NAME

atomic_flag_clear, atomic_flag_clear_explicit — clear an atomic flag

SYNOPSIS

#include <stdatomic.h>

void atomic_flag_clear(volatile atomic_flag *object);
void atomic_flag_clear_explicit(volatile atomic_flag *object,
       memory_order order);


DESCRIPTION

^[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.

Implementations that define the macro __STDC_NO_ATOMICS__ need not provide the <stdatomic.h> header nor support these generic functions.

The atomic_flag_clear_explicit() function shall atomically place the atomic flag pointed to by object into the clear state. Memory shall be affected according to the value of order, which the application shall ensure is not memory_order_acquire nor memory_order_acq_rel.

The atomic_flag_clear() function shall be equivalent to atomic_flag_clear_explicit() called with order set to memory_order_seq_cst.

RETURN VALUE

These functions shall not return a value.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

XBD 4.15.1 Memory Ordering, <stdatomic.h>

CHANGE HISTORY

First released in Issue 8. Included for alignment with the ISO/IEC 9899:2018 standard.