Interrupt a sleeping Thread

Question

Is there a way to Interupt a sleeping thread? If I have code similar to this.

while(true){
    if(DateTime.Now.Subtract(_lastExecuteTime).TotalHours > 1){
        DoWork();
        _lastExecuteTime = DateTime.Now();
        continue; 
    }
    Thread.Sleep(10000) //Sleep 10 seconds
    if(somethingIndicatingQuit){
        break;
    }

}

I'm wanting to execute DoWork() every hour. So, I'd like to sleep a little longer then 10 seconds. Say check every 10 minutes or so. However, if set my sleep to 10 minutes, and I want to kill this background task, I have to wait for the sleep to resume.

My actual code is using a Threading.ManualResetEvent to shut down the background work, but my issue is with the ThreadSleep code. I can post more code if necessary.

OK, I'm going to add a bit more complete code here as I think it will answer some of the questions.

private readonly ManualResetEvent _shutdownEvent = new ManualResetEvent(false);
private readonly ManualResetEvent _pauseEvent = new ManualResetEvent(true);
private Thread _backGroundWorkerThread;

//This starts our work
public void Start() {
    _backGroundWorkerThread = new Thread(ExecuteWorker) {IsBackground = true, Name = WorkerName + "_Thread"};
    _shutdownEvent.Reset();
    _backGroundWorkerThread.Start();
}
internal void Stop() {
    //Signal the shutdown event
    _shutdownEvent.Set();

    //Make sure to resume any paused threads
    _pauseEvent.Set();

    //Wait for the thread to exit
    _backGroundWorkerThread.Join();

}

private void ExecuteWorker() {
    while (true) {
        _pauseEvent.WaitOne(Timeout.Infinite);

        //This kills our process
        if (_shutdownEvent.WaitOne(0)) {
           break;
        }

        if (!_worker.IsReadyToExecute) {
            //sleep 5 seconds before checking again. If we go any longer we keep our service from shutting down when it needs to.
            Thread.Sleep(5000);
            continue;
        }
        DoWork();

    }
}

My problem is here,

_backGroundWorkerThread.Join();

This waits for the Thread.Sleep within the ExecuteWorker() that is running in my background thread.

Answer 1

Instead of using Thread.Sleep, you can use Monitor.Wait with a timeout - and then you can use Monitor.Pulse from a different thread to wake it up.

Don't forget you'll need to lock on the monitor before calling either Wait or Pulse:

// In the background thread
lock (monitor)
{
    // If we've already been told to quit, we don't want to sleep!
    if (somethingIndicatingQuit)
    {
        break;
    }
    Monitor.Wait(monitor, TimeSpan.FromSeconds(10));
    if (somethingIndicatingQuit)
    {
        break;
    }
}

// To wake it up...
lock (monitor)
{
    somethingIndicatingQuit = true;
    Monitor.Pulse(monitor);
}