It'd be nice to include the [os_unfair_lock API](https://developer.apple.com/documentation/os/synchronization?language=objc) on macOS: - [os_unfair_lock](https://developer.apple.com/documentation/os/os_unfair_lock?language=objc) - [os_unfair_lock_t](https://developer.apple.com/documentation/os/os_unfair_lock_t?language=objc) - [OS_UNFAIR_LOCK_INIT](https://developer.apple.com/documentation/os/os_unfair_lock_init?language=objc) - [os_unfair_lock_lock](https://developer.apple.com/documentation/os/1646466-os_unfair_lock_lock?language=objc) - [os_unfair_lock_trylock](https://developer.apple.com/documentation/os/1646469-os_unfair_lock_trylock?language=objc) - [os_unfair_lock_unlock](https://developer.apple.com/documentation/os/1646463-os_unfair_lock_unlock?language=objc) - [os_unfair_lock_assert_owner](https://developer.apple.com/documentation/os/2976314-os_unfair_lock_assert_owner?language=objc) - [os_unfair_lock_assert_not_owner](https://developer.apple.com/documentation/os/2976313-os_unfair_lock_assert_not_owner?language=objc)
