mpi_status_usage.c

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

#define ROOT 0
#define COMM_TAG 1

int main(int argc, char *argv[])
{
  int communicator_size, process_rank;

  MPI_Init(&argc, &argv);
  MPI_Comm_size(MPI_COMM_WORLD, &communicator_size);
  MPI_Comm_rank(MPI_COMM_WORLD, &process_rank);


  if(process_rank == 0)
  {
    MPI_Status mpi_status_obj;
    char recv_buffer;
    MPI_Recv(&recv_buffer, 1, MPI_CHAR, MPI_ANY_SOURCE, COMM_TAG, MPI_COMM_WORLD, &mpi_status_obj);

    printf("Root got Info from Node %d\n", mpi_status_obj.MPI_SOURCE);

  }
  else
  {
    if(process_rank == communicator_size - 1)
    {
      char send_buffer = 0;
      MPI_Send(&send_buffer, 1, MPI_CHAR, ROOT, COMM_TAG, MPI_COMM_WORLD);
    }
  }
  MPI_Finalize();
  return 0;
}