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/libpthread/thread/thr_spinlock.c,v 1.21 2003/12/09 02:37:40 davidxu Exp $
33 * $DragonFly: src/lib/libthread_xu/thread/thr_spinlock.c,v 1.1 2005/02/01 12:38:27 davidxu Exp $
36 #include <sys/types.h>
37 #include <machine/atomic.h>
39 #include <libc_private.h>
41 #include "thr_private.h"
43 #define MAX_SPINLOCKS 20
46 * These data structures are used to trace all spinlocks
49 struct spinlock_extra {
53 static umtx_t spinlock_static_lock;
54 static struct spinlock_extra extra[MAX_SPINLOCKS];
55 static int spinlock_count;
56 static int initialized;
58 static void init_spinlock(spinlock_t *lck);
61 * These are for compatability only. Spinlocks of this type
66 _spinunlock(spinlock_t *lck)
68 THR_UMTX_UNLOCK(_get_curthread(), (umtx_t *)&lck->access_lock);
72 _spinlock(spinlock_t *lck)
75 PANIC("Spinlock called when not threaded.");
77 PANIC("Spinlocks not initialized.");
78 if (lck->fname == NULL)
80 THR_UMTX_LOCK(_get_curthread(), (umtx_t *)&lck->access_lock);
84 _spinlock_debug(spinlock_t *lck, char *fname, int lineno)
90 init_spinlock(spinlock_t *lck)
94 THR_UMTX_LOCK(_get_curthread(), &spinlock_static_lock);
95 if ((lck->fname == NULL) && (spinlock_count < MAX_SPINLOCKS)) {
96 lck->fname = (char *)&extra[spinlock_count];
97 extra[spinlock_count].owner = lck;
100 THR_UMTX_UNLOCK(_get_curthread(), &spinlock_static_lock);
101 if (lck->fname == NULL && ++count < 5)
102 stderr_debug("Warning: exceeded max spinlocks");
106 _thr_spinlock_init(void)
110 _thr_umtx_init(&spinlock_static_lock);
111 if (initialized != 0) {
113 * called after fork() to reset state of libc spin locks,
114 * it is not quite right since libc may be in inconsistent
115 * state, resetting the locks to allow current thread to be
116 * able to hold them may not help things too much, but
117 * anyway, we do our best.
118 * it is better to do pthread_atfork in libc.
120 for (i = 0; i < spinlock_count; i++)
121 _thr_umtx_init((umtx_t *)&extra[i].owner->access_lock);