xref: /dflybsd-src/lib/libthread_xu/thread/thr_mutex.c (revision 3cfdabcf7e1db41825b8887a61c5c931c82c4f4d)
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  */
34 
35 #include "namespace.h"
36 #include <machine/tls.h>
37 #include <errno.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <sys/queue.h>
41 #include <pthread.h>
42 #include "un-namespace.h"
43 
44 #include "thr_private.h"
45 
46 #ifdef _PTHREADS_DEBUGGING
47 
48 #include <stdio.h>
49 #include <stdarg.h>
50 #include <sys/file.h>
51 
52 #endif
53 
54 #if defined(_PTHREADS_INVARIANTS)
55 #define MUTEX_INIT_LINK(m)		do {		\
56 	(m)->m_qe.tqe_prev = NULL;			\
57 	(m)->m_qe.tqe_next = NULL;			\
58 } while (0)
59 #define MUTEX_ASSERT_IS_OWNED(m)	do {		\
60 	if ((m)->m_qe.tqe_prev == NULL)			\
61 		PANIC("mutex is not on list");		\
62 } while (0)
63 #define MUTEX_ASSERT_NOT_OWNED(m)	do {		\
64 	if (((m)->m_qe.tqe_prev != NULL) ||		\
65 	    ((m)->m_qe.tqe_next != NULL))		\
66 		PANIC("mutex is on list");		\
67 } while (0)
68 #define	THR_ASSERT_NOT_IN_SYNCQ(thr)	do {		\
69 	THR_ASSERT(((thr)->sflags & THR_FLAGS_IN_SYNCQ) == 0, \
70 	    "thread in syncq when it shouldn't be.");	\
71 } while (0);
72 #else
73 #define MUTEX_INIT_LINK(m)
74 #define MUTEX_ASSERT_IS_OWNED(m)
75 #define MUTEX_ASSERT_NOT_OWNED(m)
76 #define	THR_ASSERT_NOT_IN_SYNCQ(thr)
77 #endif
78 
79 #define THR_IN_MUTEXQ(thr)	(((thr)->sflags & THR_FLAGS_IN_SYNCQ) != 0)
80 #define	MUTEX_DESTROY(m) do {		\
81 	__free(m);			\
82 } while (0)
83 
84 umtx_t	_mutex_static_lock;
85 
86 #ifdef _PTHREADS_DEBUGGING
87 
88 static
89 void
90 mutex_log(const char *ctl, ...)
91 {
92 	char buf[256];
93 	va_list va;
94 	size_t len;
95 
96 	va_start(va, ctl);
97 	len = vsnprintf(buf, sizeof(buf), ctl, va);
98 	va_end(va);
99 	_thr_log(buf, len);
100 }
101 
102 #else
103 
104 static __inline
105 void
106 mutex_log(const char *ctl __unused, ...)
