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

/*

 *  (C) 2017 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpiimpl.h"

/*

 * Linear

 *

 * Simple send to each outgoing neighbor and recv from each incoming

 * neighbor.

 */

#undef FUNCNAME

#define FUNCNAME MPIR_Ineighbor_alltoallw_sched_allcomm_linear

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Ineighbor_alltoallw_sched_allcomm_linear(const void *sendbuf, const int sendcounts[],

                                                  const MPI_Aint sdispls[],

                                                  const MPI_Datatype sendtypes[], void *recvbuf,

                                                  const int recvcounts[], const MPI_Aint rdispls[],

                                                  const MPI_Datatype recvtypes[],

                                                  MPIR_Comm * comm_ptr, MPIR_Sched_t s)

{

    int mpi_errno = MPI_SUCCESS;

    int indegree, outdegree, weighted;

    int k, l;

    int *srcs, *dsts;

    MPIR_CHKLMEM_DECL(2);

    mpi_errno = MPIR_Topo_canon_nhb_count(comm_ptr, &indegree, &outdegree, &weighted);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    MPIR_CHKLMEM_MALLOC(srcs, int *, indegree * sizeof(int), mpi_errno, "srcs", MPL_MEM_COMM);

    MPIR_CHKLMEM_MALLOC(dsts, int *, outdegree * sizeof(int), mpi_errno, "dsts", MPL_MEM_COMM);

    mpi_errno = MPIR_Topo_canon_nhb(comm_ptr,

                                    indegree, srcs, MPI_UNWEIGHTED,

                                    outdegree, dsts, MPI_UNWEIGHTED);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    for (k = 0; k < outdegree; ++k) {

        char *sb;

        MPIR_Ensure_Aint_fits_in_pointer(MPIR_VOID_PTR_CAST_TO_MPI_AINT sendbuf + sdispls[k]);

        sb = ((char *) sendbuf) + sdispls[k];

        mpi_errno = MPIR_Sched_send(sb, sendcounts[k], sendtypes[k], dsts[k], comm_ptr, s);

        if (mpi_errno)

            MPIR_ERR_POP(mpi_errno);

    }

    for (l = 0; l < indegree; ++l) {

        char *rb;

        MPIR_Ensure_Aint_fits_in_pointer(MPIR_VOID_PTR_CAST_TO_MPI_AINT recvbuf + rdispls[l]);

        rb = ((char *) recvbuf) + rdispls[l];

        mpi_errno = MPIR_Sched_recv(rb, recvcounts[l], recvtypes[l], srcs[l], comm_ptr, s);

        if (mpi_errno)

            MPIR_ERR_POP(mpi_errno);

    }

    MPIR_SCHED_BARRIER(s);

  fn_exit:

    MPIR_CHKLMEM_FREEALL();

    return mpi_errno;

  fn_fail:

    goto fn_exit;

}