标准库头文件 <semaphore> (C++20)
来自 cppreference.com
此头文件是 线程支持 库的一部分。
类 | |
(C++20) |
模拟非负资源计数的信号量 (类模板) |
(C++20) |
只有两种状态的信号量 (typedef) |
[编辑] 概要
namespace std { template<ptrdiff_t LeastMaxValue = /* implementation-defined */> class counting_semaphore; using binary_semaphore = counting_semaphore<1>; }
[编辑] 类模板 std::counting_semaphore
namespace std { template<ptrdiff_t LeastMaxValue = /* implementation-defined */> class counting_semaphore { public: static constexpr ptrdiff_t max() noexcept; constexpr explicit counting_semaphore(ptrdiff_t desired); ~counting_semaphore(); counting_semaphore(const counting_semaphore&) = delete; counting_semaphore& operator=(const counting_semaphore&) = delete; void release(ptrdiff_t update = 1); void acquire(); bool try_acquire() noexcept; template<class Rep, class Period> bool try_acquire_for(const chrono::duration<Rep, Period>& rel_time); template<class Clock, class Duration> bool try_acquire_until(const chrono::time_point<Clock, Duration>& abs_time); private: ptrdiff_t counter; // exposition only }; }