/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpiimpl.h"

/* Remote Gather Local Bcast

 *

 * This is done differently from the intercommunicator allgather

 * because we don't have all the information to do a local

 * intracommunictor gather (sendcount can be different on each

 * process). Therefore, we do the following: Each group first does an

 * intercommunicator gather to rank 0 and then does an

 * intracommunicator broadcast.

 */

#undef FUNCNAME

#define FUNCNAME MPIR_Allgatherv_inter_remote_gather_local_bcast

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Allgatherv_inter_remote_gather_local_bcast(const void *sendbuf, int sendcount,

                                                    MPI_Datatype sendtype, void *recvbuf,

                                                    const int *recvcounts, const int

                                                    *displs, MPI_Datatype recvtype,

                                                    MPIR_Comm * comm_ptr, MPIR_Errflag_t * errflag)

{

    int remote_size, mpi_errno, root, rank;

    int mpi_errno_ret = MPI_SUCCESS;

    MPIR_Comm *newcomm_ptr = NULL;

    MPI_Datatype newtype = MPI_DATATYPE_NULL;

    remote_size = comm_ptr->remote_size;

    rank = comm_ptr->rank;

    /* first do an intercommunicator gatherv from left to right group,

     * then from right to left group */

    if (comm_ptr->is_low_group) {

        /* gatherv from right group */

        root = (rank == 0) ? MPI_ROOT : MPI_PROC_NULL;

        mpi_errno = MPIR_Gatherv(sendbuf, sendcount, sendtype, recvbuf,

                                 recvcounts, displs, recvtype, root, comm_ptr, errflag);

        if (mpi_errno) {

            /* for communication errors, just record the error but continue */

            *errflag =

                MPIX_ERR_PROC_FAILED ==

                MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;

            MPIR_ERR_SET(mpi_errno, *errflag, "**fail");

            MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);

        }

        /* gatherv to right group */

        root = 0;

        mpi_errno = MPIR_Gatherv(sendbuf, sendcount, sendtype, recvbuf,

                                 recvcounts, displs, recvtype, root, comm_ptr, errflag);

        if (mpi_errno) {

            /* for communication errors, just record the error but continue */

            *errflag =

                MPIX_ERR_PROC_FAILED ==

                MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;

            MPIR_ERR_SET(mpi_errno, *errflag, "**fail");

            MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);

        }

    } else {

        /* gatherv to left group  */

        root = 0;

        mpi_errno = MPIR_Gatherv(sendbuf, sendcount, sendtype, recvbuf,

                                 recvcounts, displs, recvtype, root, comm_ptr, errflag);

        if (mpi_errno) {

            /* for communication errors, just record the error but continue */

            *errflag =

                MPIX_ERR_PROC_FAILED ==

                MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;

            MPIR_ERR_SET(mpi_errno, *errflag, "**fail");

            MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);

        }

        /* gatherv from left group */

        root = (rank == 0) ? MPI_ROOT : MPI_PROC_NULL;

        mpi_errno = MPIR_Gatherv(sendbuf, sendcount, sendtype, recvbuf,

                                 recvcounts, displs, recvtype, root, comm_ptr, errflag);

        if (mpi_errno) {

            /* for communication errors, just record the error but continue */

            *errflag =

                MPIX_ERR_PROC_FAILED ==

                MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;

            MPIR_ERR_SET(mpi_errno, *errflag, "**fail");

            MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);

        }

    }

    /* now do an intracommunicator broadcast within each group. we use

     * a derived datatype to handle the displacements */

    /* Get the local intracommunicator */

    if (!comm_ptr->local_comm) {

        mpi_errno = MPII_Setup_intercomm_localcomm(comm_ptr);

        if (mpi_errno)

            MPIR_ERR_POP(mpi_errno);

    }

    newcomm_ptr = comm_ptr->local_comm;

    mpi_errno = MPIR_Type_indexed_impl(remote_size, recvcounts, displs, recvtype, &newtype);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    mpi_errno = MPIR_Type_commit_impl(&newtype);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    mpi_errno = MPIR_Bcast_intra_auto(recvbuf, 1, newtype, 0, newcomm_ptr, errflag);

    if (mpi_errno) {

        /* for communication errors, just record the error but continue */

        *errflag =

            MPIX_ERR_PROC_FAILED ==

            MPIR_ERR_GET_CLASS(mpi_errno) ? MPIR_ERR_PROC_FAILED : MPIR_ERR_OTHER;

        MPIR_ERR_SET(mpi_errno, *errflag, "**fail");

        MPIR_ERR_ADD(mpi_errno_ret, mpi_errno);

    }

    MPIR_Type_free_impl(&newtype);

  fn_exit:

    if (mpi_errno_ret)

        mpi_errno = mpi_errno_ret;

    else if (*errflag != MPIR_ERR_NONE)

        MPIR_ERR_SET(mpi_errno, MPI_ERR_OTHER, "**coll_fail");

    return mpi_errno;

  fn_fail:

    /* --BEGIN ERROR HANDLING-- */

    if (newtype != MPI_DATATYPE_NULL)

        MPIR_Type_free_impl(&newtype);

    goto fn_exit;

    /* --END ERROR HANDLING-- */

}