Nicer wait with timeout API

[tinywombat765]

liburing has a way to block until completion events come in. I'd be nice to have that functionality in this library. Some like https://unixism.net/loti/ref-liburing/completion.html#c.io_uring_wait_cqe

[tinywombat765]

Or does submit_and_wait do that? If so, is there a way to set a timeout?

[tinywombat765]

Okay, I see how this is supposed to work. The thing I'm after is waiting with a timeout. I believe the way to do this is to submit a timeout event then call submit_and_wait. I'd be nice to have a simple wait with timeout function like liburing has.

[quininer]

You can also use SubmitArgs, see https://github.com/tokio-rs/io-uring/blob/master/io-uring-test/src/tests/timeout.rs#L266

[tinywombat765]

Thanks! That's exactly what I'm looking for. Maybe add doc comment saying that's what that timespec does.