Robert :

How can I use the TaskScheduler in a Windows Service application? In the sample console MUDServer, I see that you are using an infinite loop which does not allow the Main method to exit:
while (true) {
Scheduler.Step();
Scheduler.WaitForWorkItems();
}

How can I start the task scheduler in my service’s OnStart method? OnStart must finish so that Windows considers the service as successfully started.

There is also the complementary action: stopping… How can I end the taskscheduler in OnStop?

Hi Robert,

I haven’t personally tried writing a Service using the TaskScheduler. My suggestion would be to try using the windows message pump to provide the Step/Wait functionality, because then the scheduler stops automatically with your message pump. I use this approach in graphical applications and servers and in both cases it works well because you can use the standard System.Windows.Forms.Application methods/events to handle things like system shutdown. Having a message pump within a Service is well understood in Win32 and I’m pretty sure there are examples for how to do it in C#.

FYI, to create a scheduler based on the windows message pump, you just do:
new TaskScheduler(JobQueue.WindowsMessageBased)
Any tasks queued to the scheduler will run automatically by the windows message pump (they get mapped to windows messages).

A few gotchas:

• Scheduling using the windows message pump is considerably slower than the normal way (you peak at around 30000-50000 task “steps” per second, compared to millions/sec with the normal approach), so if you’re doing complex computations using communication between tasks, you’ll get bottlenecked. If you need to do complex computation via tasks, you can always run a normal scheduler in a worker thread.

• WaitForNextStep will no longer work since windows’ message pump has no concept of ‘steps’.

• Since you’re running on the UI thread inside the message pump, if your individual tasks block (by waiting on a WaitHandle, or doing a bunch of computation, etc) that will block your UI thread and Windows will act like your app has hung.

How can I start the task scheduler in my service’s OnStart method? OnStart must finish so that Windows considers the service as successfully started.

There is also the complementary action: stopping… How can I end the taskscheduler in OnStop?