#include <iostream>
#include <stdio.h>
#include "mpi.h";
#include <ctime>

using namespace std;

void msg_show(int* msg, int dim) {
	int rank;
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);
	cout << "rank: " << rank << ", msg =  ";
	for (int i = 0; i < dim; i++) {
		cout << msg[i] << ' ';
	}
	cout << endl;
}
// создаем сообщение
int* create_msg(int dim) {
	int* msg;
	int rank;
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);

	if (rank == 0) {
		msg = (int*)malloc(dim * sizeof(int));
		for (int i = 0; i < dim; i++) {
			msg[i] = 1;
		}
		return msg;
	}

	if (rank == 1) {
		msg = (int*)malloc(dim * sizeof(int));
		for (int i = 0; i < dim; i++) {
			msg[i] = 5;
		}
		return msg;
	}
}


int main(int* argc, char** argv) {
	int rank, size, n = 4 * 8;
	int dim_msg = n / 4;
	int* msg;
	int msg_tag_from_zero = 27;
	int msg_tag_from_first = 20;
	int rank_zero_proc = 0;
	int rank_first_proc = 1;
	int buf_elems;
	double time_start_1, time_start_0, time_stop_1, time_stop_0;

	MPI_Request request_from_0_to_1, request_from_1_to_0;
	MPI_Status status_from_0_to_1, status_from_1_to_0;

	MPI_Init(argc, &argv);

	MPI_Comm_rank(MPI_COMM_WORLD, &rank);
	MPI_Comm_size(MPI_COMM_WORLD, &size);

	if (rank == 0) {
		msg = create_msg(dim_msg);
		msg_show(msg, dim_msg);

		time_start_0 = MPI_Wtime();
//отправляем сообщение
		MPI_Isend(msg, dim_msg, MPI_INT, rank_first_proc, msg_tag_from_zero, MPI_COMM_WORLD, &request_from_0_to_1);
		//выделяем память сообщению
		int* msg_recv;
		msg_recv = (int*)malloc(dim_msg * sizeof(int));
//принимаем сообщение
		MPI_Irecv(msg_recv, dim_msg, MPI_INT, rank_first_proc, msg_tag_from_first, MPI_COMM_WORLD, &request_from_1_to_0);
//ждем, пока не примем сообщение до конца
		MPI_Wait(&request_from_1_to_0, &status_from_1_to_0);
		time_stop_1 = MPI_Wtime();
		msg_show(msg_recv, dim_msg);


		MPI_Status status;
		MPI_Send(&time_stop_1, 1, MPI_DOUBLE, 1, 200, MPI_COMM_WORLD);
		MPI_Recv(&time_stop_0, 1, MPI_DOUBLE, 1, 100, MPI_COMM_WORLD, &status);
		cout << "time_0 = " << time_stop_0 - time_start_0 << endl;
	}
	if (rank == 1) {
		msg = create_msg(dim_msg);
		msg_show(msg, dim_msg);

		time_start_1 = MPI_Wtime();
// отправляем сообщение
		MPI_Isend(msg, dim_msg, MPI_INT, rank_zero_proc, msg_tag_from_first, MPI_COMM_WORLD, &request_from_1_to_0);

		int* msg_recv;
		msg_recv = (int*)malloc(dim_msg * sizeof(int));
//принимаем его
		MPI_Irecv(msg_recv, dim_msg, MPI_INT, rank_zero_proc, msg_tag_from_zero, MPI_COMM_WORLD, &request_from_0_to_1);
		MPI_Wait(&request_from_0_to_1, &status_from_0_to_1);
		time_stop_0 = MPI_Wtime();
		msg_show(msg_recv, dim_msg);

		MPI_Status status;
		MPI_Send(&time_stop_0, 1, MPI_DOUBLE, 0, 100, MPI_COMM_WORLD);
		MPI_Recv(&time_stop_1, 1, MPI_DOUBLE, 0, 200, MPI_COMM_WORLD, &status);
		cout << "time_1 = " << time_stop_1 - time_start_1 << endl;
	}
	MPI_Finalize();
	return 0;
}