std::atomic_flag_clear, std::atomic_flag_clear_explicit

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Atomic operations library

Types

atomic (C++11)

atomic_ref (C++20)

Functions

atomic_storeatomic_store_explicit (C++11)(C++11)

atomic_loadatomic_load_explicit (C++11)(C++11)

atomic_exchangeatomic_exchange_explicit (C++11)(C++11)

atomic_compare_exchange_weakatomic_compare_exchange_weak_explicitatomic_compare_exchange_strongatomic_compare_exchange_strong_explicit (C++11)(C++11)(C++11)(C++11)

atomic_fetch_addatomic_fetch_add_explicit (C++11)(C++11)

atomic_fetch_subatomic_fetch_sub_explicit (C++11)(C++11)

atomic_fetch_andatomic_fetch_and_explicit (C++11)(C++11)

atomic_fetch_oratomic_fetch_or_explicit (C++11)(C++11)

atomic_fetch_xoratomic_fetch_xor_explicit (C++11)(C++11)

atomic_is_lock_free (C++11)

Atomic flags

atomic_flag (C++11)

atomic_flag_test_and_setatomic_flag_test_and_set_explicit (C++11)(C++11)

atomic_flag_clearatomic_flag_clear_explicit (C++11)(C++11)

Initialization

atomic_init (C++11)

ATOMIC_VAR_INIT (C++11)

ATOMIC_FLAG_INIT (C++11)

Memory ordering

memory_order (C++11)

kill_dependency (C++11)

atomic_thread_fence (C++11)

atomic_signal_fence (C++11)

Defined in header <atomic>
	(1)	(since C++11)
void atomic_flag_clear( volatile std::atomic_flag* p ) noexcept;
void atomic_flag_clear( std::atomic_flag* p ) noexcept;
			(2)	(since C++11)
void atomic_flag_clear_explicit( volatile std::atomic_flag* p, std::memory_order order ) noexcept;
void atomic_flag_clear_explicit( std::atomic_flag* p, std::memory_order order ) noexcept;

Atomically changes the state of a std::atomic_flag pointed to by p to clear (false).

Parameters

p	-	pointer to std::atomic_flag to access
order	-	the memory synchronization ordering for this operation: only std::memory_order_relaxed, std::memory_order_release, or std::memory_order_seq_cst are permitted.

Return value

none.

Possible implementation

First version
void atomic_flag_clear(volatile std::atomic_flag* p) { p->clear(); }
Second version
void atomic_flag_clear(std::atomic_flag* p) { p->clear(); }
Third version
void atomic_flag_clear_explicit(volatile std::atomic_flag* p, std::memory_order order) { p->clear(order); }
Fourth version
void atomic_flag_clear_explicit(std::atomic_flag* p, std::memory_order order) { p->clear(order); }

See also

atomic_flag (C++11)	the lock-free boolean atomic type (class)
atomic_flag_test_and_setatomic_flag_test_and_set_explicit (C++11)(C++11)	atomically sets the flag to true and returns its previous value (function)
memory_order (C++11)	defines memory ordering constraints for the given atomic operation (enum)