/* -*- 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_MPI_T_CVAR_INFO_BLOCK ===

cvars:

    - name        : MPIR_CVAR_SCAN_INTRA_ALGORITHM

      category    : COLLECTIVE

      type        : string

      default     : auto

      class       : device

      verbosity   : MPI_T_VERBOSITY_USER_BASIC

      scope       : MPI_T_SCOPE_ALL_EQ

      description : |-

        Variable to select allgather algorithm

        auto               - Internal algorithm selection

        nb                 - Force nonblocking algorithm

        recursive_doubling - Force recursive doubling algorithm

    - name        : MPIR_CVAR_SCAN_DEVICE_COLLECTIVE

      category    : COLLECTIVE

      type        : boolean

      default     : true

      class       : device

      verbosity   : MPI_T_VERBOSITY_USER_BASIC

      scope       : MPI_T_SCOPE_ALL_EQ

      description : >-

        If set to true, MPI_Scan will allow the device to override the

        MPIR-level collective algorithms. The device still has the

        option to call the MPIR-level algorithms manually.

        If set to false, the device-level scan function will not be

        called.

=== END_MPI_T_CVAR_INFO_BLOCK ===

*/

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

#if defined(HAVE_PRAGMA_WEAK)

#pragma weak MPI_Scan = PMPI_Scan

#elif defined(HAVE_PRAGMA_HP_SEC_DEF)

#pragma _HP_SECONDARY_DEF PMPI_Scan  MPI_Scan

#elif defined(HAVE_PRAGMA_CRI_DUP)

#pragma _CRI duplicate MPI_Scan as PMPI_Scan

#elif defined(HAVE_WEAK_ATTRIBUTE)

int MPI_Scan(const void *sendbuf, void *recvbuf, int count, MPI_Datatype datatype, MPI_Op op,

             MPI_Comm comm)

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

#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_Scan

#define MPI_Scan PMPI_Scan

#undef FUNCNAME

#define FUNCNAME MPIR_Scan_intra_auto

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Scan_intra_auto(const void *sendbuf, void *recvbuf, int count,

                         MPI_Datatype datatype, MPI_Op op, MPIR_Comm * comm_ptr,

                         MPIR_Errflag_t * errflag)

{

    int mpi_errno = MPI_SUCCESS;

    /* In order to use the SMP-aware algorithm, the "op" can be

     * either commutative or non-commutative, but we require a

     * communicator in which all the nodes contain processes with

     * consecutive ranks. */

    if (MPII_Comm_is_node_consecutive(comm_ptr)) {

        mpi_errno = MPIR_Scan_intra_smp(sendbuf, recvbuf, count, datatype, op, comm_ptr, errflag);

    } else {

        mpi_errno =

            MPIR_Scan_intra_recursive_doubling(sendbuf, recvbuf, count, datatype, op, comm_ptr,

                                               errflag);

    }

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

  fn_exit:

    if (*errflag != MPIR_ERR_NONE)

        MPIR_ERR_SET(mpi_errno, *errflag, "**coll_fail");

    return mpi_errno;

  fn_fail:

    goto fn_exit;

}

#undef FUNCNAME

#define FUNCNAME MPIR_Scan_impl

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Scan_impl(const void *sendbuf, void *recvbuf, int count,

                   MPI_Datatype datatype, MPI_Op op, MPIR_Comm * comm_ptr, MPIR_Errflag_t * errflag)

{

    int mpi_errno = MPI_SUCCESS;

    switch (MPIR_Scan_intra_algo_choice) {

        case MPIR_SCAN_INTRA_ALGO_RECURSIVE_DOUBLING:

            mpi_errno =

                MPIR_Scan_intra_recursive_doubling(sendbuf, recvbuf, count, datatype, op, comm_ptr,

                                                   errflag);

            break;

        case MPIR_SCAN_INTRA_ALGO_NB:

            mpi_errno =

                MPIR_Scan_allcomm_nb(sendbuf, recvbuf, count, datatype, op, comm_ptr, errflag);

            break;

        case MPIR_SCAN_INTRA_ALGO_AUTO:

            MPL_FALLTHROUGH;

        default:

            mpi_errno =

                MPIR_Scan_intra_auto(sendbuf, recvbuf, count, datatype, op, comm_ptr, errflag);

            break;

    }

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

  fn_exit:

    return mpi_errno;

  fn_fail:

    goto fn_exit;

}

#undef FUNCNAME

#define FUNCNAME MPIR_Scan

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Scan(const void *sendbuf, void *recvbuf, int count,

              MPI_Datatype datatype, MPI_Op op, MPIR_Comm * comm_ptr, MPIR_Errflag_t * errflag)

{

    int mpi_errno = MPI_SUCCESS;

    if (MPIR_CVAR_SCAN_DEVICE_COLLECTIVE && MPIR_CVAR_DEVICE_COLLECTIVES) {

        mpi_errno = MPID_Scan(sendbuf, recvbuf, count, datatype, op, comm_ptr, errflag);

