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Modules used for the scrip library (in oasis3/lib/scrip/src) :

timers : uses F90 cpu time routines to allowing setting of multiple CPU timers
used in scrip.F,

      use kinds_mod
      USE mod_unit          -----------------------> defined in oasis3/src

      implicit none

      integer (kind=int_kind), parameter :: 
     &     max_timers = 99  ! max number of timers allowed

      integer (kind=int_kind), save ::
     &     cycles_max       ! max value of clock allowed by system

      integer (kind=int_kind), dimension(max_timers), save ::
     &     cycles1,         ! cycle number at start for each timer
     &     cycles2          ! cycle number at stop  for each timer

      real (kind=real_kind), save :: 
     &     clock_rate       ! clock_rate in seconds for each cycle

      real (kind=real_kind), dimension(max_timers), save :: 
     &     cputime          ! accumulated cpu time in each timer

      character (len=8), dimension(max_timers), save :: 
     &     status           ! timer status string

!***********************************************************************

      contains

!***********************************************************************

      subroutine timer_check(timer)

!-----------------------------------------------------------------------
!
!     This routine checks a given timer.  This is primarily used to
!     periodically accumulate time in the timer to prevent timer cycles
!     from wrapping around max_cycles.
!
!-----------------------------------------------------------------------

!-----------------------------------------------------------------------
!
!     Input Variables:
!
!-----------------------------------------------------------------------

      integer (kind=int_kind), intent(in) :: 
     &    timer            ! timer number

!-----------------------------------------------------------------------

      if (status(timer) .eq. 'running') then
        call timer_stop (timer)
        call timer_start(timer)
      endif

!-----------------------------------------------------------------------

      end subroutine timer_check

!***********************************************************************

      subroutine timer_clear(timer)

!-----------------------------------------------------------------------
!
!     This routine resets a given timer.
!
!-----------------------------------------------------------------------

!-----------------------------------------------------------------------
!
!     Input Variables:
!
!-----------------------------------------------------------------------

      integer (kind=int_kind), intent(in) :: 
     &    timer            ! timer number

!-----------------------------------------------------------------------

      cputime(timer) = 0.0_real_kind  ! clear the timer

!-----------------------------------------------------------------------

      end subroutine timer_clear

!***********************************************************************

      function timer_get(timer)

!-----------------------------------------------------------------------
!
!     This routine returns the result of a given timer.  This can be
!     called instead of timer_print so that the calling routine can
!     print it in desired format.
!
!-----------------------------------------------------------------------

!-----------------------------------------------------------------------
!
!     Input Variables:
!
!-----------------------------------------------------------------------

      integer (kind=int_kind), intent(in) :: 
     &    timer            ! timer number

!-----------------------------------------------------------------------
!
!     Output Variables:
!
!-----------------------------------------------------------------------

      real (kind=real_kind) :: 
     &     timer_get   ! accumulated cputime in given timer

!-----------------------------------------------------------------------

      if (status(timer) .eq. 'stopped') then
        timer_get = cputime(timer)
      else
        call timer_stop(timer)
        timer_get = cputime(timer)
        call timer_start(timer)
      endif

!-----------------------------------------------------------------------

      end function timer_get

!***********************************************************************

      subroutine timer_print(timer)

!-----------------------------------------------------------------------
!
!     This routine prints the accumulated cpu time in given timer.
!
!-----------------------------------------------------------------------

!-----------------------------------------------------------------------
!
!     Input Variables:
!
!-----------------------------------------------------------------------

      integer (kind=int_kind), intent(in) :: 
     &    timer            ! timer number

!-----------------------------------------------------------------------

      !---
      !--- print the cputime accumulated for timer
      !--- make sure timer is stopped
      !---

      if (status(timer) .eq. 'stopped') then
        write(nulou,"(' CPU time for timer',i3,':',1p,e16.8)") 
     &       timer,cputime(timer)
      else
        call timer_stop(timer)
        write(nulou,"(' CPU time for timer',i3,':',1p,e16.8)") 
     &       timer,cputime(timer)
        call timer_start(timer)
      endif

!-----------------------------------------------------------------------

      end subroutine timer_print

!***********************************************************************

      subroutine timer_start(timer)

!-----------------------------------------------------------------------
!
!     This routine starts a given timer.
!
!-----------------------------------------------------------------------

!-----------------------------------------------------------------------
!
!     Input Variables:
!
!-----------------------------------------------------------------------

      integer (kind=int_kind), intent(in) :: 
     &    timer            ! timer number

!-----------------------------------------------------------------------

      !---
      !--- Start the timer and change timer status.
      !---

      if (status(timer) .eq. 'stopped') then
        call system_clock(count=cycles1(timer))
        status(timer) = 'running'
      endif

!-----------------------------------------------------------------------

      end subroutine timer_start

!***********************************************************************

      subroutine timer_stop(timer)

!-----------------------------------------------------------------------
!
!     This routine stops a given timer.
!
!-----------------------------------------------------------------------

!-----------------------------------------------------------------------
!
!     Input Variables:
!
!-----------------------------------------------------------------------

      integer (kind=int_kind), intent(in) :: 
     &    timer            ! timer number

!-----------------------------------------------------------------------

      if (status(timer) .eq. 'running') then

        !---
        !--- Stop the desired timer.
        !---

        call system_clock(count=cycles2(timer))

        !---
        !--- check and correct for cycle wrapping
        !---

        if (cycles2(timer) .ge. cycles1(timer)) then
          cputime(timer) = cputime(timer) + clock_rate* 
     &                     (cycles2(timer) - cycles1(timer))
        else
          cputime(timer) = cputime(timer) + clock_rate* 
     &                (cycles2(timer) - cycles1(timer) + cycles_max)
        endif

        !---
        !--- Change timer status.
        !---

        status(timer)='stopped'

      endif

!-----------------------------------------------------------------------

      end subroutine timer_stop

!***********************************************************************

      subroutine timers_init

!-----------------------------------------------------------------------
!
!     This routine initializes some machine parameters necessary for
!     computing cpu time from F90 intrinsics.
!
!-----------------------------------------------------------------------

      integer (kind=int_kind) :: cycles ! count rate return by sys_clock

!-----------------------------------------------------------------------

      !---
      !--- Initialize timer arrays and clock_rate.
      !---

      clock_rate = 0.0_real_kind
      cycles1    = 0
      cycles2    = 0
      cputime    = 0.0_real_kind
      status     = 'stopped'

      !---
      !--- Call F90 intrinsic system_clock to determine clock rate
      !--- and maximum cycles.  If no clock available, print message.
      !---

      call system_clock(count_rate=cycles, count_max=cycles_max)

      if (cycles /= 0) then
        clock_rate = 1.0_real_kind/real(cycles)
      else
        clock_rate = 0.0_real_kind
        WRITE(nulou,*) '--- No system clock available ---'
      endif

!-----------------------------------------------------------------------

      end subroutine timers_init