xref: /freebsd/lib/libthr/thread/thr_mutex.c (revision ab2043b81eaba0d7d7769b4a58b2b6d17bc464a3)
1 /*
2  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
3  * Copyright (c) 2006 David Xu <davidxu@freebsd.org>.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
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.
20  *
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
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD$
34  */
35 
36 #include "namespace.h"
37 #include <stdlib.h>
38 #include <errno.h>
39 #include <string.h>
40 #include <sys/param.h>
41 #include <sys/queue.h>
42 #include <pthread.h>
43 #include <pthread_np.h>
44 #include "un-namespace.h"
45 
46 #include "thr_private.h"
47 
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;			\
52 } while (0)
53 #define MUTEX_ASSERT_IS_OWNED(m)	do {		\
54 	if (__predict_false((m)->m_qe.tqe_prev == NULL))\
55 		PANIC("mutex is not on list");		\
56 } while (0)
57 #define MUTEX_ASSERT_NOT_OWNED(m)	do {		\
58 	if (__predict_false((m)->m_qe.tqe_prev != NULL ||	\
59 	    (m)->m_qe.tqe_next != NULL))	\
60 		PANIC("mutex is on list");		\
61 } while (0)
62 #else
63 #define MUTEX_INIT_LINK(m)
64 #define MUTEX_ASSERT_IS_OWNED(m)
65 #define MUTEX_ASSERT_NOT_OWNED(m)
66 #endif
67 
68 /*
69  * For adaptive mutexes, how many times to spin doing trylock2
70  * before entering the kernel to block
71  */
72 #define MUTEX_ADAPTIVE_SPINS	2000
73 
74 /*
75  * Prototypes
76  */
77 int	__pthread_mutex_init(pthread_mutex_t *mutex,
78 		const pthread_mutexattr_t *mutex_attr);
79 int	__pthread_mutex_trylock(pthread_mutex_t *mutex);
80 int	__pthread_mutex_lock(pthread_mutex_t *mutex);
81 int	__pthread_mutex_timedlock(pthread_mutex_t *mutex,
82 		const struct timespec *abstime);
83 int	_pthread_mutex_init_calloc_cb(pthread_mutex_t *mutex,
84     		void *(calloc_cb)(size_t, size_t));
85 int	_pthread_mutex_getspinloops_np(pthread_mutex_t *mutex, int *count);
86 int	_pthread_mutex_setspinloops_np(pthread_mutex_t *mutex, int count);
87 int	__pthread_mutex_setspinloops_np(pthread_mutex_t *mutex, int count);
88 int	_pthread_mutex_setyieldloops_np(pthread_mutex_t *mutex, int count);
89 int	_pthread_mutex_getyieldloops_np(pthread_mutex_t *mutex, int *count);
90 int	__pthread_mutex_setyieldloops_np(pthread_mutex_t *mutex, int count);
91 
92 static int	mutex_self_trylock(pthread_mutex_t);
93 static int	mutex_self_lock(pthread_mutex_t,
94 				const struct timespec *abstime);
95 static int	mutex_unlock_common(struct pthread_mutex *, int, int *);
96 static int	mutex_lock_sleep(struct pthread *, pthread_mutex_t,
97 				const struct timespec *);
98 
99 __weak_reference(__pthread_mutex_init, pthread_mutex_init);
100 __strong_reference(__pthread_mutex_init, _pthread_mutex_init);
101 __weak_reference(__pthread_mutex_lock, pthread_mutex_lock);
102 __strong_reference(__pthread_mutex_lock, _pthread_mutex_lock);
103 __weak_reference(__pthread_mutex_timedlock, pthread_mutex_timedlock);
104 __strong_reference(__pthread_mutex_timedlock, _pthread_mutex_timedlock);
105 __weak_reference(__pthread_mutex_trylock, pthread_mutex_trylock);
106 __strong_reference(__pthread_mutex_trylock, _pthread_mutex_trylock);
107 
108 /* Single underscore versions provided for libc internal usage: */
