2 * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
3 * Copyright (c) 2006 David Xu <yfxu@corp.netease.com>.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by John Birrell.
17 * 4. Neither the name of the author nor the names of any co-contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * $DragonFly: src/lib/libthread_xu/thread/thr_mutex.c,v 1.14 2006/04/13 11:53:39 davidxu Exp $
36 #include "namespace.h"
37 #include <machine/tls.h>
42 #include <sys/queue.h>
44 #include "un-namespace.h"
46 #include "thr_private.h"
48 #if defined(_PTHREADS_INVARIANTS)
49 #define MUTEX_INIT_LINK(m) do { \
50 (m)->m_qe.tqe_prev = NULL; \
51 (m)->m_qe.tqe_next = NULL; \
53 #define MUTEX_ASSERT_IS_OWNED(m) do { \
54 if ((m)->m_qe.tqe_prev == NULL) \
55 PANIC("mutex is not on list"); \
57 #define MUTEX_ASSERT_NOT_OWNED(m) do { \
58 if (((m)->m_qe.tqe_prev != NULL) || \
59 ((m)->m_qe.tqe_next != NULL)) \
60 PANIC("mutex is on list"); \
62 #define THR_ASSERT_NOT_IN_SYNCQ(thr) do { \
63 THR_ASSERT(((thr)->sflags & THR_FLAGS_IN_SYNCQ) == 0, \
64 "thread in syncq when it shouldn't be."); \
67 #define MUTEX_INIT_LINK(m)
68 #define MUTEX_ASSERT_IS_OWNED(m)
69 #define MUTEX_ASSERT_NOT_OWNED(m)
70 #define THR_ASSERT_NOT_IN_SYNCQ(thr)
73 #define THR_IN_MUTEXQ(thr) (((thr)->sflags & THR_FLAGS_IN_SYNCQ) != 0)
74 #define MUTEX_DESTROY(m) do { \
78 umtx_t _mutex_static_lock;
83 static int mutex_self_trylock(pthread_mutex_t);
84 static int mutex_self_lock(pthread_mutex_t,
85 const struct timespec *abstime);
86 static int mutex_unlock_common(pthread_mutex_t *);
88 int __pthread_mutex_init(pthread_mutex_t *mutex,
89 const pthread_mutexattr_t *mutex_attr);
90 int __pthread_mutex_trylock(pthread_mutex_t *mutex);
91 int __pthread_mutex_lock(pthread_mutex_t *mutex);
92 int __pthread_mutex_timedlock(pthread_mutex_t *mutex,
93 const struct timespec *abs_timeout);
96 mutex_init(pthread_mutex_t *mutex,
97 const pthread_mutexattr_t *mutex_attr, int private)
99 const struct pthread_mutex_attr *attr;
100 struct pthread_mutex *pmutex;
102 if (mutex_attr == NULL) {
103 attr = &_pthread_mutexattr_default;
106 if (attr->m_type < PTHREAD_MUTEX_ERRORCHECK ||
107 attr->m_type >= MUTEX_TYPE_MAX)
109 if (attr->m_protocol < PTHREAD_PRIO_NONE ||
110 attr->m_protocol > PTHREAD_PRIO_PROTECT)
114 if ((pmutex = (pthread_mutex_t)
115 malloc(sizeof(struct pthread_mutex))) == NULL)
118 _thr_umtx_init(&pmutex->m_lock);
119 pmutex->m_type = attr->m_type;
120 pmutex->m_protocol = attr->m_protocol;
121 TAILQ_INIT(&pmutex->m_queue);
122 pmutex->m_owner = NULL;
123 pmutex->m_flags = attr->m_flags | MUTEX_FLAGS_INITED;
125 pmutex->m_flags |= MUTEX_FLAGS_PRIVATE;
127 pmutex->m_refcount = 0;
128 if (attr->m_protocol == PTHREAD_PRIO_PROTECT)
129 pmutex->m_prio = attr->m_ceiling;
132 pmutex->m_saved_prio = 0;
133 MUTEX_INIT_LINK(pmutex);
139 init_static(struct pthread *thread, pthread_mutex_t *mutex)
143 THR_LOCK_ACQUIRE(thread, &_mutex_static_lock);
146 ret = mutex_init(mutex, NULL, 0);
150 THR_LOCK_RELEASE(thread, &_mutex_static_lock);
156 init_static_private(struct pthread *thread, pthread_mutex_t *mutex)