107 {
108 }
109 
110 #endif
111 
112 #ifdef _PTHREADS_DEBUGGING2
113 
114 static void
115 mutex_log2(struct pthread *curthread, struct pthread_mutex *m, int op)
116 {
117 	if (curthread) {
118 		if (curthread->tid < 32)
119 			m->m_lastop[curthread->tid] =
120 				(__sys_getpid() << 16) | op;
121 	} else {
122 			m->m_lastop[0] =
123 				(__sys_getpid() << 16) | op;
124 	}
125 }
126 
127 #else
128 
129 static __inline
130 void
131 mutex_log2(struct pthread *curthread __unused,
132 	   struct pthread_mutex *m __unused, int op __unused)
133 {
134 }
135 
136 #endif
137 
138 /*
139  * Prototypes
140  */
141 static int	mutex_self_trylock(pthread_mutex_t);
142 static int	mutex_self_lock(pthread_mutex_t,
143 			const struct timespec *abstime);
144 static int	mutex_unlock_common(pthread_mutex_t *);
145 
146 int __pthread_mutex_init(pthread_mutex_t *mutex,
147 	const pthread_mutexattr_t *mutex_attr);
148 int __pthread_mutex_trylock(pthread_mutex_t *mutex);
149 int __pthread_mutex_lock(pthread_mutex_t *mutex);
150 int __pthread_mutex_timedlock(pthread_mutex_t *mutex,
151 	const struct timespec *abs_timeout);
152 
153 static int
154 mutex_check_attr(const struct pthread_mutex_attr *attr)
155 {
156 	if (attr->m_type < PTHREAD_MUTEX_ERRORCHECK ||
157 	    attr->m_type >= PTHREAD_MUTEX_TYPE_MAX)
158 		return (EINVAL);
159 	if (attr->m_protocol < PTHREAD_PRIO_NONE ||
160 	    attr->m_protocol > PTHREAD_PRIO_PROTECT)
161 		return (EINVAL);
162 	return (0);
163 }
164 
165 static void
166 mutex_init_body(struct pthread_mutex *pmutex,
167     const struct pthread_mutex_attr *attr, int private)
168 {
169 	_thr_umtx_init(&pmutex->m_lock);
170 	pmutex->m_type = attr->m_type;
171 	pmutex->m_protocol = attr->m_protocol;
172 	TAILQ_INIT(&pmutex->m_queue);
173 	mutex_log2(tls_get_curthread(), pmutex, 32);
174 	pmutex->m_owner = NULL;
175 	pmutex->m_flags = attr->m_flags | MUTEX_FLAGS_INITED;
176 	if (private)
177 		pmutex->m_flags |= MUTEX_FLAGS_PRIVATE;
178 	pmutex->m_count = 0;
179 	pmutex->m_refcount = 0;
180 	if (attr->m_protocol == PTHREAD_PRIO_PROTECT)
181 		pmutex->m_prio = attr->m_ceiling;
182 	else
183 		pmutex->m_prio = -1;
184 	pmutex->m_saved_prio = 0;
185 	MUTEX_INIT_LINK(pmutex);
186 }
187 
188 static int
189 mutex_init(pthread_mutex_t *mutex,
190     const pthread_mutexattr_t *mutex_attr, int private)
191 {
192 	const struct pthread_mutex_attr *attr;
193 	struct pthread_mutex *pmutex;
194 	int error;
195 
196 	if (mutex_attr == NULL) {
197 		attr = &_pthread_mutexattr_default;
198 	} else {
199 		attr = *mutex_attr;
200 		error = mutex_check_attr(attr);
201 		if (error != 0)
202 			return (error);
203 	}
204 
205 	pmutex = __malloc(sizeof(struct pthread_mutex));
206 	if (pmutex == NULL)
207 		return (ENOMEM);
208 	mutex_init_body(pmutex, attr, private);
209 	*mutex = pmutex;
210 	return (0);
211 }
212 
213 static int
214 init_static(struct pthread *thread, pthread_mutex_t *mutex)
215 {
216 	int ret;
217 
218 	THR_LOCK_ACQUIRE(thread, &_mutex_static_lock);
219 
220 	if (*mutex == NULL)
221 		ret = mutex_init(mutex, NULL, 0);
222 	else
223 		ret = 0;
224 	THR_LOCK_RELEASE(thread, &_mutex_static_lock);
225 
226 	return (ret);
227 }
228 
