/* 
Jonathan Hauenstein - University of Notre Dame
Center for Applied Mathematics Minicourse on Parallel Computing
April 24, May 1, May 8, 2008
Sample programs are designed for educational use 
*/

#include "test.h"
#include <mpi.h>

// creates the MPI datatype mpi_aStruct
void create_aStruct(MPI_Datatype *mpi_aStruct)
{
  MPI_Aint sAdd, add;
  aStruct A;

  // arrays for length, displacement and datatypes
  int blockLen[3] = {1,1,1}; // 1 element in each block
  MPI_Datatype types[3] = {MPI_INT, MPI_CHAR, MPI_DOUBLE};
  MPI_Aint indices[3] = {0,0,0};

  // calculate the starting address
  MPI_Address(&A.a, &sAdd);

  // calculate the second address and compute the displacement
  MPI_Address(&A.s, &add);
  indices[1] = add - sAdd;

  // calculate the third address and compute the displacement
  MPI_Address(&A.r, &add);
  indices[2] = add - sAdd;

  // build the mpi datatype
  MPI_Type_struct(3, blockLen, indices, types, mpi_aStruct);
  
  // commit the mpi datatype
  MPI_Type_commit(mpi_aStruct);

  return;
}