/* -*- 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"

#undef FUNCNAME

#define FUNCNAME MPIR_Scan_intra_smp

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Scan_intra_smp(const void *sendbuf, void *recvbuf, int count,

                        MPI_Datatype datatype, MPI_Op op, MPIR_Comm * comm_ptr,

                        MPIR_Errflag_t * errflag)

{

    int mpi_errno = MPI_SUCCESS;

    int mpi_errno_ret = MPI_SUCCESS;

    MPIR_CHKLMEM_DECL(3);

    int rank = comm_ptr->rank;

    MPI_Status status;

    void *tempbuf = NULL, *localfulldata = NULL, *prefulldata = NULL;

    MPI_Aint true_lb, true_extent, extent;

    int noneed = 1;             /* noneed=1 means no need to bcast tempbuf and

                                 * reduce tempbuf & recvbuf */

    MPIR_Type_get_true_extent_impl(datatype, &true_lb, &true_extent);

    MPIR_Datatype_get_extent_macro(datatype, extent);

    MPIR_Ensure_Aint_fits_in_pointer(count * MPL_MAX(extent, true_extent));

    MPIR_CHKLMEM_MALLOC(tempbuf, void *, count * (MPL_MAX(extent, true_extent)),

                        mpi_errno, "temporary buffer", MPL_MEM_BUFFER);

    tempbuf = (void *) ((char *) tempbuf - true_lb);

    /* Create prefulldata and localfulldata on local roots of all nodes */

    if (comm_ptr->node_roots_comm != NULL) {

        MPIR_CHKLMEM_MALLOC(prefulldata, void *, count * (MPL_MAX(extent, true_extent)),

                            mpi_errno, "prefulldata for scan", MPL_MEM_BUFFER);

        prefulldata = (void *) ((char *) prefulldata - true_lb);

        if (comm_ptr->node_comm != NULL) {

            MPIR_CHKLMEM_MALLOC(localfulldata, void *, count * (MPL_MAX(extent, true_extent)),

                                mpi_errno, "localfulldata for scan", MPL_MEM_BUFFER);

            localfulldata = (void *) ((char *) localfulldata - true_lb);

        }

    }

    /* perform intranode scan to get temporary result in recvbuf. if there is only

     * one process, just copy the raw data. */

    if (comm_ptr->node_comm != NULL) {

        mpi_errno = MPIR_Scan(sendbuf, recvbuf, count, datatype, op, comm_ptr->node_comm, 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 if (sendbuf != MPI_IN_PLACE) {

        mpi_errno = MPIR_Localcopy(sendbuf, count, datatype, recvbuf, count, datatype);

        if (mpi_errno)

            MPIR_ERR_POP(mpi_errno);

    }

    /* get result from local node's last processor which

     * contains the reduce result of the whole node. Name it as

     * localfulldata. For example, localfulldata from node 1 contains

     * reduced data of rank 1,2,3. */

    if (comm_ptr->node_roots_comm != NULL && comm_ptr->node_comm != NULL) {

        mpi_errno = MPIC_Recv(localfulldata, count, datatype,

                              comm_ptr->node_comm->local_size - 1, MPIR_SCAN_TAG,

                              comm_ptr->node_comm, &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);

        }

    } else if (comm_ptr->node_roots_comm == NULL &&

               comm_ptr->node_comm != NULL &&

               MPIR_Get_intranode_rank(comm_ptr, rank) == comm_ptr->node_comm->local_size - 1) {

        mpi_errno = MPIC_Send(recvbuf, count, datatype,

                              0, MPIR_SCAN_TAG, comm_ptr->node_comm, 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 if (comm_ptr->node_roots_comm != NULL) {

        localfulldata = recvbuf;

    }

    /* do scan on localfulldata to prefulldata. for example,

     * prefulldata on rank 4 contains reduce result of ranks

     * 1,2,3,4,5,6. it will be sent to rank 7 which is master

     * process of node 3. */

    if (comm_ptr->node_roots_comm != NULL) {

        mpi_errno = MPIR_Scan(localfulldata, prefulldata, count, datatype,

                              op, comm_ptr->node_roots_comm, 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);

        }

        if (MPIR_Get_internode_rank(comm_ptr, rank) != comm_ptr->node_roots_comm->local_size - 1) {

            mpi_errno = MPIC_Send(prefulldata, count, datatype,

                                  MPIR_Get_internode_rank(comm_ptr, rank) + 1,

                                  MPIR_SCAN_TAG, comm_ptr->node_roots_comm, 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);

            }

        }

        if (MPIR_Get_internode_rank(comm_ptr, rank) != 0) {

            mpi_errno = MPIC_Recv(tempbuf, count, datatype,

                                  MPIR_Get_internode_rank(comm_ptr, rank) - 1,

                                  MPIR_SCAN_TAG, comm_ptr->node_roots_comm, &status, errflag);

            noneed = 0;

            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 tempbuf contains all the data needed to get the correct

     * scan result. for example, to node 3, it will have reduce result

     * of rank 1,2,3,4,5,6 in tempbuf.

     * then we should broadcast this result in the local node, and

     * reduce it with recvbuf to get final result if nessesary. */

    if (comm_ptr->node_comm != NULL) {

        mpi_errno = MPIR_Bcast(&noneed, 1, MPI_INT, 0, comm_ptr->node_comm, 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);

        }

    }

    if (noneed == 0) {

        if (comm_ptr->node_comm != NULL) {

            mpi_errno = MPIR_Bcast(tempbuf, count, datatype, 0, comm_ptr->node_comm, 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);

            }

        }

        mpi_errno = MPIR_Reduce_local(tempbuf, recvbuf, count, datatype, op);

    }

  fn_exit:

    MPIR_CHKLMEM_FREEALL();

    if (mpi_errno_ret)

        mpi_errno = mpi_errno_ret;

    else if (*errflag != MPIR_ERR_NONE)

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

    return mpi_errno;

  fn_fail:

    goto fn_exit;

}