xref: /freebsd/lib/libthr/thread/thr_umtx.c (revision 7447ca0eb235974642312b9555caec00b57d8fc1)
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 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
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 
37 	if (_umtx_op(obj, op, val, uaddr, uaddr2) == -1)
38 		return (errno);
39 	return (0);
40 }
41 #endif
42 
43 void
44 _thr_umutex_init(struct umutex *mtx)
45 {
46 	static const struct umutex default_mtx = DEFAULT_UMUTEX;
47 
48 	*mtx = default_mtx;
49 }
50 
51 void
52 _thr_urwlock_init(struct urwlock *rwl)
53 {
54 	static const struct urwlock default_rwl = DEFAULT_URWLOCK;
55 
56 	*rwl = default_rwl;
57 }
58 
59 int
60 __thr_umutex_lock(struct umutex *mtx, uint32_t id)
61 {
62 	uint32_t owner;
63 
64 	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) != 0)
65 		return	(_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0));
66 
67 	for (;;) {
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 		if (owner == UMUTEX_RB_OWNERDEAD &&
73 		     atomic_cmpset_acq_32(&mtx->m_owner, owner,
74 		     id | UMUTEX_CONTESTED))
75 			return (EOWNERDEAD);
76 		if (owner == UMUTEX_RB_NOTRECOV)
77 			return (ENOTRECOVERABLE);
78 
79 		/* wait in kernel */
80 		_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
81 	}
82 }
83 
84 #define SPINLOOPS 1000
85 
86 int
87 __thr_umutex_lock_spin(struct umutex *mtx, uint32_t id)
88 {
89 	uint32_t owner;
90 	int count;
91 
92 	if (!_thr_is_smp)
93 		return (__thr_umutex_lock(mtx, id));
94 	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) != 0)
95 		return	(_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0));
96 
97 	for (;;) {
98 		count = SPINLOOPS;
99 		while (count--) {
100 			owner = mtx->m_owner;
101 			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
102 			    atomic_cmpset_acq_32(&mtx->m_owner, owner,
103 			    id | owner))
104 				return (0);
105 			if (__predict_false(owner == UMUTEX_RB_OWNERDEAD) &&
106 			    atomic_cmpset_acq_32(&mtx->m_owner, owner,
107 			    id | UMUTEX_CONTESTED))
108 				return (EOWNERDEAD);
109 			if (__predict_false(owner == UMUTEX_RB_NOTRECOV))
110 				return (ENOTRECOVERABLE);
111 			CPU_SPINWAIT;
112 		}
113 
114 		/* wait in kernel */
115 		_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
116 	}
117 }
118 
119 int
120 __thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
121 	const struct timespec *abstime)
122 {
123 	struct _umtx_time *tm_p, timeout;
124 	size_t tm_size;
125 	uint32_t owner;
126 	int ret;
127 
128 	if (abstime == NULL) {
129 		tm_p = NULL;
130 		tm_size = 0;
131 	} else {
132 		timeout._clockid = CLOCK_REALTIME;
133 		timeout._flags = UMTX_ABSTIME;
134 		timeout._timeout = *abstime;
135 		tm_p = &timeout;
136 		tm_size = sizeof(timeout);
137 	}
138 
139 	for (;;) {
140 		if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT |
141 		    UMUTEX_PRIO_INHERIT)) == 0) {
142 			/* try to lock it */
143 			owner = mtx->m_owner;
144 			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
145 			     atomic_cmpset_acq_32(&mtx->m_owner, owner,
146 			     id | owner))
147 				return (0);
148 			if (__predict_false(owner == UMUTEX_RB_OWNERDEAD) &&
149 			     atomic_cmpset_acq_32(&mtx->m_owner, owner,
150 			     id | UMUTEX_CONTESTED))
151 				return (EOWNERDEAD);
152 			if (__predict_false(owner == UMUTEX_RB_NOTRECOV))
153 				return (ENOTRECOVERABLE);
154 			/* wait in kernel */
155 			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0,
156 			    (void *)tm_size, __DECONST(void *, tm_p));
157 		} else {
158 			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0,
159 			    (void *)tm_size, __DECONST(void *, tm_p));
160 			if (ret == 0 || ret == EOWNERDEAD ||
161 			    ret == ENOTRECOVERABLE)
162 				break;
163 		}
164 		if (ret == ETIMEDOUT)
165 			break;
166 	}
167 	return (ret);
168 }
169 
170 int
171 __thr_umutex_unlock(struct umutex *mtx, uint32_t id)
172 {
173 
174 	return (_umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0));
175 }
176 
177 int
178 __thr_umutex_trylock(struct umutex *mtx)
179 {
180 
181 	return (_umtx_op_err(mtx, UMTX_OP_MUTEX_TRYLOCK, 0, 0, 0));
182 }
183 
184 int
185 __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
186     uint32_t *oldceiling)
187 {
188 
189 	return (_umtx_op_err(mtx, UMTX_OP_SET_CEILING, ceiling, oldceiling, 0));
190 }
191 
192 int
193 _thr_umtx_wait(volatile long *mtx, long id, const struct timespec *timeout)
194 {
195 
