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. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 #include "namespace.h"
34 #include <sys/types.h>
35 #include <machine/atomic.h>
37 #include <libc_private.h>
38 #include "un-namespace.h"
40 #include "thr_private.h"
42 #define MAX_SPINLOCKS 72
44 struct spinlock_extra {
52 struct spinlock_extra *extra; /* overlays fname in spinlock_t */
55 typedef struct nv_spinlock nv_spinlock_t;
57 static void init_spinlock(spinlock_t *lck);
59 static struct pthread_mutex_attr static_mutex_attr =
60 PTHREAD_MUTEXATTR_STATIC_INITIALIZER;
61 static pthread_mutexattr_t static_mattr = &static_mutex_attr;
63 static pthread_mutex_t spinlock_static_lock;
64 static struct spinlock_extra extra[MAX_SPINLOCKS];
65 static int spinlock_count = 0;
66 static int initialized = 0;
69 * These are for compatability only. Spinlocks of this type
74 _spinunlock(spinlock_t *lck)
76 struct spinlock_extra *sl_extra;
78 sl_extra = ((nv_spinlock_t *)lck)->extra;
79 _pthread_mutex_unlock(&sl_extra->lock);
83 * Lock a location for the running thread. Yield to allow other
84 * threads to run if this thread is blocked because the lock is
85 * not available. Note that this function does not sleep. It
86 * assumes that the lock will be available very soon.
89 _spinlock(spinlock_t *lck)
91 struct spinlock_extra *sl_extra;
94 PANIC("Spinlock called when not threaded.");
96 PANIC("Spinlocks not initialized.");
98 * Try to grab the lock and loop if another thread grabs
101 if (lck->fname == NULL)
103 sl_extra = ((nv_spinlock_t *)lck)->extra;
104 _pthread_mutex_lock(&sl_extra->lock);
108 * Lock a location for the running thread. Yield to allow other
109 * threads to run if this thread is blocked because the lock is
110 * not available. Note that this function does not sleep. It
111 * assumes that the lock will be available very soon.
113 * This function checks if the running thread has already locked the
114 * location, warns if this occurs and creates a thread dump before
118 _spinlock_debug(spinlock_t *lck, char *fname __unused, int lineno __unused)
124 init_spinlock(spinlock_t *lck)
126 _pthread_mutex_lock(&spinlock_static_lock);
127 if ((lck->fname == NULL) && (spinlock_count < MAX_SPINLOCKS)) {
128 lck->fname = (char *)&extra[spinlock_count];
129 extra[spinlock_count].owner = lck;
132 _pthread_mutex_unlock(&spinlock_static_lock);
133 if (lck->fname == NULL)
134 PANIC("Exceeded max spinlocks");
138 _thr_spinlock_init(void)
142 if (initialized != 0) {
143 _thr_mutex_reinit(&spinlock_static_lock);
144 for (i = 0; i < spinlock_count; i++)
145 _thr_mutex_reinit(&extra[i].lock);
147 if (_pthread_mutex_init(&spinlock_static_lock, &static_mattr))
148 PANIC("Cannot initialize spinlock_static_lock");
149 for (i = 0; i < MAX_SPINLOCKS; i++) {
150 if (_pthread_mutex_init(&extra[i].lock, &static_mattr))
151 PANIC("Cannot initialize spinlock extra");