thr_umtx.h revision 197445
1144518Sdavidxu/*- 2144518Sdavidxu * Copyright (c) 2005 David Xu <davidxu@freebsd.org> 3144518Sdavidxu * All rights reserved. 4144518Sdavidxu * 5144518Sdavidxu * Redistribution and use in source and binary forms, with or without 6144518Sdavidxu * modification, are permitted provided that the following conditions 7144518Sdavidxu * are met: 8144518Sdavidxu * 1. Redistributions of source code must retain the above copyright 9144518Sdavidxu * notice, this list of conditions and the following disclaimer. 10144518Sdavidxu * 2. Redistributions in binary form must reproduce the above copyright 11144518Sdavidxu * notice, this list of conditions and the following disclaimer in the 12144518Sdavidxu * documentation and/or other materials provided with the distribution. 13144518Sdavidxu * 14144518Sdavidxu * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15144518Sdavidxu * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16144518Sdavidxu * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17144518Sdavidxu * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18144518Sdavidxu * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19144518Sdavidxu * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20144518Sdavidxu * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21144518Sdavidxu * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22144518Sdavidxu * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23144518Sdavidxu * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24144518Sdavidxu * SUCH DAMAGE. 25144518Sdavidxu * 26144518Sdavidxu * $FreeBSD: head/lib/libthr/thread/thr_umtx.h 197445 2009-09-23 21:38:57Z attilio $ 27144518Sdavidxu */ 28144518Sdavidxu 29144518Sdavidxu#ifndef _THR_FBSD_UMTX_H_ 30144518Sdavidxu#define _THR_FBSD_UMTX_H_ 31144518Sdavidxu 32162061Sdavidxu#include <strings.h> 33144518Sdavidxu#include <sys/umtx.h> 34144518Sdavidxu 35173801Sdavidxu#define DEFAULT_UMUTEX {0,0, {0,0},{0,0,0,0}} 36162061Sdavidxu 37179970Sdavidxuint __thr_umutex_lock(struct umutex *mtx, uint32_t id) __hidden; 38179970Sdavidxuint __thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 39161680Sdavidxu const struct timespec *timeout) __hidden; 40179970Sdavidxuint __thr_umutex_unlock(struct umutex *mtx, uint32_t id) __hidden; 41163334Sdavidxuint __thr_umutex_trylock(struct umutex *mtx) __hidden; 42161680Sdavidxuint __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling, 43161680Sdavidxu uint32_t *oldceiling) __hidden; 44161680Sdavidxu 45163334Sdavidxuvoid _thr_umutex_init(struct umutex *mtx) __hidden; 46173801Sdavidxuint _thr_umtx_wait(volatile long *mtx, long exp, 47162061Sdavidxu const struct timespec *timeout) __hidden; 48173801Sdavidxuint _thr_umtx_wait_uint(volatile u_int *mtx, u_int exp, 49178647Sdavidxu const struct timespec *timeout, int shared) __hidden; 50178647Sdavidxuint _thr_umtx_wake(volatile void *mtx, int count, int shared) __hidden; 51164877Sdavidxuint _thr_ucond_wait(struct ucond *cv, struct umutex *m, 52164902Sdavidxu const struct timespec *timeout, int check_unpaking) __hidden; 53164902Sdavidxuvoid _thr_ucond_init(struct ucond *cv) __hidden; 54164902Sdavidxuint _thr_ucond_signal(struct ucond *cv) __hidden; 55164902Sdavidxuint _thr_ucond_broadcast(struct ucond *cv) __hidden; 56162061Sdavidxu 57177850Sdavidxuint __thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) __hidden; 58177850Sdavidxuint __thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) __hidden; 59177850Sdavidxuint __thr_rwlock_unlock(struct urwlock *rwlock) __hidden; 60177850Sdavidxu 61144518Sdavidxustatic inline int 62161680Sdavidxu_thr_umutex_trylock(struct umutex *mtx, uint32_t id) 63161680Sdavidxu{ 64161680Sdavidxu if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id)) 65161680Sdavidxu return (0); 66161680Sdavidxu if ((mtx->m_flags & UMUTEX_PRIO_PROTECT) == 0) 67161680Sdavidxu return (EBUSY); 68163334Sdavidxu return (__thr_umutex_trylock(mtx)); 69161680Sdavidxu} 70161680Sdavidxu 71161680Sdavidxustatic inline int 72165206Sdavidxu_thr_umutex_trylock2(struct umutex *mtx, uint32_t id) 73165206Sdavidxu{ 74179970Sdavidxu if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id) != 0) 75165206Sdavidxu return (0); 76179970Sdavidxu if ((uint32_t)mtx->m_owner == UMUTEX_CONTESTED && 77179970Sdavidxu __predict_true((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0)) 78179970Sdavidxu