hello_hybrid.cpp

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

int main(int argc, char* argv[])
{
	MPI_Init(&argc, &argv);
	
	int my_rank = -1;
	int process_count = -1;
	
	MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
	MPI_Comm_size(MPI_COMM_WORLD, &process_count);
	
	char hostname[MPI_MAX_PROCESSOR_NAME];
	int hostname_length = -1;
	MPI_Get_processor_name(hostname, &hostname_length);
	
	std::cout << "Hello from main thread of process " << my_rank
		<< " of " << process_count << " on " << hostname << std::endl;

	#pragma omp parallel default(none) shared(my_rank, hostname, std::cout)
	{
		#pragma omp critical(stdout)
		std::cout << "\tHello from thread " << omp_get_thread_num()
				  << " of " << omp_get_num_threads() << " of process "
				  << my_rank << " on " << hostname << std::endl;
	}
	
	MPI_Finalize();
}