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: stable/10/lib/libthr/thread/thr_umtx.c 294639 2016-01-23 20:49:52Z vangyzen $
27 *
28 */
29
30 #include "thr_private.h"
31 #include "thr_umtx.h"
32
33 #ifndef HAS__UMTX_OP_ERR
_umtx_op_err(void * obj,int op,u_long val,void * uaddr,void * uaddr2)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
_thr_umutex_init(struct umutex * mtx)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
_thr_urwlock_init(struct urwlock * rwl)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
__thr_umutex_lock(struct umutex * mtx,uint32_t id)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
__thr_umutex_lock_spin(struct umutex * mtx,uint32_t id)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
__thr_umutex_timedlock(struct umutex * mtx,uint32_t id,const struct timespec * abstime)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
__thr_umutex_unlock(struct umutex * mtx,uint32_t id)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
__thr_umutex_trylock(struct umutex * mtx)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
__thr_umutex_set_ceiling(struct umutex * mtx,uint32_t ceiling,uint32_t * oldceiling)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
_thr_umtx_wait(volatile long * mtx,long id,const struct timespec * timeout)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
_thr_umtx_wait_uint(volatile u_int * mtx,u_int id,const struct timespec * timeout,int shared)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
_thr_umtx_timedwait_uint(volatile u_int * mtx,u_int id,int clockid,const struct timespec * abstime,int shared)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
_thr_umtx_wake(volatile void * mtx,int nr_wakeup,int shared)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
_thr_ucond_init(struct ucond * cv)226 _thr_ucond_init(struct ucond *cv)
227 {
228 bzero(cv, sizeof(struct ucond));
229 }
230
231 int
_thr_ucond_wait(struct ucond * cv,struct umutex * m,const struct timespec * timeout,int flags)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
_thr_ucond_signal(struct ucond * cv)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
_thr_ucond_broadcast(struct ucond * cv)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
__thr_rwlock_rdlock(struct urwlock * rwlock,int flags,const struct timespec * tsp)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
__thr_rwlock_wrlock(struct urwlock * rwlock,const struct timespec * tsp)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
__thr_rwlock_unlock(struct urwlock * rwlock)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
_thr_rwl_rdlock(struct urwlock * rwlock)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
_thr_rwl_wrlock(struct urwlock * rwlock)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
_thr_rwl_unlock(struct urwlock * rwlock)339 _thr_rwl_unlock(struct urwlock *rwlock)
340 {
341 if (_thr_rwlock_unlock(rwlock))
342 PANIC("unlock error");
343 }
344