#include <stdio.h>
#include <mpi.h>

#define INIT_RANK int rank = 0; \
MPI_Comm_rank(MPI_COMM_WORLD, &rank);

#define INIT_SIZE int size = 0; \
MPI_Comm_size(MPI_COMM_WORLD, &size);

int main(int argc, char **argv)
{
	MPI_Init(&argc, &argv);
	INIT_RANK
	INIT_SIZE

	MPI_Status status;
	MPI_Request requestS, requestR;

	int data[4], data2[4];

	if (rank == 0)
	{
		for (int i = 0; i < 4; ++i)
			data[i] = i + 1;
		MPI_Isend(&data, 4, MPI_INT, 1, 47, MPI_COMM_WORLD, &requestS);
		MPI_Irecv(&data2, 4, MPI_INT, 1, 42, MPI_COMM_WORLD, &requestR);

		MPI_Wait(&requestR, &status);
	}
	else if (rank == 1)
	{
		for (int i = 0; i < 4; ++i)
			data2[i] = i + 100;
		MPI_Isend(&data2, 4, MPI_INT, 0, 42, MPI_COMM_WORLD, &requestS);
		MPI_Irecv(&data, 4, MPI_INT, 0, 47, MPI_COMM_WORLD, &requestR);

		MPI_Wait(&requestR, &status);
	}

	printf("I thread #%i\n", rank);
	for (int i = 0; i < 4; ++i)
	{
		printf("Data[%i] = %i\n", i, data[i]);
	}

	printf("\n");

	for (int i = 0; i < 4; ++i)
	{
		printf("Data2[%i] = %i\n", i, data2[i]);
	}

	printf("\n");

	MPI_Finalize();
}