109 /* No difference between libc and application usage of these: */
110 __weak_reference(_pthread_mutex_destroy, pthread_mutex_destroy);
111 __weak_reference(_pthread_mutex_unlock, pthread_mutex_unlock);
112 
113 __weak_reference(_pthread_mutex_getprioceiling, pthread_mutex_getprioceiling);
114 __weak_reference(_pthread_mutex_setprioceiling, pthread_mutex_setprioceiling);
115 
116 __weak_reference(__pthread_mutex_setspinloops_np, pthread_mutex_setspinloops_np);
117 __strong_reference(__pthread_mutex_setspinloops_np, _pthread_mutex_setspinloops_np);
118 __weak_reference(_pthread_mutex_getspinloops_np, pthread_mutex_getspinloops_np);
119 
120 __weak_reference(__pthread_mutex_setyieldloops_np, pthread_mutex_setyieldloops_np);
121 __strong_reference(__pthread_mutex_setyieldloops_np, _pthread_mutex_setyieldloops_np);
122 __weak_reference(_pthread_mutex_getyieldloops_np, pthread_mutex_getyieldloops_np);
123 __weak_reference(_pthread_mutex_isowned_np, pthread_mutex_isowned_np);
124 
125 static int
126 mutex_init(pthread_mutex_t *mutex,
127     const struct pthread_mutex_attr *mutex_attr,
128     void *(calloc_cb)(size_t, size_t))
129 {
130 	const struct pthread_mutex_attr *attr;
131 	struct pthread_mutex *pmutex;
132 
133 	if (mutex_attr == NULL) {
134 		attr = &_pthread_mutexattr_default;
135 	} else {
136 		attr = mutex_attr;
137 		if (attr->m_type < PTHREAD_MUTEX_ERRORCHECK ||
138 		    attr->m_type >= PTHREAD_MUTEX_TYPE_MAX)
139 			return (EINVAL);
140 		if (attr->m_protocol < PTHREAD_PRIO_NONE ||
141 		    attr->m_protocol > PTHREAD_PRIO_PROTECT)
142 			return (EINVAL);
143 	}
144 	if ((pmutex = (pthread_mutex_t)
145 		calloc_cb(1, sizeof(struct pthread_mutex))) == NULL)
146 		return (ENOMEM);
147 
148 	pmutex->m_flags = attr->m_type;
149 	pmutex->m_owner = NULL;
150 	pmutex->m_count = 0;
151 	pmutex->m_spinloops = 0;
152 	pmutex->m_yieldloops = 0;
153 	MUTEX_INIT_LINK(pmutex);
154 	switch(attr->m_protocol) {
155 	case PTHREAD_PRIO_NONE:
156 		pmutex->m_lock.m_owner = UMUTEX_UNOWNED;
157 		pmutex->m_lock.m_flags = 0;
158 		break;
159 	case PTHREAD_PRIO_INHERIT:
160 		pmutex->m_lock.m_owner = UMUTEX_UNOWNED;
161 		pmutex->m_lock.m_flags = UMUTEX_PRIO_INHERIT;
162 		break;
163 	case PTHREAD_PRIO_PROTECT:
164 		pmutex->m_lock.m_owner = UMUTEX_CONTESTED;
165 		pmutex->m_lock.m_flags = UMUTEX_PRIO_PROTECT;
166 		pmutex->m_lock.m_ceilings[0] = attr->m_ceiling;
167 		break;
168 	}
169 
170 	if (PMUTEX_TYPE(pmutex->m_flags) == PTHREAD_MUTEX_ADAPTIVE_NP) {
171 		pmutex->m_spinloops =
172 		    _thr_spinloops ? _thr_spinloops: MUTEX_ADAPTIVE_SPINS;
173 		pmutex->m_yieldloops = _thr_yieldloops;
174 	}
175 
176 	*mutex = pmutex;
177 	return (0);
178 }
179 
180 static int
181 init_static(struct pthread *thread, pthread_mutex_t *mutex)
182 {
183 	int ret;
184 
185 	THR_LOCK_ACQUIRE(thread, &_mutex_static_lock);
186 
187 	if (*mutex == THR_MUTEX_INITIALIZER)
188 		ret = mutex_init(mutex, &_pthread_mutexattr_default, calloc);
189 	else if (*mutex == THR_ADAPTIVE_MUTEX_INITIALIZER)
190 		ret = mutex_init(mutex, &_pthread_mutexattr_adaptive_default, calloc);
191 	else
192 		ret = 0;
193 	THR_LOCK_RELEASE(thread, &_mutex_static_lock);
194 
195 	return (ret);
196 }
197 
198 static void
199 set_inherited_priority(struct pthread *curthread, struct pthread_mutex *m)
200 {
