Hi,

I'm trying to implement a cancellable worker thread using the new threading constructs in System.Threading.Tasks namespace. So far I have have come up with this implementation:

public sealed class Scheduler
{
    private CancellationTokenSource _cancellationTokenSource;
    public System.Threading.Tasks.Task Worker { get; private set; }

    public void Start()
    {
        _cancellationTokenSource = new CancellationTokenSource();

        Worker = System.Threading.Tasks.Task.Factory.StartNew(
            () => RunTasks(_cancellationTokenSource.Token),
             _cancellationTokenSource.Token
        );
    }

    private static void RunTasks(CancellationToken cancellationToken)
    {
        while (!cancellationToken.IsCancellationRequested)
        {
            Thread.Sleep(1000); // simulate work
        }
    }

    public void Stop()
    {
        try
        {
            _cancellationTokenSource.Cancel();
            Worker.Wait(_cancellationTokenSource.Token);
        }
        catch (OperationCanceledException)
        {
            // OperationCanceledException is expected when a Task is cancelled.
        }
    }
}

When Stop() returns I expect Worker.Status to be TaskStatus.Canceled.
My unit tests have shown that under certain conditions Worker.Status remains set to TaskStatus.Running.

Is this a correct way to implement a cancellable worker thread?