text: /*
      Copyright (c) 2005-2019 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"
  
  #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 */
  }
  
  // Algorithm parameters
  const int Max_OMP_Outer_Threads = 8;
  
  // Global variables
  int max_outer_threads = Max_OMP_Outer_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"
  	  "    -o<num> : max # of threads OMP should use at outer level\n"
  	  "\n  Help:\n"
  	  "    -h : print this help message\n");
  }
  
  // Process command-line arguments
  void process_args(int argc, char *argv[], int *max_outer_t) {
    (*max_outer_t) = omp_get_max_threads();
    for (int i=1; i<argc; ++i) {  
      if (argv[i][0] == '-') {
        switch (argv[i][1]) {
        case 'o': // set max_outer_threads
  	if (sscanf(&argv[i][2], "%d", max_outer_t) != 1 || *max_outer_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]);
      }
    }
  }
  
  int main(int argc, char *argv[]) { 
    process_args(argc, argv, &max_outer_threads);
  #ifdef LOG_THREADS
    TotalThreadLevel.init();
  #endif
  
    double start, end;
    start = omp_get_wtime( );
    
  #pragma omp parallel num_threads(max_outer_threads)
    {
      int omp_thread = omp_get_thread_num();
  #ifdef LOG_THREADS
      if (omp_thread == 0)
        TotalThreadLevel.change_level(omp_get_num_threads(), omp_outer);
  #endif
      if (omp_thread == 0) {
        MilliSleep(3000);
  #ifdef LOG_THREADS
        TotalThreadLevel.change_level(-1, omp_outer);
  #endif
  #pragma omp parallel
        {
  	int my_omp_thread = omp_get_thread_num();
  #ifdef LOG_THREADS
  	if (my_omp_thread == 0)
  	  TotalThreadLevel.change_level(omp_get_num_threads(), omp_inner);
  #endif
  	printf("Inner thread %d nested inside outer thread %d\n", my_omp_thread, omp_thread);
  #ifdef LOG_THREADS
  	if (my_omp_thread == 0)
  	  TotalThreadLevel.change_level(-omp_get_num_threads(), omp_inner);
  #endif
        }
  #ifdef LOG_THREADS
        TotalThreadLevel.change_level(1, omp_outer);
  #endif
      }
      else {
        MilliSleep(6000);
      }
  #ifdef LOG_THREADS
      if (omp_thread == 0)
        TotalThreadLevel.change_level(-omp_get_num_threads(), omp_outer);
  #endif
    }
    end = omp_get_wtime( );
    printf("Simple test of nested OMP (%d outer threads max) took: %6.6f\n",
  	 max_outer_threads, end-start);
  #ifdef LOG_THREADS
    TotalThreadLevel.dump();
  #endif
    return 0;
  }
  