[thread.req.lockable.shared] (original) (raw)

32 Concurrency support library [thread]

32.2 Requirements [thread.req]

32.2.5 Requirements for Cpp17Lockable types [thread.req.lockable]

32.2.5.5 Cpp17SharedLockable requirements [thread.req.lockable.shared]

A type L meets the Cpp17SharedLockable requirements if the following expressions are well-formed, have the specified semantics, and the expression m.try_lock_shared() has type bool(m denotes a value of type L):

Effects: Blocks until a lock can be acquired for the current execution agent.

If an exception is thrown then a lock shall not have been acquired for the current execution agent.

Effects: Attempts to acquire a lock for the current execution agent without blocking.

If an exception is thrown then a lock shall not have been acquired for the current execution agent.

Returns: true if the lock was acquired, false otherwise.

Preconditions: The current execution agent holds a shared lock on m.

Effects: Releases a shared lock on m held by the current execution agent.