several_for.cpp

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

int main(int argc, char* argv[])
{
	int thread_count = omp_get_max_threads();
	if ( argc >= 2 )
		thread_count = atoi(argv[1]);
	
	int iteration_count = thread_count;
	if ( argc >= 3 )
		iteration_count = atoi(argv[2]);

	#pragma omp parallel num_threads(thread_count) \
		default(none) shared(iteration_count, std::cout)
	{
		#pragma omp for
		for ( int iteration = 0; iteration < iteration_count; ++iteration )
		{
			#pragma omp critical(cout)
			std::cout << "stage 1: " << omp_get_thread_num() << '/' << omp_get_num_threads() <<
				": iteration " << iteration << '/' << iteration_count << std::endl;
		}
		//#pragma omp barrier

		#pragma omp for
		for ( int iteration = 0; iteration < iteration_count; ++iteration )
		{
			#pragma omp critical(cout)
			std::cout << "stage 2: " << omp_get_thread_num() << '/' << omp_get_num_threads() <<
				": iteration " << iteration << '/' << iteration_count << std::endl;
		}

		#pragma omp for
		for ( int iteration = 0; iteration < iteration_count; ++iteration )
		{
			#pragma omp critical(cout)
			std::cout << "stage 3: " << omp_get_thread_num() << '/' << omp_get_num_threads() <<
				": iteration " << iteration << '/' << iteration_count << std::endl;
		}
	}

	return 0;
}