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/*
* Copyright (c) 2004 Roman Shaposhnik
* Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)
*
* Many thanks to Steven M. Schultz for providing clever ideas and
* to Michael Niedermayer <michaelni@gmx.at> for writing initial
* implementation.
*
* 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
*/
/**
* @file
* Multithreading support functions
* @see doc/multithreading.txt
*/
#include "libavutil/thread.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "pthread_internal.h"
#include "thread.h"
/**
* Set the threading algorithms used.
*
* Threading requires more than one thread.
* Frame threading requires entire frames to be passed to the codec,
* and introduces extra decoding delay, so is incompatible with low_delay.
*
* @param avctx The context.
*/
static void validate_thread_parameters(AVCodecContext *avctx)
{
int frame_threading_supported = (avctx->codec->capabilities & AV_CODEC_CAP_FRAME_THREADS)
&& !(avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
&& !(avctx->flags2 & AV_CODEC_FLAG2_CHUNKS);
if (avctx->thread_count == 1) {
avctx->active_thread_type = 0;
} else if (frame_threading_supported && (avctx->thread_type & FF_THREAD_FRAME)) {
avctx->active_thread_type = FF_THREAD_FRAME;
} else if (avctx->codec->capabilities & AV_CODEC_CAP_SLICE_THREADS &&
avctx->thread_type & FF_THREAD_SLICE) {
avctx->active_thread_type = FF_THREAD_SLICE;
} else if (!(ffcodec(avctx->codec)->caps_internal & FF_CODEC_CAP_AUTO_THREADS)) {
avctx->thread_count = 1;
avctx->active_thread_type = 0;
}
if (avctx->thread_count > MAX_AUTO_THREADS)
av_log(avctx, AV_LOG_WARNING,
"Application has requested %d threads. Using a thread count greater than %d is not recommended.\n",
avctx->thread_count, MAX_AUTO_THREADS);
}
int ff_thread_init(AVCodecContext *avctx)
{
validate_thread_parameters(avctx);
if (avctx->active_thread_type&FF_THREAD_SLICE)
return ff_slice_thread_init(avctx);
else if (avctx->active_thread_type&FF_THREAD_FRAME)
return ff_frame_thread_init(avctx);
return 0;
}
void ff_thread_free(AVCodecContext *avctx)
{
if (avctx->active_thread_type&FF_THREAD_FRAME)
ff_frame_thread_free(avctx, avctx->thread_count);
else
ff_slice_thread_free(avctx);
}
av_cold void ff_pthread_free(void *obj, const unsigned offsets[])
{
unsigned cnt = *(unsigned*)((char*)obj + offsets[0]);
const unsigned *cur_offset = offsets;
*(unsigned*)((char*)obj + offsets[0]) = 0;
for (; *(++cur_offset) != THREAD_SENTINEL && cnt; cnt--)
pthread_mutex_destroy((pthread_mutex_t*)((char*)obj + *cur_offset));
for (; *(++cur_offset) != THREAD_SENTINEL && cnt; cnt--)
pthread_cond_destroy ((pthread_cond_t *)((char*)obj + *cur_offset));
}
av_cold int ff_pthread_init(void *obj, const unsigned offsets[])
{
const unsigned *cur_offset = offsets;
unsigned cnt = 0;
int err;
#define PTHREAD_INIT_LOOP(type) \
for (; *(++cur_offset) != THREAD_SENTINEL; cnt++) { \
pthread_ ## type ## _t *dst = (void*)((char*)obj + *cur_offset); \
err = pthread_ ## type ## _init(dst, NULL); \
if (err) { \
err = AVERROR(err); \
goto fail; \
} \
}
PTHREAD_INIT_LOOP(mutex)
PTHREAD_INIT_LOOP(cond)
fail:
*(unsigned*)((char*)obj + offsets[0]) = cnt;
return err;
}