openmpi/src/mpi/c/graph_create.c

/*
 * $HEADERS$
 */
#include "ompi_config.h"
#include <stdio.h>

#include "mpi.h"
#include "mpi/c/bindings.h"
#include "communicator/communicator.h"
#include "errhandler/errhandler.h"
#include "mca/topo/topo.h"

#if OMPI_HAVE_WEAK_SYMBOLS && OMPI_PROFILING_DEFINES
#pragma weak MPI_Graph_create = PMPI_Graph_create
#endif

#if OMPI_PROFILING_DEFINES
#include "mpi/c/profile/defines.h"
#endif

int MPI_Graph_create(MPI_Comm old_comm, int nnodes, int *index,
                     int *edges, int reorder, MPI_Comm *comm_graph) {

    int err;
    bool re_order = false;

    /* check the arguments */
    if (MPI_PARAM_CHECK) {
        if (MPI_COMM_NULL == old_comm) {
            return OMPI_ERRHANDLER_INVOKE (MPI_COMM_WORLD, MPI_ERR_COMM,
                                          "MPI_Graph_create");
        }
        if (OMPI_COMM_IS_INTER(old_comm)) {
            return OMPI_ERRHANDLER_INVOKE (MPI_COMM_WORLD, MPI_ERR_COMM,
                                          "MPI_Graph_create");
        }
        if (1 > nnodes || NULL == index || NULL == edges) {
            return OMPI_ERRHANDLER_INVOKE (MPI_COMM_WORLD, MPI_ERR_ARG,
                                          "MPI_Graph_create");
        }

        if (nnodes > ompi_comm_size(old_comm)) {
            return OMPI_ERRHANDLER_INVOKE (MPI_COMM_WORLD, MPI_ERR_ARG,
                                          "MPI_Graph_create");
        }

        if (0 > reorder || 1 < reorder) {
            return OMPI_ERRHANDLER_INVOKE (MPI_COMM_WORLD, MPI_ERR_ARG,
                                          "MPI_Graph_create: boo");
        }
    }

    /* 
     * everything seems to be alright with the communicator, we can go 
     * ahead and select a topology module for this purpose and create 
     * the new graph communicator
     */

    re_order = (1 == reorder) ? true:false;

    err = ompi_topo_create ((struct ompi_communicator_t *)old_comm,
                            nnodes,
                            index,
                            edges,
                            re_order,
                            (struct ompi_communicator_t **)comm_graph,
                            OMPI_COMM_GRAPH);

    /* check the error status */
    if (MPI_SUCCESS != err) {
        return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, err, "MPI_Graph_create");
    }
    
    /* All done */
    return MPI_SUCCESS;
}