if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_CONTESTED, id | UMUTEX_CONTESTED)) 79179970Sdavidxu return (0); 80165206Sdavidxu return (EBUSY); 81165206Sdavidxu} 82165206Sdavidxu 83165206Sdavidxustatic inline int 84161680Sdavidxu_thr_umutex_lock(struct umutex *mtx, uint32_t id) 85161680Sdavidxu{ 86179970Sdavidxu if (_thr_umutex_trylock2(mtx, id) == 0) 87161680Sdavidxu return (0); 88179970Sdavidxu return (__thr_umutex_lock(mtx, id)); 89161680Sdavidxu} 90161680Sdavidxu 91161680Sdavidxustatic inline int 92161680Sdavidxu_thr_umutex_timedlock(struct umutex *mtx, uint32_t id, 93161680Sdavidxu const struct timespec *timeout) 94161680Sdavidxu{ 95179970Sdavidxu if (_thr_umutex_trylock2(mtx, id) == 0) 96161680Sdavidxu return (0); 97179970Sdavidxu return (__thr_umutex_timedlock(mtx, id, timeout)); 98161680Sdavidxu} 99161680Sdavidxu 100161680Sdavidxustatic inline int 101161680Sdavidxu_thr_umutex_unlock(struct umutex *mtx, uint32_t id) 102161680Sdavidxu{ 103161680Sdavidxu if (atomic_cmpset_rel_32(&mtx->m_owner, id, UMUTEX_UNOWNED)) 104161680Sdavidxu return (0); 105179970Sdavidxu return (__thr_umutex_unlock(mtx, id)); 106161680Sdavidxu} 107161680Sdavidxu 108177850Sdavidxustatic inline int 109177850Sdavidxu_thr_rwlock_tryrdlock(struct urwlock *rwlock, int flags) 110177850Sdavidxu{ 111177850Sdavidxu int32_t state; 112177850Sdavidxu int32_t wrflags; 113177850Sdavidxu 114177850Sdavidxu if (flags & URWLOCK_PREFER_READER || rwlock->rw_flags & URWLOCK_PREFER_READER) 115177850Sdavidxu wrflags = URWLOCK_WRITE_OWNER; 116177850Sdavidxu else 117177850Sdavidxu wrflags = URWLOCK_WRITE_OWNER | URWLOCK_WRITE_WAITERS; 118177850Sdavidxu state = rwlock->rw_state; 119177850Sdavidxu while (!(state & wrflags)) { 120177850Sdavidxu if (__predict_false(URWLOCK_READER_COUNT(state) == URWLOCK_MAX_READERS)) 121177850Sdavidxu return (EAGAIN); 122177850Sdavidxu if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state + 1)) 123177850Sdavidxu return (0); 124177850Sdavidxu state = rwlock->rw_state; 125177850Sdavidxu } 126177850Sdavidxu 127177850Sdavidxu return (EBUSY); 128177850Sdavidxu} 129177850Sdavidxu 130177850Sdavidxustatic inline int 131177850Sdavidxu_thr_rwlock_trywrlock(struct urwlock *rwlock) 132177850Sdavidxu{ 133177850Sdavidxu int32_t state; 134177850Sdavidxu 135177850Sdavidxu state = rwlock->rw_state; 136177850Sdavidxu while (!(state & URWLOCK_WRITE_OWNER) && URWLOCK_READER_COUNT(state) == 0) { 137177850Sdavidxu if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state | URWLOCK_WRITE_OWNER)) 138177850Sdavidxu return (0); 139177850Sdavidxu state = rwlock->rw_state; 140177850Sdavidxu } 141177850Sdavidxu 142177850Sdavidxu return (EBUSY); 143177850Sdavidxu} 144177850Sdavidxu 145177850Sdavidxustatic inline int 146177850Sdavidxu_thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) 147177850Sdavidxu{ 148177850Sdavidxu if (_thr_rwlock_tryrdlock(rwlock, flags) == 0) 149177850Sdavidxu return (0); 150177850Sdavidxu return (__thr_rwlock_rdlock(rwlock, flags, tsp)); 151177850Sdavidxu} 152177850Sdavidxu 153177850Sdavidxustatic inline int 154177850Sdavidxu_thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) 155177850Sdavidxu{ 156177850Sdavidxu if (_thr_rwlock_trywrlock(rwlock) == 0) 157177850Sdavidxu return (0); 158177850Sdavidxu return (__thr_rwlock_wrlock(rwlock, tsp)); 159177850Sdavidxu} 160177850Sdavidxu 161177850Sdavidxustatic inline int 162177850Sdavidxu_thr_rwlock_unlock(struct urwlock *rwlock) 163177850Sdavidxu{ 164177850Sdavidxu int32_t state; 165177850Sdavidxu 166177850Sdavidxu state = rwlock->rw_state; 167177850Sdavidxu if (state & URWLOCK_WRITE_OWNER) { 168177850Sdavidxu if (atomic_cmpset_rel_32(&rwlock->rw_state, URWLOCK_WRITE_OWNER, 0)) 169177850Sdavidxu return (0); 170177850Sdavidxu } else { 171177850Sdavidxu for (;;) { 172177850Sdavidxu if (__predict_false(URWLOCK_READER_COUNT(state) == 0)) 173177850Sdavidxu return (EPERM); 174197445Sattilio if (!((state & (URWLOCK_WRITE_WAITERS | 175197445Sattilio URWLOCK_READ_WAITERS)) && 176197445Sattilio URWLOCK_READER_COUNT(state) == 1)) { 177197445Sattilio if (atomic_cmpset_rel_32(&rwlock->rw_state, 178197445Sattilio state, state-1)) 179177850Sdavidxu return (0); 180177850Sdavidxu state = rwlock->rw_state; 181177850Sdavidxu } else { 182177850Sdavidxu break; 183177850Sdavidxu } 184177850Sdavidxu } 185177850Sdavidxu } 186177850Sdavidxu return (__thr_rwlock_unlock(rwlock)); 187177850Sdavidxu} 188144518Sdavidxu#endif 189