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 _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; 47 48 void _thr_umutex_init(struct umutex *mtx) __hidden; 49 void _thr_urwlock_init(struct urwlock *rwl) __hidden; 50 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 check_unpaking) __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; 63 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; 69 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; 74 75 static inline int 76 _thr_umutex_trylock(struct umutex *mtx, uint32_t id) 77 { 78 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id)) 79 return (0); 80 if ((mtx->m_flags & UMUTEX_PRIO_PROTECT) == 0) 81 return (EBUSY); 82 return (__thr_umutex_trylock(mtx)); 83 } 84 85 static inline int 86 _thr_umutex_trylock2(struct umutex *mtx, uint32_t id) 87 { 88 if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id) != 0) 89 return (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)) 93 return (0); 94 return (EBUSY); 95 } 96 97 static inline int 98 _thr_umutex_lock(struct umutex *mtx, uint32_t id) 99 { 100 if (_thr_umutex_trylock2(mtx, id) == 0) 101 return (0); 102 return (__thr_umutex_lock(mtx, id)); 103 } 104 105 static inline int 106 _thr_umutex_lock_spin(struct umutex *mtx, uint32_t id) 107 { 108 if (_thr_umutex_trylock2(mtx, id) == 0) 109 return (0); 110 return (__thr_umutex_lock_spin(mtx, id)); 111 } 112 113 static inline int 114 _thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 115 const struct timespec *timeout) 116 { 117 if (_thr_umutex_trylock2(mtx, id) == 0) 118 return (0); 119 return (__thr_umutex_timedlock(mtx, id, timeout)); 120 } 121 122 static inline int 123 _thr_umutex_unlock(struct umutex *mtx, uint32_t id) 124 { 125 uint32_t flags = mtx->m_flags; 126 127 if ((flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) { 128 uint32_t owner; 129 do { 130 owner = mtx->m_owner; 131 if (__predict_false((owner & ~UMUTEX_CONTESTED) != id)) 132 return (EPERM); 133 } while (__predict_false(!atomic_cmpset_rel_32(&mtx->m_owner, 134 owner, UMUTEX_UNOWNED))); 135 if ((owner & UMUTEX_CONTESTED)) 136 (void)_umtx_op_err(mtx, UMTX_OP_MUTEX_WAKE2, flags, 0, 0); 137 return (0); 138 } 139 if (atomic_cmpset_rel_32(&mtx->m_owner, id, UMUTEX_UNOWNED)) 140 return (0); 141 return (__thr_umutex_unlock(mtx, id)); 142 } 143 144 static inline int 145 _thr_rwlock_tryrdlock(struct urwlock *rwlock, int flags) 146 { 147 int32_t state; 148 int32_t wrflags; 149 150 if (flags & URWLOCK_PREFER_READER || rwlock->rw_flags & URWLOCK_PREFER_READER) 151 wrflags = URWLOCK_WRITE_OWNER; 152 else 153 wrflags = URWLOCK_WRITE_OWNER | URWLOCK_WRITE_WAITERS; 154 state = rwlock->rw_state; 155 while (!(state & wrflags)) { 156 if (__predict_false(URWLOCK_READER_COUNT(state) == URWLOCK_MAX_READERS)) 157 return (EAGAIN); 158 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state + 1)) 159 return (0); 160 state = rwlock->rw_state; 161 } 162 163 return (EBUSY); 164 } 165 166 static inline int 167 _thr_rwlock_trywrlock(struct urwlock *rwlock) 168 { 169 int32_t state; 170 171 state = rwlock->rw_state; 172 while (!(state & URWLOCK_WRITE_OWNER) && URWLOCK_READER_COUNT(state) == 0) { 173 if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state | URWLOCK_WRITE_OWNER)) 174 return (0); 175 state = rwlock->rw_state; 176 } 177 178 return (EBUSY); 179 } 180 181 static inline int 182 _thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) 183 { 184 if (_thr_rwlock_tryrdlock(rwlock, flags) == 0) 185 return (0); 186 return (__thr_rwlock_rdlock(rwlock, flags, tsp)); 187 } 188 189 static inline int 190 _thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) 191 { 192 if (_thr_rwlock_trywrlock(rwlock) == 0) 193 return (0); 194 return (__thr_rwlock_wrlock(rwlock, tsp)); 195 } 196 197 static inline int 198 _thr_rwlock_unlock(struct urwlock *rwlock) 199 { 200 int32_t state; 201 202 state = rwlock->rw_state; 203 if (state & URWLOCK_WRITE_OWNER) { 204 if (atomic_cmpset_rel_32(&rwlock->rw_state, URWLOCK_WRITE_OWNER, 0)) 205 return (0); 206 } else { 207 for (;;) { 208 if (__predict_false(URWLOCK_READER_COUNT(state) == 0)) 209 return (EPERM); 210 if (!((state & (URWLOCK_WRITE_WAITERS | 211 URWLOCK_READ_WAITERS)) && 212 URWLOCK_READER_COUNT(state) == 1)) { 213 if (atomic_cmpset_rel_32(&rwlock->rw_state, 214 state, state-1)) 215 return (0); 216 state = rwlock->rw_state; 217 } else { 218 break; 219 } 220 } 221 } 222 return (__thr_rwlock_unlock(rwlock)); 223 } 224 #endif 225