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std::counting_semaphore<LeastMaxValue>:: try_acquire_for

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std::counting_semaphore
template < class Rep, class Period >
bool try_acquire_for ( const std:: chrono :: duration < Rep, Period > & rel_time ) ;
(C++20 起)

尝试在内部计数器大于 1 时原子性地将其递减 1 ；否则会阻塞直到计数器大于 ​ 0 ​ 且能成功递减内部计数器，或超过 rel_time 持续时间。

目录

前置条件

(无)

参数

rel_time - 函数必须等待其失败的最短持续时间

返回值

true 表示成功递减内部计数器，否则返回 false 。

异常

可能抛出 std::system_error 或与超时相关的异常。

注释

实际上，该函数可能需要比 rel_time 更长的时间才会失败。

参阅

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可递减前保持阻塞
(公开成员函数)
尝试非阻塞地递减内部计数器
(公开成员函数)
尝试递减内部计数器，阻塞直至指定时间点
(公开成员函数)