std::atomic_flag_notify_one

 

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Free functions for atomic flags atomic_flag_test_and_setatomic_flag_test_and_set_explicit (C++11)(C++11) atomic_flag_clearatomic_flag_clear_explicit (C++11)(C++11) atomic_flag_testatomic_flag_test_explicit (C++20)(C++20) atomic_flag_waitatomic_flag_wait_explicit (C++20)(C++20) atomic_flag_notify_one (C++20) atomic_flag_notify_all (C++20) Memory ordering memory_order (C++11) kill_dependency (C++11) atomic_thread_fence (C++11) atomic_signal_fence (C++11) Mutual exclusion mutex (C++11) recursive_mutex (C++11) shared_mutex (C++17) timed_mutex (C++11) recursive_timed_mutex (C++11) shared_timed_mutex (C++14) Generic lock management lock_guard (C++11) scoped_lock (C++17) unique_lock (C++11) shared_lock (C++14) defer_lock_ttry_to_lock_tadopt_lock_t (C++11)(C++11)(C++11) lock (C++11) try_lock (C++11) defer_locktry_to_lockadopt_lock (C++11)(C++11)(C++11) once_flag (C++11) call_once (C++11) Condition variables condition_variable (C++11) condition_variable_any (C++11) notify_all_at_thread_exit (C++11) cv_status (C++11) Semaphores counting_semaphorebinary_semaphore (C++20)(C++20) Latches and barriers latch (C++20) barrier (C++20) Futures promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11) launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

 

Defined in header <atomic>
		(since C++20)
void atomic_flag_notify_one( std::atomic_flag* object ) noexcept;
void atomic_flag_notify_one( volatile std::atomic_flag* object ) noexcept;

Performs atomic notifying operations.

If there is a thread blocked in an atomic waiting operation (i.e. std::atomic_flag_wait(), std::atomic_flag_wait_explicit(), or std::atomic_flag::wait()) on *object, then unblocks at least one such thread; otherwise does nothing.

Equivalent to object->notify_one().

Parameters

object

-

pointer to the atomic_flag object to notify

Return value

(none)

Notes

This form of change-detection is often more efficient than simple polling or pure spinlocks.

See also

notify_one (C++20)	notifies at least one thread waiting on the atomic object (public member function of std::atomic_flag)
notify_all (C++20)	notifies all threads blocked waiting on the atomic object (public member function of std::atomic_flag)
atomic_flag_notify_all (C++20)	notifies all threads blocked in atomic_flag_wait (function)