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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2003 David Xu <davidxu@freebsd.org>
* Copyright (c) 2016 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <errno.h>
#include <stdlib.h>
#include <pthread.h>
#include "un-namespace.h"
#include "thr_private.h"
_Static_assert(sizeof(struct pthread_spinlock) <= PAGE_SIZE,
"pthread_spinlock is too large for off-page");
#define SPIN_COUNT 100000
__weak_reference(_pthread_spin_init, pthread_spin_init);
__weak_reference(_pthread_spin_destroy, pthread_spin_destroy);
__weak_reference(_pthread_spin_trylock, pthread_spin_trylock);
__weak_reference(_pthread_spin_lock, pthread_spin_lock);
__weak_reference(_pthread_spin_unlock, pthread_spin_unlock);
int
_pthread_spin_init(pthread_spinlock_t *lock, int pshared)
{
struct pthread_spinlock *lck;
if (lock == NULL)
return (EINVAL);
if (pshared == PTHREAD_PROCESS_PRIVATE) {
lck = malloc(sizeof(struct pthread_spinlock));
if (lck == NULL)
return (ENOMEM);
*lock = lck;
} else if (pshared == PTHREAD_PROCESS_SHARED) {
lck = __thr_pshared_offpage(lock, 1);
if (lck == NULL)
return (EFAULT);
*lock = THR_PSHARED_PTR;
} else {
return (EINVAL);
}
_thr_umutex_init(&lck->s_lock);
return (0);
}
int
_pthread_spin_destroy(pthread_spinlock_t *lock)
{
void *l;
int ret;
if (lock == NULL || *lock == NULL) {
ret = EINVAL;
} else if (*lock == THR_PSHARED_PTR) {
l = __thr_pshared_offpage(lock, 0);
if (l != NULL)
__thr_pshared_destroy(l);
ret = 0;
} else {
free(*lock);
*lock = NULL;
ret = 0;
}
return (ret);
}
int
_pthread_spin_trylock(pthread_spinlock_t *lock)
{
struct pthread_spinlock *lck;
if (lock == NULL || *lock == NULL)
return (EINVAL);
lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
if (lck == NULL)
return (EINVAL);
return (THR_UMUTEX_TRYLOCK(_get_curthread(), &lck->s_lock));
}
int
_pthread_spin_lock(pthread_spinlock_t *lock)
{
struct pthread *curthread;
struct pthread_spinlock *lck;
int count;
if (lock == NULL)
return (EINVAL);
lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
if (lck == NULL)
return (EINVAL);
curthread = _get_curthread();
count = SPIN_COUNT;
while (THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock) != 0) {
while (lck->s_lock.m_owner) {
if (!_thr_is_smp) {
_pthread_yield();
} else {
CPU_SPINWAIT;
if (--count <= 0) {
count = SPIN_COUNT;
_pthread_yield();
}
}
}
}
return (0);
}
int
_pthread_spin_unlock(pthread_spinlock_t *lock)
{
struct pthread_spinlock *lck;
if (lock == NULL)
return (EINVAL);
lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
if (lck == NULL)
return (EINVAL);
return (THR_UMUTEX_UNLOCK(_get_curthread(), &lck->s_lock));
}
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