154 lines
4.1 KiB
C
154 lines
4.1 KiB
C
/*-
|
|
* 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));
|
|
}
|