Friday, October 7, 2016


Peter Steinberger measured the new os_unfair_lock against OSSpinLock, pthread_mutex, NSLock, dispatch queues, and @synchronized.

Pierre Habouzit (via David Smith):

Apple’s libplatform is now OSS too with user-land os_unfair_lock (os/lock.c) in all its strict glory.

Stephan Tolksdorf:

If you use it from Swift, you have to be careful, because it’s a struct and Swift doesn’t prevent you from copying or moving it around, which normally would be an error.

Previously: OSSpinLock Is Unsafe, Mutexes and Closure Capture in Swift.

Update (2023-01-27): David Smith:

A decade or so ago, “what lock should I use?” was a fairly complicated question on macOS/iOS.

2 Comments RSS · Twitter

From what I've seen in some crash reports, os_unfair_lock is not happy with forked processes.


BUG IN CLIENT OF LIBPLATFORM: os_unfair_lock is corrupt.

Moving to posix_spawn seems to make it happier.

[…] os_unfair_lock is the new synchronization hotness! […]

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