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 #define DEFAULT_URWLOCK {0,0,0,0,{0,0,0,0}} 37 38 int __thr_umutex_lock(struct umutex *mtx, uint32_t id) __hidden; 39 int __thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 40 const struct timespec *timeout) __hidden; 41 int __thr_umutex_unlock(struct umutex *mtx, uint32_t id) __hidden; 42 int __thr_umutex_trylock(struct umutex *mtx) __hidden; 43 int __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling, 44 uint32_t *oldceiling) __hidden; 45 46 void _thr_umutex_init(struct umutex *mtx) __hidden; 47 void _thr_urwlock_init(struct urwlock *rwl) __hidden; 48 49 int _thr_umtx_wait(volatile long *mtx, long exp, 50 const struct timespec *timeout) __hidden; 51 int _thr_umtx_wait_uint(volatile u_int *mtx, u_int exp, 52 const struct timespec *timeout, int shared) __hidden; 53 int _thr_umtx_wake(volatile void *mtx, int count, int shared) __hidden; 54 int _thr_ucond_wait(struct ucond *cv, struct umutex *m, 55 const struct timespec *timeout, int check_unpaking) __hidden; 56 void _thr_ucond_init(struct ucond *cv) __hidden; 57 int _thr_ucond_signal(struct ucond *cv) __hidden; 58 int _thr_ucond_broadcast(struct ucond *cv) __hidden; 59 60 int __thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) __hidden; 61 int __thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) __hidden; 62 int __thr_rwlock_unlock(struct urwlock *rwlock) __hidden; 63 64 /* Internal used only */ 65 void _thr_rwl_rdlock(struct urwlock *rwlock) __hidden; 66 void _thr_rwl_wrlock(struct urwlock *rwlock) __hidden; 67 void _thr_rwl_unlock(struct urwlock *rwlock) __hidden; 68 69 static inline int 70 _thr_umutex_trylock(struct umutex *mtx, uint32_t id) 71 { 72 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id)) 73 return (0); 74 if ((mtx->m_flags & UMUTEX_PRIO_PROTECT) == 0) 75 return (EBUSY); 76 return (__thr_umutex_trylock(mtx)); 77 } 78 79 static inline int 80 _thr_umutex_trylock2(struct umutex *mtx, uint32_t id) 81 { 82 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id) != 0) 83 return (0); 84 if ((uint32_t)mtx->m_owner == UMUTEX_CONTESTED && 85 __predict_true((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0)) 86 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_CONTESTED, id | UMUTEX_CONTESTED)) 87 return (0); 88 return (EBUSY); 89 } 90 91 static inline int 92 _thr_umutex_lock(struct umutex *mtx, uint32_t id) 93 { 94 if (_thr_umutex_trylock2(mtx, id) == 0) 95 return (0); 96 return (__thr_umutex_lock(mtx, id)); 97 } 98 99 static inline int 100 _thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 101 const struct timespec *timeout) 102 { 103 if (_thr_umutex_trylock2(mtx, id) == 0) 104 return (0); 105 return (__thr_umutex_timedlock(mtx, id, timeout)); 106 } 107 108 static inline int 109 _thr_umutex_unlock(struct umutex *mtx, uint32_t id) 110 { 111 if (atomic_cmpset_rel_32(&mtx->m_owner, id, UMUTEX_UNOWNED)) 112 return (0); 113 return (__thr_umutex_unlock(mtx, id)); 114 } 115 116 static inline int 117 _thr_rwlock_tryrdlock(struct urwlock *rwlock, int flags) 118 { 119 int32_t state; 120 int32_t wrflags; 121 122 if (flags & URWLOCK_PREFER_READER || rwlock->rw_flags & URWLOCK_PREFER_READER) 123 wrflags = URWLOCK_WRITE_OWNER; 124 else 125 wrflags = URWLOCK_WRITE_OWNER | URWLOCK_WRITE_WAITERS; 126 state = rwlock->rw_state; 127 while (!(state & wrflags)) { 128 if (__predict_false(URWLOCK_READER_COUNT(state) == URWLOCK_MAX_READERS)) 129 return (EAGAIN); 130 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state + 1)) 131 return (0); 132 state = rwlock->rw_state; 133 } 134 135 return (EBUSY); 136 } 137 138 static inline int 139 _thr_rwlock_trywrlock(struct urwlock *rwlock) 140 { 141 int32_t state; 142 143 state = rwlock->rw_state; 144 while (!(state & URWLOCK_WRITE_OWNER) && URWLOCK_READER_COUNT(state) == 0) { 145 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state | URWLOCK_WRITE_OWNER)) 146 return (0); 147 state = rwlock->rw_state; 148 } 149 150 return (EBUSY); 151 } 152 153 static inline int 154 _thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) 155 { 156 if (_thr_rwlock_tryrdlock(rwlock, flags) == 0) 157 return (0); 158 return (__thr_rwlock_rdlock(rwlock, flags, tsp)); 159 } 160 161 static inline int 162 _thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) 163 { 164 if (_thr_rwlock_trywrlock(rwlock) == 0) 165 return (0); 166 return (__thr_rwlock_wrlock(rwlock, tsp)); 167 } 168 169 static inline int 170 _thr_rwlock_unlock(struct urwlock *rwlock) 171 { 172 int32_t state; 173 174 state = rwlock->rw_state; 175 if (state & URWLOCK_WRITE_OWNER) { 176 if (atomic_cmpset_rel_32(&rwlock->rw_state, URWLOCK_WRITE_OWNER, 0)) 177 return (0); 178 } else { 179 for (;;) { 180 if (__predict_false(URWLOCK_READER_COUNT(state) == 0)) 181 return (EPERM); 182 if (!((state & (URWLOCK_WRITE_WAITERS | 183 URWLOCK_READ_WAITERS)) && 184 URWLOCK_READER_COUNT(state) == 1)) { 185 if (atomic_cmpset_rel_32(&rwlock->rw_state, 186 state, state-1)) 187 return (0); 188 state = rwlock->rw_state; 189 } else { 190 break; 191 } 192 } 193 } 194 return (__thr_rwlock_unlock(rwlock)); 195 } 196 #endif 197