229 static int
230 init_static_private(struct pthread *thread, pthread_mutex_t *mutex)
231 {
232 	int ret;
233 
234 	THR_LOCK_ACQUIRE(thread, &_mutex_static_lock);
235 
236 	if (*mutex == NULL)
237 		ret = mutex_init(mutex, NULL, 1);
238 	else
239 		ret = 0;
240 
241 	THR_LOCK_RELEASE(thread, &_mutex_static_lock);
242 
243 	return (ret);
244 }
245 
246 int
247 _pthread_mutex_init(pthread_mutex_t * __restrict mutex,
248     const pthread_mutexattr_t * __restrict mutex_attr)
249 {
250 	return mutex_init(mutex, mutex_attr, 1);
251 }
252 
253 int
254 __pthread_mutex_init(pthread_mutex_t *mutex,
255     const pthread_mutexattr_t *mutex_attr)
256 {
257 	return mutex_init(mutex, mutex_attr, 0);
258 }
259 
260 #if 0
261 int
262 _mutex_reinit(pthread_mutex_t *mutexp)
263 {
264 	pthread_mutex_t mutex = *mutexp;
265 
266 	_thr_umtx_init(&mutex->m_lock);
267 	TAILQ_INIT(&mutex->m_queue);
268 	MUTEX_INIT_LINK(mutex);
269 	mutex_log2(tls_get_curthread(), mutex, 33);
270 	mutex->m_owner = NULL;
271 	mutex->m_count = 0;
272 	mutex->m_refcount = 0;
273 	mutex->m_prio = 0;
274 	mutex->m_saved_prio = 0;
275 
276 	return (0);
277 }
278 #endif
279 
280 void
281 _mutex_fork(struct pthread *curthread)
282 {
283 	struct pthread_mutex *m;
284 
285 	TAILQ_FOREACH(m, &curthread->mutexq, m_qe)
286 		m->m_lock = UMTX_LOCKED;
287 }
288 
289 int
290 _pthread_mutex_destroy(pthread_mutex_t *mutex)
291 {
292 	struct pthread *curthread = tls_get_curthread();
293 	pthread_mutex_t m;
294 	int ret = 0;
295 
296 	if (mutex == NULL) {
297 		ret = EINVAL;
298 	} else if (*mutex == NULL) {
299 		ret = 0;
300 	} else {
301 		/*
302 		 * Try to lock the mutex structure, we only need to
303 		 * try once, if failed, the mutex is in use.
304 		 */
305 		ret = THR_UMTX_TRYLOCK(curthread, &(*mutex)->m_lock);
306 		if (ret)
307 			return (ret);
308 
309 		/*
310 		 * Check mutex other fields to see if this mutex is
311 		 * in use. Mostly for prority mutex types, or there
312 		 * are condition variables referencing it.
313 		 */
314 		if (((*mutex)->m_owner != NULL) ||
315 		    (TAILQ_FIRST(&(*mutex)->m_queue) != NULL) ||
316 		    ((*mutex)->m_refcount != 0)) {
317 			THR_UMTX_UNLOCK(curthread, &(*mutex)->m_lock);
318 			ret = EBUSY;
319 		} else {
320 			/*
321 			 * Save a pointer to the mutex so it can be free'd
322 			 * and set the caller's pointer to NULL:
323 			 */
324 			m = *mutex;
325 			*mutex = NULL;
326 
327 			/* Unlock the mutex structure: */
328 			THR_UMTX_UNLOCK(curthread, &m->m_lock);
329 
330 			/*
331 			 * Free the memory allocated for the mutex
332 			 * structure:
333 			 */
334 			MUTEX_ASSERT_NOT_OWNED(m);
335 			MUTEX_DESTROY(m);
336 		}
337 	}
338 
339 	/* Return the completion status: */
340 	return (ret);
341 }
342 
343 static int
344 mutex_trylock_common(struct pthread *curthread, pthread_mutex_t *mutex)
345 {
346 	struct pthread_mutex *m;
347 	int ret;
348 
349 	m = *mutex;
350 	mutex_log("mutex_lock_trylock_common %p\n", m);
351 	ret = THR_UMTX_TRYLOCK(curthread, &m->m_lock);
352 	if (ret == 0) {
353 		mutex_log2(curthread, m, 1);
354 		m->m_owner = curthread;
355 		/* Add to the list of owned mutexes: */
356 		MUTEX_ASSERT_NOT_OWNED(m);