201 	struct pthread_mutex *m2;
202 
203 	m2 = TAILQ_LAST(&curthread->pp_mutexq, mutex_queue);
204 	if (m2 != NULL)
205 		m->m_lock.m_ceilings[1] = m2->m_lock.m_ceilings[0];
206 	else
207 		m->m_lock.m_ceilings[1] = -1;
208 }
209 
210 int
211 __pthread_mutex_init(pthread_mutex_t *mutex,
212     const pthread_mutexattr_t *mutex_attr)
213 {
214 	return mutex_init(mutex, mutex_attr ? *mutex_attr : NULL, calloc);
215 }
216 
217 /* This function is used internally by malloc. */
218 int
219 _pthread_mutex_init_calloc_cb(pthread_mutex_t *mutex,
220     void *(calloc_cb)(size_t, size_t))
221 {
222 	static const struct pthread_mutex_attr attr = {
223 		.m_type = PTHREAD_MUTEX_NORMAL,
224 		.m_protocol = PTHREAD_PRIO_NONE,
225 		.m_ceiling = 0
226 	};
227 	int ret;
228 
229 	ret = mutex_init(mutex, &attr, calloc_cb);
230 	if (ret == 0)
231 		(*mutex)->m_flags |= PMUTEX_FLAG_PRIVATE;
232 	return (ret);
233 }
234 
235 void
236 _mutex_fork(struct pthread *curthread)
237 {
238 	struct pthread_mutex *m;
239 
240 	/*
241 	 * Fix mutex ownership for child process.
242 	 * note that process shared mutex should not
243 	 * be inherited because owner is forking thread
244 	 * which is in parent process, they should be
245 	 * removed from the owned mutex list, current,
246 	 * process shared mutex is not supported, so I
247 	 * am not worried.
248 	 */
249 
250 	TAILQ_FOREACH(m, &curthread->mutexq, m_qe)
251 		m->m_lock.m_owner = TID(curthread);
252 	TAILQ_FOREACH(m, &curthread->pp_mutexq, m_qe)
253 		m->m_lock.m_owner = TID(curthread) | UMUTEX_CONTESTED;
254 }
255 
256 int
257 _pthread_mutex_destroy(pthread_mutex_t *mutex)
258 {
259 	pthread_mutex_t m;
260 	int ret;
261 
262 	m = *mutex;
263 	if (m < THR_MUTEX_DESTROYED) {
264 		ret = 0;
265 	} else if (m == THR_MUTEX_DESTROYED) {
266 		ret = EINVAL;
267 	} else {
268 		if (m->m_owner != NULL) {
269 			ret = EBUSY;
270 		} else {
271 			*mutex = THR_MUTEX_DESTROYED;
272 			MUTEX_ASSERT_NOT_OWNED(m);
273 			free(m);
274 			ret = 0;
275 		}
276 	}
277 
278 	return (ret);
279 }
280 
281 #define ENQUEUE_MUTEX(curthread, m)  					\
282 	do {								\
283 		(m)->m_owner = curthread;				\
284 		/* Add to the list of owned mutexes: */			\
285 		MUTEX_ASSERT_NOT_OWNED((m));				\
286 		if (((m)->m_lock.m_flags & UMUTEX_PRIO_PROTECT) == 0)	\
287 			TAILQ_INSERT_TAIL(&curthread->mutexq, (m), m_qe);\
288 		else							\
289 			TAILQ_INSERT_TAIL(&curthread->pp_mutexq, (m), m_qe);\
290 	} while (0)
291 
292 #define DEQUEUE_MUTEX(curthread, m)					\
293 		(m)->m_owner = NULL;					\
294 		MUTEX_ASSERT_IS_OWNED(m);				\
295 		if (__predict_true(((m)->m_lock.m_flags & UMUTEX_PRIO_PROTECT) == 0)) \
296 			TAILQ_REMOVE(&curthread->mutexq, (m), m_qe);		\
297 		else {							\
298 			TAILQ_REMOVE(&curthread->pp_mutexq, (m), m_qe);	\
299 			set_inherited_priority(curthread, m);		\
300 		}							\
301 		MUTEX_INIT_LINK(m);
302 
303 #define CHECK_AND_INIT_MUTEX						\
304 	if (__predict_false((m = *mutex) <= THR_MUTEX_DESTROYED)) {	\
305 		if (m == THR_MUTEX_DESTROYED)				\
306 			return (EINVAL);				\
307 		int ret;						\
308 		ret = init_static(_get_curthread(), mutex);		\
309 		if (ret)						\
310 			return (ret);					\
311 		m = *mutex;						\
312 	}
313 
314 static int
315 mutex_trylock_common(pthread_mutex_t *mutex)
316 {
