Question

Is there an integration point into the async/await mechanisms to hook in and know when an async method is started?

Can a custom TaskScheduler provide this hook? A custom SynchronizationContext?

I want to be able to track certain method calls and know which Task (or code) they’re associated with.

Thanks!

Answer 1

According to the Task-based Asynchronous Pattern in section “Task Status”:

All tasks returned from TAP methods must be “hot” […] meaning that the asynchronous operations they represent have already been initiated and their TaskStatus is an enumeration value other than Created.

That means that you will always start the Task as soon as you create it (at least if the factory method implements the TAP, which is true for all methods provided by the .Net framework).

If you create and return a “cold” (non-running) Task using new Task(), there is no clean way to find out if the Task.Start() method was called. You can only check the TaskStatus property periodically.