several_for.c

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


int main(int argc, char* argv[])
{
	int thread_count = omp_get_max_threads();
	if ( argc >= 2 )
		thread_count = atoi( argv[1] );
	
	int iterations = thread_count;
	if ( argc >= 3 )
		iterations = atoi( argv[2] );
	
	#pragma omp parallel num_threads(thread_count) default(none) shared(iterations, stderr)
	{
		#pragma omp for
		for ( int iteration = 0; iteration < iterations; ++iteration )
			fprintf(stderr, "stage 1: %d/%d: iteration %d/%d\n", omp_get_thread_num(), omp_get_num_threads(), iteration, iterations );
	
		//#pragma omp barrier
		#pragma omp for
		for ( int iteration = 0; iteration < iterations; ++iteration )
			fprintf(stderr, "stage 2: %d/%d: iteration %d/%d\n", omp_get_thread_num(), omp_get_num_threads(), iteration, iterations );
		
		#pragma omp for
		for ( int iteration = 0; iteration < iterations; ++iteration )
			fprintf(stderr, "stage 3: %d/%d: iteration %d/%d\n", omp_get_thread_num(), omp_get_num_threads(), iteration, iterations );
	}
	
	return 0;
}