124 lines
2.7 KiB
C
124 lines
2.7 KiB
C
/*
|
|
* Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "atomic.h"
|
|
|
|
#if !HAVE_ATOMICS_NATIVE
|
|
|
|
#if HAVE_PTHREADS
|
|
|
|
#include <pthread.h>
|
|
|
|
static pthread_mutex_t atomic_lock = PTHREAD_MUTEX_INITIALIZER;
|
|
|
|
int avpriv_atomic_int_get(volatile int *ptr)
|
|
{
|
|
int res;
|
|
|
|
pthread_mutex_lock(&atomic_lock);
|
|
res = *ptr;
|
|
pthread_mutex_unlock(&atomic_lock);
|
|
|
|
return res;
|
|
}
|
|
|
|
void avpriv_atomic_int_set(volatile int *ptr, int val)
|
|
{
|
|
pthread_mutex_lock(&atomic_lock);
|
|
*ptr = val;
|
|
pthread_mutex_unlock(&atomic_lock);
|
|
}
|
|
|
|
int avpriv_atomic_int_add_and_fetch(volatile int *ptr, int inc)
|
|
{
|
|
int res;
|
|
|
|
pthread_mutex_lock(&atomic_lock);
|
|
*ptr += inc;
|
|
res = *ptr;
|
|
pthread_mutex_unlock(&atomic_lock);
|
|
|
|
return res;
|
|
}
|
|
|
|
void *avpriv_atomic_ptr_cas(void * volatile *ptr, void *oldval, void *newval)
|
|
{
|
|
void *ret;
|
|
pthread_mutex_lock(&atomic_lock);
|
|
ret = *ptr;
|
|
if (*ptr == oldval)
|
|
*ptr = newval;
|
|
pthread_mutex_unlock(&atomic_lock);
|
|
return ret;
|
|
}
|
|
|
|
#elif !HAVE_THREADS
|
|
|
|
int avpriv_atomic_int_get(volatile int *ptr)
|
|
{
|
|
return *ptr;
|
|
}
|
|
|
|
void avpriv_atomic_int_set(volatile int *ptr, int val)
|
|
{
|
|
*ptr = val;
|
|
}
|
|
|
|
int avpriv_atomic_int_add_and_fetch(volatile int *ptr, int inc)
|
|
{
|
|
*ptr += inc;
|
|
return *ptr;
|
|
}
|
|
|
|
void *avpriv_atomic_ptr_cas(void * volatile *ptr, void *oldval, void *newval)
|
|
{
|
|
if (*ptr == oldval) {
|
|
*ptr = newval;
|
|
return oldval;
|
|
}
|
|
return *ptr;
|
|
}
|
|
|
|
#else
|
|
|
|
#error "Threading is enabled, but there is no implementation of atomic operations available"
|
|
|
|
#endif /* HAVE_PTHREADS */
|
|
|
|
#endif /* !HAVE_MEMORYBARRIER && !HAVE_SYNC_VAL_COMPARE_AND_SWAP && !HAVE_MACHINE_RW_BARRIER */
|
|
|
|
#ifdef TEST
|
|
#include "avassert.h"
|
|
|
|
int main(void)
|
|
{
|
|
volatile int val = 1;
|
|
int res;
|
|
|
|
res = avpriv_atomic_int_add_and_fetch(&val, 1);
|
|
av_assert0(res == 2);
|
|
avpriv_atomic_int_set(&val, 3);
|
|
res = avpriv_atomic_int_get(&val);
|
|
av_assert0(res == 3);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|