65f1d45dcc
These could be used for reference counting, or for keeping track of decoding progress in references in multithreaded decoders. Support is provided by gcc/msvc/suncc intrinsics, with a fallback using pthread mutexes. Signed-off-by: Anton Khirnov <anton@khirnov.net>
75 lines
2.2 KiB
C
75 lines
2.2 KiB
C
/*
|
|
* 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_MEMORYBARRIER
|
|
#include "atomic_win32.h"
|
|
#elif HAVE_SYNC_SYNCHRONIZE
|
|
#include "atomic_gcc.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 */
|