org.lsst.ccs.subsystem.shutter

Class Watchdog

java.lang.Object

org.lsst.ccs.subsystem.shutter.Watchdog

All Implemented Interfaces:

org.lsst.ccs.framework.HasLifecycle

public class Watchdog
extends Object
implements org.lsst.ccs.framework.HasLifecycle

Keeps track of the number of PLC messages received and if none are received within a configurable interval, raise a PLC_WATCHDOG alert of severity WARNING. A small state machine is run by its own thread. The initial state is DISABLED, in which any event but enable() is ignored. In the ENABLED state, the countMessage() event causes the event counter to be incremented and the checkMessageCount() event causes a check to be made of the current message count. If the count is zero then a WARNING alert is raised and the count is reset to zero. The count is also reset upon entry to the DISABLED state .

Author:

tether

Constructor Summary

Constructors

Constructor and Description
Watchdog()

Method Summary

Modifier and Type	Method and Description
void	checkMessageCount() If this is in the enabled state, raise an alert if no messages have yet been received and then reset the count of messages received.
void	countMessage() If this is in the enabled state, increment the count of messages received.
void	disable() If this is in the enabled state, switch to the disabled state and set the count of messages received to zero.
void	enable() If this is in the disabled state, switch to the enabled state.
void	shutdown()
void	start()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.lsst.ccs.framework.HasLifecycle

build, init, postBuild, postInit, postShutdown, postStart

Constructor Detail

Watchdog

public Watchdog()

Method Detail

start

public void start()

Specified by:

start in interface org.lsst.ccs.framework.HasLifecycle

shutdown

public void shutdown()

Specified by:

shutdown in interface org.lsst.ccs.framework.HasLifecycle

enable

public void enable()
            throws InterruptedException

If this is in the disabled state, switch to the enabled state.

Throws:

InterruptedException

disable

public void disable()
             throws InterruptedException

If this is in the enabled state, switch to the disabled state and set the count of messages received to zero.

Throws:

InterruptedException

countMessage

public void countMessage()
                  throws InterruptedException

If this is in the enabled state, increment the count of messages received.

Throws:

InterruptedException

checkMessageCount

public void checkMessageCount()
                       throws InterruptedException

If this is in the enabled state, raise an alert if no messages have yet been received and then reset the count of messages received.

Throws:

InterruptedException