source: palm/trunk/SOURCE/pmc_handle_communicator.f90 @ 1818

 MODULE PMC_handle_communicator

!--------------------------------------------------------------------------------!
! This file is part of PALM.
!
! PALM is free software: you can redistribute it and/or modify it under the terms
! of the GNU General Public License as published by the Free Software Foundation,
! either version 3 of the License, or (at your option) any later version.
!
! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
! A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
!
! You should have received a copy of the GNU General Public License along with
! PALM. If not, see <http://www.gnu.org/licenses/>.
!
! Copyright 1997-2016 Leibniz Universitaet Hannover
!--------------------------------------------------------------------------------!
!
! Current revisions:
! ------------------
!
!
! Former revisions:
! -----------------
! $Id: pmc_handle_communicator.f90 1818 2016-04-06 15:53:27Z maronga $
!
! 1808 2016-04-05 19:44:00Z raasch
! MPI module used by default on all machines
!
! 1797 2016-03-21 16:50:28Z raasch
! introduction of different datatransfer modes,
! export of comm_world_nesting
!
! 1791 2016-03-11 10:41:25Z raasch
! m_nrofcpl renamed m_ncpl,
! pmc_get_local_model_info renamed pmc_get_model_info, some keywords also
! renamed and some added,
! debug write-statements commented out
!
! 1786 2016-03-08 05:49:27Z raasch
! Bugfix: nesting_mode is broadcast now
!
! 1779 2016-03-03 08:01:28Z raasch
! only the total number of PEs is given in the nestpar-NAMELIST,
! additional comments included
!
! 1764 2016-02-28 12:45:19Z raasch
! pmc_layout type: comm_cpl and comm_parent removed, character "name" moved at
! the beginning of the variable list,
! domain layout is read with new NAMELIST nestpar from standard file PARIN,
! MPI-datatype REAL8 replaced by REAL, kind=8 replaced by wp,
! variable domain_layouts instead of m_couplers introduced for this NAMELIST,
! general format changed to PALM style
!
! 1762 2016-02-25 12:31:13Z hellstea
! Initial revision by K. Ketelsen
!
! Description:
! ------------
! Handle MPI communicator in PALM model coupler
!------------------------------------------------------------------------------!

#if defined( __parallel )
    USE kinds

#if defined( __mpifh )
    INCLUDE "mpif.h"
#else
    USE MPI
#endif

   USE pmc_general,                                                            &
       ONLY: pmc_status_ok, pmc_status_error, pmc_max_modell

   IMPLICIT NONE

   TYPE pmc_layout

      CHARACTER(len=32) ::  name

      INTEGER  ::  id
      INTEGER  ::  parent_id
      INTEGER  ::  npe_total

      REAL(wp) ::  lower_left_x
      REAL(wp) ::  lower_left_y

   END TYPE pmc_layout

   PUBLIC  pmc_status_ok, pmc_status_error

   INTEGER, PARAMETER, PUBLIC ::  pmc_error_npes          = 1  ! illegal number of PEs
   INTEGER, PARAMETER, PUBLIC ::  pmc_namelist_error      = 2  ! error(s) in nestpar namelist
   INTEGER, PARAMETER, PUBLIC ::  pmc_no_namelist_found   = 3  ! No couple layout file found

   ! Coupler Setup

   INTEGER                                    :: m_world_comm !global nesting communicator
   INTEGER                                    :: m_my_CPL_id  !Coupler id of this model
   INTEGER                                    :: m_Parent_id  !Coupler id of parent of this model
   INTEGER                                    :: m_ncpl       !Number of Couplers in layout file

   TYPE(PMC_layout),DIMENSION(PMC_MAX_MODELL) :: m_couplers   !Information of all couplers

