openmpi/examples/connectivity_c.c

68 lines
1.8 KiB
C

/*
* Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved.
*/
/*
* Test the connectivity between all processes.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <unistd.h>
#include <mpi.h>
int
main(int argc, char **argv)
{
MPI_Status status;
int verbose = 0;
int rank;
int np; /* number of processes in job */
int peer;
int i;
int j;
int length;
char name[MPI_MAX_PROCESSOR_NAME+1];
MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &np);
/*
* If we cannot get the name for whatever reason, just
* set it to unknown. */
if (MPI_SUCCESS != MPI_Get_processor_name(name, &length)) {
strcpy(name, "unknown");
}
if (argc>1 && strcmp(argv[1], "-v")==0)
verbose = 1;
for (i=0; i<np; i++) {
if (rank==i) {
/* rank i sends to and receives from each higher rank */
for(j=i+1; j<np; j++) {
if (verbose)
printf("checking connection between rank %d on %s and rank %-4d\n",
i, name, j);
MPI_Send(&rank, 1, MPI_INT, j, rank, MPI_COMM_WORLD);
MPI_Recv(&peer, 1, MPI_INT, j, j, MPI_COMM_WORLD, &status);
}
} else if (rank>i) {
/* receive from and reply to rank i */
MPI_Recv(&peer, 1, MPI_INT, i, i, MPI_COMM_WORLD, &status);
MPI_Send(&rank, 1, MPI_INT, i, rank, MPI_COMM_WORLD);
}
}
MPI_Barrier(MPI_COMM_WORLD);
if (rank==0)
printf("Connectivity test on %d processes PASSED.\n", np);
MPI_Finalize();
return 0;
}