ATOMIC_DEC(3)

NAME
atomic_dec, atomic_dec_32, atomic_dec_uint, atomic_dec_ulong, atomic_dec_ptr, atomic_dec_64, atomic_dec_32_nv, atomic_dec_uint_nv, atomic_dec_ulong_nv, atomic_dec_ptr_nv, atomic_dec_64_nv - atomic decrement operations

SYNOPSIS
#include <sys/atomic.h>
void
atomic_dec_32(volatile uint32_t *ptr);
void
atomic_dec_uint(volatile unsigned int *ptr);
void
atomic_dec_ulong(volatile unsigned long *ptr);
void
atomic_dec_ptr(volatile void *ptr);
void
atomic_dec_64(volatile uint64_t *ptr);
uint32_t
atomic_dec_32_nv(volatile uint32_t *ptr);
unsigned int
atomic_dec_uint_nv(volatile unsigned int *ptr);
unsigned long
atomic_dec_ulong_nv(volatile unsigned long *ptr);
void *
atomic_dec_ptr_nv(volatile void *ptr);
uint64_t
atomic_dec_64_nv(volatile uint64_t *ptr);

DESCRIPTION
The atomic_dec family of functions decrement (by one) the variable referenced by ptr in an atomic fashion.

The *_nv() variants of these functions return the new value.

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_dec functions first appeared in NetBSD 5.0.