suplib/src/WatchDog.i3


 Copyright 1996-2003 John D. Polstra.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgment:
 *      This product includes software developed by John D. Polstra.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $Id: WatchDog.i3.html,v 1.3 2010-04-29 17:20:03 wagner Exp $ 

INTERFACE WatchDog;

IMPORT Thread, Time;

TYPE
  T <: ROOT;

PROCEDURE New(timeout: Time.T;
              target: Thread.T := NIL): T;
Returns a new watchdog, set to alert target after timeout expires.
 The target parameter defaults to the calling thread. 

PROCEDURE Reset(wd: T;
                timeout: Time.T := -1.0d0);
Resets the timeout interval of the watchdog timer wd.
 If timeout is unspecified, the most recent value is used again. 

PROCEDURE Cancel(wd: T);
Cancels the watchdog timer wd. The watchdog timer may not be used after this is called.

PROCEDURE Expired(wd: T): BOOLEAN;
Returns TRUE if the watchdog timer has expired and alerted the target thread.

END WatchDog.