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 … Continue reading os_unfair_lock