[thread.timedmutex.recursive] (original) (raw)

32 Concurrency support library [thread]

32.6 Mutual exclusion [thread.mutex]

32.6.4 Mutex requirements [thread.mutex.requirements]

32.6.4.3 Timed mutex types [thread.timedmutex.requirements]

32.6.4.3.3 Class recursive_timed_mutex [thread.timedmutex.recursive]

namespace std { class recursive_timed_mutex { public: recursive_timed_mutex();~recursive_timed_mutex(); recursive_timed_mutex(const recursive_timed_mutex&) = delete; recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;void lock(); bool try_lock() noexcept;template<class Rep, class Period> bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);template<class Clock, class Duration> bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);void unlock();using native_handle_type = implementation-defined; native_handle_type native_handle(); };}

The class recursive_timed_mutex provides a recursive mutex with exclusive ownership semantics.

If one thread owns a recursive_timed_mutex object, attempts by another thread to acquire ownership of that object will fail (fortry_lock()) or block (for lock(), try_lock_for(), andtry_lock_until()) until the owning thread has completely released ownership or the call to try_lock_for() or try_lock_until()times out (having failed to obtain ownership).

A thread that owns a recursive_timed_mutex object may acquire additional levels of ownership by calling lock(), try_lock(),try_lock_for(), or try_lock_until() on that object.

It is unspecified how many levels of ownership may be acquired by a single thread.

If a thread has already acquired the maximum level of ownership for arecursive_timed_mutex object, additional calls to try_lock(),try_lock_for(), or try_lock_until() fail, and additional calls to lock() throw an exception of type system_error.

A thread shall call unlock() once for each level of ownership acquired by calls to lock(), try_lock(), try_lock_for(), andtry_lock_until().

Only when all levels of ownership have been released may ownership of the object be acquired by another thread.

The behavior of a program is undefined if