196 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
197 	    timeout->tv_nsec <= 0)))
198 		return (ETIMEDOUT);
199 	return (_umtx_op_err(__DEVOLATILE(void *, mtx), UMTX_OP_WAIT, id, 0,
200 	    __DECONST(void*, timeout)));
201 }
202 
203 int
204 _thr_umtx_wait_uint(volatile u_int *mtx, u_int id,
205     const struct timespec *timeout, int shared)
206 {
207 
208 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
209 	    timeout->tv_nsec <= 0)))
210 		return (ETIMEDOUT);
211 	return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
212 	    UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id, 0,
213 	    __DECONST(void*, timeout)));
214 }
215 
216 int
217 _thr_umtx_timedwait_uint(volatile u_int *mtx, u_int id, int clockid,
218     const struct timespec *abstime, int shared)
219 {
220 	struct _umtx_time *tm_p, timeout;
221 	size_t tm_size;
222 
223 	if (abstime == NULL) {
224 		tm_p = NULL;
225 		tm_size = 0;
226 	} else {
227 		timeout._clockid = clockid;
228 		timeout._flags = UMTX_ABSTIME;
229 		timeout._timeout = *abstime;
230 		tm_p = &timeout;
231 		tm_size = sizeof(timeout);
232 	}
233 
234 	return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
235 	    UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id,
236 	    (void *)tm_size, __DECONST(void *, tm_p)));
237 }
238 
239 int
240 _thr_umtx_wake(volatile void *mtx, int nr_wakeup, int shared)
241 {
242 
243 	return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
244 	    UMTX_OP_WAKE : UMTX_OP_WAKE_PRIVATE, nr_wakeup, 0, 0));
245 }
246 
247 void
248 _thr_ucond_init(struct ucond *cv)
249 {
250 
251 	bzero(cv, sizeof(struct ucond));
252 }
253 
254 int
255 _thr_ucond_wait(struct ucond *cv, struct umutex *m,
256 	const struct timespec *timeout, int flags)
257 {
258 	struct pthread *curthread;
259 
260 	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
261 	    timeout->tv_nsec <= 0))) {
262 		curthread = _get_curthread();
263 		_thr_umutex_unlock(m, TID(curthread));
264                 return (ETIMEDOUT);
265 	}
266 	return (_umtx_op_err(cv, UMTX_OP_CV_WAIT, flags, m,
267 	    __DECONST(void*, timeout)));
268 }
269 
270 int
271 _thr_ucond_signal(struct ucond *cv)
272 {
273 
274 	if (!cv->c_has_waiters)
275 		return (0);
276 	return (_umtx_op_err(cv, UMTX_OP_CV_SIGNAL, 0, NULL, NULL));
277 }
278 
279 int
280 _thr_ucond_broadcast(struct ucond *cv)
281 {
282 
283 	if (!cv->c_has_waiters)
284 		return (0);
285 	return (_umtx_op_err(cv, UMTX_OP_CV_BROADCAST, 0, NULL, NULL));
286 }
287 
288 int
289 __thr_rwlock_rdlock(struct urwlock *rwlock, int flags,
290 	const struct timespec *tsp)
291 {
292 	struct _umtx_time timeout, *tm_p;
293 	size_t tm_size;
294 
295 	if (tsp == NULL) {
296 		tm_p = NULL;
297 		tm_size = 0;
298 	} else {
299 		timeout._timeout = *tsp;
300 		timeout._flags = UMTX_ABSTIME;
301 		timeout._clockid = CLOCK_REALTIME;
302 		tm_p = &timeout;
303 		tm_size = sizeof(timeout);
304 	}
305 	return (_umtx_op_err(rwlock, UMTX_OP_RW_RDLOCK, flags,
306 	    (void *)tm_size, tm_p));
307 }
308 
309 int
310 __thr_rwlock_wrlock(struct urwlock *rwlock, const struct timespec *tsp)
311 {
312 	struct _umtx_time timeout, *tm_p;
313 	size_t tm_size;
314 
315 	if (tsp == NULL) {
316 		tm_p = NULL;
317 		tm_size = 0;
318 	} else {
319 		timeout._timeout = *tsp;
320 		timeout._flags = UMTX_ABSTIME;
321 		timeout._clockid = CLOCK_REALTIME;
322 		tm_p = &timeout;
323 		tm_size = sizeof(timeout);
324 	}
325 	return (_umtx_op_err(rwlock, UMTX_OP_RW_WRLOCK, 0, (void *)tm_size,
326 	    tm_p));
327 }
328 
329 int
330 __thr_rwlock_unlock(struct urwlock *rwlock)
331 {
332 
333 	return (_umtx_op_err(rwlock, UMTX_OP_RW_UNLOCK, 0, NULL, NULL));
334 }
335 
336 void
337 _thr_rwl_rdlock(struct urwlock *rwlock)
338 {
339 	int ret;
340 
341 	for (;;) {
342 		if (_thr_rwlock_tryrdlock(rwlock, URWLOCK_PREFER_READER) == 0)
343 			return;
344 		ret = __thr_rwlock_rdlock(rwlock, URWLOCK_PREFER_READER, NULL);
345 		if (ret == 0)
346 			return;
347 		if (ret != EINTR)
348 			PANIC("rdlock error");
349 	}
350 }
351 
352 void
353 _thr_rwl_wrlock(struct urwlock *rwlock)
354 {
355 	int ret;
356 
357 	for (;;) {
358 		if (_thr_rwlock_trywrlock(rwlock) == 0)
359 			return;
360 		ret = __thr_rwlock_wrlock(rwlock, NULL);
361 		if (ret == 0)
362 			return;
363 		if (ret != EINTR)
364 			PANIC("wrlock error");
365 	}
366 }
367 
368 void
369 _thr_rwl_unlock(struct urwlock *rwlock)
370 {
371 
372 	if (_thr_rwlock_unlock(rwlock))
373 		PANIC("unlock error");
374 }
375