1 /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
3 * (C) 2001 by Argonne National Laboratory.
4 * See COPYRIGHT in top-level directory.
10 #define MAX_PROCESSES 10
12 int main( int argc, char **argv )
15 int table[MAX_PROCESSES][MAX_PROCESSES];
16 int row[MAX_PROCESSES];
21 MTest_Init( &argc, &argv );
22 MPI_Comm_rank( MPI_COMM_WORLD, &rank );
23 MPI_Comm_size( MPI_COMM_WORLD, &size );
25 comm = MPI_COMM_WORLD;
27 /* A maximum of MAX_PROCESSES processes can participate */
28 if ( size > MAX_PROCESSES ) {
29 participants = MAX_PROCESSES;
30 MPI_Comm_split( MPI_COMM_WORLD, rank < MAX_PROCESSES, rank, &comm );
34 MPI_Comm_dup( MPI_COMM_WORLD, &comm );
36 if ( (rank < participants) ) {
37 int send_count = MAX_PROCESSES;
38 int recv_count = MAX_PROCESSES;
40 /* If I'm the root (process 0), then fill out the big table */
42 for ( i=0; i<participants; i++)
43 for ( j=0; j<MAX_PROCESSES; j++ )
46 /* Scatter the big table to everybody's little table */
47 MPI_Scatter(&table[0][0], send_count, MPI_INT,
48 &row[0] , recv_count, MPI_INT, 0, comm );
50 /* Now see if our row looks right */
51 for (i=0; i<MAX_PROCESSES; i++)
52 if ( row[i] != i+rank ) errors++;
55 MPI_Comm_free( &comm );
57 MTest_Finalize( errors );
59 return MTestReturnValue( errors );