freebsd-dev/lib/libpthread/thread/thr_pspinlock.c
Daniel Eischen e62165c8b0 Add compatibility symbol maps. libpthread (.so.1 and .so.2)
used LIBTHREAD_1_0 as its version definition, but now needs
to define its symbols in the same namespace used by libc.
The compatibility hooks allows you to use libraries and
binaries built and linked to libpthread before libc was
built with symbol versioning.  The shims can be removed if
libpthread is given a version bump.

Reviewed by:	davidxu
2006-03-13 00:59:51 +00:00

175 lines
4.2 KiB
C

/*-
* Copyright (c) 2003 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.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <errno.h>
#include <pthread.h>
#include <stdint.h>
#include <stdlib.h>
#include "atomic_ops.h"
#include "thr_private.h"
#define SPIN_COUNT 10000
LT10_COMPAT_PRIVATE(_pthread_spin_init);
LT10_COMPAT_DEFAULT(pthread_spin_init);
LT10_COMPAT_PRIVATE(_pthread_spin_destroy);
LT10_COMPAT_DEFAULT(pthread_spin_destroy);
LT10_COMPAT_PRIVATE(_pthread_spin_trylock);
LT10_COMPAT_DEFAULT(pthread_spin_trylock);
LT10_COMPAT_PRIVATE(_pthread_spin_lock);
LT10_COMPAT_DEFAULT(pthread_spin_lock);
LT10_COMPAT_PRIVATE(_pthread_spin_unlock);
LT10_COMPAT_DEFAULT(pthread_spin_unlock);
__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;
int ret;
if (lock == NULL || pshared != PTHREAD_PROCESS_PRIVATE)
ret = EINVAL;
else if ((lck = malloc(sizeof(struct pthread_spinlock))) == NULL)
ret = ENOMEM;
else {
lck->s_lock = 0;
lck->s_owner= NULL;
*lock = lck;
ret = 0;
}
return (ret);
}
int
_pthread_spin_destroy(pthread_spinlock_t *lock)
{
int ret;
if (lock == NULL || *lock == NULL)
ret = EINVAL;
else if ((*lock)->s_owner != NULL)
ret = EBUSY;
else {
free(*lock);
*lock = NULL;
ret = 0;
}
return (ret);
}
int
_pthread_spin_trylock(pthread_spinlock_t *lock)
{
struct pthread_spinlock *lck;
struct pthread *self = _pthread_self();
int oldval, ret;
if (lock == NULL || (lck = *lock) == NULL)
ret = EINVAL;
else if (lck->s_owner == self)
ret = EDEADLK;
else if (lck->s_lock != 0)
ret = EBUSY;
else {
atomic_swap_int((int *)&(lck)->s_lock, 1, &oldval);
if (oldval)
ret = EBUSY;
else {
lck->s_owner = _pthread_self();
ret = 0;
}
}
return (ret);
}
int
_pthread_spin_lock(pthread_spinlock_t *lock)
{
struct pthread_spinlock *lck;
struct pthread *self = _pthread_self();
int count, oldval, ret;
if (lock == NULL || (lck = *lock) == NULL)
ret = EINVAL;
else if (lck->s_owner == self)
ret = EDEADLK;
else {
do {
count = SPIN_COUNT;
while (lck->s_lock) {
#ifdef __i386__
/* tell cpu we are spinning */
__asm __volatile("pause");
#endif
if (--count <= 0) {
count = SPIN_COUNT;
_pthread_yield();
}
}
atomic_swap_int((int *)&(lck)->s_lock, 1, &oldval);
} while (oldval);
lck->s_owner = self;
ret = 0;
}
return (ret);
}
int
_pthread_spin_unlock(pthread_spinlock_t *lock)
{
struct pthread_spinlock *lck;
int ret;
if (lock == NULL || (lck = *lock) == NULL)
ret = EINVAL;
else {
if (lck->s_owner != _pthread_self())
ret = EPERM;
else {
lck->s_owner = NULL;
atomic_swap_int((int *)&lck->s_lock, 0, &ret);
ret = 0;
}
}
return (ret);
}