2 * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
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.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $FreeBSD: src/lib/libc_r/uthread/uthread_spinlock.c,v 1.8.2.2 2002/10/17 19:37:39 fjoe Exp $
33 * $DragonFly: src/lib/libc_r/uthread/uthread_spinlock.c,v 1.6 2007/06/26 23:30:05 josepht Exp $
37 #include <sys/fcntl.h>
39 #include <sys/sched.h>
43 #include "pthread_private.h"
45 extern char *__progname;
48 _spinunlock(spinlock_t *lck)
54 * Lock a location for the running thread. Yield to allow other
55 * threads to run if this thread is blocked because the lock is
56 * not available. Note that this function does not sleep. It
57 * assumes that the lock will be available very soon.
60 _spinlock(spinlock_t *lck)
62 struct pthread *curthread = _get_curthread();
65 * Try to grab the lock and loop if another thread grabs
68 while(_atomic_lock(&lck->access_lock)) {
69 /* Block the thread until the lock. */
70 curthread->data.spinlock = lck;
71 _thread_kern_sched_state(PS_SPINBLOCK, __FILE__, __LINE__);
74 /* The running thread now owns the lock: */
75 lck->lock_owner = (long) curthread;
79 * Lock a location for the running thread. Yield to allow other
80 * threads to run if this thread is blocked because the lock is
81 * not available. Note that this function does not sleep. It
82 * assumes that the lock will be available very soon.
84 * This function checks if the running thread has already locked the
85 * location, warns if this occurs and creates a thread dump before
89 _spinlock_debug(spinlock_t *lck, char *fname, int lineno)
91 struct pthread *curthread = _get_curthread();
95 * Try to grab the lock and loop if another thread grabs
98 while(_atomic_lock(&lck->access_lock)) {
102 snprintf(str, sizeof(str), "%s - Warning: Thread %p attempted to lock %p from %s (%d) was left locked from %s (%d)\n", __progname, curthread, lck, fname, lineno, lck->fname, lck->lineno);
103 __sys_extpwrite(2, str, strlen(str), O_FBLOCKING, -1);
108 /* Block the thread until the lock. */
109 curthread->data.spinlock = lck;
110 _thread_kern_sched_state(PS_SPINBLOCK, fname, lineno);
113 /* The running thread now owns the lock: */
114 lck->lock_owner = (long) curthread;
116 lck->lineno = lineno;