/* -*- 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"

/* -- Begin Profiling Symbol Block for routine MPI_Get_count */

#if defined(HAVE_PRAGMA_WEAK)

#pragma weak MPI_Get_count = PMPI_Get_count

#elif defined(HAVE_PRAGMA_HP_SEC_DEF)

#pragma _HP_SECONDARY_DEF PMPI_Get_count  MPI_Get_count

#elif defined(HAVE_PRAGMA_CRI_DUP)

#pragma _CRI duplicate MPI_Get_count as PMPI_Get_count

#elif defined(HAVE_WEAK_ATTRIBUTE)

int MPI_Get_count(const MPI_Status * status, MPI_Datatype datatype, int *count)

    __attribute__ ((weak, alias("PMPI_Get_count")));

#endif

/* -- End Profiling Symbol Block */

/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build

   the MPI routines */

#ifndef MPICH_MPI_FROM_PMPI

#undef MPI_Get_count

#define MPI_Get_count PMPI_Get_count

#undef FUNCNAME

#define FUNCNAME MPIR_Get_count_impl

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

void MPIR_Get_count_impl(const MPI_Status * status, MPI_Datatype datatype, MPI_Aint * count)

{

    MPI_Aint size;

    MPIR_Datatype_get_size_macro(datatype, size);

    MPIR_Assert(size >= 0 && MPIR_STATUS_GET_COUNT(*status) >= 0);

    if (size != 0) {

        /* MPI-3 says return MPI_UNDEFINED if too large for an int */

        if ((MPIR_STATUS_GET_COUNT(*status) % size) != 0)

            (*count) = MPI_UNDEFINED;

        else

            (*count) = (MPI_Aint) (MPIR_STATUS_GET_COUNT(*status) / size);

    } else {

        if (MPIR_STATUS_GET_COUNT(*status) > 0) {

            /* --BEGIN ERROR HANDLING-- */

            /* case where datatype size is 0 and count is > 0 should

             * never occur.

             */

            (*count) = MPI_UNDEFINED;

            /* --END ERROR HANDLING-- */

        } else {

            /* This is ambiguous.  However, discussions on MPI Forum

             * reached a consensus that this is the correct return

             * value

             */

            (*count) = 0;

        }

    }

}

#endif

#undef FUNCNAME

#define FUNCNAME MPI_Get_count

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

/*@

  MPI_Get_count - Gets the number of "top level" elements

Input Parameters:

+ status - return status of receive operation (Status)

- datatype - datatype of each receive buffer element (handle)

Output Parameters:

. count - number of received elements (integer)

Notes:

If the size of the datatype is zero, this routine will return a count of

zero.  If the amount of data in 'status' is not an exact multiple of the

size of 'datatype' (so that 'count' would not be integral), a 'count' of

'MPI_UNDEFINED' is returned instead.

.N Fortran

.N Errors

.N MPI_SUCCESS

.N MPI_ERR_TYPE

@*/

int MPI_Get_count(const MPI_Status * status, MPI_Datatype datatype, int *count)

{

    int mpi_errno = MPI_SUCCESS;

    MPI_Aint count_x;

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_GET_COUNT);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_GET_COUNT);

#ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

            MPIR_Datatype *datatype_ptr = NULL;

            MPIR_ERRTEST_ARGNULL(status, "status", mpi_errno);

            MPIR_ERRTEST_ARGNULL(count, "count", mpi_errno);

            MPIR_ERRTEST_DATATYPE(datatype, "datatype", mpi_errno);

            /* Validate datatype_ptr */

            if (HANDLE_GET_KIND(datatype) != HANDLE_KIND_BUILTIN) {

                MPIR_Datatype_get_ptr(datatype, datatype_ptr);

                MPIR_Datatype_valid_ptr(datatype_ptr, mpi_errno);

                if (mpi_errno)

                    goto fn_fail;

                /* Q: Must the type be committed to be used with this function? */

            }

        }

        MPID_END_ERROR_CHECKS;

    }

#endif /* HAVE_ERROR_CHECKING */

    /* ... body of routine ...  */

    MPIR_Get_count_impl(status, datatype, &count_x);

    /* clip the value if it cannot be correctly returned to the user */

    *count = (count_x > INT_MAX) ? MPI_UNDEFINED : (int) count_x;

    /* ... end of body of routine ... */

#ifdef HAVE_ERROR_CHECKING

  fn_exit:

#endif

    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_GET_COUNT);

    return mpi_errno;

    /* --BEGIN ERROR HANDLING-- */

#ifdef HAVE_ERROR_CHECKING

  fn_fail:

    {

        mpi_errno =

            MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER,

                                 "**mpi_get_count", "**mpi_get_count %p %D %p", status, datatype,

                                 count);

    }

    mpi_errno = MPIR_Err_return_comm(0, FCNAME, mpi_errno);

    goto fn_exit;

#endif

    /* --END ERROR HANDLING-- */

}