357 		TAILQ_INSERT_TAIL(&curthread->mutexq, m, m_qe);
358 	} else if (m->m_owner == curthread) {
359 		mutex_log2(curthread, m, 2);
360 		ret = mutex_self_trylock(m);
361 	} /* else {} */
362 	mutex_log("mutex_lock_trylock_common %p (returns %d)\n", m, ret);
363 
364 	return (ret);
365 }
366 
367 int
368 __pthread_mutex_trylock(pthread_mutex_t *m)
369 {
370 	struct pthread *curthread = tls_get_curthread();
371 	int ret;
372 
373 	if (__predict_false(m == NULL))
374 		return(EINVAL);
375 	/*
376 	 * If the mutex is statically initialized, perform the dynamic
377 	 * initialization:
378 	 */
379 	if (__predict_false(*m == NULL)) {
380 		ret = init_static(curthread, m);
381 		if (__predict_false(ret != 0))
382 			return (ret);
383 	}
384 	return (mutex_trylock_common(curthread, m));
385 }
386 
387 int
388 _pthread_mutex_trylock(pthread_mutex_t *m)
389 {
390 	struct pthread	*curthread = tls_get_curthread();
391 	int	ret = 0;
392 
393 	/*
394 	 * If the mutex is statically initialized, perform the dynamic
395 	 * initialization marking the mutex private (delete safe):
396 	 */
397 	if (__predict_false(*m == NULL)) {
398 		ret = init_static_private(curthread, m);
399 		if (__predict_false(ret != 0))
400 			return (ret);
401 	}
402 	return (mutex_trylock_common(curthread, m));
403 }
404 
405 static int
406 mutex_lock_common(struct pthread *curthread, pthread_mutex_t *mutex,
407 	const struct timespec * abstime)
408 {
409 	struct  timespec ts, ts2;
410 	struct  pthread_mutex *m;
411 	int	ret = 0;
412 
413 	m = *mutex;
414 	mutex_log("mutex_lock_common %p\n", m);
415 	ret = THR_UMTX_TRYLOCK(curthread, &m->m_lock);
416 	if (ret == 0) {
417 		mutex_log2(curthread, m, 3);
418 		m->m_owner = curthread;
419 		/* Add to the list of owned mutexes: */
420 		MUTEX_ASSERT_NOT_OWNED(m);
421 		TAILQ_INSERT_TAIL(&curthread->mutexq, m, m_qe);
422 	} else if (m->m_owner == curthread) {
423 		ret = mutex_self_lock(m, abstime);
424 	} else {
425 		if (abstime == NULL) {
426 			THR_UMTX_LOCK(curthread, &m->m_lock);
427 			ret = 0;
428 		} else if (__predict_false(
429 			abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
430 			abstime->tv_nsec >= 1000000000)) {
431 				ret = EINVAL;
432 		} else {
433 			clock_gettime(CLOCK_REALTIME, &ts);
434 			timespecsub(abstime, &ts, &ts2);
435 			ret = THR_UMTX_TIMEDLOCK(curthread, &m->m_lock, &ts2);
436 		}
437 		if (ret == 0) {
438 			mutex_log2(curthread, m, 4);
439 			m->m_owner = curthread;
440 			/* Add to the list of owned mutexes: */
441 			MUTEX_ASSERT_NOT_OWNED(m);
442 			TAILQ_INSERT_TAIL(&curthread->mutexq, m, m_qe);
443 		}
444 	}
445 	mutex_log("mutex_lock_common %p (returns %d) lock %d,%d\n",
446 		  m, ret, m->m_lock, m->m_count);
447 	return (ret);
448 }
449 
450 int
451 __pthread_mutex_lock(pthread_mutex_t *m)
452 {
453 	struct pthread *curthread;
454 	int	ret;
455 
456 	if (__predict_false(m == NULL))
457 		return(EINVAL);
458 
459 	/*
460 	 * If the mutex is statically initialized, perform the dynamic
461 	 * initialization:
462 	 */
463 	curthread = tls_get_curthread();
464 	if (__predict_false(*m == NULL)) {
465 		ret = init_static(curthread, m);
466 		if (__predict_false(ret))
467 			return (ret);