   ! MPI settings

   INTEGER,PUBLIC                    :: m_model_comm          !Communicator of this model
   INTEGER,PUBLIC                    :: m_to_server_comm      !Communicator to the server
   INTEGER,DIMENSION(PMC_MAX_MODELL) :: m_to_client_comm      !Communicator to the client(s)
   INTEGER,PUBLIC                    :: m_world_rank
   INTEGER                           :: m_world_npes
   INTEGER,PUBLIC                    :: m_model_rank
   INTEGER,PUBLIC                    :: m_model_npes
   INTEGER                           :: m_server_remote_size  !Number of Server PE's

   PUBLIC m_to_client_comm

   !Indicates this PE is server for Cleint NR

   INTEGER,DIMENSION(:),POINTER,PUBLIC :: PMC_Server_for_Client

   INTERFACE pmc_is_rootmodel
      MODULE PROCEDURE pmc_is_rootmodel
   END INTERFACE pmc_is_rootmodel

   INTERFACE pmc_get_model_info
      MODULE PROCEDURE pmc_get_model_info
   END INTERFACE pmc_get_model_info

   PUBLIC pmc_get_model_info, pmc_init_model, pmc_is_rootmodel

 CONTAINS

   SUBROUTINE pmc_init_model( comm, nesting_datatransfer_mode, nesting_mode,   &
                              pmc_status )

      USE control_parameters,                                                  &
          ONLY:  message_string

      USE pegrid,                                                              &
          ONLY:  myid

      IMPLICIT NONE

      CHARACTER(LEN=7), INTENT(OUT) ::  nesting_mode
      CHARACTER(LEN=7), INTENT(OUT) ::  nesting_datatransfer_mode

      INTEGER, INTENT(OUT)                ::  comm
      INTEGER, INTENT(OUT)                ::  pmc_status

      INTEGER                             ::  i, ierr, istat
      INTEGER,DIMENSION(pmc_max_modell+1) ::  start_pe
      INTEGER                             ::  m_my_cpl_rank
      INTEGER                             ::  tag, clientcount
      INTEGER,DIMENSION(pmc_max_modell)   ::  activeserver  ! I am active server for this client ID

      pmc_status   = pmc_status_ok
      comm         = -1
      m_world_comm = MPI_COMM_WORLD
      m_my_cpl_id  = -1
      clientcount  =  0
      activeserver = -1
      start_pe(:)  =  0

      CALL  MPI_COMM_RANK( MPI_COMM_WORLD, m_world_rank, istat )
      CALL  MPI_COMM_SIZE( MPI_COMM_WORLD, m_world_npes, istat )
!
!--   Only PE 0 of root model reads
      IF ( m_world_rank == 0 )  THEN

         CALL read_coupling_layout( nesting_datatransfer_mode, nesting_mode,   &
                                    pmc_status )

         IF ( pmc_status /= pmc_no_namelist_found  .AND.                       &
              pmc_status /= pmc_namelist_error )                               &
         THEN
!
!--         Calculate start PE of every model
            start_pe(1) = 0
            DO  i = 2, m_ncpl+1
               start_pe(i) = start_pe(i-1) + m_couplers(i-1)%npe_total
            ENDDO

!
!--         The number of cores provided with the run must be the same as the
!--         total sum of cores required by all nest domains
            IF ( start_pe(m_ncpl+1) /= m_world_npes )  THEN
               WRITE ( message_string, '(A,I6,A,I6,A)' )                       &
                               'nesting-setup requires more MPI procs (',      &
                               start_pe(m_ncpl+1), ') than provided (',        &
                               m_world_npes,')'
               CALL message( 'pmc_init_model', 'PA0229', 3, 2, 0, 6, 0 )
            ENDIF

         ENDIF

      ENDIF
!
!--   Broadcast the read status. This synchronises all other PEs with PE 0 of
!--   the root model. Without synchronisation, they would not behave in the
!--   correct way (e.g. they would not return in case of a missing NAMELIST)
      CALL MPI_BCAST( pmc_status, 1, MPI_INTEGER, 0, MPI_COMM_WORLD, istat )

