$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 n 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.
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 n 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.
p 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 .
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