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/*-
* Copyright (c) 2002, Jeffrey Roberson <jeff@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 unmodified, 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 ``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 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 _SYS_UMTX_H_
#define _SYS_UMTX_H_
#include <sys/limits.h>
/*
* See pthread_*
*/
#define UMTX_UNOWNED 0x0
#define UMTX_CONTESTED LONG_MIN
struct umtx {
void *u_owner; /* Owner of the mutex. */
};
/* op code for _umtx_op */
#define UMTX_OP_LOCK 0
#define UMTX_OP_UNLOCK 1
#define UMTX_OP_WAIT 2
#define UMTX_OP_WAKE 3
#ifndef _KERNEL
/*
* System calls for acquiring and releasing contested mutexes.
*/
/* deprecated becaues it can only use thread id */
int _umtx_lock(struct umtx *mtx);
/* deprecated becaues it can only use thread id */
int _umtx_unlock(struct umtx *mtx);
int _umtx_op(struct umtx *umtx, int op, long id, void *uaddr, void *uaddr2);
/*
* Standard api. Try uncontested acquire/release and asks the
* kernel to resolve failures.
*/
static __inline void
umtx_init(struct umtx *umtx)
{
umtx->u_owner = UMTX_UNOWNED;
}
static __inline long
umtx_owner(struct umtx *umtx)
{
return ((long)umtx->u_owner & ~LONG_MIN);
}
static __inline int
umtx_lock(struct umtx *umtx, long id)
{
if (atomic_cmpset_acq_ptr(&umtx->u_owner, (void *)UMTX_UNOWNED,
(void *)id) == 0)
if (_umtx_lock(umtx) == -1)
return (errno);
return (0);
}
static __inline int
umtx_trylock(struct umtx *umtx, long id)
{
if (atomic_cmpset_acq_ptr(&umtx->u_owner, (void *)UMTX_UNOWNED,
(void *)id) == 0)
return (EBUSY);
return (0);
}
static __inline int
umtx_timedlock(struct umtx *umtx, long id, const struct timespec *timeout)
{
if (atomic_cmpset_acq_ptr(&umtx->u_owner, (void *)UMTX_UNOWNED,
(void *)id) == 0)
if (_umtx_op(umtx, UMTX_OP_LOCK, id, 0, (void *)timeout) == -1)
return (errno);
return (0);
}
static __inline int
umtx_unlock(struct umtx *umtx, long id)
{
if (atomic_cmpset_rel_ptr(&umtx->u_owner, (void *)id,
(void *)UMTX_UNOWNED) == 0)
if (_umtx_unlock(umtx) == -1)
return (errno);
return (0);
}
static __inline int
umtx_wait(struct umtx *umtx, long id, const struct timespec *timeout)
{
if (_umtx_op(umtx, UMTX_OP_WAIT, id, 0, (void *)timeout) == -1)
return (errno);
return (0);
}
/* Wake threads waiting on a user address. */
static __inline int
umtx_wake(struct umtx *umtx, int nr_wakeup)
{
if (_umtx_op(umtx, UMTX_OP_WAKE, nr_wakeup, 0, 0) == -1)
return (errno);
return (0);
}
#else
struct umtx_q *umtxq_alloc(void);
void umtxq_free(struct umtx_q *);
struct thread;
int kern_umtx_wake(struct thread *td, void *uaddr, int n_wake);
#endif /* !_KERNEL */
#endif /* !_SYS_UMTX_H_ */
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