[thread.sharedtimedmutex.class] # 32 Concurrency support library [[thread]](./#thread) ## 32.6 Mutual exclusion [[thread.mutex]](thread.mutex#thread.sharedtimedmutex.class) ### 32.6.4 Mutex requirements [[thread.mutex.requirements]](thread.mutex.requirements#thread.sharedtimedmutex.class) #### 32.6.4.5 Shared timed mutex types [[thread.sharedtimedmutex.requirements]](thread.sharedtimedmutex.requirements#thread.sharedtimedmutex.class) #### 32.6.4.5.2 Class shared_timed_mutex [thread.sharedtimedmutex.class] [🔗](#lib:shared_timed_mutex) namespace std {class shared_timed_mutex {public: shared_timed_mutex(); ~shared_timed_mutex(); shared_timed_mutex(const shared_timed_mutex&) = delete; shared_timed_mutex& operator=(const shared_timed_mutex&) = delete; // exclusive ownershipvoid lock(); // blockingbool try_lock(); templatebool try_lock_for(const chrono::duration& rel_time); templatebool try_lock_until(const chrono::time_point& abs_time); void unlock(); // shared ownershipvoid lock_shared(); // blockingbool try_lock_shared(); templatebool try_lock_shared_for(const chrono::duration& rel_time); templatebool try_lock_shared_until(const chrono::time_point& abs_time); void unlock_shared(); };} [1](#1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/threads.tex#L8123) The class shared_timed_mutex provides a non-recursive mutex with shared ownership semantics[.](#1.sentence-1) [2](#2) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/threads.tex#L8127) The class shared_timed_mutex meets all of the shared timed mutex requirements ([[thread.sharedtimedmutex.requirements]](thread.sharedtimedmutex.requirements "32.6.4.5 Shared timed mutex types"))[.](#2.sentence-1) It is a standard-layout class ([[class.prop]](class.prop "11.2 Properties of classes"))[.](#2.sentence-2) [3](#3) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/threads.tex#L8132) The behavior of a program is undefined if - [(3.1)](#3.1) it destroys a shared_timed_mutex object owned by any thread, - [(3.2)](#3.2) a thread attempts to recursively gain any ownership of a shared_timed_mutex, or - [(3.3)](#3.3) a thread terminates while possessing any ownership of a shared_timed_mutex[.](#3.sentence-1)