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/*
* Copyright (C) by Argonne National Laboratory
* See COPYRIGHT in top-level directory
*/
#include "mpi.h"
#include <stdio.h>
#include "mpitest.h"
#define MAX_PROCESSES 10
int main(int argc, char **argv)
{
int rank, size, i, j;
int table[MAX_PROCESSES][MAX_PROCESSES];
int errors = 0;
int participants;
MTest_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
/* A maximum of MAX_PROCESSES processes can participate */
if (size > MAX_PROCESSES)
participants = MAX_PROCESSES;
else
participants = size;
if (MAX_PROCESSES % participants) {
fprintf(stderr, "Number of processors must divide %d\n", MAX_PROCESSES);
MPI_Abort(MPI_COMM_WORLD, 1);
}
/* while (MAX_PROCESSES % participants) participants--; */
if ((rank < participants)) {
/* Determine what rows are my responsibility */
int block_size = MAX_PROCESSES / participants;
int begin_row = rank * block_size;
int end_row = (rank + 1) * block_size;
int send_count = block_size * MAX_PROCESSES;
int recv_count = send_count;
/* Paint my rows my color */
for (i = begin_row; i < end_row; i++)
for (j = 0; j < MAX_PROCESSES; j++)
table[i][j] = rank + 10;
/* Everybody gets the gathered table */
MPI_Allgather(MPI_IN_PLACE, 0, MPI_DATATYPE_NULL,
&table[0][0], recv_count, MPI_INT, MPI_COMM_WORLD);
/* Everybody should have the same table now, */
/* This test does not in any way guarantee there are no errors */
/* Print out a table or devise a smart test to make sure it's correct */
for (i = 0; i < MAX_PROCESSES; i++) {
if ((table[i][0] - table[i][MAX_PROCESSES - 1] != 0))
errors++;
}
}
MTest_Finalize(errors);
return MTestReturnValue(errors);
}
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