Resource locking with async/await

Question

I have an application where I have a shared resource (a Motion system) which can be accessed by multiple clients. I have individual Operations that require access to the sy

Answer 1

There's SemaphoreSlim.WaitAsync which fits closely here. (I found it in a similar question).

Answer 2

My question: does anybody know of a good pattern to deal with acquiring exclusive access in the presence of thread switching due to async/await?

Yes, you can use AsyncLock, which is also available as part of my AsyncEx library. If you want to have a "TryLock" kind of operation, then you may have to create your own primitive.

You do lose some of the capability to do safety checks: there is no way to check whether the currently-executing thread has a specific AsyncLock.

Other options include ConcurrentExclusiveSchedulerPair (which I blog about here) or TPL Dataflow.