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Mutex
Inherits: RefCounted < Object
A binary Semaphore for synchronization of multiple Threads.
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.
Tutorials
Methods
void |
lock() |
try_lock() |
|
void |
unlock() |
Method Descriptions
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.
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.