(************************************************************************)
(* This file is part of SKS.  SKS 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 2 of the License, or (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
   USA *)
(***********************************************************************)

(** Simple timer module *)
open StdLabels
open MoreLabels

type t = { mutable start_time : float;
	   mutable stop_time : float; 
	   mutable running : bool;
	 }

let create () = { start_time = 0.0;
		  stop_time = 0.0;
		  running = false;
		}

let reset timer = 
  timer.start_time <- 0.0;
  timer.stop_time <- 0.0;
  timer.running <- false

let start timer = 
  ( timer.start_time <- Unix.gettimeofday ();
    timer.running <- true )

let stop timer = 
  if not timer.running then failwith "Timer stopped when not running."
  else ( timer.stop_time <- Unix.gettimeofday ();
	 timer.running <- false )

let read timer = 
  if timer.running 
  then failwith "Timer read at wrong time"
  else timer.stop_time -. timer.start_time

let read_ms timer = 1000.0 *. (read timer)
let read_us timer = (1000.0 *. 1000.0) *. (read timer)