160 THR_LOCK_ACQUIRE(thread, &_mutex_static_lock);
163 ret = mutex_init(mutex, NULL, 1);
167 THR_LOCK_RELEASE(thread, &_mutex_static_lock);
173 _pthread_mutex_init(pthread_mutex_t *mutex,
174 const pthread_mutexattr_t *mutex_attr)
176 return mutex_init(mutex, mutex_attr, 1);
180 __pthread_mutex_init(pthread_mutex_t *mutex,
181 const pthread_mutexattr_t *mutex_attr)
183 return mutex_init(mutex, mutex_attr, 0);
187 _mutex_reinit(pthread_mutex_t *mutex)
189 _thr_umtx_init(&(*mutex)->m_lock);
190 TAILQ_INIT(&(*mutex)->m_queue);
191 MUTEX_INIT_LINK(*mutex);
192 (*mutex)->m_owner = NULL;
193 (*mutex)->m_count = 0;
194 (*mutex)->m_refcount = 0;
195 (*mutex)->m_prio = 0;
196 (*mutex)->m_saved_prio = 0;
201 _mutex_fork(struct pthread *curthread)
203 struct pthread_mutex *m;
205 TAILQ_FOREACH(m, &curthread->mutexq, m_qe)
206 m->m_lock = UMTX_LOCKED;
210 _pthread_mutex_destroy(pthread_mutex_t *mutex)
212 struct pthread *curthread = tls_get_curthread();
216 if (mutex == NULL || *mutex == NULL)
220 * Try to lock the mutex structure, we only need to
221 * try once, if failed, the mutex is in used.
223 ret = THR_UMTX_TRYLOCK(curthread, &(*mutex)->m_lock);
228 * Check mutex other fields to see if this mutex is
229 * in use. Mostly for prority mutex types, or there
230 * are condition variables referencing it.
232 if (((*mutex)->m_owner != NULL) ||
233 (TAILQ_FIRST(&(*mutex)->m_queue) != NULL) ||
234 ((*mutex)->m_refcount != 0)) {
235 THR_UMTX_UNLOCK(curthread, &(*mutex)->m_lock);
239 * Save a pointer to the mutex so it can be free'd
240 * and set the caller's pointer to NULL:
245 /* Unlock the mutex structure: */
246 THR_UMTX_UNLOCK(curthread, &m->m_lock);
249 * Free the memory allocated for the mutex
252 MUTEX_ASSERT_NOT_OWNED(m);
257 /* Return the completion status: */
262 mutex_trylock_common(struct pthread *curthread, pthread_mutex_t *mutex)
264 struct pthread_mutex *m;
268 ret = THR_UMTX_TRYLOCK(curthread, &m->m_lock);
270 m->m_owner = curthread;
271 /* Add to the list of owned mutexes: */
272 MUTEX_ASSERT_NOT_OWNED(m);
273 TAILQ_INSERT_TAIL(&curthread->mutexq,
275 } else if (m->m_owner == curthread) {
276 ret = mutex_self_trylock(m);
283 __pthread_mutex_trylock(pthread_mutex_t *m)
285 struct pthread *curthread = tls_get_curthread();
289 * If the mutex is statically initialized, perform the dynamic
292 if (__predict_false(*m == NULL)) {
293 ret = init_static(curthread, m);
294 if (__predict_false(ret != 0))
297 return (mutex_trylock_common(curthread, m));
301 _pthread_mutex_trylock(pthread_mutex_t *m)
303 struct pthread *curthread = tls_get_curthread();
307 * If the mutex is statically initialized, perform the dynamic
308 * initialization marking the mutex private (delete safe):
310 if (__predict_false(*m == NULL)) {
311 ret = init_static_private(curthread, m);
312 if (__predict_false(ret != 0))
315 return (mutex_trylock_common(curthread, m));
319 mutex_lock_common(struct pthread *curthread, pthread_mutex_t *mutex,
320 const struct timespec * abstime)
322 struct timespec ts, ts2;
323 struct pthread_mutex *m;
327 ret = THR_UMTX_TRYLOCK(curthread, &m->m_lock);