468 	}
469 	return (mutex_lock_common(curthread, m, NULL));
470 }
471 
472 int
473 _pthread_mutex_lock(pthread_mutex_t *m)
474 {
475 	struct pthread *curthread;
476 	int	ret;
477 
478 	_thr_check_init();
479 
480 	if (__predict_false(m == NULL))
481 		return(EINVAL);
482 
483 	/*
484 	 * If the mutex is statically initialized, perform the dynamic
485 	 * initialization marking it private (delete safe):
486 	 */
487 	curthread = tls_get_curthread();
488 	if (__predict_false(*m == NULL)) {
489 		ret = init_static_private(curthread, m);
490 		if (__predict_false(ret))
491 			return (ret);
492 	}
493 	return (mutex_lock_common(curthread, m, NULL));
494 }
495 
496 int
497 __pthread_mutex_timedlock(pthread_mutex_t * __restrict m,
498     const struct timespec * __restrict abs_timeout)
499 {
500 	struct pthread *curthread;
501 	int	ret;
502 
503 	_thr_check_init();
504 
505 	if (__predict_false(m == NULL))
506 		return(EINVAL);
507 
508 	/*
509 	 * If the mutex is statically initialized, perform the dynamic
510 	 * initialization:
511 	 */
512 	curthread = tls_get_curthread();
513 	if (__predict_false(*m == NULL)) {
514 		ret = init_static(curthread, m);
515 		if (__predict_false(ret))
516 			return (ret);
517 	}
518 	return (mutex_lock_common(curthread, m, abs_timeout));
519 }
520 
521 int
522 _pthread_mutex_timedlock(pthread_mutex_t *m,
523 	const struct timespec *abs_timeout)
524 {
525 	struct pthread *curthread;
526 	int	ret;
527 
528 	if (__predict_false(m == NULL))
529 		return(EINVAL);
530 
531 	curthread = tls_get_curthread();
532 
533 	/*
534 	 * If the mutex is statically initialized, perform the dynamic
535 	 * initialization marking it private (delete safe):
536 	 */
537 	if (__predict_false(*m == NULL)) {
538 		ret = init_static_private(curthread, m);
539 		if (__predict_false(ret))
540 			return (ret);
541 	}
542 	return (mutex_lock_common(curthread, m, abs_timeout));
543 }
544 
545 int
546 _pthread_mutex_unlock(pthread_mutex_t *m)
547 {
548 	if (__predict_false(m == NULL))
549 		return(EINVAL);
550 	return (mutex_unlock_common(m));
551 }
552 
553 static int
554 mutex_self_trylock(pthread_mutex_t m)
555 {
556 	int	ret;
557 
558 	switch (m->m_type) {
559 	/* case PTHREAD_MUTEX_DEFAULT: */
560 	case PTHREAD_MUTEX_ERRORCHECK:
561 	case PTHREAD_MUTEX_NORMAL:
562 		ret = EBUSY;
563 		break;
564 
565 	case PTHREAD_MUTEX_RECURSIVE:
566 		/* Increment the lock count: */
567 		if (m->m_count + 1 > 0) {
568 			m->m_count++;
569 			ret = 0;
570 		} else
571 			ret = EAGAIN;
572 		break;
573 
574 	default:
575 		/* Trap invalid mutex types; */
576 		ret = EINVAL;
577 	}
578 
579 	return (ret);
580 }
581 
582 static int
583 mutex_self_lock(pthread_mutex_t m, const struct timespec *abstime)
584 {
585 	struct timespec ts1, ts2;
586 	int ret;
587 
588 	switch (m->m_type) {
589 	/* case PTHREAD_MUTEX_DEFAULT: */
590 	case PTHREAD_MUTEX_ERRORCHECK:
591 		if (abstime) {
592 			clock_gettime(CLOCK_REALTIME, &ts1);
593 			timespecsub(abstime, &ts1, &ts2);
594 			__sys_nanosleep(&ts2, NULL);
595 			ret = ETIMEDOUT;
596 		} else {
597 			/*
598 			 * POSIX specifies that mutexes should return
599 			 * EDEADLK if a recursive lock is detected.
