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/*
* Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_ATOMIC_H
#define AVUTIL_ATOMIC_H
#include "config.h"
#if HAVE_SYNC_VAL_COMPARE_AND_SWAP
#include "atomic_gcc.h"
#elif HAVE_MEMORYBARRIER
#include "atomic_win32.h"
#elif HAVE_MACHINE_RW_BARRIER
#include "atomic_suncc.h"
#else
/**
* Load the current value stored in an atomic integer.
*
* @param ptr atomic integer
* @return the current value of the atomic integer
* @note This acts as a memory barrier.
*/
int avpriv_atomic_int_get(volatile int *ptr);
/**
* Store a new value in an atomic integer.
*
* @param ptr atomic integer
* @param val the value to store in the atomic integer
* @note This acts as a memory barrier.
*/
void avpriv_atomic_int_set(volatile int *ptr, int val);
/**
* Add a value to an atomic integer.
*
* @param ptr atomic integer
* @param inc the value to add to the atomic integer (may be negative)
* @return the new value of the atomic integer.
* @note This does NOT act as a memory barrier. This is primarily
* intended for reference counting.
*/
int avpriv_atomic_int_add_and_fetch(volatile int *ptr, int inc);
/**
* Atomic pointer compare and swap.
*
* @param ptr pointer to the pointer to operate on
* @param oldval do the swap if the current value of *ptr equals to oldval
* @param newval value to replace *ptr with
* @return the value of *ptr before comparison
*/
void *avpriv_atomic_ptr_cas(void * volatile *ptr, void *oldval, void *newval);
#endif /* HAVE_MEMORYBARRIER */
#endif /* AVUTIL_ATOMIC_H */
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