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/* Copyright (c) 2012-2018. The SimGrid Team.
* All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#include <stdio.h>
#include <mpi.h>
int main(int argc, char **argv)
{
int size;
int rank;
int success = 1;
int retval;
int sendcount = 1; // one double to each process
int recvcount = 1;
double *sndbuf = NULL;
double rcvd;
int root = 0; // arbitrary choice
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
// on root, initialize sendbuf
if (root == rank) {
sndbuf = malloc(size * sizeof(double));
for (int i = 0; i < size; i++) {
sndbuf[i] = (double) i;
}
}
retval = MPI_Scatter(sndbuf, sendcount, MPI_DOUBLE, &rcvd, recvcount, MPI_DOUBLE, root, MPI_COMM_WORLD);
if (root == rank) {
free(sndbuf);
}
if (retval != MPI_SUCCESS) {
fprintf(stderr, "(%s:%d) MPI_Scatter() returned retval=%d\n", __FILE__, __LINE__, retval);
return 0;
}
// verification
if ((double) rank != rcvd) {
fprintf(stderr, "[%d] has %f instead of %d\n", rank, rcvd, rank);
success = 0;
}
/* test 1 */
if (0 == rank)
printf("** Small Test Result: ...\n");
if (!success)
printf("\t[%d] failed.\n", rank);
else
printf("\t[%d] ok.\n", rank);
MPI_Finalize();
return 0;
}
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