/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *  (C) 2010 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpiimpl.h"

/*

=== BEGIN_MPI_T_CVAR_INFO_BLOCK ===

cvars:

    - name        : MPIR_CVAR_IGATHER_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 igather algorithm

        auto     - Internal algorithm selection

        binomial - Force binomial algorithm

        tree     - Force genetric transport based tree algorithm

    - name        : MPIR_CVAR_IGATHER_TREE_KVAL

      category    : COLLECTIVE

      type        : int

      default     : 2

      class       : device

      verbosity   : MPI_T_VERBOSITY_USER_BASIC

      scope       : MPI_T_SCOPE_ALL_EQ

      description : >-

        k value for tree based igather

    - name        : MPIR_CVAR_IGATHER_INTER_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 igather algorithm

        auto        - Internal algorithm selection

        long_inter  - Force long inter algorithm

        short_inter - Force short inter algorithm

    - name        : MPIR_CVAR_IGATHER_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_Igather 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 igather function will not be

        called.

=== END_MPI_T_CVAR_INFO_BLOCK ===

*/

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

#if defined(HAVE_PRAGMA_WEAK)

#pragma weak MPI_Igather = PMPI_Igather

#elif defined(HAVE_PRAGMA_HP_SEC_DEF)

#pragma _HP_SECONDARY_DEF PMPI_Igather  MPI_Igather

#elif defined(HAVE_PRAGMA_CRI_DUP)

#pragma _CRI duplicate MPI_Igather as PMPI_Igather

#elif defined(HAVE_WEAK_ATTRIBUTE)

int MPI_Igather(const void *sendbuf, int sendcount, MPI_Datatype sendtype, void *recvbuf,

                int recvcount, MPI_Datatype recvtype, int root, MPI_Comm comm,

                MPI_Request * request)

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

#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_Igather

#define MPI_Igather PMPI_Igather

#undef FUNCNAME

#define FUNCNAME MPIR_Igather_sched_intra_auto

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Igather_sched_intra_auto(const void *sendbuf, int sendcount, MPI_Datatype sendtype,

                                  void *recvbuf, int recvcount, MPI_Datatype recvtype, int root,

                                  MPIR_Comm * comm_ptr, MPIR_Sched_t s)

{

    int mpi_errno = MPI_SUCCESS;

    mpi_errno =

        MPIR_Igather_sched_intra_binomial(sendbuf, sendcount, sendtype, recvbuf, recvcount,

                                          recvtype, root, comm_ptr, s);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

  fn_exit:

    return mpi_errno;

  fn_fail:

    goto fn_exit;

}

#undef FUNCNAME

#define FUNCNAME MPIR_Igather_sched_inter_auto

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Igather_sched_inter_auto(const void *sendbuf, int sendcount, MPI_Datatype sendtype,

                                  void *recvbuf, int recvcount, MPI_Datatype recvtype, int root,

                                  MPIR_Comm * comm_ptr, MPIR_Sched_t s)

{

    int mpi_errno = MPI_SUCCESS;

    MPI_Aint local_size, remote_size;

    MPI_Aint recvtype_size, sendtype_size, nbytes;

    if (root == MPI_PROC_NULL) {

        /* local processes other than root do nothing */

        goto fn_exit;

    }

    remote_size = comm_ptr->remote_size;

    local_size = comm_ptr->local_size;

    if (root == MPI_ROOT) {

        MPIR_Datatype_get_size_macro(recvtype, recvtype_size);

        nbytes = recvtype_size * recvcount * remote_size;

    } else {

        /* remote side */

        MPIR_Datatype_get_size_macro(sendtype, sendtype_size);

        nbytes = sendtype_size * sendcount * local_size;

    }

    if (nbytes < MPIR_CVAR_GATHER_INTER_SHORT_MSG_SIZE) {

        mpi_errno =

            MPIR_Igather_sched_inter_short(sendbuf, sendcount, sendtype, recvbuf, recvcount,

                                           recvtype, root, comm_ptr, s);

    } else {

        mpi_errno =

            MPIR_Igather_sched_inter_long(sendbuf, sendcount, sendtype, recvbuf, recvcount,

                                          recvtype, root, comm_ptr, s);

    }

  fn_exit:

    return mpi_errno;