329 m->m_owner = curthread;
330 /* Add to the list of owned mutexes: */
331 MUTEX_ASSERT_NOT_OWNED(m);
332 TAILQ_INSERT_TAIL(&curthread->mutexq,
334 } else if (m->m_owner == curthread) {
335 ret = mutex_self_lock(m, abstime);
337 if (abstime == NULL) {
338 THR_UMTX_LOCK(curthread, &m->m_lock);
340 } else if (__predict_false(
341 abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
342 abstime->tv_nsec >= 1000000000)) {
345 clock_gettime(CLOCK_REALTIME, &ts);
346 TIMESPEC_SUB(&ts2, abstime, &ts);
347 ret = THR_UMTX_TIMEDLOCK(curthread,
350 * Timed out wait is not restarted if
351 * it was interrupted, not worth to do it.
357 m->m_owner = curthread;
358 /* Add to the list of owned mutexes: */
359 MUTEX_ASSERT_NOT_OWNED(m);
360 TAILQ_INSERT_TAIL(&curthread->mutexq,
368 __pthread_mutex_lock(pthread_mutex_t *m)
370 struct pthread *curthread;
375 curthread = tls_get_curthread();
378 * If the mutex is statically initialized, perform the dynamic
381 if (__predict_false(*m == NULL)) {
382 ret = init_static(curthread, m);
383 if (__predict_false(ret))
386 return (mutex_lock_common(curthread, m, NULL));
390 _pthread_mutex_lock(pthread_mutex_t *m)
392 struct pthread *curthread;
397 curthread = tls_get_curthread();
400 * If the mutex is statically initialized, perform the dynamic
401 * initialization marking it private (delete safe):
403 if (__predict_false(*m == NULL)) {
404 ret = init_static_private(curthread, m);
405 if (__predict_false(ret))
408 return (mutex_lock_common(curthread, m, NULL));
412 __pthread_mutex_timedlock(pthread_mutex_t *m,
413 const struct timespec *abs_timeout)
415 struct pthread *curthread;
420 curthread = tls_get_curthread();
423 * If the mutex is statically initialized, perform the dynamic
426 if (__predict_false(*m == NULL)) {
427 ret = init_static(curthread, m);
428 if (__predict_false(ret))
431 return (mutex_lock_common(curthread, m, abs_timeout));
435 _pthread_mutex_timedlock(pthread_mutex_t *m,
436 const struct timespec *abs_timeout)
438 struct pthread *curthread;
443 curthread = tls_get_curthread();
446 * If the mutex is statically initialized, perform the dynamic
447 * initialization marking it private (delete safe):
449 if (__predict_false(*m == NULL)) {
450 ret = init_static_private(curthread, m);
451 if (__predict_false(ret))
454 return (mutex_lock_common(curthread, m, abs_timeout));
458 _pthread_mutex_unlock(pthread_mutex_t *m)
460 return (mutex_unlock_common(m));
464 mutex_self_trylock(pthread_mutex_t m)
469 /* case PTHREAD_MUTEX_DEFAULT: */
470 case PTHREAD_MUTEX_ERRORCHECK:
471 case PTHREAD_MUTEX_NORMAL:
475 case PTHREAD_MUTEX_RECURSIVE:
476 /* Increment the lock count: */
477 if (m->m_count + 1 > 0) {
485 /* Trap invalid mutex types; */
493 mutex_self_lock(pthread_mutex_t m, const struct timespec *abstime)
495 struct timespec ts1, ts2;
499 /* case PTHREAD_MUTEX_DEFAULT: */
500 case PTHREAD_MUTEX_ERRORCHECK:
502 clock_gettime(CLOCK_REALTIME, &ts1);
503 TIMESPEC_SUB(&ts2, abstime, &ts1);
504 __sys_nanosleep(&ts2, NULL);
508 * POSIX specifies that mutexes should return
509 * EDEADLK if a recursive lock is detected.
