Namespaces
Variants
Views
Actions

std::atomic_flag::clear

From cppreference.com
< cpp‎ | atomic‎ | atomic flag
 
 
Concurrency support library
Threads
(C++11)
(C++20)
(C++20)
this_thread namespace
(C++11)
(C++11)
(C++11)
Mutual exclusion
(C++11)
(C++11)  
Generic lock management
(C++11)
(C++11)
(C++11)
(C++11)(C++11)(C++11)
(C++11)
(C++11)
Condition variables
(C++11)
Semaphores
Latches and Barriers
(C++20)
(C++20)
Futures
(C++11)
(C++11)
(C++11)
(C++11)
Safe Reclamation
(C++26)
(C++26)
Hazard Pointers

Atomic types
(C++11)
(C++20)
Initialization of atomic types
(C++11)(deprecated in C++20)
(C++11)(deprecated in C++20)
Memory ordering
Free functions for atomic operations
Free functions for atomic flags
 
 
Defined in header <atomic>
void clear( std::memory_order order =
                std::memory_order_seq_cst ) volatile noexcept;
(1) (since C++11)
void clear( std::memory_order order =
                std::memory_order_seq_cst ) noexcept;
(2) (since C++11)

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

If order is one of std::memory_order_consume, std::memory_order_acquire and std::memory_order_acq_rel, the behavior is undefined.

[edit] Parameters

order - the memory synchronization ordering

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2138 C++11 order could be std::memory_order_consume the behavior is undefined in this case

[edit] See also

atomically sets the flag to true and obtains its previous value
(public member function) [edit]
atomically sets the value of the flag to false
(function) [edit]
defines memory ordering constraints for the given atomic operation
(enum) [edit]