xref: /freebsd/lib/libthr/thread/thr_umtx.c (revision aa64588d28258aef88cc33b8043112e8856948d0)
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 int
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 
70 int
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 
112 int
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 
125 int
126 __thr_umutex_trylock(struct umutex *mtx)
127 {
128 	return _umtx_op_err(mtx, UMTX_OP_MUTEX_TRYLOCK, 0, 0, 0);
129 }
130 
131 int
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 
138 int
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 
148 int
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 
159 int
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 
166 void
167 _thr_ucond_init(struct ucond *cv)
168 {
169 	bzero(cv, sizeof(struct ucond));
170 }
171 
172 int
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 
187 int
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 
195 int
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 
203 int
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 
209 int
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 
215 int
216 __thr_rwlock_unlock(struct urwlock *rwlock)
217 {
218 	return _umtx_op_err(rwlock, UMTX_OP_RW_UNLOCK, 0, NULL, NULL);
219 }
220