Class reference
Mutex
Inherits RefCounted
Description
A synchronization mutex (mutual exclusion). This is used to synchronize multiple Threads, and is equivalent to a binary Semaphore. It guarantees that only one thread can access a critical section at a time. This is a reentrant mutex, meaning that it can be locked multiple times by one thread, provided it also unlocks it as many times. Warning: Mutexes must be used carefully to avoid deadlocks. Warning: To ensure proper cleanup without crashes or deadlocks, the following conditions must be met: - When a Mutex's reference count reaches zero and it is therefore destroyed, no threads (including the one on which the destruction will happen) must have it locked. - When a Thread's reference count reaches zero and it is therefore destroyed, it must not have any mutex locked.
Methods
void lock()
Locks this Mutex, blocks until it is unlocked by the current owner. Note: This function returns without blocking if the thread already has ownership of the mutex.
bool try_lock()
bool try_lock()Tries locking this Mutex, but does not block. Returns true on success, false otherwise. Note: This function returns true if the thread already has ownership of the mutex.
void unlock()
Unlocks this Mutex, leaving it to other threads. Note: If a thread called lock() or try_lock() multiple times while already having ownership of the mutex, it must also call unlock() the same number of times in order to unlock it correctly. Warning: Calling unlock() more times that lock() on a given thread, thus ending up trying to unlock a non-locked mutex, is wrong and may causes crashes or deadlocks.