/*

  * 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
  * Slice multithreading support functions
  * @see doc/multithreading.txt
  */
 
 #include "config.h"
 
 #include "avcodec.h"
 #include "internal.h"
 #include "pthread_internal.h"
 #include "thread.h"
 

 #include "libavutil/avassert.h"

 #include "libavutil/common.h"
 #include "libavutil/cpu.h"
 #include "libavutil/mem.h"

 #include "libavutil/thread.h"

 #include "libavutil/slicethread.h"

 
 typedef int (action_func)(AVCodecContext *c, void *arg);
 typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);

 typedef int (main_func)(AVCodecContext *c);

 typedef struct SliceThreadContext {

     AVSliceThread *thread;

     action_func *func;
     action_func2 *func2;

     main_func *mainfunc;

     void *args;
     int *rets;
     int job_size;
 

     int *entries;
     int entries_count;
     int thread_count;
     pthread_cond_t *progress_cond;
     pthread_mutex_t *progress_mutex;

 } SliceThreadContext;

 static void main_function(void *priv) {
     AVCodecContext *avctx = priv;
     SliceThreadContext *c = avctx->internal->thread_ctx;
     c->mainfunc(avctx);
 }
 

 static void worker_func(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads)

 {

     AVCodecContext *avctx = priv;

     SliceThreadContext *c = avctx->internal->thread_ctx;

     int ret;
 
     ret = c->func ? c->func(avctx, (char *)c->args + c->job_size * jobnr)
                   : c->func2(avctx, c->args, jobnr, threadnr);
     if (c->rets)
         c->rets[jobnr] = ret;

 }
 
 void ff_slice_thread_free(AVCodecContext *avctx)
 {

     SliceThreadContext *c = avctx->internal->thread_ctx;

     int i;
 

     avpriv_slicethread_free(&c->thread);

     for (i = 0; i < c->thread_count; i++) {
         pthread_mutex_destroy(&c->progress_mutex[i]);
         pthread_cond_destroy(&c->progress_cond[i]);
     }
 
     av_freep(&c->entries);
     av_freep(&c->progress_mutex);
     av_freep(&c->progress_cond);

     av_freep(&avctx->internal->thread_ctx);

 }
 
 static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)
 {

     SliceThreadContext *c = avctx->internal->thread_ctx;

 
     if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)
         return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);
 
     if (job_count <= 0)
         return 0;
 
     c->job_size = job_size;
     c->args = arg;
     c->func = func;

     c->rets = ret;

     avpriv_slicethread_execute(c->thread, job_count, !!c->mainfunc  );

     return 0;
 }
 
 static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
 {

     SliceThreadContext *c = avctx->internal->thread_ctx;

     c->func2 = func2;
     return thread_execute(avctx, NULL, arg, ret, job_count, 0);
 }
 

 int ff_slice_thread_execute_with_mainfunc(AVCodecContext *avctx, action_func2* func2, main_func *mainfunc, void *arg, int *ret, int job_count)
 {
     SliceThreadContext *c = avctx->internal->thread_ctx;
     c->func2 = func2;
     c->mainfunc = mainfunc;
     return thread_execute(avctx, NULL, arg, ret, job_count, 0);
 }
 

 int ff_slice_thread_init(AVCodecContext *avctx)
 {

     SliceThreadContext *c;

     int thread_count = avctx->thread_count;

     static void (*mainfunc)(void *);

     // We cannot do this in the encoder init as the threads are created before
     if (av_codec_is_encoder(avctx->codec) &&
         avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO &&
         avctx->height > 2800)
         thread_count = avctx->thread_count = 1;
 

     if (!thread_count) {
         int nb_cpus = av_cpu_count();

         if  (avctx->height)
             nb_cpus = FFMIN(nb_cpus, (avctx->height+15)/16);

         // use number of cores + 1 as thread count if there is more than one
         if (nb_cpus > 1)
             thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
         else
             thread_count = avctx->thread_count = 1;
     }
 
     if (thread_count <= 1) {
         avctx->active_thread_type = 0;
         return 0;
     }
 

     avctx->internal->thread_ctx = c = av_mallocz(sizeof(*c));

     mainfunc = avctx->codec->caps_internal & FF_CODEC_CAP_SLICE_THREAD_HAS_MF ? &main_function : NULL;
     if (!c || (thread_count = avpriv_slicethread_create(&c->thread, avctx, worker_func, mainfunc, thread_count)) <= 1) {

         if (c)
             avpriv_slicethread_free(&c->thread);
         av_freep(&avctx->internal->thread_ctx);
         avctx->thread_count = 1;
         avctx->active_thread_type = 0;
         return 0;

     }

     avctx->thread_count = thread_count;

 
     avctx->execute = thread_execute;
     avctx->execute2 = thread_execute2;
     return 0;
 }

 
 void ff_thread_report_progress2(AVCodecContext *avctx, int field, int thread, int n)
 {

     SliceThreadContext *p = avctx->internal->thread_ctx;

     int *entries = p->entries;
 
     pthread_mutex_lock(&p->progress_mutex[thread]);
     entries[field] +=n;
     pthread_cond_signal(&p->progress_cond[thread]);
     pthread_mutex_unlock(&p->progress_mutex[thread]);
 }
 
 void ff_thread_await_progress2(AVCodecContext *avctx, int field, int thread, int shift)
 {

     SliceThreadContext *p  = avctx->internal->thread_ctx;

     int *entries      = p->entries;
 
     if (!entries || !field) return;
 
     thread = thread ? thread - 1 : p->thread_count - 1;
 
     pthread_mutex_lock(&p->progress_mutex[thread]);
     while ((entries[field - 1] - entries[field]) < shift){
         pthread_cond_wait(&p->progress_cond[thread], &p->progress_mutex[thread]);
     }
     pthread_mutex_unlock(&p->progress_mutex[thread]);
 }
 
 int ff_alloc_entries(AVCodecContext *avctx, int count)
 {
     int i;
 
     if (avctx->active_thread_type & FF_THREAD_SLICE)  {

         SliceThreadContext *p = avctx->internal->thread_ctx;

 
         if (p->entries) {
             av_assert0(p->thread_count == avctx->thread_count);
             av_freep(&p->entries);
         }
 

         p->thread_count  = avctx->thread_count;

         p->entries       = av_mallocz_array(count, sizeof(int));

         if (!p->progress_mutex) {
             p->progress_mutex = av_malloc_array(p->thread_count, sizeof(pthread_mutex_t));
             p->progress_cond  = av_malloc_array(p->thread_count, sizeof(pthread_cond_t));
         }

 
         if (!p->entries || !p->progress_mutex || !p->progress_cond) {
             av_freep(&p->entries);
             av_freep(&p->progress_mutex);
             av_freep(&p->progress_cond);

             return AVERROR(ENOMEM);
         }
         p->entries_count  = count;
 
         for (i = 0; i < p->thread_count; i++) {
             pthread_mutex_init(&p->progress_mutex[i], NULL);
             pthread_cond_init(&p->progress_cond[i], NULL);
         }
     }
 
     return 0;
 }
 
 void ff_reset_entries(AVCodecContext *avctx)
 {

     SliceThreadContext *p = avctx->internal->thread_ctx;

     memset(p->entries, 0, p->entries_count * sizeof(int));
 }