/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2005 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2005 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.
 * $COPYRIGHT$
 * 
 * Additional copyrights may follow
 * 
 * $HEADER$
 */
#include "ompi_config.h"
#include <stdio.h>

#include "mpi/c/bindings.h"
#include "ompi/datatype/datatype.h"

#if OMPI_HAVE_WEAK_SYMBOLS && OMPI_PROFILING_DEFINES
#pragma weak MPI_Scatterv = PMPI_Scatterv
#endif

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

static const char FUNC_NAME[] = "MPI_Scatterv";


int MPI_Scatterv(void *sendbuf, int *sendcounts, int *displs,
                 MPI_Datatype sendtype, void *recvbuf, int recvcount,
                 MPI_Datatype recvtype, int root, MPI_Comm comm) 
{
    int i, size, err;
    
    if (MPI_PARAM_CHECK) {
        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 ((ompi_comm_rank(comm) != root && MPI_IN_PLACE == recvbuf) ||
                   MPI_IN_PLACE == sendbuf) {
            return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
        }

        /* Errors for intracommunicators */

        if (OMPI_COMM_IS_INTRA(comm)) {

          /* Errors for all ranks */

          if ((root >= ompi_comm_size(comm)) || (root < 0)) {
            return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ROOT, FUNC_NAME);
          }

          if (MPI_IN_PLACE != recvbuf) {
              if (recvcount < 0) {
                  return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_COUNT, 
                                                FUNC_NAME);
              }
              
              if (MPI_DATATYPE_NULL == recvtype) {
                  return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_TYPE, 
                                                FUNC_NAME); 
              }
          }

          /* Errors for the root.  Some of these could have been
             combined into compound if statements above, but since
             this whole section can be compiled out (or turned off at
             run time) for efficiency, it's more clear to separate
             them out into individual tests. */

          if (ompi_comm_rank(comm) == root) {
            if (NULL == displs) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
            }

            if (NULL == sendcounts) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_COUNT, FUNC_NAME);
            }

            size = ompi_comm_size(comm);
            for (i = 0; i < size; ++i) {
              OMPI_CHECK_DATATYPE_FOR_SEND(err, sendtype, sendcounts[i]);
              OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
            }
          }
        }

        /* Errors for intercommunicators */

        else {
          if (! ((root >= 0 && root < ompi_comm_remote_size(comm)) ||
                 MPI_ROOT == root || MPI_PROC_NULL == root)) {
            return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ROOT, FUNC_NAME);
          }

          /* Errors for the receivers */

          if (MPI_ROOT != root && MPI_PROC_NULL != root) {
            if (recvcount < 0) {
              return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_COUNT, FUNC_NAME);
            }

            if (MPI_DATATYPE_NULL == recvtype) {
              return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_TYPE, FUNC_NAME); 
            }
          }

          /* Errors for the root.  Ditto on the comment above -- these
             error checks could have been combined above, but let's
             make the code easier to read. */

          else if (MPI_ROOT == root) {
            if (NULL == displs) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
            }

            if (NULL == sendcounts) {
                return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_COUNT, FUNC_NAME);
            }

            size = ompi_comm_size(comm);
            for (i = 0; i < size; ++i) {
              OMPI_CHECK_DATATYPE_FOR_SEND(err, sendtype, sendcounts[i]);
              OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
            }
          }
        }
    }

    /* If we have nothing to do, just return */

    if (0 == recvcount && ompi_comm_rank(comm) != root) {
        return MPI_SUCCESS;
    }

    /* Invoke the coll component to perform the back-end operation */
	
    err = comm->c_coll.coll_scatterv(sendbuf, sendcounts, displs, sendtype, 
                                     recvbuf, recvcount, recvtype, root, comm);
    OMPI_ERRHANDLER_RETURN(err, comm, err, FUNC_NAME);
}