317 	struct pthread *curthread = _get_curthread();
318 	struct pthread_mutex *m = *mutex;
319 	uint32_t id;
320 	int ret;
321 
322 	id = TID(curthread);
323 	if (m->m_flags & PMUTEX_FLAG_PRIVATE)
324 		THR_CRITICAL_ENTER(curthread);
325 	ret = _thr_umutex_trylock(&m->m_lock, id);
326 	if (__predict_true(ret == 0)) {
327 		ENQUEUE_MUTEX(curthread, m);
328 	} else if (m->m_owner == curthread) {
329 		ret = mutex_self_trylock(m);
330 	} /* else {} */
331 	if (ret && (m->m_flags & PMUTEX_FLAG_PRIVATE))
332 		THR_CRITICAL_LEAVE(curthread);
333 	return (ret);
334 }
335 
336 int
337 __pthread_mutex_trylock(pthread_mutex_t *mutex)
338 {
339 	struct pthread_mutex *m;
340 
341 	CHECK_AND_INIT_MUTEX
342 
343 	return (mutex_trylock_common(mutex));
344 }
345 
346 static int
347 mutex_lock_sleep(struct pthread *curthread, struct pthread_mutex *m,
348 	const struct timespec *abstime)
349 {
350 	uint32_t	id, owner;
351 	int	count;
352 	int	ret;
353 
354 	if (m->m_owner == curthread)
355 		return mutex_self_lock(m, abstime);
356 
357 	id = TID(curthread);
358 	/*
359 	 * For adaptive mutexes, spin for a bit in the expectation
360 	 * that if the application requests this mutex type then
361 	 * the lock is likely to be released quickly and it is
362 	 * faster than entering the kernel
363 	 */
364 	if (__predict_false(
365 		(m->m_lock.m_flags &
366 		 (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) != 0))
367 			goto sleep_in_kernel;
368 
369 	if (!_thr_is_smp)
370 		goto yield_loop;
371 
372 	count = m->m_spinloops;
373 	while (count--) {
374 		owner = m->m_lock.m_owner;
375 		if ((owner & ~UMUTEX_CONTESTED) == 0) {
376 			if (atomic_cmpset_acq_32(&m->m_lock.m_owner, owner, id|owner)) {
377 				ret = 0;
378 				goto done;
379 			}
380 		}
381 		CPU_SPINWAIT;
382 	}
383 
384 yield_loop:
385 	count = m->m_yieldloops;
386 	while (count--) {
387 		_sched_yield();
388 		owner = m->m_lock.m_owner;
389 		if ((owner & ~UMUTEX_CONTESTED) == 0) {
390 			if (atomic_cmpset_acq_32(&m->m_lock.m_owner, owner, id|owner)) {
391 				ret = 0;
392 				goto done;
393 			}
394 		}
395 	}
396 
397 sleep_in_kernel:
398 	if (abstime == NULL) {
399 		ret = __thr_umutex_lock(&m->m_lock, id);
400 	} else if (__predict_false(
401 		   abstime->tv_nsec < 0 ||
402 		   abstime->tv_nsec >= 1000000000)) {
403 		ret = EINVAL;
404 	} else {
405 		ret = __thr_umutex_timedlock(&m->m_lock, id, abstime);
406 	}
407 done:
408 	if (ret == 0)
409 		ENQUEUE_MUTEX(curthread, m);
410 
411 	return (ret);
412 }
413 
414 static inline int
415 mutex_lock_common(struct pthread_mutex *m,
416 	const struct timespec *abstime, int cvattach)
417 {
418 	struct pthread *curthread  = _get_curthread();
419 	int ret;
420 
421 	if (!cvattach && m->m_flags & PMUTEX_FLAG_PRIVATE)
422 		THR_CRITICAL_ENTER(curthread);
423 	if (_thr_umutex_trylock2(&m->m_lock, TID(curthread)) == 0) {
424 		ENQUEUE_MUTEX(curthread, m);
425 		ret = 0;
426 	} else {
427 		ret = mutex_lock_sleep(curthread, m, abstime);
428 	}
429 	if (ret && (m->m_flags & PMUTEX_FLAG_PRIVATE) && !cvattach)
430 		THR_CRITICAL_LEAVE(curthread);
431 	return (ret);
432 }
433 
434 int
435 __pthread_mutex_lock(pthread_mutex_t *mutex)
436 {
437 	struct pthread_mutex	*m;
438 
439 	_thr_check_init();
440 
441 	CHECK_AND_INIT_MUTEX
442 
