thr_umtx.c revision 212076 
1/*
2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    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 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: head/lib/libthr/thread/thr_umtx.c 212076 2010-09-01 02:18:33Z davidxu $
27 *
28 */
29
30#include "thr_private.h"
31#include "thr_umtx.h"
32
33#ifndef HAS__UMTX_OP_ERR
34int _umtx_op_err(void *obj, int op, u_long val, void *uaddr, void *uaddr2)
35{
36	if (_umtx_op(obj, op, val, uaddr, uaddr2) == -1)
37		return (errno);
38	return (0);
39}
40#endif
41
42void
43_thr_umutex_init(struct umutex *mtx)
44{
45	static struct umutex default_mtx = DEFAULT_UMUTEX;
46
47	*mtx = default_mtx;
48}
49
50int
51__thr_umutex_lock(struct umutex *mtx, uint32_t id)
52{
53	uint32_t owner;
54
55	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
56		for (;;) {
57			/* wait in kernel */
58			_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
59
60			owner = mtx->m_owner;
61			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
62			     atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
63				return (0);
64		}
65	}
66
67	return	_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0);
68}
69
70int
71__thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
72	const struct timespec *ets)
73{
74	struct timespec timo, cts;
75	uint32_t owner;
76	int ret;
77
78	clock_gettime(CLOCK_REALTIME, &cts);
79	TIMESPEC_SUB(&timo, ets, &cts);
80
81	if (timo.tv_sec < 0)
82		return (ETIMEDOUT);
83
84	for (;;) {
85		if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
86
87			/* wait in kernel */
88			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, &timo);
89
90			/* now try to lock it */
91			owner = mtx->m_owner;
92			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
93			     atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
94				return (0);
95		} else {
96			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, &timo);
97			if (ret == 0)
98				break;
99		}
100		if (ret == ETIMEDOUT)
101			break;
102		clock_gettime(CLOCK_REALTIME, &cts);
103		TIMESPEC_SUB(&timo, ets, &cts);
104		if (timo.tv_sec < 0 || (timo.tv_sec == 0 && timo.tv_nsec == 0)) {
105			ret = ETIMEDOUT;
106			break;
107		}
108	}
109	return (ret);
110}
111
112int
113__thr_umutex_unlock(struct umutex *mtx, uint32_t id)
114{
115#ifndef __ia64__
116	/* XXX this logic has a race-condition on ia64. */
117	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
118		atomic_cmpset_rel_32(&mtx->m_owner, id | UMUTEX_CONTESTED, UMUTEX_CONTESTED);
119		return _umtx_op_err(mtx, UMTX_OP_MUTEX_WAKE, 0, 0, 0);
120	}
121#endif /* __ia64__ */
122	return _umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0);
123}
124
125int
126__thr_umutex_trylock(struct umutex *mtx)
127{
128	return _umtx_op_err(mtx, UMTX_OP_MUTEX_TRYLOCK, 0, 0, 0);
129}
130
131int
132__thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
133	uint32_t *oldceiling)
134{
135	return _umtx_op_err(mtx, UMTX_OP_SET_CEILING, ceiling, oldceiling, 0);
136}
137
138int
139_thr_umtx_wait(volatile long *mtx, long id, const struct timespec *timeout)
140{
141	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
142		timeout->tv_nsec <= 0)))
143		return (ETIMEDOUT);
144	return _umtx_op_err(__DEVOLATILE(void *, mtx), UMTX_OP_WAIT, id, 0,
145		__DECONST(void*, timeout));
146}
147
148int
149_thr_umtx_wait_uint(volatile u_int *mtx, u_int id, const struct timespec *timeout, int shared)
150{
151	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
152		timeout->tv_nsec <= 0)))
153		return (ETIMEDOUT);
154	return _umtx_op_err(__DEVOLATILE(void *, mtx),
155			shared ? UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id, 0,
156			__DECONST(void*, timeout));
157}
158
159int
160_thr_umtx_wake(volatile void *mtx, int nr_wakeup, int shared)
161{
162	return _umtx_op_err(__DEVOLATILE(void *, mtx), shared ? UMTX_OP_WAKE : UMTX_OP_WAKE_PRIVATE,
163		nr_wakeup, 0, 0);
164}
165
166void
167_thr_ucond_init(struct ucond *cv)
168{
169	bzero(cv, sizeof(struct ucond));
170}
171
172int
173_thr_ucond_wait(struct ucond *cv, struct umutex *m,
174	const struct timespec *timeout, int check_unparking)
175{
176	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
177	    timeout->tv_nsec <= 0))) {
178		struct pthread *curthread = _get_curthread();
179		_thr_umutex_unlock(m, TID(curthread));
180                return (ETIMEDOUT);
181	}
182	return _umtx_op_err(cv, UMTX_OP_CV_WAIT,
183		     check_unparking ? UMTX_CHECK_UNPARKING : 0,
184		     m, __DECONST(void*, timeout));
185}
186
187int
188_thr_ucond_signal(struct ucond *cv)
189{
190	if (!cv->c_has_waiters)
191		return (0);
192	return _umtx_op_err(cv, UMTX_OP_CV_SIGNAL, 0, NULL, NULL);
193}
194
195int
196_thr_ucond_broadcast(struct ucond *cv)
197{
198	if (!cv->c_has_waiters)
199		return (0);
200	return _umtx_op_err(cv, UMTX_OP_CV_BROADCAST, 0, NULL, NULL);
201}
202
203int
204__thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp)
205{
206	return _umtx_op_err(rwlock, UMTX_OP_RW_RDLOCK, flags, NULL, tsp);
207}
208
209int
210__thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp)
211{
212	return _umtx_op_err(rwlock, UMTX_OP_RW_WRLOCK, 0, NULL, tsp);
213}
214
215int
216__thr_rwlock_unlock(struct urwlock *rwlock)
217{
218	return _umtx_op_err(rwlock, UMTX_OP_RW_UNLOCK, 0, NULL, NULL);
219}
220
221void
222_thr_rwl_rdlock(struct urwlock *rwlock)
223{
224	int ret;
225
226	for (;;) {
227		if (_thr_rwlock_tryrdlock(rwlock, URWLOCK_PREFER_READER) == 0)
228			return;
229		ret = __thr_rwlock_rdlock(rwlock, URWLOCK_PREFER_READER, NULL);
230		if (ret == 0)
231			return;
232		if (ret != EINTR)
233			PANIC("rdlock error");
234	}
235}
236
237void
238_thr_rwl_wrlock(struct urwlock *rwlock)
239{
240	int ret;
241
242	for (;;) {
243		if (_thr_rwlock_trywrlock(rwlock) == 0)
244			return;
245		ret = __thr_rwlock_wrlock(rwlock, NULL);
246		if (ret == 0)
247			return;
248		if (ret != EINTR)
249			PANIC("wrlock error");
250	}
251}
252
253void
254_thr_rwl_unlock(struct urwlock *rwlock)
255{
256	if (_thr_rwlock_unlock(rwlock))
257		PANIC("unlock error");
258}
259