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std::counting_semaphore<LeastMaxValue>:: try_acquire

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std::counting_semaphore
bool try_acquire ( ) noexcept ;
(C++20 起)

尝试在内部计数器大于 ​ 0 ​ 时原子性地将其递减 1 ；无论结果如何都不会发生阻塞。

返回值

true 表示成功递减内部计数器，否则返回 false 。

注释

实现允许在计数器大于 ​ 0 ​ 时仍不进行递减操作——即允许出现伪失败并返回 false 。

参见

递增内部计数器并解除获取者的阻塞
(公开成员函数)
递减内部计数器或在能够递减前阻塞
(公开成员函数)
尝试递减内部计数器，最多阻塞一段持续时间
(公开成员函数)
尝试递减内部计数器，阻塞直到某个时间点
(公开成员函数)