/* -*- 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) 2004-2012 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      Research Organization for Information Science
 *                         and Technology (RIST). 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"

#if OPAL_HAVE_WEAK_SYMBOLS && OMPI_PROFILING_DEFINES
#pragma weak MPI_Alltoall = PMPI_Alltoall
#endif

#if OMPI_PROFILING_DEFINES
#include "ompi/mpi/c/profile/defines.h"
#endif

static const char FUNC_NAME[] = "MPI_Alltoall";


int MPI_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;

    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 */

        if (MPI_IN_PLACE == sendbuf) {
            sendcount = recvcount;
            sendtype = recvtype;
        }

        err = MPI_SUCCESS;
        OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
        if (ompi_comm_invalid(comm)) {
            return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_COMM, 
                                          FUNC_NAME);
        } else if (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);
        }

        if (MPI_IN_PLACE != sendbuf && !OMPI_COMM_IS_INTER(comm)) {
            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);
            }
        }
    }

    /* Do we need to do anything? */

    ompi_datatype_type_size(sendtype, &sendtype_size);
    ompi_datatype_type_size(recvtype, &recvtype_size);
    if (((MPI_IN_PLACE == sendbuf) ||
         (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 */
    /* XXX -- CONST -- do not cast away const -- update mca/coll */
    err = comm->c_coll.coll_alltoall((void *) sendbuf, sendcount, sendtype,
                                     recvbuf, recvcount, recvtype,
                                     comm, comm->c_coll.coll_alltoall_module);
    OMPI_ERRHANDLER_RETURN(err, comm, err, FUNC_NAME);
}