Make RawReentrantMutex public

[coolreader18]

This is useful for any use case that you'd be using a raw mutex for, where you also want reentrancy.

[coolreader18]

I don't think the android build failure is related to my changes, right?

[coolreader18]

Oh, hmm, this isn't sound, since when RawMutex::lock() succeeds Mutex assumes that it's completely exclusive. Maybe there could be another marker type on RawMutex to allow unifying Mutex and ReentrantMutex to the same generic type?

[Amanieu]

You're right, you can't implement the RawMutex trait for a reentrant mutex since it would allow you to produce mutable &mut to the same data.

I don't think there is much of a use case for a raw reentrant mutex since you can always use ReentrantMutex<()> instead.

[coolreader18]

Maybe ReentrantMutex<()> could expose an API that's similar to RawMutex? Idk, I probably have like the only use case for this that wouldn't need to use unsafe other than maybe ReentrantMutex::force_unlock; I'm implementing a Lock class for python, where all the other data structures are atomic/mutex-backed as well, but the lock is used for synchronization of multiple different operations that might modify multiple different data structures. The current implementation that I'm basing on this branch uses a trait with an associated RawMutex type, and I use that to implement reentrant and non-reentrant locks. I could probably just use a macro, though, or duplicate a bit of code.

[coolreader18]

Maybe RawReentrantMutex could be made public with just the methods from the RawMutex* traits, but not actually implementing them?

[Amanieu]

If you really want to expose it publicly then you should keep the methods as they are instead of using traits.