package er.extensions.foundation;
import sun.misc.Signal;
import sun.misc.SignalHandler;
import com.webobjects.foundation.NSMutableArray;
import com.webobjects.foundation.NSMutableDictionary;
/**
* There can only be one handler for any signal, so we have our own handler that
* maintains a list. Simply register your handlers to this one.
*
* @author ak
*
*/
public class ERXSignalHandler implements SignalHandler {
static ERXSignalHandler _handler;
private NSMutableDictionary<String, NSMutableArray<SignalHandler>> signals = new NSMutableDictionary();
/**
* Adds your handler with the supplied signal name to the queue.
* @param signalName eg HUP. TERM etc.
* @param handler SignalHandler object
*/
public synchronized static void register(String signalName, SignalHandler handler) {
signalName = normalize(signalName);
if(_handler == null) {
_handler = new ERXSignalHandler();
}
NSMutableArray<SignalHandler> listeners = _handler.signals.objectForKey(signalName);
if(listeners == null) {
listeners = new NSMutableArray<SignalHandler>();
Signal signal = new Signal(signalName);
Signal.handle(signal, _handler);
_handler.signals.setObjectForKey(listeners, signalName);
}
listeners.addObject(handler);
}
/**
* Removes your handler with the supplied signal name from the queue.
* @param signalName eg HUP. TERM etc.
* @param handler SignalHandler object
*/
public synchronized static void unregister(String signalName, SignalHandler handler) {
signalName = normalize(signalName);
NSMutableArray<SignalHandler> listeners = _handler.signals.objectForKey(signalName);
if(listeners == null) {
listeners = new NSMutableArray<SignalHandler>();
}
listeners.removeObject(handler);
}
/**
* Implementation of the SignalHandler interface.
*/
public void handle(Signal signal) {
NSMutableArray<SignalHandler> listeners = signals.objectForKey(normalize(signal.getName()));
if(listeners != null) {
for (SignalHandler handler : listeners) {
handler.handle(signal);
}
}
}
private static String normalize(String signalName) {
return signalName.toUpperCase();
}
}