Mutex

二元 Semaphore，用于在多 Thread 间进行同步。

描述

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: 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.

教程

方法

void	lock()
bool	try_lock()
void	unlock()

方法说明

void lock() 🔗

锁定此 Mutex，直到被当前所有者解锁为止。

注意：如果线程已经拥有互斥锁的所有权，该函数将无阻塞地返回。

bool try_lock() 🔗

尝试锁定该 Mutex，但不会阻塞。成功时返回 true，否则返回 false。

注意：如果该线程已经拥有了该互斥器的所有权，则函数返回 true。

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 than lock() on a given thread, thus ending up trying to unlock a non-locked mutex, is wrong and may causes crashes or deadlocks.