Example : Simple.C

Classes/Techniques Demonstrated :

• Threads
• Semaphores

class MyThread: public HPCxx_Thread{
  HPCxx_CSem *c;
  int my_num;
public:
  MyThread( HPCxx_CSem * s , int m ):  HPCxx_Thread(){
    my_num = m;
    c = s;
    printf("constructor complete\n");
  }
  void run(){
    printf("hi from thread %d\n", my_num);
    double a = 1;
    for(int i = 0; i < 10000; i++)
      for(int j = 0; j < 1000; j++) a += sqrt((double) 1.0*j);
    printf("done with thinking in %d\n", my_num);
    c->incr();
    printf("done with write in %d\n", my_num);
  }
};

int foo(int n){
  HPCxx_CSem c(n);
  MyThread *t[100];
  for(int i = 0; i < n; i++){
    t[i] = new MyThread(&c, i);
    t[i]->start();
  }
  c.wait();
  return 0;
}

int main(int argc, char *argv[]){
  HPCxx_Group *g;
  hpcxx_init(argc, argv, g);
  int x;
  cout << "num threads:" ;
  cin >> x;
  cout << "doing " << x << "threads.";
  for(int i = 0; i < 10; i++){
    double a;
    cout << "*** iteration " << i << " ***" << endl;
    foo(x);
    for(int i = 0; i < 100000; i++)
      for(int j = 0; j < 1000; j++) a += sqrt((double) 1.0*j);
  }
  printf("done with read\n");
  hpcxx_exit(g);
  return(0);
} /* main() */