Lab_2_MPI

// Lab2MPI.cpp: определяет точку входа для консольного приложения.
//

#include "stdafx.h"
#include <iostream>
#include <vector>
#include <mpi.h>
#include <stddef.h>
using namespace std;

const int N=10; //size of vector
const int n = 4;

#define MSMPI_NO_DEPRECATE_20

struct sub_vec {
    vector < double > a;
    double left,right;
    int rank;
};


MPI_Datatype createUserType()
{
    // Set-up the arguments for the type constructor
    MPI_Datatype new_type;

    int count = 4;
    int blocklens[] = { N/n,1,1,1};

    MPI_Aint indices[4];
    indices[0] = (MPI_Aint)offsetof(struct sub_vec, a);
    indices[1] = (MPI_Aint)offsetof(struct sub_vec, left);
    indices[2] = (MPI_Aint)offsetof(struct sub_vec, right);
    indices[3] = (MPI_Aint)offsetof(struct sub_vec, rank);

    MPI_Datatype old_types[] = { MPI_DOUBLE ,MPI_DOUBLE ,MPI_DOUBLE ,MPI_INT };

    MPI_Type_struct(count, blocklens, indices, old_types, &new_type);
    MPI_Type_commit(&new_type);

    return new_type;
}

int main(int argc, char *argv[])
{
    int num_proc=4;
    int my_rank;
    vector <double> main_vec(N); //вектор, в ктором хранится наш начальный массив
    main_vec[0] = main_vec[N / 2] = main_vec[N - 1] = 1;
    sub_vec main_struct;    // наша структура


    if (MPI_Init(&argc, &argv) != MPI_SUCCESS) {
        cout<< "Error :(" << endl;
    }
    MPI_Request request;
    MPI_Status status;
    MPI_Comm_size(MPI_COMM_WORLD, &num_proc);
    MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);


    if (my_rank==0)
    {
        for (int i = 1; i <= num_proc; i++)
        {
            cout << "rank: " << my_rank << endl;
            main_struct.a.assign( main_vec.begin() + (i - 1)*N / num_proc, main_vec.begin() + (i*N / num_proc));
            main_struct.rank = i;
            if (i == 1) main_struct.left = NULL;
            else main_struct.left = main_vec[(i - 1)*N / num_proc-1];
            if (i == num_proc) main_struct.right = NULL;
            else main_struct.right = main_vec[i *N / num_proc];

        //  cout << "rank: " << my_rank << "  1left: " << main_struct.left << endl;
        //  cout << "rank: " << my_rank << "  1right: " << main_struct.right << endl;
        //  cout << "rank: " << my_rank << "  1rank: " << my_rank << endl;
            MPI_Isend(&main_struct, 1, createUserType(), i,0, MPI_COMM_WORLD, &request);
            MPI_Wait(&request, &status);
        }
    }

    else
    {
        cout << "rank: " << my_rank << endl;
        for (int i = 1; i <= num_proc; i++)
        {
            MPI_Irecv(&main_struct, 1, createUserType(), 0, 0, MPI_COMM_WORLD, &request);
        //  cout <<"rank: "<<main_struct.rank<< "  left: "<< main_struct.left<<endl;
        //  cout << "rank: " << main_struct.rank << "  right: " << main_struct.right<<endl;
        //  cout << "rank: " << main_struct.rank << "  elements: " << main_struct.a[0] <<" "<< main_struct.a[1] << endl;
            for (int j = 0; j <3; j++)
            {
                cout<< "rank: " << main_struct.rank << "  elements: " << main_struct.a[j] << endl;
            }
            MPI_Wait(&request, &status);
        }
    }



    MPI_Finalize();
    system("pause");
    return 0;
}