astro.c

The example for Boor USING MPI2

#include "mpi.h"

int main( int argc, char *argv[] )
{
    MPI_File     fh;
    int          gsizes[4], distribs[4], dargs[4], psizes[4];
    int          i, nprocs, rank;
    int          local_array_size;
    int          global_size_in_each_dim;
    MPI_Status   status;
    float        header[6];
    float        *array1, *array2, *array3, *array4, *array5, *array6;
    MPI_Datatype filetype;

    MPI_Init( &argc, &argv );

    /* ... */

    /* Define the header, the array sizes, allocate the arrays, and
       set the values */

    MPI_File_open(MPI_COMM_WORLD, "/pfs/restartfile", 
		  MPI_MODE_CREATE | MPI_MODE_WRONLY, 
		  MPI_INFO_NULL, &fh);

    MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    if (rank == 0) 
	MPI_File_write(fh, header, 6, MPI_FLOAT, &status);
    
    for (i=0; i<3; i++) {
	gsizes[i] = global_size_in_each_dim;
	distribs[i] = MPI_DISTRIBUTE_BLOCK;
	dargs[i] = MPI_DISTRIBUTE_DFLT_DARG;
	psizes[i] = 0;
    }
    MPI_Dims_create(nprocs, 3, psizes);
    MPI_Type_create_darray(nprocs, rank, 3, gsizes, distribs, dargs,
			   psizes, MPI_ORDER_FORTRAN, MPI_FLOAT, 
			   &filetype);
    MPI_Type_commit(&filetype);
    
    MPI_File_set_view(fh, 6*sizeof(float), MPI_FLOAT, filetype, 
		      "native", MPI_INFO_NULL);
    
    MPI_File_write_all(fh, array1, local_array_size, MPI_FLOAT, 
		       MPI_STATUS_IGNORE);
    MPI_File_write_all(fh, array2, local_array_size, MPI_FLOAT, 
		       MPI_STATUS_IGNORE);
    MPI_File_write_all(fh, array3, local_array_size, MPI_FLOAT, 
		       MPI_STATUS_IGNORE);
    MPI_File_write_all(fh, array4, local_array_size, MPI_FLOAT, 
		       MPI_STATUS_IGNORE);
    MPI_File_write_all(fh, array5, local_array_size, MPI_FLOAT, 
		       MPI_STATUS_IGNORE);
    MPI_File_write_all(fh, array6, local_array_size, MPI_FLOAT, 
		       MPI_STATUS_IGNORE);
    MPI_File_close(&fh);

    /* ... */
    MPI_Finalize();
    
    return 0;
}