xref: /illumos-gate/usr/src/man/man3c/atomic_add.3c (revision dd72704bd9e794056c558153663c739e2012d721)
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Copyright (c) 2005, Sun Microsystems, Inc. All Rights Reserved.
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ATOMIC_ADD 3C "May 13, 2005"
NAME
atomic_add, atomic_add_8, atomic_add_char, atomic_add_16, atomic_add_short, atomic_add_32, atomic_add_int, atomic_add_long, atomic_add_64, atomic_add_ptr, atomic_add_8_nv, atomic_add_char_nv, atomic_add_16_nv, atomic_add_short_nv, atomic_add_32_nv, atomic_add_int_nv, atomic_add_long_nv, atomic_add_64_nv, atomic_add_ptr_nv - atomic add operations
SYNOPSIS

#include <atomic.h>

void atomic_add_8(volatile uint8_t *target, int8_t delta);

void atomic_add_char(volatile uchar_t *target, signed char delta);

void atomic_add_16(volatile uint16_t *target, int16_t delta);

void atomic_add_short(volatile ushort_t *target, short delta);

void atomic_add_32(volatile uint32_t *target, int32_t delta);

void atomic_add_int(volatile uint_t *target, int delta);

void atomic_add_long(volatile ulong_t *target, long delta);

void atomic_add_64(volatile uint64_t *target, int64_t delta);

void atomic_add_ptr(volatile void *target, ssize_t delta);

uint8_t atomic_add_8_nv(volatile uint8_t *target, int8_t delta);

uchar_t atomic_add_char_nv(volatile uchar_t *target, signed char delta);

uint16_t atomic_add_16_nv(volatile uint16_t *target, int16_t delta);

ushort_t atomic_add_short_nv(volatile ushort_t *target, shortdelta);

uint32_t atomic_add_32_nv(volatile uint32_t *target, int32_t delta);

uint_t atomic_add_int_nv(volatile uint_t *target, int delta);

ulong_t atomic_add_long_nv(volatile ulong_t *target, long delta);

uint64_t atomic_add_64_nv(volatile uint64_t *target, int64_t delta);

void *atomic_add_ptr_nv(volatile void *target, ssize_t delta);
DESCRIPTION

These functions enable the addition of delta to the value stored in target to occur in an atomic manner.

RETURN VALUES

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

ERRORS

No errors are defined.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Stable
MT-Level MT-Safe
SEE ALSO

atomic_and (3C), atomic_bits (3C), atomic_cas (3C), atomic_dec (3C), atomic_inc (3C), atomic_or (3C), atomic_swap (3C), membar_ops (3C), attributes (7), atomic_ops (9F)

NOTES

The *_nv() variants are substantially more expensive on some platforms than the versions that do not return values. Do not use them unless you need to know the new value atomically (for example, when decrementing a reference count and checking whether it went to zero).