Remove onLock clauses from ExchangeScope

[alexandrepiveteau]

Preparing for Kotlin/kotlinx.coroutines#2794.

[qwwdfsad]

Hi!

It seems like you are one of the users of onLock, could you please elaborate on whether onLock removal significantly affects you? E.g. was your onLock usage important for API design or it was just made similar to Mutex?

[alexandrepiveteau]

Hi, I was using onLock very similarly to a standard Mutex, and its deprecation won’t affect the API much.

In this project, a bunch of coroutines are receiving events to be added to a mutable event log. Access to the event log requires mutual exclusion, and selection using onLock simply let each coroutine select on either adding events to the log, or receiving some more events (which would be added to the event lock when it becomes available). Naively using Mutex.withLock after each event reception is the alternative I’ve implemented (even if it means events won’t be batch-inserted anymore).