xref: /freebsd/lib/libthr/thread/thr_umtx.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
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 const 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 const struct urwlock default_rwl = DEFAULT_URWLOCK;
54 
55 	*rwl = default_rwl;
56 }
57 
58 int
59 __thr_umutex_lock(struct umutex *mtx, uint32_t id)
60 {
61 	uint32_t owner;
62 
63 	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
64 		for (;;) {
65 			/* wait in kernel */
66 			_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
67 
68 			owner = mtx->m_owner;
69 			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
70 			     atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
71 				return (0);
72 		}
73 	}
74 
75 	return	_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0);
76 }
77 
78 #define SPINLOOPS 1000
79 
80 int
81 __thr_umutex_lock_spin(struct umutex *mtx, uint32_t id)
82 {
83 	uint32_t owner;
84 
85 	if (!_thr_is_smp)
86 		return __thr_umutex_lock(mtx, id);
87 
88 	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
89 		for (;;) {
90 			int count = SPINLOOPS;
91 			while (count--) {
92 				owner = mtx->m_owner;
93 				if ((owner & ~UMUTEX_CONTESTED) == 0) {
94 					if (atomic_cmpset_acq_32(
95 					    &mtx->m_owner,
96 					    owner, id|owner)) {
97 						return (0);
98 					}
99 				}
100 				CPU_SPINWAIT;
101 			}
102 
103 			/* wait in kernel */
104 			_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
105 		}
106 	}
107 
108 	return	_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0);
109 }
110 
111 int
112 __thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
113 	const struct timespec *abstime)
114 {
115 	struct _umtx_time *tm_p, timeout;
116 	size_t tm_size;
117 	uint32_t owner;
118 	int ret;
119 
120 	if (abstime == NULL) {
121 		tm_p = NULL;
122 		tm_size = 0;
123 	} else {
124 		timeout._clockid = CLOCK_REALTIME;
125 		timeout._flags = UMTX_ABSTIME;
126 		timeout._timeout = *abstime;
127 		tm_p = &timeout;
128 		tm_size = sizeof(timeout);
129 	}
130 
131 	for (;;) {
132 		if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
133 
134 			/* wait in kernel */
135 			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0,
136 				 (void *)tm_size, __DECONST(void *, tm_p));
137 
138 			/* now try to lock it */
139 			owner = mtx->m_owner;
140 			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
141 			     atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
142 				return (0);
143 		} else {
144 			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0,
145 				 (void *)tm_size, __DECONST(void *, tm_p));
146 			if (ret == 0)
147 				break;
148 		}
149 		if (ret == ETIMEDOUT)
150 			break;
151 	}
152 	return (ret);
153 }
154 
155 int
156 __thr_umutex_unlock(struct umutex *mtx, uint32_t id)
157 {
158 	return _umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0);
159 }
160 
161 int
162 __thr_umutex_trylock(struct umutex *mtx)
163 {
164 	return _umtx_op_err(mtx, UMTX_OP_MUTEX_TRYLOCK, 0, 0, 0);
165 }
166 
167 int
168 __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
169 	uint32_t *oldceiling)
170 {
171 	return _umtx_op_err(mtx, UMTX_OP_SET_CEILING, ceiling, oldceiling, 0);
172 }
173 
174 int
175 _thr_umtx_wait(volatile long *mtx, long id, const struct timespec *timeout)
176 {
177 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
178 		timeout->tv_nsec <= 0)))
179 		return (ETIMEDOUT);
180 	return _umtx_op_err(__DEVOLATILE(void *, mtx), UMTX_OP_WAIT, id, 0,
181 		__DECONST(void*, timeout));
182 }
183 
184 int
185 _thr_umtx_wait_uint(volatile u_int *mtx, u_int id, const struct timespec *timeout, int shared)
186 {
187 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
188 		timeout->tv_nsec <= 0)))
189 		return (ETIMEDOUT);
190 	return _umtx_op_err(__DEVOLATILE(void *, mtx),
