b6cbf7203b
This patch imports the unmodified current version of NetBSD libc. The NetBSD includes are in /nbsd_include, while the libc code itself is split between lib/nbsd_libc and common/lib/libc.
77 lines
2.7 KiB
Groff
77 lines
2.7 KiB
Groff
.\" $NetBSD: atomic_swap.3,v 1.1 2008/06/23 10:22:40 ad Exp $
|
|
.\"
|
|
.\" Copyright (c) 2007 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Jason R. Thorpe.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
.\" POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.Dd April 11, 2007
|
|
.Dt ATOMIC_SWAP 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm atomic_swap ,
|
|
.Nm atomic_swap_32 ,
|
|
.Nm atomic_swap_uint ,
|
|
.Nm atomic_swap_ulong ,
|
|
.Nm atomic_swap_ptr ,
|
|
.Nm atomic_swap_64
|
|
.Nd atomic swap operations
|
|
.\" .Sh LIBRARY
|
|
.\" .Lb libc
|
|
.Sh SYNOPSIS
|
|
.In sys/atomic.h
|
|
.Ft uint32_t
|
|
.Fn atomic_swap_32 "volatile uint32_t *ptr" "uint32_t new"
|
|
.Ft unsigned int
|
|
.Fn atomic_swap_uint "volatile unsigned int *ptr" "unsigned int new"
|
|
.Ft unsigned long
|
|
.Fn atomic_swap_ulong "volatile unsigned long *ptr" "unsigned long new"
|
|
.Ft void *
|
|
.Fn atomic_swap_ptr "volatile void *ptr" "void *new"
|
|
.Ft uint64_t
|
|
.Fn atomic_swap_64 "volatile uint64_t *ptr" "uint64_t new"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm atomic_swap
|
|
family of functions perform a swap operation in an atomic fashion.
|
|
The value of the variable referenced by
|
|
.Fa ptr
|
|
is replaced by
|
|
.Fa new
|
|
and the old value returned.
|
|
.Pp
|
|
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
|
|
.Dv __HAVE_ATOMIC64_OPS
|
|
is defined.
|
|
.Sh SEE ALSO
|
|
.Xr atomic_ops 3
|
|
.Sh HISTORY
|
|
The
|
|
.Nm atomic_swap
|
|
functions first appeared in
|
|
.Nx 5.0 .
|