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/* -*- Mode: C; c-basic-offset:4 ; -*- */
#include "mpi.h"
#include "mpio.h" /* not necessary with MPICH 1.1.1 or HPMPI 1.4 */
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
/* A 32^3 array. For other array sizes, change array_of_gsizes below. */
/* Uses split collective I/O. Writes a 3D block-distributed array to a file
corresponding to the global array in row-major (C) order, reads it
back, and checks that the data read is correct. */
/* The file name is taken as a command-line argument. */
/* Note that the file access pattern is noncontiguous. */
int main(int argc, char **argv)
{
MPI_Datatype newtype;
int i, ndims, array_of_gsizes[3], array_of_distribs[3];
int order, nprocs, j, len;
int array_of_dargs[3], array_of_psizes[3];
int *readbuf, *writebuf, bufcount, mynod, *tmpbuf, array_size;
char *filename;
MPI_File fh;
MPI_Status status;
MPI_Request request;
MPI_Init(&argc,&argv);
MPI_Comm_rank(MPI_COMM_WORLD, &mynod);
MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
/* process 0 takes the file name as a command-line argument and
broadcasts it to other processes */
if (!mynod) {
i = 1;
while ((i < argc) && strcmp("-fname", *argv)) {
i++;
argv++;
}
if (i >= argc) {
fprintf(stderr, "\n*# Usage: coll_test -fname filename\n\n");
MPI_Abort(MPI_COMM_WORLD, 1);
}
argv++;
len = strlen(*argv);
filename = (char *) malloc(len+1);
strcpy(filename, *argv);
MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);
MPI_Bcast(filename, len+1, MPI_CHAR, 0, MPI_COMM_WORLD);
}
else {
MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);
filename = (char *) malloc(len+1);
MPI_Bcast(filename, len+1, MPI_CHAR, 0, MPI_COMM_WORLD);
}
/* create the distributed array filetype */
ndims = 3;
order = MPI_ORDER_C;
array_of_gsizes[0] = 32;
array_of_gsizes[1] = 32;
array_of_gsizes[2] = 32;
array_of_distribs[0] = MPI_DISTRIBUTE_BLOCK;
array_of_distribs[1] = MPI_DISTRIBUTE_BLOCK;
array_of_distribs[2] = MPI_DISTRIBUTE_BLOCK;
array_of_dargs[0] = MPI_DISTRIBUTE_DFLT_DARG;
array_of_dargs[1] = MPI_DISTRIBUTE_DFLT_DARG;
array_of_dargs[2] = MPI_DISTRIBUTE_DFLT_DARG;
for (i=0; i<ndims; i++) array_of_psizes[i] = 0;
MPI_Dims_create(nprocs, ndims, array_of_psizes);
MPI_Type_create_darray(nprocs, mynod, ndims, array_of_gsizes,
array_of_distribs, array_of_dargs,
array_of_psizes, order, MPI_INT, &newtype);
MPI_Type_commit(&newtype);
/* initialize writebuf */
MPI_Type_size(newtype, &bufcount);
bufcount = bufcount/sizeof(int);
writebuf = (int *) malloc(bufcount * sizeof(int));
for (i=0; i<bufcount; i++) writebuf[i] = 1;
array_size = array_of_gsizes[0]*array_of_gsizes[1]*array_of_gsizes[2];
tmpbuf = (int *) calloc(array_size, sizeof(int));
MPI_Irecv(tmpbuf, 1, newtype, mynod, 10, MPI_COMM_WORLD, &request);
MPI_Send(writebuf, bufcount, MPI_INT, mynod, 10, MPI_COMM_WORLD);
MPI_Wait(&request, &status);
j = 0;
for (i=0; i<array_size; i++)
if (tmpbuf[i]) {
writebuf[j] = i;
j++;
}
free(tmpbuf);
if (j != bufcount) {
fprintf(stderr, "Error in initializing writebuf on process %d\n", mynod);
MPI_Abort(MPI_COMM_WORLD, 1);
}
/* end of initialization */
/* write the array to the file */
MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE | MPI_MODE_RDWR,
MPI_INFO_NULL, &fh);
MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", MPI_INFO_NULL);
MPI_File_write_all_begin(fh, writebuf, bufcount, MPI_INT);
MPI_File_write_all_end(fh, writebuf, &status);
MPI_File_close(&fh);
/* now read it back */
readbuf = (int *) malloc(bufcount * sizeof(int));
MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE | MPI_MODE_RDWR,
MPI_INFO_NULL, &fh);
MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", MPI_INFO_NULL);
MPI_File_read_all_begin(fh, readbuf, bufcount, MPI_INT);
MPI_File_read_all_end(fh, readbuf, &status);
MPI_File_close(&fh);
/* check the data read */
for (i=0; i<bufcount; i++)
if (readbuf[i] != writebuf[i])
fprintf(stderr, "Process %d, readbuf %d, writebuf %d, i %d\n", mynod, readbuf[i], writebuf[i], i);
if (!mynod) fprintf(stderr, "Done\n");
MPI_Type_free(&newtype);
free(readbuf);
free(writebuf);
free(filename);
MPI_Finalize();
return 0;
}
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