191 			shared ? UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id, 0,
192 			__DECONST(void*, timeout));
193 }
194 
195 int
196 _thr_umtx_timedwait_uint(volatile u_int *mtx, u_int id, int clockid,
197 	const struct timespec *abstime, int shared)
198 {
199 	struct _umtx_time *tm_p, timeout;
200 	size_t tm_size;
201 
202 	if (abstime == NULL) {
203 		tm_p = NULL;
204 		tm_size = 0;
205 	} else {
206 		timeout._clockid = clockid;
207 		timeout._flags = UMTX_ABSTIME;
208 		timeout._timeout = *abstime;
209 		tm_p = &timeout;
210 		tm_size = sizeof(timeout);
211 	}
212 
213 	return _umtx_op_err(__DEVOLATILE(void *, mtx),
214 		shared ? UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id,
215 		(void *)tm_size, __DECONST(void *, tm_p));
216 }
217 
218 int
219 _thr_umtx_wake(volatile void *mtx, int nr_wakeup, int shared)
220 {
221 	return _umtx_op_err(__DEVOLATILE(void *, mtx), shared ? UMTX_OP_WAKE : UMTX_OP_WAKE_PRIVATE,
222 		nr_wakeup, 0, 0);
223 }
224 
225 void
226 _thr_ucond_init(struct ucond *cv)
227 {
228 	bzero(cv, sizeof(struct ucond));
229 }
230 
231 int
232 _thr_ucond_wait(struct ucond *cv, struct umutex *m,
233 	const struct timespec *timeout, int flags)
234 {
235 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
236 	    timeout->tv_nsec <= 0))) {
237 		struct pthread *curthread = _get_curthread();
238 		_thr_umutex_unlock(m, TID(curthread));
239                 return (ETIMEDOUT);
240 	}
241 	return _umtx_op_err(cv, UMTX_OP_CV_WAIT, flags,
242 		     m, __DECONST(void*, timeout));
243 }
244 
245 int
246 _thr_ucond_signal(struct ucond *cv)
247 {
248 	if (!cv->c_has_waiters)
249 		return (0);
250 	return _umtx_op_err(cv, UMTX_OP_CV_SIGNAL, 0, NULL, NULL);
251 }
252 
253 int
254 _thr_ucond_broadcast(struct ucond *cv)
255 {
256 	if (!cv->c_has_waiters)
257 		return (0);
258 	return _umtx_op_err(cv, UMTX_OP_CV_BROADCAST, 0, NULL, NULL);
259 }
260 
261 int
262 __thr_rwlock_rdlock(struct urwlock *rwlock, int flags,
263 	const struct timespec *tsp)
264 {
265 	struct _umtx_time timeout, *tm_p;
266 	size_t tm_size;
267 
268 	if (tsp == NULL) {
269 		tm_p = NULL;
270 		tm_size = 0;
271 	} else {
272 		timeout._timeout = *tsp;
273 		timeout._flags = UMTX_ABSTIME;
274 		timeout._clockid = CLOCK_REALTIME;
275 		tm_p = &timeout;
276 		tm_size = sizeof(timeout);
277 	}
278 	return _umtx_op_err(rwlock, UMTX_OP_RW_RDLOCK, flags, (void *)tm_size, tm_p);
279 }
280 
281 int
282 __thr_rwlock_wrlock(struct urwlock *rwlock, const struct timespec *tsp)
283 {
284 	struct _umtx_time timeout, *tm_p;
285 	size_t tm_size;
286 
287 	if (tsp == NULL) {
288 		tm_p = NULL;
289 		tm_size = 0;
290 	} else {
291 		timeout._timeout = *tsp;
292 		timeout._flags = UMTX_ABSTIME;
293 		timeout._clockid = CLOCK_REALTIME;
294 		tm_p = &timeout;
295 		tm_size = sizeof(timeout);
296 	}
297 	return _umtx_op_err(rwlock, UMTX_OP_RW_WRLOCK, 0, (void *)tm_size, tm_p);
298 }
299 
300 int
301 __thr_rwlock_unlock(struct urwlock *rwlock)
302 {
303 	return _umtx_op_err(rwlock, UMTX_OP_RW_UNLOCK, 0, NULL, NULL);
304 }
305 
306 void
307 _thr_rwl_rdlock(struct urwlock *rwlock)
308 {
309 	int ret;
310 
311 	for (;;) {
312 		if (_thr_rwlock_tryrdlock(rwlock, URWLOCK_PREFER_READER) == 0)
313 			return;
314 		ret = __thr_rwlock_rdlock(rwlock, URWLOCK_PREFER_READER, NULL);
315 		if (ret == 0)
316 			return;
317 		if (ret != EINTR)
318 			PANIC("rdlock error");
319 	}
320 }
321 
322 void
323 _thr_rwl_wrlock(struct urwlock *rwlock)
324 {
325 	int ret;
326 
327 	for (;;) {
328 		if (_thr_rwlock_trywrlock(rwlock) == 0)
329 			return;
330 		ret = __thr_rwlock_wrlock(rwlock, NULL);
331 		if (ret == 0)
332 			return;
333 		if (ret != EINTR)
334 			PANIC("wrlock error");
335 	}
336 }
337 
338 void
339 _thr_rwl_unlock(struct urwlock *rwlock)
340 {
341 	if (_thr_rwlock_unlock(rwlock))
342 		PANIC("unlock error");
343 }
344