2 * Copyright (c) 2003 David Xu <davidxu@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/lib/libpthread/thread/thr_pspinlock.c,v 1.2 2003/11/04 19:56:12 deischen Exp $
27 * $DragonFly: src/lib/libthread_xu/thread/thr_pspinlock.c,v 1.1 2005/02/01 12:38:27 davidxu Exp $
33 #include "thr_private.h"
35 #define SPIN_COUNT 100000
37 __weak_reference(_pthread_spin_init, pthread_spin_init);
38 __weak_reference(_pthread_spin_destroy, pthread_spin_destroy);
39 __weak_reference(_pthread_spin_trylock, pthread_spin_trylock);
40 __weak_reference(_pthread_spin_lock, pthread_spin_lock);
41 __weak_reference(_pthread_spin_unlock, pthread_spin_unlock);
44 _pthread_spin_init(pthread_spinlock_t *lock, int pshared)
46 struct pthread_spinlock *lck;
49 if (lock == NULL || pshared != PTHREAD_PROCESS_PRIVATE)
51 else if ((lck = malloc(sizeof(struct pthread_spinlock))) == NULL)
54 _thr_umtx_init(&lck->s_lock);
63 _pthread_spin_destroy(pthread_spinlock_t *lock)
67 if (lock == NULL || *lock == NULL)
79 _pthread_spin_trylock(pthread_spinlock_t *lock)
81 struct pthread *curthread = _get_curthread();
82 struct pthread_spinlock *lck;
85 if (lock == NULL || (lck = *lock) == NULL)
88 ret = THR_UMTX_TRYLOCK(curthread, &lck->s_lock);
93 _pthread_spin_lock(pthread_spinlock_t *lock)
95 struct pthread *curthread = _get_curthread();
96 struct pthread_spinlock *lck;
99 if (lock == NULL || (lck = *lock) == NULL)
103 while ((ret = THR_UMTX_TRYLOCK(curthread, &lck->s_lock)) != 0) {
104 while (lck->s_lock) {
106 /* tell cpu we are spinning */
107 __asm __volatile("pause");
122 _pthread_spin_unlock(pthread_spinlock_t *lock)
124 struct pthread *curthread = _get_curthread();
125 struct pthread_spinlock *lck;
128 if (lock == NULL || (lck = *lock) == NULL)
131 ret = THR_UMTX_UNLOCK(curthread, &lck->s_lock);