std::shared_mutex

 

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std::shared_mutex

Member functions

shared_mutex::shared_mutex

Exclusive locking

shared_mutex::lock

shared_mutex::try_lock

shared_mutex::try_lock_for

shared_mutex::try_lock_until

shared_mutex::unlock

Shared locking

shared_mutex::lock_shared

shared_mutex::try_lock_shared

shared_mutex::try_lock_shared_for

shared_mutex::try_lock_shared_until

shared_mutex::unlock_shared

 

Defined in header <mutex>
class shared_mutex;		(since C++14)

The shared_mutex class is a synchronization primitive that can be used to protect shared data from being simultaneously accessed by multiple threads. Differently from other mutex types, there are two levels of access:

• shared - several threads can share ownership of the same mutex.

• exclusive - only one thread can own the mutex.

Shared mutexes are usually used in situations, when multiple readers can access the same resource at the same time without causing data races, but only one writer can do so.

In a manner similar to timed_mutex, shared_mutex provides the ability to attempt to claim ownership of a shared_mutex with a timeout via the try_lock_for(), try_lock_until(), try_lock_shared_for(), try_lock_shared_until() methods.

The shared_mutex class is non-copyable.

Member functions

(constructor)	constructs the mutex (public member function)
Exclusive locking
lock	locks the mutex, blocks if the mutex is not available (public member function)
try_lock	tries to lock the mutex, returns if the mutex is not available (public member function)
try_lock_for	tries to lock the mutex, returns if the mutex has been unavailable for the specified timeout duration (public member function)
try_lock_until	tries to lock the mutex, returns if the mutex has been unavailable until specified time point has been reached (public member function)
unlock	unlocks the mutex (public member function)
Shared locking
lock_shared	locks the mutex for shared ownership, blocks if the mutex is not available (public member function)
try_lock_shared	tries to lock the mutex for shared ownership, returns if the mutex is not available (public member function)
try_lock_shared_for	tries to lock the mutex for shared ownership, returns if the mutex has been unavailable for the specified timeout duration (public member function)
try_lock_shared_until	tries to lock the mutex for shared ownership, returns if the mutex has been unavailable until specified time point has been reached (public member function)
unlock_shared	unlocks the mutex (shared ownership) (public member function)