/* -*- 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"

/* Intercommunicator broadcast

 *

 * Root sends to rank 0 in remote group.  Remote group does local

 * intracommunicator broadcast.

 */

#undef FUNCNAME

#define FUNCNAME MPIR_Bcast_inter_remote_send_local_bcast

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Bcast_inter_remote_send_local_bcast(void *buffer,

                                             int count,

                                             MPI_Datatype datatype,

                                             int root,

                                             MPIR_Comm * comm_ptr, MPIR_Errflag_t * errflag)

{

    int rank, mpi_errno;

    int mpi_errno_ret = MPI_SUCCESS;

    MPI_Status status;

    MPIR_Comm *newcomm_ptr = NULL;

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPIR_BCAST_INTER);

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPIR_BCAST_INTER);

    if (root == MPI_PROC_NULL) {

        /* local processes other than root do nothing */

        mpi_errno = MPI_SUCCESS;

    } else if (root == MPI_ROOT) {

        /* root sends to rank 0 on remote group and returns */

        mpi_errno = MPIC_Send(buffer, count, datatype, 0, MPIR_BCAST_TAG, 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 {

        /* remote group. rank 0 on remote group receives from root */

        rank = comm_ptr->rank;

        if (rank == 0) {

            mpi_errno = MPIC_Recv(buffer, count, datatype, root,

                                  MPIR_BCAST_TAG, comm_ptr, &status, 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);

            }

        }

        /* Get the local intracommunicator */

        if (!comm_ptr->local_comm) {

            mpi_errno = MPII_Setup_intercomm_localcomm(comm_ptr);

            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);

            }

        }

        newcomm_ptr = comm_ptr->local_comm;

        /* now do the usual broadcast on this intracommunicator

         * with rank 0 as root. */

        mpi_errno = MPIR_Bcast_intra_auto(buffer, count, datatype, 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_FUNC_TERSE_EXIT(MPID_STATE_MPIR_BCAST_INTER);

    /* --BEGIN ERROR HANDLING-- */

    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");

    /* --END ERROR HANDLING-- */

    return mpi_errno;

}