program timingdemo

  use timing

  implicit none

  real :: x = 0.1
  integer :: j, k
  ! make max1 bigger if your computer is fast; increase until the whole
  ! program exectution takes about 20 seconds
  integer, parameter :: max1 = 10000000, max2 = 100 
  integer, parameter :: checkpoint_interval = 5     ! in seconds

  call initialize_timer()
  call initialize_checkpoint_timer()

  do k = 1, max2
    do j = 1, max1
      x = x*x - x
    end do
    if ( should_checkpoint(checkpoint_interval) ) then
      write(0,*) 'TIME TO CHECKPOINT!'
      write(0,*)
      call initialize_checkpoint_timer()
    end if
    call print_time('s')
  end do

end program timingdemo