Lock.swift

struct Lock {
	private var unfairLock = os_unfair_lock_s()
	
	mutating func lock(_ work: () -> Void) {
		self.lock()
		work()
		self.unlock()
	}
	
	mutating func trylock(_ work: () -> Void) -> Bool {
		if self.trylock() {
			work()
			self.unlock()
			return true
		} else {
			return false
		}
	}
	
	mutating func lock() {
		os_unfair_lock_lock(&unfairLock)
	}
	
	mutating func trylock() -> Bool {
		os_unfair_lock_trylock(&unfairLock)
	}
	
	mutating func unlock() {
		os_unfair_lock_unlock(&unfairLock)
	}
	
	mutating func assertOwner() {
		os_unfair_lock_assert_owner(&unfairLock)
	}
	
	mutating func assertNotOwner() {
		os_unfair_lock_assert_not_owner(&unfairLock)
	}
}