}

#undef FUNCNAME

#define FUNCNAME MPIR_Igather_sched_impl

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Igather_sched_impl(const void *sendbuf, int sendcount, MPI_Datatype sendtype,

                            void *recvbuf, int recvcount, MPI_Datatype recvtype,

                            int root, MPIR_Comm * comm_ptr, MPIR_Sched_t s)

{

    int mpi_errno = MPI_SUCCESS;

    if (comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM) {

        /* intracommunicator */

        switch (MPIR_Igather_intra_algo_choice) {

            case MPIR_IGATHER_INTRA_ALGO_BINOMIAL:

                mpi_errno = MPIR_Igather_sched_intra_binomial(sendbuf, sendcount, sendtype,

                                                              recvbuf, recvcount, recvtype, root,

                                                              comm_ptr, s);

                break;

            case MPIR_IGATHER_INTRA_ALGO_AUTO:

                MPL_FALLTHROUGH;

            default:

                mpi_errno = MPIR_Igather_sched_intra_auto(sendbuf, sendcount, sendtype,

                                                          recvbuf, recvcount, recvtype, root,

                                                          comm_ptr, s);

                break;

        }

    } else {

        /* intercommunicator */

        switch (MPIR_Igather_inter_algo_choice) {

            case MPIR_IGATHER_INTER_ALGO_LONG:

                mpi_errno = MPIR_Igather_sched_inter_long(sendbuf, sendcount, sendtype,

                                                          recvbuf, recvcount, recvtype, root,

                                                          comm_ptr, s);

                break;

            case MPIR_IGATHER_INTER_ALGO_SHORT:

                mpi_errno = MPIR_Igather_sched_inter_short(sendbuf, sendcount, sendtype,

                                                           recvbuf, recvcount, recvtype, root,

                                                           comm_ptr, s);

                break;

            case MPIR_IGATHER_INTER_ALGO_AUTO:

                MPL_FALLTHROUGH;

            default:

                mpi_errno = MPIR_Igather_sched_inter_auto(sendbuf, sendcount, sendtype, recvbuf,

                                                          recvcount, recvtype, root, comm_ptr, s);

        }

    }

    return mpi_errno;

}

#undef FUNCNAME

#define FUNCNAME MPIR_Igather_sched

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Igather_sched(const void *sendbuf, int sendcount, MPI_Datatype sendtype,

                       void *recvbuf, int recvcount, MPI_Datatype recvtype,

                       int root, MPIR_Comm * comm_ptr, MPIR_Sched_t s)

{

    int mpi_errno = MPI_SUCCESS;

    if (MPIR_CVAR_IGATHER_DEVICE_COLLECTIVE && MPIR_CVAR_DEVICE_COLLECTIVES) {

        mpi_errno = MPID_Igather_sched(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype,

                                       root, comm_ptr, s);

    } else {

        mpi_errno = MPIR_Igather_sched_impl(sendbuf, sendcount, sendtype, recvbuf, recvcount,

                                            recvtype, root, comm_ptr, s);

    }

    return mpi_errno;

}

#undef FUNCNAME

#define FUNCNAME MPIR_Igather_impl

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Igather_impl(const void *sendbuf, int sendcount,

                      MPI_Datatype sendtype, void *recvbuf, int recvcount,

                      MPI_Datatype recvtype, int root, MPIR_Comm * comm_ptr,

                      MPIR_Request ** request)

{

    int mpi_errno = MPI_SUCCESS;

    int tag = -1;

    MPIR_Sched_t s = MPIR_SCHED_NULL;

    *request = NULL;

    /* If the user picks one of the transport-enabled algorithms, branch there

     * before going down to the MPIR_Sched-based algorithms. */

    /* TODO - Eventually the intention is to replace all of the

     * MPIR_Sched-based algorithms with transport-enabled algorithms, but that

     * will require sufficient performance testing and replacement algorithms. */

    if (comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM) {

        /* intracommunicator */

        switch (MPIR_Igather_intra_algo_choice) {

            case MPIR_IGATHER_INTRA_ALGO_TREE:

                mpi_errno =

                    MPIR_Igather_intra_tree(sendbuf, sendcount, sendtype,

                                            recvbuf, recvcount, recvtype, root, comm_ptr, request);

                if (mpi_errno)

                    MPIR_ERR_POP(mpi_errno);

                goto fn_exit;

                break;

            default:

                /* go down to the MPIR_Sched-based algorithms */

                break;