      IF ( pmc_status == pmc_no_namelist_found )  THEN
!
!--      Not a nested run; return the MPI_WORLD communicator
         comm = MPI_COMM_WORLD
         RETURN

      ELSEIF ( pmc_status == pmc_namelist_error )  THEN
!
!--      Only the root model gives the error message. Others are aborted by the
!--      message-routine with MPI_ABORT. Must be done this way since myid and
!--      comm2d have not yet been assigned at this point.
         IF ( m_world_rank == 0 )  THEN
            message_string = 'errors in \$nestpar'
            CALL message( 'pmc_init_model', 'PA0223', 3, 2, 0, 6, 0 )
         ENDIF

      ENDIF

      CALL MPI_BCAST( m_ncpl,          1, MPI_INTEGER, 0, MPI_COMM_WORLD, istat)
      CALL MPI_BCAST( start_pe, m_ncpl+1, MPI_INTEGER, 0, MPI_COMM_WORLD, istat)

!
!--   Broadcast coupling layout
      DO  i = 1, m_ncpl
         CALL MPI_BCAST( m_couplers(i)%name, LEN( m_couplers(i)%name ), MPI_CHARACTER, 0, MPI_COMM_WORLD, istat )
         CALL MPI_BCAST( m_couplers(i)%id,           1, MPI_INTEGER, 0, MPI_COMM_WORLD, istat )
         CALL MPI_BCAST( m_couplers(i)%Parent_id,    1, MPI_INTEGER, 0, MPI_COMM_WORLD, istat )
         CALL MPI_BCAST( m_couplers(i)%npe_total,    1, MPI_INTEGER, 0, MPI_COMM_WORLD, istat )
         CALL MPI_BCAST( m_couplers(i)%lower_left_x, 1, MPI_REAL,    0, MPI_COMM_WORLD, istat )
         CALL MPI_BCAST( m_couplers(i)%lower_left_y, 1, MPI_REAL,    0, MPI_COMM_WORLD, istat )
!--      TO_DO: the next two calls can and should probably moved outside this loop
         CALL MPI_BCAST( nesting_mode, LEN( nesting_mode ), MPI_CHARACTER, 0, MPI_COMM_WORLD, istat )
         CALL MPI_BCAST( nesting_datatransfer_mode, LEN(nesting_datatransfer_mode), MPI_CHARACTER, 0, MPI_COMM_WORLD, istat )
      ENDDO

!
!--   Assign global MPI processes to individual models by setting the couple id
      DO  i = 1, m_ncpl
         IF ( m_world_rank >= start_pe(i)  .AND.  m_world_rank < start_pe(i+1) ) &
         THEN
            m_my_cpl_id = i
            EXIT
         ENDIF
      ENDDO
      m_my_cpl_rank = m_world_rank - start_pe(i)

!
!--   MPI_COMM_WORLD is the communicator for ALL models (MPI-1 approach).
!--   The communictors for the individual models as created by MPI_COMM_SPLIT.
!--   The color of the model is represented by the coupler id
      CALL MPI_COMM_SPLIT( MPI_COMM_WORLD, m_my_cpl_id, m_my_cpl_rank, comm,   &
                           istat )
!
!--   Get size and rank of the model running on this PE
      CALL  MPI_COMM_RANK( comm, m_model_rank, istat )
      CALL  MPI_COMM_SIZE( comm, m_model_npes, istat )

!
!--   Broadcast (from PE 0) the parent id and id of every model
      DO  i = 1, m_ncpl
         CALL MPI_BCAST( m_couplers(i)%parent_id, 1, MPI_INTEGER, 0,           &
                         MPI_COMM_WORLD, istat )
         CALL MPI_BCAST( m_couplers(i)%id,        1, MPI_INTEGER, 0,           &
                         MPI_COMM_WORLD, istat )
      ENDDO

!
!--   Save the current model communicator for PMC internal use
      m_model_comm = comm

