Limit timer thread execution time

Question

How can I restrict timer thread execution time? I have long running timer work that should work no more than 30 seconds.

Answer 1

The only way to do this is to have a second thread (possibly the one that created the worker thread) monitor and then kill it or gracefully call it to quit immediately. Killing threads you should avoid, and only use as the last resort. Here is example how:

        Thread t = new Thread(myLongThreadProc);
        t.Start();
        Thread.Sleep(30000);
        t.Abort();

By 'gracefully call it to quit', I mean to set some stop variable to some value, and give the thread some short time to quit itself, otherwise you kill it. But it is the design of your thread function to make it actually quit. Here is the sample code:

        Thread t = new Thread(myLongThreadProc);
        threadRun = true;
        t.Start();
        Thread.Sleep(30000);
        threadRun = false; //this variable is monitored by thread
        if (!t.Join(1000))  //inside your thread, make sure it does quit in one second
        {                   //when this variable is set to false
            t.Abort();
        }

And should I mention that your caller thread does not have to sleep for 30 seconds, but you can use a timer instead (if it is a form thread) or do something useful and check periodically - or have a third worker thread just counting 30 seconds...

Answer 2

Just have your worker method start a 30-second timer and check to see if it's elapsed as your worker does its thing:

    bool timerElapsed;

    public void DoWork()
    {
        timerElapsed=false;
        System.Timers.Timer timer = new System.Timers.Timer(30000);
        timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
        timer.Start();

        while (true)
        {
            if (timerElapsed)
            {
                // handle 30-sec elasped error
                break;
            }
            // continue doing work and break when done
        }
        timer.Stop();
    }

    void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
    {
        timerElapsed = true;
    }