        }

    }

    mpi_errno = MPIR_Sched_next_tag(comm_ptr, &tag;;

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    mpi_errno = MPIR_Sched_create(&s);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    mpi_errno =

        MPIR_Igather_sched(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype, root,

                           comm_ptr, s);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    mpi_errno = MPIR_Sched_start(&s, comm_ptr, tag, request);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

  fn_exit:

    return mpi_errno;

  fn_fail:

    goto fn_exit;

}

#undef FUNCNAME

#define FUNCNAME MPIR_Igather

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Igather(const void *sendbuf, int sendcount, MPI_Datatype sendtype,

                 void *recvbuf, int recvcount, MPI_Datatype recvtype, int root,

                 MPIR_Comm * comm_ptr, MPIR_Request ** request)

{

    int mpi_errno = MPI_SUCCESS;

    if (MPIR_CVAR_IGATHER_DEVICE_COLLECTIVE && MPIR_CVAR_DEVICE_COLLECTIVES) {

        mpi_errno = MPID_Igather(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype,

                                 root, comm_ptr, request);

    } else {

        mpi_errno = MPIR_Igather_impl(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype,

                                      root, comm_ptr, request);

    }

    return mpi_errno;

}

#endif /* MPICH_MPI_FROM_PMPI */

#undef FUNCNAME

#define FUNCNAME MPI_Igather

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

/*@

MPI_Igather - Gathers together values from a group of processes in

              a nonblocking way

Input Parameters:

+ sendbuf - starting address of the send buffer (choice)

. sendcount - number of elements in send buffer (non-negative integer)

. sendtype - data type of send buffer elements (handle)

. recvcount - number of elements for any single receive (non-negative integer, significant only at root)

. recvtype - data type of receive buffer elements (significant only at root) (handle)

. root - rank of receiving process (integer)

- comm - communicator (handle)

Output Parameters:

+ recvbuf - starting address of the receive buffer (significant only at root) (choice)

- request - communication request (handle)

.N ThreadSafe

.N Fortran

.N Errors

@*/

int MPI_Igather(const void *sendbuf, int sendcount, MPI_Datatype sendtype,

                void *recvbuf, int recvcount, MPI_Datatype recvtype,

                int root, MPI_Comm comm, MPI_Request * request)

{

    int mpi_errno = MPI_SUCCESS;

    MPIR_Comm *comm_ptr = NULL;

    MPIR_Request *request_ptr = NULL;

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_IGATHER);

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_IGATHER);

    /* 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 *sendtype_ptr = NULL, *recvtype_ptr = NULL;

            int rank;

            MPIR_Comm_valid_ptr(comm_ptr, mpi_errno, FALSE);

            if (mpi_errno != MPI_SUCCESS)

                goto fn_fail;

            if (comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM) {

                MPIR_ERRTEST_INTRA_ROOT(comm_ptr, root, mpi_errno);

                if (sendbuf != MPI_IN_PLACE) {

                    MPIR_ERRTEST_COUNT(sendcount, mpi_errno);

                    MPIR_ERRTEST_DATATYPE(sendtype, "sendtype", mpi_errno);

                    if (HANDLE_GET_KIND(sendtype) != HANDLE_KIND_BUILTIN) {

                        MPIR_Datatype_get_ptr(sendtype, sendtype_ptr);

                        MPIR_Datatype_valid_ptr(sendtype_ptr, mpi_errno);

                        if (mpi_errno != MPI_SUCCESS)

                            goto fn_fail;

                        MPIR_Datatype_committed_ptr(sendtype_ptr, mpi_errno);

                        if (mpi_errno != MPI_SUCCESS)

                            goto fn_fail;

                    }

                    MPIR_ERRTEST_USERBUFFER(sendbuf, sendcount, sendtype, mpi_errno);

                }

                rank = comm_ptr->rank;

                if (rank == root) {

                    MPIR_ERRTEST_COUNT(recvcount, mpi_errno);

                    MPIR_ERRTEST_DATATYPE(recvtype, "recvtype", mpi_errno);

                    if (HANDLE_GET_KIND(recvtype) != HANDLE_KIND_BUILTIN) {

                        MPIR_Datatype_get_ptr(recvtype, recvtype_ptr);

                        MPIR_Datatype_valid_ptr(recvtype_ptr, mpi_errno);

