A synchronization mutex (mutual exclusion). A synchronization mutex (mutual exclusion). This is used to synchronize multiple [Thread]s, and is equivalent to a binary [Semaphore]. It guarantees that only one thread can ever acquire the lock at a time. A mutex can be used to protect a critical section; however, be careful to avoid deadlocks. https://docs.godotengine.org/en/3.4/tutorials/threads/using_multiple_threads.html Locks this [Mutex], blocks until it is unlocked by the current owner. Tries locking this [Mutex], but does not block. Returns [constant OK] on success, [constant ERR_BUSY] otherwise. Unlocks this [Mutex], leaving it to other threads.