cpp/named req/SharedTimedMutex

The requirements extend the  requirements to include shared lock ownership mode.

Requirements


Additionally, an object of  type supports timed shared operations:


 * The expression has the following properties
 * Behaves as an atomic operation.
 * Attempts to obtain shared ownership of the mutex within the duration specified by . If is less or equal, attempts to obtain the ownership without waiting (as if by ). Otherwise, this function blocks until the mutex is acquired or until the time specified by  passes. It returns within  only if it succeeds, but it allowed to fail to acquire the mutex even if at some point in time during  it was not owned by another thread. In any case, it returns  if the mutex was acquired and  otherwise.
 * If succeeds, prior  operations on the same object synchronize-with this operation (equivalent to release-acquire std).
 * 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 has the following properties
 * Behaves as an atomic operation.
 * Attempts to obtain shared ownership of the mutex within the time left until . If already passed, attempts to obtain the ownership without locking (as if by ). Otherwise, this function blocks until the mutex is acquired or until the time specified by  passes. It returns before  only if it succeeds, but it allowed to fail to acquire the mutex even if at some point in time before  it was not owned by another thread. In any case, it returns  if the mutex was acquired and  otherwise.
 * If succeeds, prior  operations on the same object synchronize-with this operation (equivalent to release-acquire std).
 * 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.

Library types
The following standard library types satisfy :
 * std