ATOMIC_SWAP(3)

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.