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/* $OpenBSD: rthread_spin_lock.c,v 1.2 2012/05/06 10:01:18 pirofti Exp $ */
/*
* Copyright (c) 2012 Paul Irofti <pirofti@openbsd.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <errno.h>
#include <stdlib.h>
#include <pthread.h>
#include "rthread.h"
int
pthread_spin_init(pthread_spinlock_t *lock, int pshared)
{
pthread_spinlock_t l = NULL;
if (lock == NULL)
return (EINVAL);
if (pshared != PTHREAD_PROCESS_PRIVATE)
return (ENOTSUP);
l = calloc(1, sizeof *l);
if (l == NULL)
return (ENOMEM);
l->lock = _SPINLOCK_UNLOCKED;
*lock = l;
return (0);
}
int
pthread_spin_destroy(pthread_spinlock_t *lock)
{
if (lock == NULL || *lock == NULL)
return (EINVAL);
if ((*lock)->owner != NULL)
return (EBUSY);
free(*lock);
*lock = NULL;
return (0);
}
int
pthread_spin_trylock(pthread_spinlock_t *lock)
{
pthread_t self = pthread_self();
pthread_spinlock_t l;
if (lock == NULL || *lock == NULL)
return (EINVAL);
l = *lock;
if (l->owner == self)
return (EDEADLK);
if (_atomic_lock(&l->lock))
return (EBUSY);
l->owner = self;
return (0);
}
int
pthread_spin_lock(pthread_spinlock_t *lock)
{
pthread_t self = pthread_self();
pthread_spinlock_t l;
if (lock == NULL || *lock == NULL)
return (EINVAL);
l = *lock;
if (l->owner == self)
return (EDEADLK);
_spinlock(&l->lock);
l->owner = self;
return (0);
}
int
pthread_spin_unlock(pthread_spinlock_t *lock)
{
pthread_t self = pthread_self();
pthread_spinlock_t l;
if (lock == NULL || *lock == NULL)
return (EINVAL);
l = *lock;
if (l->owner != self)
return (EPERM);
l->owner = NULL;
_spinunlock(&l->lock);
return (0);
}
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