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atomic_swap_32_cas.c revision 1.6.2.1 
      1  1.6.2.1     tls /*	$NetBSD: atomic_swap_32_cas.c,v 1.6.2.1 2014/08/10 06:47:06 tls Exp $	*/
      2      1.2      ad 
      3      1.2      ad /*-
      4      1.2      ad  * Copyright (c) 2007 The NetBSD Foundation, Inc.
      5      1.2      ad  * All rights reserved.
      6      1.2      ad  *
      7      1.2      ad  * This code is derived from software contributed to The NetBSD Foundation
      8      1.2      ad  * by Jason R. Thorpe.
      9      1.2      ad  *
     10      1.2      ad  * Redistribution and use in source and binary forms, with or without
     11      1.2      ad  * modification, are permitted provided that the following conditions
     12      1.2      ad  * are met:
     13      1.2      ad  * 1. Redistributions of source code must retain the above copyright
     14      1.2      ad  *    notice, this list of conditions and the following disclaimer.
     15      1.2      ad  * 2. Redistributions in binary form must reproduce the above copyright
     16      1.2      ad  *    notice, this list of conditions and the following disclaimer in the
     17      1.2      ad  *    documentation and/or other materials provided with the distribution.
     18      1.2      ad  *
     19      1.2      ad  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20      1.2      ad  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21      1.2      ad  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22      1.2      ad  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23      1.2      ad  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24      1.2      ad  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25      1.2      ad  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26      1.2      ad  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27      1.2      ad  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28      1.2      ad  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29      1.2      ad  * POSSIBILITY OF SUCH DAMAGE.
     30      1.2      ad  */
     31      1.2      ad 
     32      1.2      ad #include "atomic_op_namespace.h"
     33      1.2      ad 
     34      1.2      ad #include <sys/atomic.h>
     35      1.2      ad 
     36      1.2      ad uint32_t
     37      1.2      ad atomic_swap_32(volatile uint32_t *addr, uint32_t new)
     38      1.2      ad {
     39      1.2      ad 	uint32_t old;
     40      1.2      ad 
     41      1.2      ad 	do {
     42      1.2      ad 		old = *addr;
     43      1.2      ad 	} while (atomic_cas_32(addr, old, new) != old);
     44      1.2      ad 
     45      1.2      ad 	return (old);
     46      1.2      ad }
     47      1.2      ad 
     48  1.6.2.1     tls crt_alias(__atomic_exchange_4,_atomic_swap_32)
     49  1.6.2.1     tls 
     50      1.2      ad #undef atomic_swap_32
     51      1.2      ad atomic_op_alias(atomic_swap_32,_atomic_swap_32)
     52      1.2      ad #undef atomic_swap_uint
     53      1.2      ad atomic_op_alias(atomic_swap_uint,_atomic_swap_32)
     54      1.2      ad __strong_alias(_atomic_swap_uint,_atomic_swap_32)
     55      1.6  martin crt_alias(__sync_lock_test_and_set_4,_atomic_swap_32)
     56      1.2      ad #if !defined(_LP64)
     57      1.2      ad #undef atomic_swap_ulong
     58      1.2      ad atomic_op_alias(atomic_swap_ulong,_atomic_swap_32)
     59      1.2      ad __strong_alias(_atomic_swap_ulong,_atomic_swap_32)
     60      1.2      ad #undef atomic_swap_ptr
     61      1.2      ad atomic_op_alias(atomic_swap_ptr,_atomic_swap_32)
     62      1.2      ad __strong_alias(_atomic_swap_ptr,_atomic_swap_32)
     63      1.2      ad #endif /* _LP64 */
     64