NAME

atomic_swap, atomic_swap_32, atomic_swap_uint, atomic_swap_ulong, atomic_swap_ptr, atomic_swap_64 — atomic swap operations

SYNOPSIS

#include <sys/atomic.h>

uint32_t
atomic_swap_32(volatile uint32_t *ptr, uint32_t new);

unsigned int
atomic_swap_uint(volatile unsigned int *ptr, unsigned int new);

unsigned long
atomic_swap_ulong(volatile unsigned long *ptr, unsigned long new);

void *
atomic_swap_ptr(volatile void *ptr, void *new);

uint64_t
atomic_swap_64(volatile uint64_t *ptr, uint64_t new);

DESCRIPTION

The atomic_swap family of functions perform a swap operation in an atomic fashion. The value of the variable referenced by ptr is replaced by new and the old value returned.

The 64-bit variants of these functions are available only on platforms that can support atomic 64-bit memory access. Applications can check for the availability of 64-bit atomic memory operations by testing if the pre-processor macro __HAVE_ATOMIC64_OPS is defined.

SEE ALSO

atomic_ops(3)

HISTORY

The atomic_swap functions first appeared in NetBSD 5.0.