600 			 */
601 			ret = EDEADLK;
602 		}
603 		break;
604 
605 	case PTHREAD_MUTEX_NORMAL:
606 		/*
607 		 * What SS2 define as a 'normal' mutex.  Intentionally
608 		 * deadlock on attempts to get a lock you already own.
609 		 */
610 		ret = 0;
611 		if (abstime) {
612 			clock_gettime(CLOCK_REALTIME, &ts1);
613 			timespecsub(abstime, &ts1, &ts2);
614 			__sys_nanosleep(&ts2, NULL);
615 			ret = ETIMEDOUT;
616 		} else {
617 			ts1.tv_sec = 30;
618 			ts1.tv_nsec = 0;
619 			for (;;)
620 				__sys_nanosleep(&ts1, NULL);
621 		}
622 		break;
623 
624 	case PTHREAD_MUTEX_RECURSIVE:
625 		/* Increment the lock count: */
626 		if (m->m_count + 1 > 0) {
627 			m->m_count++;
628 			ret = 0;
629 		} else
630 			ret = EAGAIN;
631 		break;
632 
633 	default:
634 		/* Trap invalid mutex types; */
635 		ret = EINVAL;
636 	}
637 
638 	return (ret);
639 }
640 
641 static int
642 mutex_unlock_common(pthread_mutex_t *mutex)
643 {
644 	struct pthread *curthread = tls_get_curthread();
645 	struct pthread_mutex *m;
646 
647 	if (__predict_false((m = *mutex) == NULL)) {
648 		mutex_log2(curthread, m, 252);
649 		return (EINVAL);
650 	}
651 	mutex_log("mutex_unlock_common %p\n", m);
652 	if (__predict_false(m->m_owner != curthread)) {
653 		mutex_log("mutex_unlock_common %p (failedA)\n", m);
654 		mutex_log2(curthread, m, 253);
655 		return (EPERM);
656 	}
657 
658 	if (__predict_false(m->m_type == PTHREAD_MUTEX_RECURSIVE &&
659 			    m->m_count > 0)) {
660 		m->m_count--;
661 		mutex_log("mutex_unlock_common %p (returns 0, partial)\n", m);
662 		mutex_log2(curthread, m, 254);
663 	} else {
664 		/*
665 		 * Clear the count in case this is a recursive mutex.
666 		 */
667 		m->m_count = 0;
668 		m->m_owner = NULL;
669 		/* Remove the mutex from the threads queue. */
670 		MUTEX_ASSERT_IS_OWNED(m);
671 		TAILQ_REMOVE(&curthread->mutexq, m, m_qe);
672 		mutex_log2(tls_get_curthread(), m, 35);
673 		MUTEX_INIT_LINK(m);
674 		mutex_log2(tls_get_curthread(), m, 36);
675 		/*
676 		 * Hand off the mutex to the next waiting thread.
