xref: /freebsd/lib/libthr/thread/thr_umtx.c (revision a3cf0ef5a295c885c895fabfd56470c0d1db322d)
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  * $FreeBSD$
27  *
28  */
29 
30 #include "thr_private.h"
31 #include "thr_umtx.h"
32 
33 #ifndef HAS__UMTX_OP_ERR
34 int _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 
42 void
43 _thr_umutex_init(struct umutex *mtx)
44 {
45 	static struct umutex default_mtx = DEFAULT_UMUTEX;
46 
47 	*mtx = default_mtx;
48 }
49 
50 void
51 _thr_urwlock_init(struct urwlock *rwl)
52 {
53 	static struct urwlock default_rwl = DEFAULT_URWLOCK;
54 	*rwl = default_rwl;
55 }
56 
57 int
58 __thr_umutex_lock(struct umutex *mtx, uint32_t id)
59 {
60 	uint32_t owner;
61 
62 	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
63 		for (;;) {
64 			/* wait in kernel */
65 			_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
66 
67 			owner = mtx->m_owner;
68 			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
69 			     atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
70 				return (0);
71 		}
72 	}
73 
74 	return	_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0);
75 }
76 
77 int
78 __thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
79 	const struct timespec *ets)
80 {
81 	struct timespec timo, cts;
82 	uint32_t owner;
83 	int ret;
84 
85 	clock_gettime(CLOCK_REALTIME, &cts);
86 	TIMESPEC_SUB(&timo, ets, &cts);
87 
88 	if (timo.tv_sec < 0)
89 		return (ETIMEDOUT);
90 
91 	for (;;) {
92 		if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
93 
94 			/* wait in kernel */
95 			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, &timo);
96 
97 			/* now try to lock it */
98 			owner = mtx->m_owner;
99 			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
100 			     atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
101 				return (0);
102 		} else {
103 			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, &timo);
104 			if (ret == 0)
105 				break;
106 		}
107 		if (ret == ETIMEDOUT)
108 			break;
109 		clock_gettime(CLOCK_REALTIME, &cts);
110 		TIMESPEC_SUB(&timo, ets, &cts);
111 		if (timo.tv_sec < 0 || (timo.tv_sec == 0 && timo.tv_nsec == 0)) {
112 			ret = ETIMEDOUT;
113 			break;
114 		}
115 	}
116 	return (ret);
117 }
118 
119 int
120 __thr_umutex_unlock(struct umutex *mtx, uint32_t id)
121 {
122 #ifndef __ia64__
123 	/* XXX this logic has a race-condition on ia64. */
124 	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
125 		atomic_cmpset_rel_32(&mtx->m_owner, id | UMUTEX_CONTESTED, UMUTEX_CONTESTED);
126 		return _umtx_op_err(mtx, UMTX_OP_MUTEX_WAKE, 0, 0, 0);
127 	}
128 #endif /* __ia64__ */
129 	return _umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0);
130 }
131 
132 int
133 __thr_umutex_trylock(struct umutex *mtx)
134 {
135 	return _umtx_op_err(mtx, UMTX_OP_MUTEX_TRYLOCK, 0, 0, 0);
136 }
137 
138 int
139 __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
140 	uint32_t *oldceiling)
141 {
142 	return _umtx_op_err(mtx, UMTX_OP_SET_CEILING, ceiling, oldceiling, 0);
143 }
144 
145 int
146 _thr_umtx_wait(volatile long *mtx, long id, const struct timespec *timeout)
147 {
148 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
149 		timeout->tv_nsec <= 0)))
150 		return (ETIMEDOUT);
151 	return _umtx_op_err(__DEVOLATILE(void *, mtx), UMTX_OP_WAIT, id, 0,
152 		__DECONST(void*, timeout));
153 }
154 
155 int
156 _thr_umtx_wait_uint(volatile u_int *mtx, u_int id, const struct timespec *timeout, int shared)
157 {
158 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
159 		timeout->tv_nsec <= 0)))
160 		return (ETIMEDOUT);
161 	return _umtx_op_err(__DEVOLATILE(void *, mtx),
162 			shared ? UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id, 0,
163 			__DECONST(void*, timeout));
164 }
165 
166 int
167 _thr_umtx_wake(volatile void *mtx, int nr_wakeup, int shared)
168 {
169 	return _umtx_op_err(__DEVOLATILE(void *, mtx), shared ? UMTX_OP_WAKE : UMTX_OP_WAKE_PRIVATE,
170 		nr_wakeup, 0, 0);
171 }
172 
173 void
174 _thr_ucond_init(struct ucond *cv)
175 {
176 	bzero(cv, sizeof(struct ucond));
177 }
178 
179 int
180 _thr_ucond_wait(struct ucond *cv, struct umutex *m,
181 	const struct timespec *timeout, int check_unparking)
182 {
183 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
184 	    timeout->tv_nsec <= 0))) {
185 		struct pthread *curthread = _get_curthread();
186 		_thr_umutex_unlock(m, TID(curthread));
187                 return (ETIMEDOUT);
188 	}
189 	return _umtx_op_err(cv, UMTX_OP_CV_WAIT,
190 		     check_unparking ? UMTX_CHECK_UNPARKING : 0,
191 		     m, __DECONST(void*, timeout));
192 }
193 
194 int
195 _thr_ucond_signal(struct ucond *cv)
196 {
197 	if (!cv->c_has_waiters)
198 		return (0);
199 	return _umtx_op_err(cv, UMTX_OP_CV_SIGNAL, 0, NULL, NULL);
200 }
201 
202 int
203 _thr_ucond_broadcast(struct ucond *cv)
204 {
205 	if (!cv->c_has_waiters)
206 		return (0);
207 	return _umtx_op_err(cv, UMTX_OP_CV_BROADCAST, 0, NULL, NULL);
208 }
209 
210 int
211 __thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp)
212 {
213 	return _umtx_op_err(rwlock, UMTX_OP_RW_RDLOCK, flags, NULL, tsp);
214 }
215 
216 int
217 __thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp)
218 {
219 	return _umtx_op_err(rwlock, UMTX_OP_RW_WRLOCK, 0, NULL, tsp);
220 }
221 
222 int
223 __thr_rwlock_unlock(struct urwlock *rwlock)
224 {
225 	return _umtx_op_err(rwlock, UMTX_OP_RW_UNLOCK, 0, NULL, NULL);
226 }
227 
228 void
229 _thr_rwl_rdlock(struct urwlock *rwlock)
230 {
231 	int ret;
232 
233 	for (;;) {
234 		if (_thr_rwlock_tryrdlock(rwlock, URWLOCK_PREFER_READER) == 0)
235 			return;
236 		ret = __thr_rwlock_rdlock(rwlock, URWLOCK_PREFER_READER, NULL);
237 		if (ret == 0)
238 			return;
239 		if (ret != EINTR)
240 			PANIC("rdlock error");
241 	}
242 }
243 
244 void
245 _thr_rwl_wrlock(struct urwlock *rwlock)
246 {
247 	int ret;
248 
249 	for (;;) {
250 		if (_thr_rwlock_trywrlock(rwlock) == 0)
251 			return;
252 		ret = __thr_rwlock_wrlock(rwlock, NULL);
253 		if (ret == 0)
254 			return;
255 		if (ret != EINTR)
256 			PANIC("wrlock error");
257 	}
258 }
259 
260 void
261 _thr_rwl_unlock(struct urwlock *rwlock)
262 {
263 	if (_thr_rwlock_unlock(rwlock))
264 		PANIC("unlock error");
265 }
266