    } else {

        mpi_errno = MPIR_Scan_impl(sendbuf, recvbuf, count, datatype, op, comm_ptr, errflag);

    }

    return mpi_errno;

}

#endif

#undef FUNCNAME

#define FUNCNAME MPI_Scan

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

/*@

MPI_Scan - Computes the scan (partial reductions) of data on a collection of

           processes

Input Parameters:

+ sendbuf - starting address of send buffer (choice)

. count - number of elements in input buffer (integer)

. datatype - data type of elements of input buffer (handle)

. op - operation (handle)

- comm - communicator (handle)

Output Parameters:

. recvbuf - starting address of receive buffer (choice)

.N ThreadSafe

.N Fortran

.N collops

.N Errors

.N MPI_SUCCESS

.N MPI_ERR_COMM

.N MPI_ERR_COUNT

.N MPI_ERR_TYPE

.N MPI_ERR_BUFFER

.N MPI_ERR_BUFFER_ALIAS

@*/

int MPI_Scan(const void *sendbuf, void *recvbuf, int count, MPI_Datatype datatype,

             MPI_Op op, MPI_Comm comm)

{

    int mpi_errno = MPI_SUCCESS;

    MPIR_Comm *comm_ptr = NULL;

    MPIR_Errflag_t errflag = MPIR_ERR_NONE;

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_SCAN);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    MPIR_FUNC_TERSE_COLL_ENTER(MPID_STATE_MPI_SCAN);

    /* Validate parameters, especially handles needing to be converted */

#ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

            MPIR_ERRTEST_COMM(comm, mpi_errno);

        }

        MPID_END_ERROR_CHECKS;

    }

#endif /* HAVE_ERROR_CHECKING */

    /* Convert MPI object handles to object pointers */

    MPIR_Comm_get_ptr(comm, comm_ptr);

    /* Validate parameters and objects (post conversion) */

#ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

            MPIR_Datatype *datatype_ptr = NULL;

            MPIR_Op *op_ptr = NULL;

            MPIR_Comm_valid_ptr(comm_ptr, mpi_errno, FALSE);

            if (mpi_errno != MPI_SUCCESS)

                goto fn_fail;

            MPIR_ERRTEST_COMM_INTRA(comm_ptr, mpi_errno);

            MPIR_ERRTEST_COUNT(count, mpi_errno);

            MPIR_ERRTEST_DATATYPE(datatype, "datatype", mpi_errno);

            MPIR_ERRTEST_OP(op, mpi_errno);

            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 != MPI_SUCCESS)

                    goto fn_fail;

                MPIR_Datatype_committed_ptr(datatype_ptr, mpi_errno);

                if (mpi_errno != MPI_SUCCESS)

                    goto fn_fail;

            }

            /* in_place option allowed. no error check */

            MPIR_ERRTEST_USERBUFFER(sendbuf, count, datatype, mpi_errno);

            MPIR_ERRTEST_RECVBUF_INPLACE(recvbuf, count, mpi_errno);

            MPIR_ERRTEST_USERBUFFER(recvbuf, count, datatype, mpi_errno);

            if (HANDLE_GET_KIND(op) != HANDLE_KIND_BUILTIN) {

                MPIR_Op_get_ptr(op, op_ptr);

                MPIR_Op_valid_ptr(op_ptr, mpi_errno);

            }

            if (HANDLE_GET_KIND(op) == HANDLE_KIND_BUILTIN) {

                mpi_errno = (*MPIR_OP_HDL_TO_DTYPE_FN(op)) (datatype);

            }

            if (mpi_errno != MPI_SUCCESS)

                goto fn_fail;

            if (sendbuf != MPI_IN_PLACE && count != 0)

                MPIR_ERRTEST_ALIAS_COLL(sendbuf, recvbuf, mpi_errno);

        }

        MPID_END_ERROR_CHECKS;

    }

#endif /* HAVE_ERROR_CHECKING */

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

    mpi_errno = MPIR_Scan(sendbuf, recvbuf, count, datatype, op, comm_ptr, &errflag);

    if (mpi_errno)

        goto fn_fail;

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

  fn_exit:

    MPIR_FUNC_TERSE_COLL_EXIT(MPID_STATE_MPI_SCAN);

    MPID_THREAD_CS_EXIT(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    return mpi_errno;

  fn_fail:

    /* --BEGIN ERROR HANDLING-- */

#ifdef HAVE_ERROR_CHECKING

    {

        mpi_errno =

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

                                 "**mpi_scan", "**mpi_scan %p %p %d %D %O %C", sendbuf, recvbuf,

                                 count, datatype, op, comm);

    }

#endif

    mpi_errno = MPIR_Err_return_comm(comm_ptr, FCNAME, mpi_errno);

    goto fn_exit;

    /* --END ERROR HANDLING-- */

}