!=======================================================================
! RCS Header:
!   Revision     [$Revision: 1.11.1.3 $]     Named [$Name: release#2_9_b5 $]
!   Last checkin [$Date: 2002/08/16 14:42:20 $]
!   Author       [$Author: frpb $]
!=======================================================================

! *****************************COPYRIGHT*******************************
! (c) CROWN COPYRIGHT 2001, Met Office, All Rights Reserved.           
! Please refer to Copyright file in top level GCOM directory
!                 for further details
! *****************************COPYRIGHT*******************************

#include "gc_prolog.h"

      SUBROUTINE GC_INIT (PATH, ME, NPROC)
!     ******************************************************************
!     * Purpose:
!     *
!     *  Initialize all (machine dependent) variables used in the
!     *  communication. 
!     *
!     * Input:
!     *  NPROC   - OBSOLETE [ number of nodes (PVM_SRC only)   ]
!     *  PATH    - OBSOLETE [ path name of executable to be    ]
!     *                     [ spawned (PVM_SRC only) used only ]
!     *                     [ if first character is non-blank. ]
!     *
!     * Output:
!     *  NPROC   - number of nodes 
!     *  ME      - my node ID, 0..NPROC-1
!     *
!     * NOTES:       
!     *  Initialize BCAST_SYNC_WRK, REDUCESYNC (SHMEM only).
!     *
!     ******************************************************************

      IMPLICIT NONE
      CHARACTER*(*) PATH
      INTEGER ME, NPROC
#include "gc__init_common.h"
#if defined(SHM_SRC)
      INTEGER SHMEM_MY_PE, SHMEM_N_PES
      REAL TSECND
#include "gc__timeout_common.h"
#endif

#if defined(MPI_SRC)
      INCLUDE 'mpif.h'
      INTEGER INFO
      LOGICAL MPIFLAG
#if defined(BUFFERED_MPI)
      INTEGER BSEND_BUFFER(MPI_BSEND_BUFFER_SIZE)
      SAVE BSEND_BUFFER
#endif

            INTEGER IERR
#include "gc__mpi_common.h"
#endif

      LOGICAL INITED
      INTEGER I
      DATA INITED/.FALSE./
      SAVE INITED


      IF (INITED) THEN
         RETURN
      ELSE
         CALL GC__INIT_INTERNALS(INITED)
      ENDIF

#if defined(SHM_SRC) 
      ME = SHMEM_MY_PE()
      NPROC = SHMEM_N_PES()
      CALL SHMEM_SET_CACHE_INV()
!--set the default SHM_NAM timeout as ~10 seconds
      NAM_MAX_SECONDS=TSECND()
      NAM_MAX_SECONDS=300
      CALL BARRIER
#endif

#if defined(MPI_SRC)
      CALL MPI_INIT(INFO)
      CALL MPI_COMM_RANK(MPI_COMM_WORLD, ME, INFO)
      CALL MPI_COMM_SIZE(MPI_COMM_WORLD, NPROC, INFO)
      CALL MPI_ATTR_GET(MPI_COMM_WORLD,MPI_TAG_UB,GC__MPI_MAXTAG,
     $                  MPIFLAG,INFO)
#if defined(BUFFERED_MPI)
#if !defined(SGI)
      CALL MPI_BUFFER_ATTACH(BSEND_BUFFER, 
     $                       MPI_BSEND_BUFFER_SIZE*GC__ISIZE, IERR)
#else
      GC__MPI_MAXTAG=32767
#endif
#endif
#endif

#if defined(SERIAL_SRC)
      ME = 0
      NPROC = 1
#else
      IF (NPROC .GT. MAX_PROC) CALL GC__ERRLIM(0, 'INIT', 'PROC', 
     $                                         MAX_PROC, NPROC)
#endif

      GC__NPROC = NPROC
      GC__ME = ME
      GC__INITED = .TRUE.
      
      IF (GC__ME .EQ. 0) CALL GC__STAMP()
      
      RETURN
      END