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
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INTERFACE IOWatchDog;
IMPORT Rd, Time, Wr;
TYPE
T <: Public;
Public = Private OBJECT METHODS
init(timeout: Time.T;
pollInterval: Time.T := 60.0d0): T;
alert();
END;
Private <: ROOT;
The init method primes the watchdog timer to call its alert method
after the interval timeout expires. pollInterval is the number of
seconds between polls conducted by the watchdog timer.
The default alert method calls Thread.Alert on the thread that
initialized the watchdog timer.
PROCEDURE AddRd(wd: T;
rd: Rd.T);
Adds the given reader to the set monitored by the watchdog timer.
PROCEDURE AddWr(wd: T;
wr: Wr.T);
Adds the given writer to the set monitored by the watchdog timer.
Both readers and writers are removed automatically when it is discovered
that they are closed.
PROCEDURE Cancel(wd: T);
Cancels the watchdog timer.
PROCEDURE Expired(wd: T): BOOLEAN;
Returns TRUE if the watchdog timer has expired and alerted the target
thread.
END IOWatchDog.