443 	return (mutex_lock_common(m, NULL, 0));
444 }
445 
446 int
447 __pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *abstime)
448 {
449 	struct pthread_mutex	*m;
450 
451 	_thr_check_init();
452 
453 	CHECK_AND_INIT_MUTEX
454 
455 	return (mutex_lock_common(m, abstime, 0));
456 }
457 
458 int
459 _pthread_mutex_unlock(pthread_mutex_t *mutex)
460 {
461 	struct pthread_mutex *mp;
462 
463 	mp = *mutex;
464 	return (mutex_unlock_common(mp, 0, NULL));
465 }
466 
467 int
468 _mutex_cv_lock(struct pthread_mutex *m, int count)
469 {
470 	int	error;
471 
472 	error = mutex_lock_common(m, NULL, 1);
473 	if (error == 0)
474 		m->m_count = count;
475 	return (error);
476 }
477 
478 int
479 _mutex_cv_unlock(struct pthread_mutex *m, int *count, int *defer)
480 {
481 
482 	/*
483 	 * Clear the count in case this is a recursive mutex.
484 	 */
485 	*count = m->m_count;
486 	m->m_count = 0;
487 	(void)mutex_unlock_common(m, 1, defer);
488         return (0);
489 }
490 
491 int
492 _mutex_cv_attach(struct pthread_mutex *m, int count)
493 {
494 	struct pthread *curthread = _get_curthread();
495 
496 	ENQUEUE_MUTEX(curthread, m);
497 	m->m_count = count;
498 	return (0);
499 }
500 
501 int
502 _mutex_cv_detach(struct pthread_mutex *mp, int *recurse)
503 {
504 	struct pthread *curthread = _get_curthread();
505 	int     defered;
506 	int     error;
507 
508 	if ((error = _mutex_owned(curthread, mp)) != 0)
509                 return (error);
510 
511 	/*
512 	 * Clear the count in case this is a recursive mutex.
513 	 */
514 	*recurse = mp->m_count;
515 	mp->m_count = 0;
516 	DEQUEUE_MUTEX(curthread, mp);
517 
518 	/* Will this happen in real-world ? */
519         if ((mp->m_flags & PMUTEX_FLAG_DEFERED) != 0) {
520 		defered = 1;
521 		mp->m_flags &= ~PMUTEX_FLAG_DEFERED;
522 	} else
523 		defered = 0;
524 
525 	if (defered)  {
526 		_thr_wake_all(curthread->defer_waiters,
527 				curthread->nwaiter_defer);
528 		curthread->nwaiter_defer = 0;
529 	}
530 	return (0);
531 }
532 
533 static int
534 mutex_self_trylock(struct pthread_mutex *m)
535 {
536 	int	ret;
537 
538 	switch (PMUTEX_TYPE(m->m_flags)) {
539 	case PTHREAD_MUTEX_ERRORCHECK:
540 	case PTHREAD_MUTEX_NORMAL:
541 	case PTHREAD_MUTEX_ADAPTIVE_NP:
542 		ret = EBUSY;
543 		break;
544 
545 	case PTHREAD_MUTEX_RECURSIVE:
546 		/* Increment the lock count: */
547 		if (m->m_count + 1 > 0) {
548 			m->m_count++;
549 			ret = 0;
550 		} else
551 			ret = EAGAIN;
552 		break;
553 
554 	default:
555 		/* Trap invalid mutex types; */
556 		ret = EINVAL;
557 	}
558 
559 	return (ret);
560 }
561 
562 static int
563 mutex_self_lock(struct pthread_mutex *m, const struct timespec *abstime)
564 {
565 	struct timespec	ts1, ts2;
566 	int	ret;
567 
568 	switch (PMUTEX_TYPE(m->m_flags)) {
569 	case PTHREAD_MUTEX_ERRORCHECK:
570 	case PTHREAD_MUTEX_ADAPTIVE_NP:
571 		if (abstime) {
572 			if (abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
573 			    abstime->tv_nsec >= 1000000000) {
574 				ret = EINVAL;
575 			} else {
576 				clock_gettime(CLOCK_REALTIME, &ts1);
577 				TIMESPEC_SUB(&ts2, abstime, &ts1);
578 				__sys_nanosleep(&ts2, NULL);
579 				ret = ETIMEDOUT;
580 			}
581 		} else {
582 			/*
583 			 * POSIX specifies that mutexes should return
584 			 * EDEADLK if a recursive lock is detected.
