Question

I have a windows service developed in C#. On it’s Start method I have a initialization such as:

Task _backgroundTask = null;

CancellationTokenSource _backgroundCancellationSource = null;

protected override void OnStart(string[] args)
{

......

_backgroundCancellationSource = new CancellationTokenSource();

CancellationToken token = backgroundCancellationSource.Token;

_backgroundTask = new Task(() => BackgroundFoldersProcessing(token), token, TaskCreationOptions.LongRunning);

.......
}

Now the method BackgroundFoldersProcessing looks like this:

void BackgroundFoldersProcessing(CancellationToken token)
{

            while (true)
            {
                try
                {
                    if (token.IsCancellationRequested)
                    {                        
                        return;
                    }

                    DoSomeWork()
                }
                catch (Exception ex)
                {
                    .........
                }
            }
}

Now, the Stop method is as follows:

protected override void OnStop()
{
.................

_backgroundCancellationSource.Cancel();
_backgroundTask.Wait();

_backgroundCancellationSource.Dispose();
_backgroundTask.Dispose();

_backgroundTask = null;
_backgroundCancellationSource = null;

.................
}

Now the problem is when I try to stop the service in a middle of processing, the Wait method of _backgroundTask would not stop the service until and unless the DoSomeWork() method inside the BackgroundFoldersProcessing gets completed, the Windows Service would not stop.

Is there any way, though which I can stop the service and the execution of _backgroundTask would be terminated, even though the DoSomeWork() method gets completed/executed or not? I have also tried token.ThrowIfCancellationRequested() in BackgroundFoldersProcessing method, but that also did not worked. I want that whenever I try to Stop the service from Service Control Manager (SCM), the service should be stopped immediately and the __backgroundTask should stop executing the BackgroundFoldersProcessing method and be terminated as well. How can I achieve this?

Answer 1

You can try use ThreadAbortException:

defining the thread:

ThreadStart threadDelegate = new ThreadStart(BackgroundFoldersProcessing);
Thread thread_ = new Thread(threadDelegate);
thread_.Start();

Add catch to BackgroundFoldersProcessing

catch (ThreadAbortException e)
{
     return;
}

and when you want to shut it down use:

thread_.Abort();
thread_.Join();

Then when Abort() will be called ThreadAbortException will be thrown.