!
!--   Create intercommunicator between server and clients.
!--   MPI_INTERCOMM_CREATE creates an intercommunicator between 2 groups of
!--   different colors.
!--   The grouping was done above with MPI_COMM_SPLIT
      DO  i = 2, m_ncpl

         IF ( m_couplers(i)%parent_id == m_my_cpl_id )  THEN
!
!--         Collect server PEs.
!--         Every model exept the root model has a parent model which acts as
!--         server model. Create an intercommunicator to connect current PE to
!--         all client PEs
            tag = 500 + i
            CALL MPI_INTERCOMM_CREATE( comm, 0, MPI_COMM_WORLD, start_pe(i),   &
                                       tag, m_to_client_comm(i), istat)
            clientcount = clientcount + 1
            activeserver(i) = 1

         ELSEIF ( i == m_my_cpl_id)  THEN
!
!--         Collect client PEs.
!--         Every model exept the root model has a paremt model which acts as
!--         server model. Create an intercommunicator to connect current PE to
!--         all server PEs
            tag = 500 + i
            CALL MPI_INTERCOMM_CREATE( comm, 0, MPI_COMM_WORLD,                &
                                       start_pe(m_couplers(i)%parent_id),      &
                                       tag, m_to_server_comm, istat )
         ENDIF

      ENDDO

!
!--   If I am server, count the number of clients that I have
!--   Although this loop is symmetric on all processes, the "activeserver" flag
!--   is true (==1) on the respective individual PE only.
      ALLOCATE( pmc_server_for_client(clientcount+1) )

      clientcount = 0
      DO  i = 2, m_ncpl
         IF ( activeserver(i) == 1 )  THEN
            clientcount = clientcount + 1
            pmc_server_for_client(clientcount) = i
         ENDIF
      ENDDO
!
!--   Get the size of the server model
      IF ( m_my_cpl_id > 1 )  THEN
         CALL MPI_COMM_REMOTE_SIZE( m_to_server_comm, m_server_remote_size,    &
                                    istat)
      ELSE
!
!--      The root model does not have a server
         m_server_remote_size = -1             !
      ENDIF
!
!--   Set myid to non-tero value except for the root domain. This is a setting
!--   for the message routine which is called at the end of pmci_init. That
!--   routine outputs messages for myid = 0, only. However, myid has not been
!--   assigened so far, so that all PEs of the root model would output a
!--   message. To avoid this, set myid to some other value except for PE0 of the
!--   root domain.
      IF ( m_world_rank /= 0 )  myid = 1

   END SUBROUTINE PMC_init_model


!
!-- Provide module private variables of the pmc for PALM
    SUBROUTINE pmc_get_model_info( comm_world_nesting, cpl_id, cpl_name,       &
                                   cpl_parent_id, lower_left_x, lower_left_y,  &
                                   ncpl, npe_total, request_for_cpl_id )

      USE kinds

      IMPLICIT NONE

      CHARACTER(LEN=*), INTENT(OUT), OPTIONAL ::  cpl_name

      INTEGER, INTENT(IN), OPTIONAL ::  request_for_cpl_id

      INTEGER, INTENT(OUT), OPTIONAL ::  comm_world_nesting
      INTEGER, INTENT(OUT), OPTIONAL ::  cpl_id
      INTEGER, INTENT(OUT), OPTIONAL ::  cpl_parent_id
      INTEGER, INTENT(OUT), OPTIONAL ::  ncpl
      INTEGER, INTENT(OUT), OPTIONAL ::  npe_total

      INTEGER ::  requested_cpl_id

      REAL(wp), INTENT(OUT), OPTIONAL ::  lower_left_x
      REAL(wp), INTENT(OUT), OPTIONAL ::  lower_left_y

