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/*-
* Copyright (c) 2005 David Xu <davidxu@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _THR_FBSD_UMTX_H_
#define _THR_FBSD_UMTX_H_
#include <strings.h>
#include <sys/umtx.h>
#define DEFAULT_UMUTEX {0,0, {0,0},{0,0,0,0}}
int __thr_umutex_lock(struct umutex *mtx, uint32_t id) __hidden;
int __thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
const struct timespec *timeout) __hidden;
int __thr_umutex_unlock(struct umutex *mtx, uint32_t id) __hidden;
int __thr_umutex_trylock(struct umutex *mtx) __hidden;
int __thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
uint32_t *oldceiling) __hidden;
void _thr_umutex_init(struct umutex *mtx) __hidden;
int _thr_umtx_wait(volatile long *mtx, long exp,
const struct timespec *timeout) __hidden;
int _thr_umtx_wait_uint(volatile u_int *mtx, u_int exp,
const struct timespec *timeout, int shared) __hidden;
int _thr_umtx_wake(volatile void *mtx, int count, int shared) __hidden;
int _thr_ucond_wait(struct ucond *cv, struct umutex *m,
const struct timespec *timeout, int check_unpaking) __hidden;
void _thr_ucond_init(struct ucond *cv) __hidden;
int _thr_ucond_signal(struct ucond *cv) __hidden;
int _thr_ucond_broadcast(struct ucond *cv) __hidden;
int __thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp) __hidden;
int __thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp) __hidden;
int __thr_rwlock_unlock(struct urwlock *rwlock) __hidden;
static inline int
_thr_umutex_trylock(struct umutex *mtx, uint32_t id)
{
if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id))
return (0);
if ((mtx->m_flags & UMUTEX_PRIO_PROTECT) == 0)
return (EBUSY);
return (__thr_umutex_trylock(mtx));
}
static inline int
_thr_umutex_trylock2(struct umutex *mtx, uint32_t id)
{
if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_UNOWNED, id) != 0)
return (0);
if ((uint32_t)mtx->m_owner == UMUTEX_CONTESTED &&
__predict_true((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0))
if (atomic_cmpset_acq_32(&mtx->m_owner, UMUTEX_CONTESTED, id | UMUTEX_CONTESTED))
return (0);
return (EBUSY);
}
static inline int
_thr_umutex_lock(struct umutex *mtx, uint32_t id)
{
if (_thr_umutex_trylock2(mtx, id) == 0)
return (0);
return (__thr_umutex_lock(mtx, id));
}
static inline int
_thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
const struct timespec *timeout)
{
if (_thr_umutex_trylock2(mtx, id) == 0)
return (0);
return (__thr_umutex_timedlock(mtx, id, timeout));
}
static inline int
_thr_umutex_unlock(struct umutex *mtx, uint32_t id)
{
if (atomic_cmpset_rel_32(&mtx->m_owner, id, UMUTEX_UNOWNED))
return (0);
return (__thr_umutex_unlock(mtx, id));
}
static inline int
_thr_rwlock_tryrdlock(struct urwlock *rwlock, int flags)
{
int32_t state;
int32_t wrflags;
if (flags & URWLOCK_PREFER_READER || rwlock->rw_flags & URWLOCK_PREFER_READER)
wrflags = URWLOCK_WRITE_OWNER;
else
wrflags = URWLOCK_WRITE_OWNER | URWLOCK_WRITE_WAITERS;
state = rwlock->rw_state;
while (!(state & wrflags)) {
if (__predict_false(URWLOCK_READER_COUNT(state) == URWLOCK_MAX_READERS))
return (EAGAIN);
if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state + 1))
return (0);
state = rwlock->rw_state;
}
return (EBUSY);
}
static inline int
_thr_rwlock_trywrlock(struct urwlock *rwlock)
{
int32_t state;
state = rwlock->rw_state;
while (!(state & URWLOCK_WRITE_OWNER) && URWLOCK_READER_COUNT(state) == 0) {
if (atomic_cmpset_acq_32(&rwlock->rw_state, state, state | URWLOCK_WRITE_OWNER))
return (0);
state = rwlock->rw_state;
}
return (EBUSY);
}
static inline int
_thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp)
{
if (_thr_rwlock_tryrdlock(rwlock, flags) == 0)
return (0);
return (__thr_rwlock_rdlock(rwlock, flags, tsp));
}
static inline int
_thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp)
{
if (_thr_rwlock_trywrlock(rwlock) == 0)
return (0);
return (__thr_rwlock_wrlock(rwlock, tsp));
}
static inline int
_thr_rwlock_unlock(struct urwlock *rwlock)
{
int32_t state;
state = rwlock->rw_state;
if (state & URWLOCK_WRITE_OWNER) {
if (atomic_cmpset_rel_32(&rwlock->rw_state, URWLOCK_WRITE_OWNER, 0))
return (0);
} else {
for (;;) {
if (__predict_false(URWLOCK_READER_COUNT(state) == 0))
return (EPERM);
if (!((state & (URWLOCK_WRITE_WAITERS |
URWLOCK_READ_WAITERS)) &&
URWLOCK_READER_COUNT(state) == 1)) {
if (atomic_cmpset_rel_32(&rwlock->rw_state,
state, state-1))
return (0);
state = rwlock->rw_state;
} else {
break;
}
}
}
return (__thr_rwlock_unlock(rwlock));
}
#endif
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