C $Header: /home/ubuntu/mnt/e9_copy/MITgcm_contrib/nesting_sannino/nest_parent/nest_parent_check.F,v 1.3 2010/11/29 14:24:14 jmc Exp $
C $Name:  $

#include "NEST_PARENT_OPTIONS.h"

CBOP
C     !ROUTINE: NEST_PARENT_CHECK

C     !INTERFACE:
      SUBROUTINE NEST_PARENT_CHECK( myThid )

C     !DESCRIPTION:
C     *==========================================================*
C     | SUBROUTINE NEST_PARENT_CHECK
C     | o Validate basic package setup and inter-package
C     | dependencies.
C     *==========================================================*

C     !USES:
      IMPLICIT NONE

C     === Global variables ===
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "EESUPPORT.h"
#include "NEST_PARENT_PARAMS.h"

C     !INPUT/OUTPUT PARAMETERS:
C     myThid    :: my Thread Id number
      INTEGER myThid
CEOP

C     !LOCAL VARIABLES:
C     msgBuf    :: Informational/error message buffer
      CHARACTER*(MAX_LEN_MBUF) msgBuf
      INTEGER nNestSteps, checkSteps
      INTEGER ierr, istatus

      WRITE(msgBuf,'(A)')
     &             'NEST_PARENT_CHECK: #define ALLOW_NEST_PARENT'
      CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
     &                    SQUEEZE_RIGHT, myThid )

      _BEGIN_MASTER( myThid )

C--   Check length of integration between components.
C-    units: number of nesting-steps (since driver ignores CLD/PAR time steps)
      nNestSteps = nTimeSteps/1
      IF ( MOD( nNestSteps, 1 ).NE.0 ) nNestSteps = -1
      IF ( mpiMyId.EQ.0 ) THEN
C-    Send to driver the number of expected nesting-exchanges with driver:
        CALL MPI_SEND( nNestSteps, 1, MPI_INTEGER,
     &                 MSTR_DRV_P(NST_LEV_P), 3000,
     &                 MPI_Comm_World, ierr )
      ENDIF

C     Receive error code (-1) from World-Master if inconsistent nNestSteps.
C     Note: This is not broadcast from MSTR_DRV_P(NST_LEV_P) since everybody
C           in the World need to catch error, call MPI_FINALIZE & stop.
      CALL MPI_BCAST( checkSteps, 1, MPI_INTEGER,
     &                0, MPI_Comm_World, ierr )
C-    Check for mismatch:
      IF ( checkSteps .EQ. -1 ) THEN
        WRITE(msgBuf,'(A,I8)')
     &       'NEST_PARENT_CHECK: Nb Nesting steps =', nNestSteps
        CALL PRINT_ERROR( msgBuf, myThid )
        WRITE(msgBuf,'(A)')
     &       'NEST_PARENT_CHECK: CHILD nb of steps does NOT match'
        CALL PRINT_ERROR( msgBuf, myThid )
        CALL MPI_FINALIZE(ierr)
        STOP 'ABNORMAL END: S/R NEST_PARENT_CHECK:'
      ENDIF

      _END_MASTER(myThid)

      RETURN
      END