/* * 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 "config.h"#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 (ret == 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 /* HAVE_THREADS */ /* This should never trigger, unless a new threading implementation * without correct atomics dependencies in configure or a corresponding * atomics implementation is added. */#error "Threading is enabled, but there is no implementation of atomic operations available" #endif /* HAVE_PTHREADS */ #endif /* !HAVE_ATOMICS_NATIVE */