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, 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. 13 * 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 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #ifndef _THR_FBSD_UMTX_H_ 30 #define _THR_FBSD_UMTX_H_ 31 32 #include <strings.h> 33 #include <sys/umtx.h> 34 35 #define DEFAULT_UMUTEX {0,0, {0,0},{0,0,0,0}} 36 37 int __thr_umutex_lock(struct umutex *mtx, uint32_t id) __hidden; 38 int __thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 39 const struct timespec *timeout) __hidden; 40 int __thr_umutex_unlock(struct umutex *mtx, uint32_t id) __hidden; 41 int __thr_umutex_trylock(struct umutex *mtx) __hidden; 42 int __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling, 43 uint32_t *oldceiling) __hidden; 44 45 void _thr_umutex_init(struct umutex *mtx) __hidden; 46 int _thr_umtx_wait(volatile long *mtx, long exp, 47 const struct timespec *timeout) __hidden; 48 int _thr_umtx_wait_uint(volatile u_int *mtx, u_int exp, 49 const struct timespec *timeout, int shared) __hidden; 50 int _thr_umtx_wake(volatile void *mtx, int count, int shared) __hidden; 51 int _thr_ucond_wait(struct ucond *cv, struct umutex *m, 52 const struct timespec *timeout, int check_unpaking) __hidden; 53 void _thr_ucond_init(struct ucond *cv) __hidden; 54 int _thr_ucond_signal(struct ucond *cv) __hidden; 55 int _thr_ucond_broadcast(struct ucond *cv) __hidden; 56 57 int __thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) __hidden; 58 int __thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) __hidden; 59 int __thr_rwlock_unlock(struct urwlock *rwlock) __hidden; 60 61 static inline int 62 _thr_umutex_trylock(struct umutex *mtx, uint32_t id) 63 { 64 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id)) 65 return (0); 66 if ((mtx->m_flags & UMUTEX_PRIO_PROTECT) == 0) 67 return (EBUSY); 68 return (__thr_umutex_trylock(mtx)); 69 } 70 71 static inline int 72 _thr_umutex_trylock2(struct umutex *mtx, uint32_t id) 73 { 74 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id) != 0) 75 return (0); 76 if ((uint32_t)mtx->m_owner == UMUTEX_CONTESTED && 77 __predict_true((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0)) 78 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_CONTESTED, id | UMUTEX_CONTESTED)) 79 return (0); 80 return (EBUSY); 81 } 82 83 static inline int 84 _thr_umutex_lock(struct umutex *mtx, uint32_t id) 85 { 86 if (_thr_umutex_trylock2(mtx, id) == 0) 87 return (0); 88 return (__thr_umutex_lock(mtx, id)); 89 } 90 91 static inline int 92 _thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 93 const struct timespec *timeout) 94 { 95 if (_thr_umutex_trylock2(mtx, id) == 0) 96 return (0); 97 return (__thr_umutex_timedlock(mtx, id, timeout)); 98 } 99 100 static inline int 101 _thr_umutex_unlock(struct umutex *mtx, uint32_t id) 102 { 103 if (atomic_cmpset_rel_32(&mtx->m_owner, id, UMUTEX_UNOWNED)) 104 return (0); 105 return (__thr_umutex_unlock(mtx, id)); 106 } 107 108 static inline int 109 _thr_rwlock_tryrdlock(struct urwlock *rwlock, int flags) 110 { 111 int32_t state; 112 int32_t wrflags; 113 114 if (flags & URWLOCK_PREFER_READER || rwlock->rw_flags & URWLOCK_PREFER_READER) 115 wrflags = URWLOCK_WRITE_OWNER; 116 else 117 wrflags = URWLOCK_WRITE_OWNER | URWLOCK_WRITE_WAITERS; 118 state = rwlock->rw_state; 119 while (!(state & wrflags)) { 120 if (__predict_false(URWLOCK_READER_COUNT(state) == URWLOCK_MAX_READERS)) 121 return (EAGAIN); 122 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state + 1)) 123 return (0); 124 state = rwlock->rw_state; 125 } 126 127 return (EBUSY); 128 } 129 130 static inline int 131 _thr_rwlock_trywrlock(struct urwlock *rwlock) 132 { 133 int32_t state; 134 135 state = rwlock->rw_state; 136 while (!(state & URWLOCK_WRITE_OWNER) && URWLOCK_READER_COUNT(state) == 0) { 137 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state | URWLOCK_WRITE_OWNER)) 138 return (0); 139 state = rwlock->rw_state; 140 } 141 142 return (EBUSY); 143 } 144 145 static inline int 146 _thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) 147 { 148 if (_thr_rwlock_tryrdlock(rwlock, flags) == 0) 149 return (0); 150 return (__thr_rwlock_rdlock(rwlock, flags, tsp)); 151 } 152 153 static inline int 154 _thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) 155 { 156 if (_thr_rwlock_trywrlock(rwlock) == 0) 157 return (0); 158 return (__thr_rwlock_wrlock(rwlock, tsp)); 159 } 160 161 static inline int 162 _thr_rwlock_unlock(struct urwlock *rwlock) 163 { 164 int32_t state; 165 166 state = rwlock->rw_state; 167 if (state & URWLOCK_WRITE_OWNER) { 168 if (atomic_cmpset_rel_32(&rwlock->rw_state, URWLOCK_WRITE_OWNER, 0)) 169 return (0); 170 } else { 171 for (;;) { 172 if (__predict_false(URWLOCK_READER_COUNT(state) == 0)) 173 return (EPERM); 174 if (!((state & URWLOCK_WRITE_WAITERS) && URWLOCK_READER_COUNT(state) == 1)) { 175 if (atomic_cmpset_rel_32(&rwlock->rw_state, state, state-1)) 176 return (0); 177 state = rwlock->rw_state; 178 } else { 179 break; 180 } 181 } 182 } 183 return (__thr_rwlock_unlock(rwlock)); 184 } 185 #endif 186