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/*
* Copyright (C) by Argonne National Laboratory
* See COPYRIGHT in top-level directory
*/
/* This test attempts to create a large number of communicators, in an effort
* to exceed the number of communicators that the MPI implementation can
* provide. It checks that the implementation detects this error correctly
* handles it.
*/
/* In this version, we create communicators that contain ranks {0}, {0,1}, ...,
* {0..P-1} from MPI_COMM_WORLD until we run out of context IDs. */
#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>
#include "mpitest.h"
#define MAX_NCOMM 200000
static const int verbose = 0;
int main(int argc, char **argv)
{
int rank, nproc, mpi_errno;
int i, ncomm, *ranks;
int errs = 1;
MPI_Comm *comm_hdls;
MPI_Group world_group;
MTest_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &nproc);
MPI_Comm_group(MPI_COMM_WORLD, &world_group);
MPI_Comm_set_errhandler(MPI_COMM_WORLD, MPI_ERRORS_RETURN);
comm_hdls = malloc(sizeof(MPI_Comm) * MAX_NCOMM);
ranks = malloc(sizeof(int) * nproc);
for (i = 0; i < nproc; i++)
ranks[i] = i;
ncomm = 0;
for (i = 0; i < MAX_NCOMM; i++) {
MPI_Group comm_group;
/* Comms include ranks: 0; 0,1; 0,1,2; ...; 0; 0,1; 0,1,2; ... */
MPI_Group_incl(world_group, (i + 1) % (nproc + 1), /* Adding 1 yields counts of 1..nproc */
ranks, &comm_group);
/* Note: the comms we create are all varying subsets of MPI_COMM_WORLD */
mpi_errno = MPI_Comm_create(MPI_COMM_WORLD, comm_group, &comm_hdls[i]);
if (mpi_errno == MPI_SUCCESS) {
ncomm++;
} else {
if (verbose)
printf("%d: Error creating comm %d\n", rank, i);
MPI_Group_free(&comm_group);
errs = 0;
break;
}
MPI_Group_free(&comm_group);
}
for (i = 0; i < ncomm; i++)
MPI_Comm_free(&comm_hdls[i]);
free(comm_hdls);
free(ranks);
MPI_Group_free(&world_group);
MTest_Finalize(errs);
return MTestReturnValue(errs);
}
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