What happens to waiting threads if I call WaitHandle.Dispose()?

Question

I have two ManualResetEvents, which I use to pass control back and forth between two threads. Essentially a coroutine.

Because the coroutine holds disposable objects (ManualResetEvents are wait handles), it should implement disposable. Also, it should dispose those ManualResetEvents when it is disposed. But, because only one thread runs at a time, one of them is (almost) always waiting on one of the handles.

What is the specified behavior if I dispose both ManualResetEvents? Will the waiting thread be stuck forever, or will disposing terminate the wait? What if I call .Set() first?

Answer 1

It is bad practice to imply on implementation of ManualResetEvents. Create supervisor class that owns by events, and using refcounter pattern (each thread increase/decrease usage) dispose supervisor when counter meets 0.

Answer 2

I recently had a similar problem, and decided to replace wait handles with a monitor and the wait/pulse pattern described by Marc Gravell here and here. Because the monitor class is completely managed, you don't have to worry about disposing any resources. Of course, you still might need to think through your shut-down procedure, but the wait/pulse pattern is a little more flexible for adding things like a shut down flag.