/**
 * Example of openmp parallel region
 * 
 * To compile, enter:
 *
 *	gcc -fopenmp openmp.c
 *
 * You should see the message "I am a parallel region" for each
 * processing core on your system.
 *
 * For those using a virtual machine, make sure you set the number of
 * processing cores > 1 to see parallel execution of the parallel region.
 */

#include <omp.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
	/* sequential code */

        int v = 0;
	int tid;
	int nthreads;

#pragma omp parallel shared(v, nthreads) private(tid)
	{
	  tid = omp_get_thread_num();
	  if (tid == 0)
	    {
	      nthreads = omp_get_num_threads();
	      printf("Number of threads = %d\n", nthreads);
	    }

#pragma omp critical (addv)
	{
	    v ++;
	}

	printf("I am a parallel region (thread id == %d)\n", tid);
	}

	/* sequential code */

        printf("value of v = %d\n", v);
	return 0;
}