// OpenMP demo program
// Christoph Federrath, 2016-2017

#include <iostream>
#include <stdlib.h>
#include <omp.h>

using namespace std;

/** ----------------------------- Main -------------------------------
 **  OMP_TEST main procedure
 ** ------------------------------------------------------------------ */
int main(int argc, char *argv[])
{
    cout << "------------------- omp_test START -------------------" << endl;

    double n = 5e9;
    double sum = 0.0;

    /*
    for (long i = 0; i <= (long)n; i++)
    {
        sum += i;
    }
    cout << "sum = " << sum << endl;
    */

    #pragma omp parallel
    {
        #pragma omp critical
        cout << "["<<omp_get_thread_num()<<"] Total number of threads = "<<omp_get_num_threads()<<endl;

        double sum_loc = 0.0;
        #pragma omp for
        for (long i = 0; i <= (long)n; i++)
        {
            sum_loc += i;
        }
        #pragma omp critical
        {
            cout << "["<<omp_get_thread_num()<<"] sum_loc = " << sum_loc << endl;
            sum += sum_loc;
        }
    }


    cout << "sum = " << sum << endl;


    cout << "------------------- omp_test END -----------------" << endl;
    exit(0);

} // end: main()