C++ named requirements: SharedTimedMutex (since C++14) (original) (raw)
The SharedTimedMutex requirements extend the TimedMutex requirements to include shared lock ownership mode.
[edit] Requirements
Additionally, an object **m** of SharedTimedMutex type supports timed shared operations:
The expression m.try_lock_shared_for(duration) has the following properties
Behaves as an atomic operation.
Attempts to obtain shared ownership of the mutex within the duration specified by
duration. Ifdurationis less or equalduration.zero(), attempts to obtain the ownership without waiting (as if bytry_lock()). Otherwise, this function blocks until the mutex is acquired or until the time specified bydurationpasses. It returns withindurationonly if it succeeds, but it allowed to fail to acquire the mutex even if at some point in time duringdurationit was not owned by another thread. In any case, it returns true if the mutex was acquired and false otherwise.If
try_lock_shared_for(duration)succeeds, priorunlock()operations on the same object synchronize-with this operation (equivalent to release-acquire std::memory_order).The behavior is undefined if the calling thread already owns the mutex in any mode.
An exception may be thrown by clock, time point, or duration during the execution (clocks, time points, and durations provided by the standard library never throw).
If an exception is thrown, the shared lock is not acquired.
The expression m.try_lock_shared_until(time_point) has the following properties
Behaves as an atomic operation.
Attempts to obtain shared ownership of the mutex within the time left until
time_point. Iftime_pointalready passed, attempts to obtain the ownership without locking (as if bytry_lock()). Otherwise, this function blocks until the mutex is acquired or until the time specified bytime_pointpasses. It returns beforetime_pointonly if it succeeds, but it allowed to fail to acquire the mutex even if at some point in time beforetime_pointit was not owned by another thread. In any case, it returns true if the mutex was acquired and false otherwise.If
try_lock_shared_until(time_point)succeeds, priorunlock()operations on the same object synchronize-with this operation (equivalent to release-acquire std::memory_order).The behavior is undefined if the calling thread already owns the mutex in any mode.
An exception may be thrown by clock, time point, or duration during the execution (clocks, time points, and durations provided by the standard library never throw).
If an exception is thrown, the shared lock is not acquired.
[edit] Standard library
The following standard library types satisfy SharedTimedMutex requirements:
| | provides shared mutual exclusion facility and implements locking with a timeout (class) [edit] | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |