Wait(this, 5000);
        }
    }
    catch (ThreadInterruptedException)
    {
        m_shouldRun = false;
    }
}

和现在我需要我的手艺停止功能。于是我开始用：

And now I need to craft my Stop function. So I started with:

public void Stop()
{
    m_shouldRun = false;
    lock (this)
    {
        Monitor.Pulse(this);
    }
    thread.Join();
}

但是，这并不工作，因为我可以在线程进行工作涌动（虽然它不是等待）。所以我加了中断：

But this doesn't work because I may be pulsing while the thread works (while it's not waiting). So I added Interrupt:

public void Stop()
{
    m_shouldRun = false;
    thread.Interrupt();
    lock (this)
    {
        Monitor.Pulse(this);
    }
    thread.Join();
}

另一种选择是使用

Another option is to use:

public void Stop()
{
    m_shouldRun = false;
    while (!thread.Join(1000))
    {
        lock (this)
        {
            Monitor.Pulse(this);
        }
    }
}

问题

什么是首选的方法？ ？是否有这是优选的第三方法

What is the preferred method? Is there a third method which is preferable?

推荐答案

另一种替代方法是使用事件：

Another alternative is to use events:

private ManualResetEvent _event = new ManualResetEvent(false);


public void Run() 
{
 while (true)
 {
    DoSomethingThatTakesSeveralSeconds();
    if (_event.WaitOne(timeout))
      break;
 }
}

public void Stop() 
{
   _event.Set();
   thread.Join();
}

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