677 		 */
678 		mutex_log("mutex_unlock_common %p (returns 0) lock %d\n",
679 			  m, m->m_lock);
680 		THR_UMTX_UNLOCK(curthread, &m->m_lock);
681 		mutex_log2(tls_get_curthread(), m, 37);
682 		mutex_log2(curthread, m, 255);
683 	}
684 	return (0);
685 }
686 
687 int
688 _pthread_mutex_getprioceiling(const pthread_mutex_t * __restrict mutex,
689     int * __restrict prioceiling)
690 {
691 	if ((mutex == NULL) || (*mutex == NULL))
692 		return (EINVAL);
693 	if ((*mutex)->m_protocol != PTHREAD_PRIO_PROTECT)
694 		return (EINVAL);
695 	*prioceiling = (*mutex)->m_prio;
696 	return (0);
697 }
698 
699 int
700 _pthread_mutex_setprioceiling(pthread_mutex_t * __restrict mutex,
701     int prioceiling, int * __restrict old_ceiling)
702 {
703 	int ret = 0;
704 	int tmp;
705 
706 	if ((mutex == NULL) || (*mutex == NULL))
707 		ret = EINVAL;
708 	else if ((*mutex)->m_protocol != PTHREAD_PRIO_PROTECT)
709 		ret = EINVAL;
710 	else if ((ret = _pthread_mutex_lock(mutex)) == 0) {
711 		tmp = (*mutex)->m_prio;
712 		(*mutex)->m_prio = prioceiling;
713 		ret = _pthread_mutex_unlock(mutex);
714 		*old_ceiling = tmp;
715 	}
716 	return(ret);
717 }
718 
719 int
720 _mutex_cv_lock(pthread_mutex_t *m, int count)
721 {
722 	int	ret;
723 
724 	if ((ret = _pthread_mutex_lock(m)) == 0) {
725 		(*m)->m_refcount--;
726 		(*m)->m_count += count;
727 	}
728 	return (ret);
729 }
730 
731 int
732 _mutex_cv_unlock(pthread_mutex_t *mutex, int *count)
733 {
734 	struct pthread *curthread = tls_get_curthread();
735 	struct pthread_mutex *m;
736 
737 	if (__predict_false(mutex == NULL))
738 		return (EINVAL);
739 	if (__predict_false((m = *mutex) == NULL))
740 		return (EINVAL);
741 	if (__predict_false(m->m_owner != curthread))
742 		return (EPERM);
743 
744 	*count = m->m_count;
745 	m->m_count = 0;
746 	m->m_refcount++;
747 	mutex_log2(tls_get_curthread(), m, 45);
748 	m->m_owner = NULL;
749 	/* Remove the mutex from the threads queue. */
750 	MUTEX_ASSERT_IS_OWNED(m);
751 	TAILQ_REMOVE(&curthread->mutexq, m, m_qe);
752 	MUTEX_INIT_LINK(m);
753 	THR_UMTX_UNLOCK(curthread, &m->m_lock);
754 	mutex_log2(curthread, m, 250);
755 	return (0);
756 }
757 
758 void
759 _mutex_unlock_private(pthread_t pthread)
760 {
761 	struct pthread_mutex	*m, *m_next;
762 
763 	for (m = TAILQ_FIRST(&pthread->mutexq); m != NULL; m = m_next) {
764 		m_next = TAILQ_NEXT(m, m_qe);
765 		if ((m->m_flags & MUTEX_FLAGS_PRIVATE) != 0)
766 			_pthread_mutex_unlock(&m);
767 	}
768 }
769 
770 __strong_reference(__pthread_mutex_init, pthread_mutex_init);
771 __strong_reference(__pthread_mutex_lock, pthread_mutex_lock);
772 __strong_reference(__pthread_mutex_timedlock, pthread_mutex_timedlock);
773 __strong_reference(__pthread_mutex_trylock, pthread_mutex_trylock);
774 
775 /* Single underscore versions provided for libc internal usage: */
776 /* No difference between libc and application usage of these: */
777 __strong_reference(_pthread_mutex_destroy, pthread_mutex_destroy);
778 __strong_reference(_pthread_mutex_unlock, pthread_mutex_unlock);
779 __strong_reference(_pthread_mutex_getprioceiling, pthread_mutex_getprioceiling);
780 __strong_reference(_pthread_mutex_setprioceiling, pthread_mutex_setprioceiling);
781