/*

 * 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

 */

#include <limits.h>

#include <stdatomic.h>

#include "pthread_internal.h"

#include "threadprogress.h"

#include "libavutil/attributes.h"

#include "libavutil/thread.h"

DEFINE_OFFSET_ARRAY(ThreadProgress, thread_progress, init,

                    (offsetof(ThreadProgress, progress_mutex)),

                    (offsetof(ThreadProgress, progress_cond)));

av_cold int ff_thread_progress_init(ThreadProgress *pro, int init_mode)

{

    atomic_init(&pro->progress, init_mode ? -1 : INT_MAX);

#if HAVE_THREADS

    if (init_mode)

        return ff_pthread_init(pro, thread_progress_offsets);

#endif

    pro->init = init_mode;

    return 0;

}

av_cold void ff_thread_progress_destroy(ThreadProgress *pro)

{

#if HAVE_THREADS

    ff_pthread_free(pro, thread_progress_offsets);

#else

    pro->init = 0;

#endif

}

void ff_thread_progress_report(ThreadProgress *pro, int n)

{

    if (atomic_load_explicit(&pro->progress, memory_order_relaxed) >= n)

        return;

    ff_mutex_lock(&pro->progress_mutex);

    atomic_store_explicit(&pro->progress, n, memory_order_release);

    ff_cond_broadcast(&pro->progress_cond);

    ff_mutex_unlock(&pro->progress_mutex);

}

void ff_thread_progress_await(const ThreadProgress *pro_c, int n)

{

    /* Casting const away here is safe, because we only read from progress

     * and will leave pro_c in the same state upon leaving the function

     * as it had at the beginning. */

    ThreadProgress *pro = (ThreadProgress*)pro_c;

    if (atomic_load_explicit(&pro->progress, memory_order_acquire) >= n)

        return;

    ff_mutex_lock(&pro->progress_mutex);

    while (atomic_load_explicit(&pro->progress, memory_order_relaxed) < n)

        ff_cond_wait(&pro->progress_cond, &pro->progress_mutex);

    ff_mutex_unlock(&pro->progress_mutex);

}