一个混合 MPI_Init() 和 gtk_init() 的实例序

int main (int argc, char *argv[])
{
  int i, n;
 
  pthread_t draw_thread;
#ifdef USEMPI
  MPI_Init(&argc, &argv);
  MPI_Comm_size(MPI_COMM_WORLD, &num_nodes);
  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
#endif
 
  // parse cmdline args
  while((i = getopt(argc, argv, "d:r:w:n:shx:y:")) != EOF) {
    switch(i) {
    case 'd':
      debug = atoi(optarg);
      break;
    case 'x':
      initpos[0] = atoi(optarg);
      break;
    case 'y':
      initpos[1] = atoi(optarg);
      break;
    case 's':
      showgui = 0;
      break;
    case 'n':
      samples = atoi(optarg);
      break;
    case 'r':
      n = strlen(optarg);
      if (sequence!=NULL && rank==0) {
printf("Can't use both -r and -w simultaneously!!!\n");
exit(1);
      }
      sequence = calloc(n+1, sizeof(char));
      strcpy(sequence, optarg);
      pt_mode = PT_READ;
      break;
    case 'w':
      n = strlen(optarg);
      if (sequence!=NULL && rank==0) {
printf("Can't use both -r and -w simultaneously!!!\n");
exit(1);
      }
      sequence = calloc(n+1, sizeof(char));
      strcpy(sequence, optarg);
      pt_mode = PT_WRITE;
      break;
    case 'h':
    default:
      if (rank==0) {
printf("Usage: partracker [options]\n"\
     "\n"\
     "       [-d <level>]\n"\
     "         Displays <level> debug information\n"\
     "\n"\
     "       [-r <basename]\n"\
     "         Reads the frames from a sequence of jpg files named\n"\
     "          <basename>*.jpg instead of from a video4linux camera.\n"\
     "         For example:\n"\
     "          partracker -r test\n"\
     "         would read all files named test*.jpg in sorted order\n"\
     "\n"\
     "       [-w <basename>]\n"\
     "         Writes the raw frames (before processing them)\n"\
     "          to a sequence of jpg files starting at <basename>0000.jpg\n"\
     "\n"\
     "       [-x <xpos>]\n"\
     "         Sets the initial x-position of the tracker to <xpos>\n"\
     "\n"\
     "       [-y <ypos>]\n"\
     "         Sets the initial y-position of the tracker to <ypos>\n"\
     "         Default initial position is (30,30)\n"\
     "\n"\
     "       [-n <samples]\n"\
     "         Sets the number of samples per iteration of the\n"\
     "         condensation filter to <samples> (default: 1000)\n"\
     "\n"\
     "       [-s]\n"\
     "         Suppresses GUI display for faster processing\n");
      }
      exit(0);
    }
  }

  if (rank==0) {
    printf("%d/%d: partracker v0.01: using d=%d, n=%d, %s %s, %s, (%d,%d)\n",
   rank, num_nodes, debug, samples,
   (sequence==NULL ? "" : (pt_mode==PT_READ ? "reading from" : "writing to")),
   (sequence==NULL? "<live feed>" : sequence),
   (showgui ? "GUI" : "no GUI"), initpos[0], initpos[1]);
  }

#ifdef NOCAM
  if (pt_mode != PT_READ) {
    printf("No capture device available!!!\nPlease specify a read sequence.  Try partracker -h for usage information.\nQuitting...\n");
    exit(1);
  }
#endif

  g_thread_init(NULL);

#ifdef GUI
  if (rank==0) {
    gtk_set_locale();
    gtk_init(&argc, &argv);
    gdk_rgb_init();
  }
#endif

  // Initialize the storage structures
  memset(&gCamera,0,sizeof(struct CaptureData));
  gCamera.current_display = SMALL_IMAGE;
  gCamera.desired.capture_size = ECS_VGA;

  pthread_mutex_init(&gCamera.desired.lock, NULL );
  pthread_cond_init(&gCamera.desired.cond, NULL );
  pthread_mutex_init(&gCamera.image.lock, NULL );

  PartrackerInit();

  open_camera( &gCamera );
  set_camera_info( &gCamera );
  get_camera_info( &gCamera );
#ifdef GUI 
  if (rank==0 && showgui) {
    mainwindow = create_mainwindow();
    gCamera.displayarea[SMALL_IMAGE].drawing_area = lookup_widget( mainwindow, "drawingarea" );
    g_assert( gCamera.displayarea[SMALL_IMAGE].drawing_area );
 
    init_capture_widgets(&gCamera);
    gtk_widget_show (mainwindow);
  }
#endif
  if ( setup_memory_mapping( &gCamera ))
    exit(1);

  gCamera.timer = g_timer_new();
  g_timer_start( gCamera.timer );

#ifdef GUI
  pthread_create(&draw_thread, NULL, (void *)&draw_image, (void *)NULL);

  gdk_threads_enter();
  gtk_main ();
  gdk_threads_leave();
 
  gQuitFlag = TRUE;
  pthread_join( draw_thread, NULL );
#else
  draw_image();
#endif

  // clean up
  close_camera( &gCamera );

  if (sequence!=NULL)
    free(sequence);

  PartrackerCleanup();

#ifdef GUI
  for ( i = 0 ; i < 2 ; i++ ) {
    if ( gCamera.displayarea[i].pixmap ) {
      gdk_pixmap_unref(gCamera.displayarea[i].pixmap);
      gCamera.displayarea[i].pixmap = NULL;
    }
  }
#endif

#ifdef USEMPI
  MPI_Finalize();
#endif
  g_timer_stop( gCamera.timer );
  g_timer_destroy(gCamera.timer);

  pthread_mutex_destroy( &gCamera.desired.lock );
  pthread_cond_destroy( &gCamera.desired.cond );
  pthread_mutex_destroy( &gCamera.image.lock );

  return 0;
}