                        if (mpi_errno != MPI_SUCCESS)

                            goto fn_fail;

                        MPIR_Datatype_committed_ptr(recvtype_ptr, mpi_errno);

                        if (mpi_errno != MPI_SUCCESS)

                            goto fn_fail;

                    }

                    MPIR_ERRTEST_RECVBUF_INPLACE(recvbuf, recvcount, mpi_errno);

                    MPIR_ERRTEST_USERBUFFER(recvbuf, recvcount, recvtype, mpi_errno);

                    /* catch common aliasing cases */

                    if (recvbuf != MPI_IN_PLACE && sendtype == recvtype && sendcount == recvcount &&

                        sendcount != 0) {

                        MPI_Aint recvtype_size;

                        MPIR_Datatype_get_size_macro(recvtype, recvtype_size);

                        MPIR_ERRTEST_ALIAS_COLL(sendbuf,

                                                (char *) recvbuf +

                                                comm_ptr->rank * recvcount * recvtype_size,

                                                mpi_errno);

                    }

                } else

                    MPIR_ERRTEST_SENDBUF_INPLACE(sendbuf, sendcount, mpi_errno);

            }

            if (comm_ptr->comm_kind == MPIR_COMM_KIND__INTERCOMM) {

                MPIR_ERRTEST_INTER_ROOT(comm_ptr, root, mpi_errno);

                if (root == MPI_ROOT) {

                    MPIR_ERRTEST_COUNT(recvcount, mpi_errno);

                    MPIR_ERRTEST_DATATYPE(recvtype, "recvtype", mpi_errno);

                    if (HANDLE_GET_KIND(recvtype) != HANDLE_KIND_BUILTIN) {

                        MPIR_Datatype_get_ptr(recvtype, recvtype_ptr);

                        MPIR_Datatype_valid_ptr(recvtype_ptr, mpi_errno);

                        if (mpi_errno != MPI_SUCCESS)

                            goto fn_fail;

                        MPIR_Datatype_committed_ptr(recvtype_ptr, mpi_errno);

                        if (mpi_errno != MPI_SUCCESS)

                            goto fn_fail;

                    }

                    MPIR_ERRTEST_RECVBUF_INPLACE(recvbuf, recvcount, mpi_errno);

                    MPIR_ERRTEST_USERBUFFER(recvbuf, recvcount, recvtype, mpi_errno);

                }

                else if (root != MPI_PROC_NULL) {

                    MPIR_ERRTEST_COUNT(sendcount, mpi_errno);

                    MPIR_ERRTEST_DATATYPE(sendtype, "sendtype", mpi_errno);

                    if (HANDLE_GET_KIND(sendtype) != HANDLE_KIND_BUILTIN) {

                        MPIR_Datatype_get_ptr(sendtype, sendtype_ptr);

                        MPIR_Datatype_valid_ptr(sendtype_ptr, mpi_errno);

                        if (mpi_errno != MPI_SUCCESS)

                            goto fn_fail;

                        MPIR_Datatype_committed_ptr(sendtype_ptr, mpi_errno);

                        if (mpi_errno != MPI_SUCCESS)

                            goto fn_fail;

                    }

                    MPIR_ERRTEST_SENDBUF_INPLACE(sendbuf, sendcount, mpi_errno);

                    MPIR_ERRTEST_USERBUFFER(sendbuf, sendcount, sendtype, mpi_errno);

                }

            }

        }

        MPID_END_ERROR_CHECKS;

    }

#endif /* HAVE_ERROR_CHECKING */

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

    mpi_errno = MPIR_Igather(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype,

                             root, comm_ptr, &request_ptr);

    if (mpi_errno)

        MPIR_ERR_POP(mpi_errno);

    /* create a complete request, if needed */

    if (!request_ptr)

        request_ptr = MPIR_Request_create_complete(MPIR_REQUEST_KIND__COLL);

    /* return the handle of the request to the user */

    *request = request_ptr->handle;

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

  fn_exit:

    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_IGATHER);

    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_igather", "**mpi_igather %p %d %D %p %d %D %d %C %p",

                                 sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype, root,

                                 comm, request);

    }

#endif

    mpi_errno = MPIR_Err_return_comm(comm_ptr, FCNAME, mpi_errno);

    goto fn_exit;

    /* --END ERROR HANDLING-- */

}