Proper Way to Stop App While Threads Are Waiting on WaitOne()

Question

I'm playing around with AutoResetEvent and my app isn't ending, and I think I know why: the threads are still running and therefore the app won't terminate. Normally, in Main(), after I press a key, the app terminates. But the console window no longer closes. I have a simple console app:

    private static EventWaitHandle waitHandle = new AutoResetEvent(false);

    static void Main(string[] args)
    {
        AutoResetEventFun();

        Console.WriteLine("Press any key to end.");
        Console.ReadKey();

        waitHandle.Close();  // This didn't cause the app to terminate.
        waitHandle.Dispose();  // Nor did this.
    }

    private static void AutoResetEventFun()
    {
        // Start all of our threads.
        new Thread(ThreadMethod1).Start();
        new Thread(ThreadMethod2).Start();
        new Thread(ThreadMethod3).Start();
        new Thread(ThreadMethod4).Start();

        while (Console.ReadKey().Key != ConsoleKey.X)
        {
            waitHandle.Set();  // Let one of our threads process.
        }
    }

    // There are four of these methods. Only showing this one for brevity.
    private static void ThreadMethod1()
    {
        Console.WriteLine("ThreadMethod1() waiting...");

        while (true)
        {
            waitHandle.WaitOne();
            Console.WriteLine("ThreadMethod1() continuing...");   
        }
    }

What's the right way to terminate this app? Do I need to retain a reference to each thread and call Abort() on each one? Is there a way to signal waitHandle so that the threads waiting on it will terminate? (I don't think so, but I thought it would be worth asking.)

Answer 1

While I'm not entirely sure what you're trying to accomplish, one way to have this app terminate is to make all thread background threads:

private static void ThreadMethod1()
{ 
    Thread.CurrentThread.IsBackground = true;
    Console.WriteLine("ThreadMethod1() waiting...");

    while (true)
    {
        waitHandle.WaitOne();
        Console.WriteLine("ThreadMethod1() continuing...");   
    }
}

Answer 2

Another way is to set a volatile 'Abort' boolean flag that the threads always check after returning from the WaitOne() call to see if they need to exit. You could then set this flag and signal the WaitHandle [no. of threads] times.