!
!--   Set the requested coupler id
      IF ( PRESENT( request_for_cpl_id ) )  THEN
         requested_cpl_id = request_for_cpl_id
!
!--      Check for allowed range of values
         IF ( requested_cpl_id < 1 .OR. requested_cpl_id > m_ncpl )  RETURN
      ELSE
         requested_cpl_id = m_my_cpl_id
      ENDIF

!
!--   Return the requested information
      IF ( PRESENT( comm_world_nesting )  )  THEN
         comm_world_nesting = m_world_comm
      ENDIF
      IF ( PRESENT( cpl_id )        )  THEN
         cpl_id = requested_cpl_id
      ENDIF
      IF ( PRESENT( cpl_parent_id ) )  THEN
         cpl_parent_id = m_couplers(requested_cpl_id)%parent_id
      ENDIF
      IF ( PRESENT( cpl_name )      )  THEN
         cpl_name = m_couplers(requested_cpl_id)%name
      ENDIF
      IF ( PRESENT( ncpl )          )  THEN
         ncpl = m_ncpl
      ENDIF
      IF ( PRESENT( npe_total )     )  THEN
         npe_total = m_couplers(requested_cpl_id)%npe_total
      ENDIF
      IF ( PRESENT( lower_left_x )  )  THEN
         lower_left_x = m_couplers(requested_cpl_id)%lower_left_x
      ENDIF
      IF ( PRESENT( lower_left_y )  )  THEN
         lower_left_y = m_couplers(requested_cpl_id)%lower_left_y
      ENDIF

   END SUBROUTINE pmc_get_model_info



   LOGICAL function pmc_is_rootmodel( )

      IMPLICIT NONE

      pmc_is_rootmodel = ( m_my_cpl_id == 1 )

   END FUNCTION pmc_is_rootmodel



 SUBROUTINE read_coupling_layout( nesting_datatransfer_mode, nesting_mode,     &
                                  pmc_status )

    IMPLICIT NONE

    CHARACTER(LEN=7), INTENT(INOUT) ::  nesting_mode
    CHARACTER(LEN=7), INTENT(INOUT) ::  nesting_datatransfer_mode

    INTEGER, INTENT(INOUT) ::  pmc_status
    INTEGER                ::  i, istat

    TYPE(pmc_layout), DIMENSION(pmc_max_modell) ::  domain_layouts


    NAMELIST /nestpar/  domain_layouts, nesting_datatransfer_mode, nesting_mode

!
!-- Initialize some coupling variables
    domain_layouts(1:pmc_max_modell)%id = -1
    m_ncpl =   0

    pmc_status = pmc_status_ok

!
!-- Open the NAMELIST-file and read the nesting layout
    CALL check_open( 11 )
    READ ( 11, nestpar, IOSTAT=istat )

    IF ( istat < 0 )  THEN
!
!--    No nestpar-NAMELIST found
       pmc_status = pmc_no_namelist_found
!
!--    Set filepointer to the beginning of the file. Otherwise PE0 will later
!--    be unable to read the inipar-NAMELIST
       REWIND ( 11 )
       RETURN

    ELSEIF ( istat > 0 )  THEN
!
!--    Errors in reading nestpar-NAMELIST
       pmc_status = pmc_namelist_error
       RETURN

    ENDIF

!
!-- Output location message
    CALL location_message( 'initialize communicators for nesting', .FALSE. )
!
!-- Assign the layout to the internally used variable
    m_couplers = domain_layouts

!
!-- Get the number of nested models given in the nestpar-NAMELIST
    DO  i = 1, pmc_max_modell
!
!--    When id=-1 is found for the first time, the list of domains is finished
       IF ( m_couplers(i)%id == -1  .OR.  i == pmc_max_modell )  THEN
          IF ( m_couplers(i)%id == -1 )  THEN
             m_ncpl = i - 1
             EXIT
          ELSE
             m_ncpl = pmc_max_modell
          ENDIF
       ENDIF

    ENDDO

 END SUBROUTINE read_coupling_layout

#endif
 END MODULE pmc_handle_communicator