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_lock_spin(struct umutex *mtx, uint32_t id) __hidden; 40 int __thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 41 const struct timespec *timeout) __hidden; 42 int __thr_umutex_unlock(struct umutex *mtx, uint32_t id) __hidden; 43 int __thr_umutex_trylock(struct umutex *mtx) __hidden; 44 int __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling, 45 uint32_t *oldceiling) __hidden; 46 47 void _thr_umutex_init(struct umutex *mtx) __hidden; 48 void _thr_urwlock_init(struct urwlock *rwl) __hidden; 49 50 int _thr_umtx_wait(volatile long *mtx, long exp, 51 const struct timespec *timeout) __hidden; 52 int _thr_umtx_wait_uint(volatile u_int *mtx, u_int exp, 53 const struct timespec *timeout, int shared) __hidden; 54 int _thr_umtx_timedwait_uint(volatile u_int *mtx, u_int exp, int clockid, 55 const struct timespec *timeout, int shared) __hidden; 56 int _thr_umtx_wake(volatile void *mtx, int count, int shared) __hidden; 57 int _thr_ucond_wait(struct ucond *cv, struct umutex *m, 58 const struct timespec *timeout, int check_unpaking) __hidden; 59 void _thr_ucond_init(struct ucond *cv) __hidden; 60 int _thr_ucond_signal(struct ucond *cv) __hidden; 61 int _thr_ucond_broadcast(struct ucond *cv) __hidden; 62 63 int __thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) __hidden; 64 int __thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) __hidden; 65 int __thr_rwlock_unlock(struct urwlock *rwlock) __hidden; 66 67 /* Internal used only */ 68 void _thr_rwl_rdlock(struct urwlock *rwlock) __hidden; 69 void _thr_rwl_wrlock(struct urwlock *rwlock) __hidden; 70 void _thr_rwl_unlock(struct urwlock *rwlock) __hidden; 71 72 static inline int 73 _thr_umutex_trylock(struct umutex *mtx, uint32_t id) 74 { 75 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id)) 76 return (0); 77 if ((mtx->m_flags & UMUTEX_PRIO_PROTECT) == 0) 78 return (EBUSY); 79 return (__thr_umutex_trylock(mtx)); 80 } 81 82 static inline int 83 _thr_umutex_trylock2(struct umutex *mtx, uint32_t id) 84 { 85 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id) != 0) 86 return (0); 87 if ((uint32_t)mtx->m_owner == UMUTEX_CONTESTED && 88 __predict_true((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0)) 89 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_CONTESTED, id | UMUTEX_CONTESTED)) 90 return (0); 91 return (EBUSY); 92 } 93 94 static inline int 95 _thr_umutex_lock(struct umutex *mtx, uint32_t id) 96 { 97 if (_thr_umutex_trylock2(mtx, id) == 0) 98 return (0); 99 return (__thr_umutex_lock(mtx, id)); 100 } 101 102 static inline int 103 _thr_umutex_lock_spin(struct umutex *mtx, uint32_t id) 104 { 105 if (_thr_umutex_trylock2(mtx, id) == 0) 106 return (0); 107 return (__thr_umutex_lock_spin(mtx, id)); 108 } 109 110 static inline int 111 _thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 112 const struct timespec *timeout) 113 { 114 if (_thr_umutex_trylock2(mtx, id) == 0) 115 return (0); 116 return (__thr_umutex_timedlock(mtx, id, timeout)); 117 } 118 119 static inline int 120 _thr_umutex_unlock(struct umutex *mtx, uint32_t id) 121 { 122 if (atomic_cmpset_rel_32(&mtx->m_owner, id, UMUTEX_UNOWNED)) 123 return (0); 124 return (__thr_umutex_unlock(mtx, id)); 125 } 126 127 static inline int 128 _thr_rwlock_tryrdlock(struct urwlock *rwlock, int flags) 129 { 130 int32_t state; 131 int32_t wrflags; 132 133 if (flags & URWLOCK_PREFER_READER || rwlock->rw_flags & URWLOCK_PREFER_READER) 134 wrflags = URWLOCK_WRITE_OWNER; 135 else 136 wrflags = URWLOCK_WRITE_OWNER | URWLOCK_WRITE_WAITERS; 137 state = rwlock->rw_state; 138 while (!(state & wrflags)) { 139 if (__predict_false(URWLOCK_READER_COUNT(state) == URWLOCK_MAX_READERS)) 140 return (EAGAIN); 141 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state + 1)) 142 return (0); 143 state = rwlock->rw_state; 144 } 145 146 return (EBUSY); 147 } 148 149 static inline int 150 _thr_rwlock_trywrlock(struct urwlock *rwlock) 151 { 152 int32_t state; 153 154 state = rwlock->rw_state; 155 while (!(state & URWLOCK_WRITE_OWNER) && URWLOCK_READER_COUNT(state) == 0) { 156 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state | URWLOCK_WRITE_OWNER)) 157 return (0); 158 state = rwlock->rw_state; 159 } 160 161 return (EBUSY); 162 } 163 164 static inline int 165 _thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) 166 { 167 if (_thr_rwlock_tryrdlock(rwlock, flags) == 0) 168 return (0); 169 return (__thr_rwlock_rdlock(rwlock, flags, tsp)); 170 } 171 172 static inline int 173 _thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) 174 { 175 if (_thr_rwlock_trywrlock(rwlock) == 0) 176 return (0); 177 return (__thr_rwlock_wrlock(rwlock, tsp)); 178 } 179 180 static inline int 181 _thr_rwlock_unlock(struct urwlock *rwlock) 182 { 183 int32_t state; 184 185 state = rwlock->rw_state; 186 if (state & URWLOCK_WRITE_OWNER) { 187 if (atomic_cmpset_rel_32(&rwlock->rw_state, URWLOCK_WRITE_OWNER, 0)) 188 return (0); 189 } else { 190 for (;;) { 191 if (__predict_false(URWLOCK_READER_COUNT(state) == 0)) 192 return (EPERM); 193 if (!((state & (URWLOCK_WRITE_WAITERS | 194 URWLOCK_READ_WAITERS)) && 195 URWLOCK_READER_COUNT(state) == 1)) { 196 if (atomic_cmpset_rel_32(&rwlock->rw_state, 197 state, state-1)) 198 return (0); 199 state = rwlock->rw_state; 200 } else { 201 break; 202 } 203 } 204 } 205 return (__thr_rwlock_unlock(rwlock)); 206 } 207 #endif 208