MPI virtual Grid Creation

virtual_grid.c

/* 
 * File:   broadcast.c
 * Author: korkmaka
 *
 * Created on 20 mars 2018, 09:52
 */

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

typedef struct meta_data {
    int rank;
    int size;
    int nameLength;
    char processName[25];
} meta_data;

meta_data *getMetaData(MPI_Comm communicator) {
    meta_data *md = malloc(sizeof (meta_data));

    int nameSize = 25;

    if (communicator == NULL) {
        MPI_Comm_rank(MPI_COMM_WORLD, &md->rank);
        MPI_Comm_size(MPI_COMM_WORLD, &md->size);
        MPI_Get_processor_name(md->processName, &nameSize);
    } else {
        MPI_Comm_rank(communicator, &md->rank);
        MPI_Comm_size(communicator, &md->size);
        MPI_Get_processor_name(md->processName, &nameSize);
    }

    return md;
}

void initArray(int *array, int size, int value) {
    for (int i = 0; i < size; i++) {
        array[i] = value;
    }
}

void printArray(int *array, int size) {
    for (int i = 0; i < size; i++) {
        printf("%d - ", array[i]);
    }
    printf("\n");
}

/*
 * this is doing reduction globally
 */
int main(int argc, char** argv) {
    MPI_Init(NULL, NULL);

    meta_data *md = getMetaData(NULL);

    int numberOfNodes = 16;
    int numberOfdimention = 2;
    int dims[2] = {4, 4};

    int periods[2] = {0, 0};


    MPI_Comm new_comm;


    int result = MPI_Dims_create(numberOfNodes, numberOfdimention, dims);

    printf("MPI_Dims_create result %d \n", result);

    result = MPI_Cart_create(MPI_COMM_WORLD, numberOfdimention, dims, periods, 0, &new_comm);

    printf("MPI_Cart_create result %d \n", result);

    md = getMetaData(new_comm);

    
    for(int i = 0; i < numberOfNodes; i++){
        int dim[2];
        MPI_Cart_coords(new_comm,i,numberOfdimention,dim);
        printf("%d --> %d - %d \n", i, dim[0], dim[1] );
    }
    
    //printf("old Rank %d new rank %d \n", oldRank, md->rank );

    MPI_Finalize();
    return (EXIT_SUCCESS);
}