585 			 */
586 			ret = EDEADLK;
587 		}
588 		break;
589 
590 	case PTHREAD_MUTEX_NORMAL:
591 		/*
592 		 * What SS2 define as a 'normal' mutex.  Intentionally
593 		 * deadlock on attempts to get a lock you already own.
594 		 */
595 		ret = 0;
596 		if (abstime) {
597 			if (abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
598 			    abstime->tv_nsec >= 1000000000) {
599 				ret = EINVAL;
600 			} else {
601 				clock_gettime(CLOCK_REALTIME, &ts1);
602 				TIMESPEC_SUB(&ts2, abstime, &ts1);
603 				__sys_nanosleep(&ts2, NULL);
604 				ret = ETIMEDOUT;
605 			}
606 		} else {
607 			ts1.tv_sec = 30;
608 			ts1.tv_nsec = 0;
609 			for (;;)
610 				__sys_nanosleep(&ts1, NULL);
611 		}
612 		break;
613 
614 	case PTHREAD_MUTEX_RECURSIVE:
615 		/* Increment the lock count: */
616 		if (m->m_count + 1 > 0) {
617 			m->m_count++;
618 			ret = 0;
619 		} else
620 			ret = EAGAIN;
621 		break;
622 
623 	default:
624 		/* Trap invalid mutex types; */
625 		ret = EINVAL;
626 	}
627 
628 	return (ret);
629 }
630 
631 static int
632 mutex_unlock_common(struct pthread_mutex *m, int cv, int *mtx_defer)
633 {
634 	struct pthread *curthread = _get_curthread();
635 	uint32_t id;
636 	int defered;
637 
638 	if (__predict_false(m <= THR_MUTEX_DESTROYED)) {
639 		if (m == THR_MUTEX_DESTROYED)
640 			return (EINVAL);
641 		return (EPERM);
642 	}
643 
644 	/*
645 	 * Check if the running thread is not the owner of the mutex.
