/*
    Copyright (c) 2005-2020 Intel Corporation

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

#include <cstddef>
#include <cstdlib>
#include <cstdio>
#include <float.h>
#include <math.h>
#include <time.h>

#include <omp.h>
#include <assert.h>

#include "thread_level.h"

#include "tbb/task.h"
#include "tbb/tick_count.h"
#include "tbb/task_scheduler_init.h"

#if _WIN32||_WIN64
#include <Windows.h> /* Need Sleep */
#else
#include <unistd.h>  /* Need usleep */
#endif

void MilliSleep( unsigned milliseconds ) {
#if _WIN32||_WIN64
    Sleep( milliseconds );
#else
    usleep( milliseconds*1000 );
#endif /* _WIN32||_WIN64 */
}

using namespace std;
using namespace tbb;

// Algorithm parameters
const int Max_TBB_Threads = 16;
const int Max_OMP_Threads = 16;

// Global variables
int max_tbb_threads = Max_TBB_Threads;
int max_omp_threads = Max_OMP_Threads;

// Print help on command-line arguments
void help_message(char *prog_name) {
  fprintf(stderr, "\n%s usage:\n", prog_name);
  fprintf(stderr, 
	  "  Parameters:\n"
	  "    -t<num> : max # of threads TBB should use\n"
	  "    -o<num> : max # of threads OMP should use\n"
	  "\n  Help:\n"
	  "    -h : print this help message\n");
}

// Process command-line arguments
void process_args(int argc, char *argv[], int *max_tbb_t, int *max_omp_t) {
  for (int i=1; i<argc; ++i) {  
    if (argv[i][0] == '-') {
      switch (argv[i][1]) {
      case 't': // set max_tbb_threads
	if (sscanf(&argv[i][2], "%d", max_tbb_t) != 1 || *max_tbb_t < 1) {
	  fprintf(stderr, "%s Warning: argument of -t option unacceptable: %s\n", argv[0], &argv[i][2]);
	  help_message(argv[0]);
	}
	break;
      case 'o': // set max_omp_threads
	if (sscanf(&argv[i][2], "%d", max_omp_t) != 1 || *max_omp_t < 1) {
	  fprintf(stderr, "%s Warning: argument of -o option unacceptable: %s\n", argv[0], &argv[i][2]);
	  help_message(argv[0]);
	}
	break;
      case 'h': // print help message
	help_message(argv[0]);
	exit(0);
	break;
      default:
	fprintf(stderr, "%s: Warning: command-line option ignored: %s\n", argv[0], argv[i]);
	help_message(argv[0]);
	break;
      }
    } else {
      fprintf(stderr, "%s: Warning: command-line option ignored: %s\n", argv[0], argv[i]);
      help_message(argv[0]);
    }
  }
}

class SimpleTask : public task {
  bool isLeaf;
  int myId;
public:
  SimpleTask(bool isLeaf_, int myId_) : isLeaf(isLeaf_), myId(myId_) {}
  task* execute() {
#ifdef LOG_THREADS
    TotalThreadLevel.change_level(1, tbb_outer);
#endif
    omp_set_num_threads(max_omp_threads);
    if (!isLeaf) {
      set_ref_count(17);
      for (int i=0; i<16; ++i) {
	SimpleTask& st = *new(allocate_child()) SimpleTask(true, i);
	spawn(st);
      }
#ifdef LOG_THREADS
      TotalThreadLevel.change_level(-1, tbb_outer);
#endif
      wait_for_all();
#ifdef LOG_THREADS
      TotalThreadLevel.change_level(1, tbb_outer);
#endif
    }
    else {
      if (myId == 0) {
	MilliSleep(3000);
#ifdef LOG_THREADS
	TotalThreadLevel.change_level(-1, tbb_outer);
#endif
#pragma omp parallel
	{
#ifdef LOG_THREADS
	  if (omp_get_thread_num() == 0)
	    TotalThreadLevel.change_level(omp_get_num_threads(), omp_inner);
#endif
	  printf("In OMP parallel region on TBB task with myId=0: thread %d of %d\n", 
		 omp_get_thread_num(), omp_get_num_threads());
#ifdef LOG_THREADS
	  if (omp_get_thread_num() == 0)
	    TotalThreadLevel.change_level(-omp_get_num_threads(), omp_inner);
#endif
	}
#ifdef LOG_THREADS
	TotalThreadLevel.change_level(1, tbb_outer);
#endif
      }
      else {
	MilliSleep(6000);
      }
    }
#ifdef LOG_THREADS
    TotalThreadLevel.change_level(-1, tbb_outer);
#endif
    return NULL;
  }
};


int main(int argc, char *argv[]) { 
#ifdef LOG_THREADS
  TotalThreadLevel.init();
  TotalThreadLevel.change_level(1, tbb_outer);
#endif
  process_args(argc, argv, &max_tbb_threads, &max_omp_threads);

  task_scheduler_init phase(max_tbb_threads);
  tick_count start, end;
  start = tick_count::now();
  SimpleTask& st = *new(task::allocate_root()) SimpleTask(false, -1);
#ifdef LOG_THREADS
  TotalThreadLevel.change_level(-1, tbb_outer);
#endif
  task::spawn_root_and_wait(st);
#ifdef LOG_THREADS
  TotalThreadLevel.change_level(1, tbb_outer);
#endif
  end = tick_count::now();
  printf("Simple Test of TBB (%d threads max) with OMP (%d threads max) inside took: %6.6f\n", 
	 max_tbb_threads, max_omp_threads, (end-start).seconds());
#ifdef LOG_THREADS
  TotalThreadLevel.change_level(-1, tbb_outer);
  TotalThreadLevel.dump();
#endif
  return 0;
}