515 case PTHREAD_MUTEX_NORMAL:
517 * What SS2 define as a 'normal' mutex. Intentionally
518 * deadlock on attempts to get a lock you already own.
522 clock_gettime(CLOCK_REALTIME, &ts1);
523 TIMESPEC_SUB(&ts2, abstime, &ts1);
524 __sys_nanosleep(&ts2, NULL);
530 __sys_nanosleep(&ts1, NULL);
534 case PTHREAD_MUTEX_RECURSIVE:
535 /* Increment the lock count: */
536 if (m->m_count + 1 > 0) {
544 /* Trap invalid mutex types; */
552 mutex_unlock_common(pthread_mutex_t *mutex)
554 struct pthread *curthread = tls_get_curthread();
555 struct pthread_mutex *m;
557 if (__predict_false((m = *mutex)== NULL))
560 if (__predict_false(m->m_owner != curthread))
564 m->m_type == PTHREAD_MUTEX_RECURSIVE &&
569 * Clear the count in case this is a recursive mutex.
573 /* Remove the mutex from the threads queue. */
574 MUTEX_ASSERT_IS_OWNED(m);
575 TAILQ_REMOVE(&curthread->mutexq, m, m_qe);
578 * Hand off the mutex to the next waiting thread.
580 THR_UMTX_UNLOCK(curthread, &m->m_lock);
586 _mutex_cv_lock(pthread_mutex_t *m, int count)
590 if ((ret = _pthread_mutex_lock(m)) == 0) {
592 (*m)->m_count += count;
598 _mutex_cv_unlock(pthread_mutex_t *mutex, int *count)
600 struct pthread *curthread = tls_get_curthread();
601 struct pthread_mutex *m;
603 if (__predict_false((m = *mutex)== NULL))
606 if (__predict_false(m->m_owner != curthread))
613 /* Remove the mutex from the threads queue. */
614 MUTEX_ASSERT_IS_OWNED(m);
615 TAILQ_REMOVE(&curthread->mutexq, m, m_qe);
617 THR_UMTX_UNLOCK(curthread, &m->m_lock);
622 _mutex_unlock_private(pthread_t pthread)
624 struct pthread_mutex *m, *m_next;
626 for (m = TAILQ_FIRST(&pthread->mutexq); m != NULL; m = m_next) {
627 m_next = TAILQ_NEXT(m, m_qe);
628 if ((m->m_flags & MUTEX_FLAGS_PRIVATE) != 0)
629 _pthread_mutex_unlock(&m);
633 __strong_reference(__pthread_mutex_init, pthread_mutex_init);
634 __strong_reference(__pthread_mutex_lock, pthread_mutex_lock);
635 __strong_reference(__pthread_mutex_timedlock, pthread_mutex_timedlock);
636 __strong_reference(__pthread_mutex_trylock, pthread_mutex_trylock);
638 /* Single underscore versions provided for libc internal usage: */
639 /* No difference between libc and application usage of these: */
640 __strong_reference(_pthread_mutex_destroy, pthread_mutex_destroy);
641 __strong_reference(_pthread_mutex_unlock, pthread_mutex_unlock);