openmpi/ompi/mpi/c/gatherv.c

/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University.
 *                         All rights reserved.
 * Copyright (c) 2004-2005 The Trustees of the University of Tennessee.
 *                         All rights reserved.
 * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
 *                         University of Stuttgart.  All rights reserved.
 * Copyright (c) 2004-2005 The Regents of the University of California.
 *                         All rights reserved.
 * $COPYRIGHT$
 * 
 * Additional copyrights may follow
 * 
 * $HEADER$
 */
#include "ompi_config.h"
#include <stdio.h>

#include "mpi.h"
#include "mpi/c/bindings.h"
#include "mca/coll/coll.h"
#include "communicator/communicator.h"
#include "datatype/datatype.h"

#if OMPI_HAVE_WEAK_SYMBOLS && OMPI_PROFILING_DEFINES
#pragma weak MPI_Gatherv = PMPI_Gatherv
#endif

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

static const char FUNC_NAME[] = "MPI_Gatherv";


int MPI_Gatherv(void *sendbuf, int sendcount, MPI_Datatype sendtype,
                void *recvbuf, int *recvcounts, int *displs,
                MPI_Datatype recvtype, int root, MPI_Comm comm) 
{
    int i, size, err;
    
    if (MPI_PARAM_CHECK) {
        err = MPI_SUCCESS;
        OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
        if (ompi_comm_invalid(comm)) {
	    return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_COMM, 
                                          FUNC_NAME);
	}

        /* Errors for intracommunicators */

        if (OMPI_COMM_IS_INTRA(comm)) {

          /* Errors for all ranks */

          if ((root >= ompi_comm_size(comm)) || (root < 0)) {
            err = MPI_ERR_ROOT;
          } else {
            OMPI_CHECK_DATATYPE_FOR_SEND(err, sendtype, sendcount);
          }
          OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);

          /* Errors for the root.  Some of these could have been
             combined into compound if statements above, but since
             this whole section can be compiled out (or turned off at
             run time) for efficiency, it's more clear to separate
             them out into individual tests. */

          if (ompi_comm_rank(comm) == root) {
            if (NULL == displs) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
            }

            if (NULL == recvcounts) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_COUNT, FUNC_NAME);
            }

            size = ompi_comm_size(comm);
            for (i = 0; i < size; ++i) {
              if (recvcounts[i] < 0) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_COUNT, FUNC_NAME);
              } else if (MPI_DATATYPE_NULL == recvtype) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_TYPE, FUNC_NAME);
              }
            }
          }
        }

        /* Errors for intercommunicators */

        else {
          if (! ((root >= 0 && root < ompi_comm_remote_size(comm)) ||
                 MPI_ROOT == root || MPI_PROC_NULL == root)) {
            return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ROOT, FUNC_NAME);
          }

          /* Errors for the senders */

          if (MPI_ROOT != root && MPI_PROC_NULL != root) {
            OMPI_CHECK_DATATYPE_FOR_SEND(err, sendtype, sendcount);
            OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
          }

          /* Errors for the root.  Ditto on the comment above -- these
             error checks could have been combined above, but let's
             make the code easier to read. */

          else if (MPI_ROOT == root) {
            if (NULL == displs) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
            }

            if (NULL == recvcounts) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_COUNT, FUNC_NAME);
            }

            size = ompi_comm_size(comm);
            for (i = 0; i < size; ++i) {
              if (recvcounts[i] < 0) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_COUNT, FUNC_NAME);
              } else if (MPI_DATATYPE_NULL == recvtype) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_TYPE, FUNC_NAME); 
              }
            }
          }
        }
    }

    /* If we have nothing to do, just return */

    if (0 == sendcount && ompi_comm_rank(comm) != root) {
        return MPI_SUCCESS;
    }

    /* Invoke the coll component to perform the back-end operation */
	
    err = comm->c_coll.coll_gatherv(sendbuf, sendcount, sendtype, recvbuf,
                                    recvcounts, displs,
                                    recvtype, root, comm);
    OMPI_ERRHANDLER_RETURN(err, comm, err, FUNC_NAME);
}