ffmpeg/libavcodec/threadprogress.h

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/*
* Copyright (c) 2022 Andreas Rheinhardt <andreas.rheinhardt@outlook.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
*/
#ifndef AVCODEC_THREADPROGRESS_H
#define AVCODEC_THREADPROGRESS_H
/**
* ThreadProgress is an API to easily notify other threads about progress
* of any kind as long as it can be packaged into an int and is consistent
* with the natural ordering of integers.
*
* Each initialized ThreadProgress can be in one of two modes: No-op mode
* or ordinary mode. In the former mode, ff_thread_report_progress() and
* ff_thread_await_progress() are no-ops to simply support usecases like
* non-frame-threading. Only in the latter case perform these functions
* what their name already implies.
*/
#include <limits.h>
#include <stdatomic.h>
#include "libavutil/thread.h"
/**
* This struct should be treated as opaque by users.
*/
typedef struct ThreadProgress {
atomic_int progress;
unsigned init;
AVMutex progress_mutex;
AVCond progress_cond;
} ThreadProgress;
/**
* Initialize a ThreadProgress.
*
* @param init_mode If zero, the ThreadProgress will be initialized
* to be in no-op mode as described above. Otherwise
* it is initialized to be in ordinary mode.
*/
int ff_thread_progress_init(ThreadProgress *pro, int init_mode);
/**
* Destroy a ThreadProgress. Can be called on a ThreadProgress that
* has never been initialized provided that the ThreadProgress struct
* has been initially zeroed. Must be called even if ff_thread_progress_init()
* failed.
*/
void ff_thread_progress_destroy(ThreadProgress *pro);
/**
* Reset the ::ThreadProgress.progress counter; must only be called
* if the ThreadProgress is not in use in any way (e.g. no thread
* may wait on it via ff_thread_progress_await()).
*/
static inline void ff_thread_progress_reset(ThreadProgress *pro)
{
atomic_init(&pro->progress, pro->init ? -1 : INT_MAX);
}
/**
* This function is a no-op in no-op mode; otherwise it notifies
* other threads that a certain level of progress has been reached.
* Later calls with lower values of progress have no effect.
*/
void ff_thread_progress_report(ThreadProgress *pro, int progress);
/**
* This function is a no-op in no-op mode; otherwise it waits
* until other threads have reached a certain level of progress:
* This function will return after another thread has called
* ff_thread_progress_report() with the same or higher value for progress.
*/
void ff_thread_progress_await(const ThreadProgress *pro, int progress);
#endif /* AVCODEC_THREADPROGRESS_H */