2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #ifndef _THR_FBSD_UMTX_H_
30 #define _THR_FBSD_UMTX_H_
35 #define DEFAULT_UMUTEX {0,0,{0,0},{0,0,0,0}}
36 #define DEFAULT_URWLOCK {0,0,0,0,{0,0,0,0}}
38 int _umtx_op_err(void *, int op, u_long, void *, void *) __hidden;
39 int __thr_umutex_lock(struct umutex *mtx, uint32_t id) __hidden;
40 int __thr_umutex_lock_spin(struct umutex *mtx, uint32_t id) __hidden;
41 int __thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
42 const struct timespec *timeout) __hidden;
43 int __thr_umutex_unlock(struct umutex *mtx, uint32_t id) __hidden;
44 int __thr_umutex_trylock(struct umutex *mtx) __hidden;
45 int __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
46 uint32_t *oldceiling) __hidden;
48 void _thr_umutex_init(struct umutex *mtx) __hidden;
49 void _thr_urwlock_init(struct urwlock *rwl) __hidden;
51 int _thr_umtx_wait(volatile long *mtx, long exp,
52 const struct timespec *timeout) __hidden;
53 int _thr_umtx_wait_uint(volatile u_int *mtx, u_int exp,
54 const struct timespec *timeout, int shared) __hidden;
55 int _thr_umtx_timedwait_uint(volatile u_int *mtx, u_int exp, int clockid,
56 const struct timespec *timeout, int shared) __hidden;
57 int _thr_umtx_wake(volatile void *mtx, int count, int shared) __hidden;
58 int _thr_ucond_wait(struct ucond *cv, struct umutex *m,
59 const struct timespec *timeout, int flags) __hidden;
60 void _thr_ucond_init(struct ucond *cv) __hidden;
61 int _thr_ucond_signal(struct ucond *cv) __hidden;
62 int _thr_ucond_broadcast(struct ucond *cv) __hidden;
64 int __thr_rwlock_rdlock(struct urwlock *rwlock, int flags,
65 const struct timespec *tsp) __hidden;
66 int __thr_rwlock_wrlock(struct urwlock *rwlock,
67 const struct timespec *tsp) __hidden;
68 int __thr_rwlock_unlock(struct urwlock *rwlock) __hidden;
70 /* Internal used only */
71 void _thr_rwl_rdlock(struct urwlock *rwlock) __hidden;
72 void _thr_rwl_wrlock(struct urwlock *rwlock) __hidden;
73 void _thr_rwl_unlock(struct urwlock *rwlock) __hidden;
76 _thr_umutex_trylock(struct umutex *mtx, uint32_t id)
78 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id))
80 if ((mtx->m_flags & UMUTEX_PRIO_PROTECT) == 0)
82 return (__thr_umutex_trylock(mtx));
86 _thr_umutex_trylock2(struct umutex *mtx, uint32_t id)
88 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id) != 0)
90 if ((uint32_t)mtx->m_owner == UMUTEX_CONTESTED &&
91 __predict_true((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0))
92 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_CONTESTED, id | UMUTEX_CONTESTED))
98 _thr_umutex_lock(struct umutex *mtx, uint32_t id)
100 if (_thr_umutex_trylock2(mtx, id) == 0)
102 return (__thr_umutex_lock(mtx, id));
106 _thr_umutex_lock_spin(struct umutex *mtx, uint32_t id)
108 if (_thr_umutex_trylock2(mtx, id) == 0)
110 return (__thr_umutex_lock_spin(mtx, id));
114 _thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
115 const struct timespec *timeout)
117 if (_thr_umutex_trylock2(mtx, id) == 0)
119 return (__thr_umutex_timedlock(mtx, id, timeout));
123 _thr_umutex_unlock2(struct umutex *mtx, uint32_t id, int *defer)
125 uint32_t flags = mtx->m_flags;
127 if ((flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
130 owner = mtx->m_owner;
131 if (__predict_false((owner & ~UMUTEX_CONTESTED) != id))
133 } while (__predict_false(!atomic_cmpset_rel_32(&mtx->m_owner,
134 owner, UMUTEX_UNOWNED)));
135 if ((owner & UMUTEX_CONTESTED)) {
137 (void)_umtx_op_err(mtx, UMTX_OP_MUTEX_WAKE2, flags, 0, 0);
143 if (atomic_cmpset_rel_32(&mtx->m_owner, id, UMUTEX_UNOWNED))
145 return (__thr_umutex_unlock(mtx, id));
149 _thr_umutex_unlock(struct umutex *mtx, uint32_t id)
151 return _thr_umutex_unlock2(mtx, id, NULL);
155 _thr_rwlock_tryrdlock(struct urwlock *rwlock, int flags)
160 if (flags & URWLOCK_PREFER_READER || rwlock->rw_flags & URWLOCK_PREFER_READER)
161 wrflags = URWLOCK_WRITE_OWNER;
163 wrflags = URWLOCK_WRITE_OWNER | URWLOCK_WRITE_WAITERS;
164 state = rwlock->rw_state;
165 while (!(state & wrflags)) {
166 if (__predict_false(URWLOCK_READER_COUNT(state) == URWLOCK_MAX_READERS))
168 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state + 1))
170 state = rwlock->rw_state;
177 _thr_rwlock_trywrlock(struct urwlock *rwlock)
181 state = rwlock->rw_state;
182 while (!(state & URWLOCK_WRITE_OWNER) && URWLOCK_READER_COUNT(state) == 0) {
183 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state | URWLOCK_WRITE_OWNER))
185 state = rwlock->rw_state;
192 _thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp)
194 if (_thr_rwlock_tryrdlock(rwlock, flags) == 0)
196 return (__thr_rwlock_rdlock(rwlock, flags, tsp));
200 _thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp)
202 if (_thr_rwlock_trywrlock(rwlock) == 0)
204 return (__thr_rwlock_wrlock(rwlock, tsp));
208 _thr_rwlock_unlock(struct urwlock *rwlock)
212 state = rwlock->rw_state;
213 if (state & URWLOCK_WRITE_OWNER) {
214 if (atomic_cmpset_rel_32(&rwlock->rw_state, URWLOCK_WRITE_OWNER, 0))
218 if (__predict_false(URWLOCK_READER_COUNT(state) == 0))
220 if (!((state & (URWLOCK_WRITE_WAITERS |
221 URWLOCK_READ_WAITERS)) &&
222 URWLOCK_READER_COUNT(state) == 1)) {
223 if (atomic_cmpset_rel_32(&rwlock->rw_state,
226 state = rwlock->rw_state;
232 return (__thr_rwlock_unlock(rwlock));