com.ibm.wbi.util
Class Signal

java.lang.Object
  |
  +--com.ibm.wbi.util.Signal

public class Signal

extends java.lang.Object

Provide operating system signal handling for a Java VM. Classes that wish to be notified about signals should implement SignalListener and add themselves to the listener list by calling Signal.addSignalListener( SignalListener ). To stop receiving signal events, SignalListeners may remove themselves by calling Signal.removeSignalListener( SignalListener ).

Field Summary

protected static java.util.Vector	listeners list of SignalListeners that wish to receive SignalEvents when signal occur
protected static boolean	registered keep track of whether our signal handler has been registered with the operating system or not

Constructor Summary

Signal()
dummy constructor so that SignalEvents can have a source, which will be a dummy instance of Signal

Method Summary

static void	addSignalListener(SignalListener sl) adds a SignalListener to the list of listeners to receive SignalEvents.
static java.util.Enumeration	getSignalListeners() retrieve an enumeration of all the signal listeners
protected static boolean	isEnabled(int type) a callback that the native signal handler uses to determine whether the signal should be passed to SignalListeners for handling or should be handled by the operating system.
protected static void	registerSignal(int signal) native method that registers a signal handler for the given signal type
static void	removeSignalListener(SignalListener sl) removes a SignalListener from the list of listeners to receive SignalEvents
protected static void	signalCaught(int signal) method called by the operating system whenever a signal occurs

Methods inherited from class java.lang.Object

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

Field Detail

registered

protected static boolean registered

keep track of whether our signal handler has been registered with the operating system or not

listeners

protected static java.util.Vector listeners

list of SignalListeners that wish to receive SignalEvents when signal occur

Constructor Detail

Signal

public Signal()

dummy constructor so that SignalEvents can have a source, which will be a dummy instance of Signal

Method Detail

registerSignal

protected static void registerSignal(int signal)

native method that registers a signal handler for the given signal type

Parameters:

signal - the signal type (see SignalEvent for a list of signal types)

signalCaught

protected static void signalCaught(int signal)

method called by the operating system whenever a signal occurs

Parameters:

signal - the type of signal that has occurred

isEnabled

protected static boolean isEnabled(int type)

a callback that the native signal handler uses to determine whether the signal should be passed to SignalListeners for handling or should be handled by the operating system.

Parameters:

signal - the type of signal that has occurred

addSignalListener

public static void addSignalListener(SignalListener sl)

adds a SignalListener to the list of listeners to receive SignalEvents. Posts a RAS trace message if the native link cannot be satisfied, but otherwise gives no hint that something is wrong.

Parameters:

the - listener to add to the list

removeSignalListener

public static void removeSignalListener(SignalListener sl)

removes a SignalListener from the list of listeners to receive SignalEvents

Parameters:

the - listener to remove from the list

getSignalListeners

public static java.util.Enumeration getSignalListeners()

retrieve an enumeration of all the signal listeners

Returns:

an enumeration of all the signal listeners