33 Concurrency support library [thread]

33.6 Mutual exclusion [thread.mutex]

33.6.5 Locks [thread.lock]

33.6.5.5 Class template shared_lock [thread.lock.shared]

33.6.5.5.3 Locking [thread.lock.shared.locking]

void lock();
Effects: As if by pm->lock_shared().
Postconditions: owns == true.
Throws: Any exception thrown by pm->lock_shared().
system_error when an exception is required ([thread.req.exception]).
Error conditions:
  • operation_not_permitted — if pm is nullptr.
  • resource_deadlock_would_occur — if on entry owns is true.
bool try_lock();
Effects: As if by pm->try_lock_shared().
Postconditions: owns == res, where res is the value returned by the call to pm->try_lock_shared().
Returns: The value returned by the call to pm->try_lock_shared().
Throws: Any exception thrown by pm->try_lock_shared().
system_error when an exception is required ([thread.req.exception]).
Error conditions:
  • operation_not_permitted — if pm is nullptr.
  • resource_deadlock_would_occur — if on entry owns is true.
template<class Clock, class Duration> bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
Preconditions: Mutex meets the Cpp17SharedTimedLockable requirements ([thread.req.lockable.shared.timed]).
Effects: As if by pm->try_lock_shared_until(abs_time).
Postconditions: owns == res, where res is the value returned by the call to pm->try_lock_shared_until(abs_time).
Returns: The value returned by the call to pm->try_lock_shared_until(abs_time).
Throws: Any exception thrown by pm->try_lock_shared_until(abs_time).
system_error when an exception is required ([thread.req.exception]).
Error conditions:
  • operation_not_permitted — if pm is nullptr.
  • resource_deadlock_would_occur — if on entry owns is true.
template<class Rep, class Period> bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
Preconditions: Mutex meets the Cpp17SharedTimedLockable requirements ([thread.req.lockable.shared.timed]).
Effects: As if by pm->try_lock_shared_for(rel_time).
Postconditions: owns == res, where res is the value returned by the call to pm->try_lock_shared_for(rel_time).
Returns: The value returned by the call to pm->try_lock_shared_for(rel_time).
Throws: Any exception thrown by pm->try_lock_shared_for(rel_time).
system_error when an exception is required ([thread.req.exception]).
Error conditions:
  • operation_not_permitted — if pm is nullptr.
  • resource_deadlock_would_occur — if on entry owns is true.
void unlock();
Effects: As if by pm->unlock_shared().
Postconditions: owns == false.
Throws: system_error when an exception is required ([thread.req.exception]).
Error conditions:
  • operation_not_permitted — if on entry owns is false.