simplelock.h revision 111520
1/*- 2 * Copyright (c) 2002 David Xu (davidxu@freebsd.org). 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/tools/KSE/rr/simplelock.h 111520 2003-02-26 01:05:10Z davidxu $ 27 */ 28 29#ifndef _SIMPLELOCK_H 30#define _SIMPLELOCK_H 31 32#include <machine/asmacros.h> 33#include <machine/atomic.h> 34 35struct simplelock { 36 int s_lock; 37}; 38 39static inline void 40simplelock_init(struct simplelock *lock) 41{ 42 lock->s_lock = 0; 43} 44 45static inline void 46simplelock_lock(struct simplelock *lock) 47{ 48 while (!atomic_cmpset_int(&lock->s_lock, 0, 1)) 49 ; 50} 51 52static inline void 53simplelock_unlock(struct simplelock *lock) 54{ 55 atomic_store_rel_int(&lock->s_lock, 0); 56} 57 58#endif 59 60