33 Thread support library [thread]

33.2 Requirements [thread.req]

33.2.5 Requirements for Lockable types [thread.req.lockable]

33.2.5.4 TimedLockable requirements [thread.req.lockable.timed]

A type L meets the TimedLockable requirements if it meets the Lockable requirements and the following expressions are well-formed and have the specified semantics (m denotes a value of type L, rel_­time denotes a value of an instantiation of duration ([time.duration]), and abs_­time denotes a value of an instantiation of time_­point ([time.point])).
m.try_lock_for(rel_time)
Effects: Attempts to acquire a lock for the current execution agent within the relative timeout ([thread.req.timing]) specified by rel_­time.
The function shall not return within the timeout specified by rel_­time unless it has obtained a lock on m for the current execution agent.
If an exception is thrown then a lock shall not have been acquired for the current execution agent.
Return type: bool.
Returns: true if the lock was acquired, false otherwise.
m.try_lock_until(abs_time)
Effects: Attempts to acquire a lock for the current execution agent before the absolute timeout ([thread.req.timing]) specified by abs_­time.
The function shall not return before the timeout specified by abs_­time unless it has obtained a lock on m for the current execution agent.
If an exception is thrown then a lock shall not have been acquired for the current execution agent.
Return type: bool.
Returns: true if the lock was acquired, false otherwise.