646 	 */
647 	if (__predict_false(m->m_owner != curthread))
648 		return (EPERM);
649 
650 	id = TID(curthread);
651 	if (__predict_false(
652 		PMUTEX_TYPE(m->m_flags) == PTHREAD_MUTEX_RECURSIVE &&
653 		m->m_count > 0)) {
654 		m->m_count--;
655 	} else {
656 		if ((m->m_flags & PMUTEX_FLAG_DEFERED) != 0) {
657 			defered = 1;
658 			m->m_flags &= ~PMUTEX_FLAG_DEFERED;
659         	} else
660 			defered = 0;
661 
662 		DEQUEUE_MUTEX(curthread, m);
663 		_thr_umutex_unlock2(&m->m_lock, id, mtx_defer);
664 
665 		if (mtx_defer == NULL && defered)  {
666 			_thr_wake_all(curthread->defer_waiters,
667 				curthread->nwaiter_defer);
668 			curthread->nwaiter_defer = 0;
669 		}
670 	}
671 	if (!cv && m->m_flags & PMUTEX_FLAG_PRIVATE)
672 		THR_CRITICAL_LEAVE(curthread);
673 	return (0);
674 }
675 
676 int
677 _pthread_mutex_getprioceiling(pthread_mutex_t *mutex,
678 			      int *prioceiling)
679 {
680 	struct pthread_mutex *m;
681 	int ret;
682 
683 	m = *mutex;
684 	if ((m <= THR_MUTEX_DESTROYED) ||
685 	    (m->m_lock.m_flags & UMUTEX_PRIO_PROTECT) == 0)
686 		ret = EINVAL;
687 	else {
688 		*prioceiling = m->m_lock.m_ceilings[0];
689 		ret = 0;
690 	}
691 
692 	return (ret);
693 }
694 
695 int
696 _pthread_mutex_setprioceiling(pthread_mutex_t *mutex,
697 			      int ceiling, int *old_ceiling)
698 {
699 	struct pthread *curthread = _get_curthread();
700 	struct pthread_mutex *m, *m1, *m2;
701 	int ret;
702 
703 	m = *mutex;
704 	if ((m <= THR_MUTEX_DESTROYED) ||
705 	    (m->m_lock.m_flags & UMUTEX_PRIO_PROTECT) == 0)
706 		return (EINVAL);
707 
708 	ret = __thr_umutex_set_ceiling(&m->m_lock, ceiling, old_ceiling);
709 	if (ret != 0)
710 		return (ret);
711 
712 	if (m->m_owner == curthread) {
713 		MUTEX_ASSERT_IS_OWNED(m);
714 		m1 = TAILQ_PREV(m, mutex_queue, m_qe);
715 		m2 = TAILQ_NEXT(m, m_qe);
716 		if ((m1 != NULL && m1->m_lock.m_ceilings[0] > (u_int)ceiling) ||
717 		    (m2 != NULL && m2->m_lock.m_ceilings[0] < (u_int)ceiling)) {
718 			TAILQ_REMOVE(&curthread->pp_mutexq, m, m_qe);
719 			TAILQ_FOREACH(m2, &curthread->pp_mutexq, m_qe) {
720 				if (m2->m_lock.m_ceilings[0] > (u_int)ceiling) {
721 					TAILQ_INSERT_BEFORE(m2, m, m_qe);
722 					return (0);
723 				}
724 			}
725 			TAILQ_INSERT_TAIL(&curthread->pp_mutexq, m, m_qe);
726 		}
727 	}
728 	return (0);
729 }
730 
731 int
732 _pthread_mutex_getspinloops_np(pthread_mutex_t *mutex, int *count)
733 {
734 	struct pthread_mutex	*m;
735 
736 	CHECK_AND_INIT_MUTEX
737 
738 	*count = m->m_spinloops;
739 	return (0);
740 }
741 
742 int
743 __pthread_mutex_setspinloops_np(pthread_mutex_t *mutex, int count)
744 {
745 	struct pthread_mutex	*m;
746 
747 	CHECK_AND_INIT_MUTEX
748 
749 	m->m_spinloops = count;
750 	return (0);
751 }
752 
753 int
754 _pthread_mutex_getyieldloops_np(pthread_mutex_t *mutex, int *count)
755 {
756 	struct pthread_mutex	*m;
757 
758 	CHECK_AND_INIT_MUTEX
759 
760 	*count = m->m_yieldloops;
761 	return (0);
762 }
763 
764 int
765 __pthread_mutex_setyieldloops_np(pthread_mutex_t *mutex, int count)
766 {
767 	struct pthread_mutex	*m;
768 
769 	CHECK_AND_INIT_MUTEX
770 
771 	m->m_yieldloops = count;
772 	return (0);
773 }
774 
775 int
776 _pthread_mutex_isowned_np(pthread_mutex_t *mutex)
777 {
778 	struct pthread_mutex	*m;
779 
780 	m = *mutex;
781 	if (m <= THR_MUTEX_DESTROYED)
782 		return (0);
783 	return (m->m_owner == _get_curthread());
784 }
785 
786 int
787 _mutex_owned(struct pthread *curthread, const struct pthread_mutex *mp)
788 {
789 	if (__predict_false(mp <= THR_MUTEX_DESTROYED)) {
790 		if (mp == THR_MUTEX_DESTROYED)
791 			return (EINVAL);
792 		return (EPERM);
793 	}
794       	if (mp->m_owner != curthread)
795 		return (EPERM);
796 	return (0);
797 }
798