ATOMIC_ADD(3) | Library Functions Manual | ATOMIC_ADD(3)

# NAME

`atomic_add`, `atomic_add_32`, `atomic_add_int`, `atomic_add_long`, `atomic_add_ptr`, `atomic_add_64`, `atomic_add_32_nv`, `atomic_add_int_nv`, `atomic_add_long_nv`, `atomic_add_ptr_nv`, `atomic_add_64_nv` —
atomic add operations

# SYNOPSIS

`#include <sys/atomic.h>`

void
`atomic_add_32`(volatile uint32_t *ptr, int32_t delta);

void
`atomic_add_int`(volatile unsigned int *ptr, int delta);

void
`atomic_add_long`(volatile unsigned long *ptr, long delta);

void
`atomic_add_ptr`(volatile void *ptr, ssize_t delta);

void
`atomic_add_64`(volatile uint64_t *ptr, int64_t delta);

uint32_t
`atomic_add_32_nv`(volatile uint32_t *ptr, int32_t delta);

unsigned int
`atomic_add_int_nv`(volatile unsigned int *ptr, int delta);

unsigned long
`atomic_add_long_nv`(volatile unsigned long *ptr, long delta);

void *
`atomic_add_ptr_nv`(volatile void *ptr, ssize_t delta);

uint64_t
`atomic_add_64_nv`(volatile uint64_t *ptr, int64_t delta);

# DESCRIPTION

The `atomic_add` family of functions add a signed value delta to 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_add` functions first appeared in NetBSD 5.0.

April 11, 2007 | NetBSD 9.0