text: /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
  /*
   * Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana
   *                         University Research and Technology
   *                         Corporation.  All rights reserved.
   * Copyright (c) 2004-2018 The University of Tennessee and The University
   *                         of Tennessee Research Foundation.  All rights
   *                         reserved.
   * Copyright (c) 2004-2008 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 (c) 2007      Cisco Systems, Inc.  All rights reserved.
   * Copyright (c) 2013      Los Alamos National Security, LLC. All rights
   *                         reserved.
   * Copyright (c) 2014-2015 Research Organization for Information Science
   *                         and Technology (RIST). All rights reserved.
   * Copyright (c) 2017      IBM Corporation.  All rights reserved.
   * $COPYRIGHT$
   *
   * Additional copyrights may follow
   *
   * $HEADER$
   */
  
  #include "ompi_config.h"
  #include <stdio.h>
  
  #include "ompi/mpi/c/bindings.h"
  #include "ompi/runtime/params.h"
  #include "ompi/communicator/communicator.h"
  #include "ompi/errhandler/errhandler.h"
  #include "ompi/datatype/ompi_datatype.h"
  #include "ompi/memchecker.h"
  #include "ompi/mca/topo/topo.h"
  #include "ompi/mca/topo/base/base.h"
  #include "ompi/runtime/ompi_spc.h"
  
  #if OMPI_BUILD_MPI_PROFILING
  #if OPAL_HAVE_WEAK_SYMBOLS
  #pragma weak MPI_Neighbor_alltoall = PMPI_Neighbor_alltoall
  #endif
  #define MPI_Neighbor_alltoall PMPI_Neighbor_alltoall
  #endif
  
  static const char FUNC_NAME[] = "MPI_Neighbor_alltoall";
  
  
  int MPI_Neighbor_alltoall(const void *sendbuf, int sendcount, MPI_Datatype sendtype,
                            void *recvbuf, int recvcount, MPI_Datatype recvtype,
                            MPI_Comm comm)
  {
      size_t sendtype_size, recvtype_size;
      int err;
  
      SPC_RECORD(OMPI_SPC_NEIGHBOR_ALLTOALL, 1);
  
      MEMCHECKER(
          memchecker_comm(comm);
          if (MPI_IN_PLACE != sendbuf) {
              memchecker_datatype(sendtype);
              memchecker_call(&opal_memchecker_base_isdefined, (void *)sendbuf, sendcount, sendtype);
          }
          memchecker_datatype(recvtype);
          memchecker_call(&opal_memchecker_base_isaddressable, recvbuf, recvcount, recvtype);
      );
  
      if (MPI_PARAM_CHECK) {
  
          /* Unrooted operation -- same checks for all ranks on both
             intracommunicators and intercommunicators */
  
          err = MPI_SUCCESS;
          OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
          if (ompi_comm_invalid(comm) || OMPI_COMM_IS_INTER(comm)) {
              return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_COMM,
                                            FUNC_NAME);
          } else if (! OMPI_COMM_IS_TOPO(comm)) {
              return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_TOPOLOGY,
                                            FUNC_NAME);
          } else if (MPI_IN_PLACE == sendbuf || MPI_IN_PLACE == recvbuf) {
              return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_ARG,
                                            FUNC_NAME);
          } else {
              OMPI_CHECK_DATATYPE_FOR_SEND(err, sendtype, sendcount);
              OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
              OMPI_CHECK_DATATYPE_FOR_RECV(err, recvtype, recvcount);
              OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
          }
  
          ompi_datatype_type_size(sendtype, &sendtype_size);
          ompi_datatype_type_size(recvtype, &recvtype_size);
          if ((sendtype_size*sendcount) != (recvtype_size*recvcount)) {
              return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_TRUNCATE, FUNC_NAME);
          }
  
          if( OMPI_COMM_IS_CART(comm) ) {
              const mca_topo_base_comm_cart_2_2_0_t *cart = comm->c_topo->mtc.cart;
              if( 0 > cart->ndims ) {
                  return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
              }
          }
          else if( OMPI_COMM_IS_GRAPH(comm) ) {
              int degree;
              mca_topo_base_graph_neighbors_count(comm, ompi_comm_rank(comm), &degree);
              if( 0 > degree ) {
                  return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
              }
          }
          else if( OMPI_COMM_IS_DIST_GRAPH(comm) ) {
              const mca_topo_base_comm_dist_graph_2_2_0_t *dist_graph = comm->c_topo->mtc.dist_graph;
              int indegree  = dist_graph->indegree;
              int outdegree = dist_graph->outdegree;
              if( indegree <  0 || outdegree <  0 ) {
                  return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
              }
          }
      }
  
      /* Do we need to do anything? */
  
      ompi_datatype_type_size(sendtype, &sendtype_size);
      ompi_datatype_type_size(recvtype, &recvtype_size);
      if (((0 == sendcount) || (0 == sendtype_size)) &&
          ((0 == recvcount) || 0 == (recvtype_size))) {
          return MPI_SUCCESS;
      }
  
      OPAL_CR_ENTER_LIBRARY();
  
      /* Invoke the coll component to perform the back-end operation */
      err = comm->c_coll->coll_neighbor_alltoall(sendbuf, sendcount, sendtype, recvbuf,
                                                recvcount, recvtype, comm,
                                                comm->c_coll->coll_neighbor_alltoall_module);
      OMPI_ERRHANDLER_RETURN(err, comm, err, FUNC_NAME);
  }
  
  