/**
* Release the tryClaim of the coordinate. It means that nobody owns the coordinate anymore.
* Requires that that this instance owns the tryClaim to the coordinate.
*/
public void releaseClaim() throws CloudnameException {
scheduler.shutdown();
zkClient.deregisterListener(this);
while (true) {
final TrackedConfig config;
synchronized (trackedConfigList) {
if (trackedConfigList.isEmpty()) {
break;
}
config = trackedConfigList.remove(0);
}
config.stop();
}
sendEventToCoordinateListener(
CoordinateListener.Event.NOT_OWNER, "Released claim of coordinate");
synchronized (lastStatusVersionMonitor) {
try {
zkClient.getZookeeper().delete(path, lastStatusVersion);
} catch (InterruptedException e) {
throw new CloudnameException(e);
} catch (KeeperException e) {
throw new CloudnameException(e);
}
}
}
/** Callbacks from zkClient */
@Override
public void connectionDown() {
List<CoordinateListener> coordinateListenerListCopy = new ArrayList<CoordinateListener>();
synchronized (coordinateListenerList) {
coordinateListenerListCopy.addAll(coordinateListenerList);
}
for (CoordinateListener coordinateListener : coordinateListenerListCopy) {
coordinateListener.onCoordinateEvent(
CoordinateListener.Event.NO_CONNECTION_TO_STORAGE, "down");
}
isSynchronizedWithZooKeeper.set(false);
}
/**
* Sends an event too all coordinate listeners. Note that the event is sent from this thread so if
* the callback code does the wrong calls, deadlocks might occur.
*
* @param event
* @param message
*/
private void sendEventToCoordinateListener(
final CoordinateListener.Event event, final String message) {
synchronized (callbacksMonitor) {
LOG.fine("Event " + event.name() + " " + message);
List<CoordinateListener> coordinateListenerListCopy = new ArrayList<CoordinateListener>();
synchronized (coordinateListenerList) {
coordinateListenerListCopy.addAll(coordinateListenerList);
}
for (CoordinateListener listener : coordinateListenerListCopy) {
listener.onCoordinateEvent(event, message);
}
}
}
/**
* Registers a coordinatelistener that will receive events when there are changes to the status
* node. Don't do any heavy lifting in the callback and don't call cloudname from the callback as
* this might create a deadlock.
*
* @param coordinateListener
*/
public void registerCoordinateListener(final CoordinateListener coordinateListener) {
String message = "New listener added, resending current state.";
synchronized (callbacksMonitor) {
coordinateListenerList.add(coordinateListener);
if (isSynchronizedWithZooKeeper.get()) {
coordinateListener.onCoordinateEvent(CoordinateListener.Event.COORDINATE_OK, message);
}
}
}
/**
* Registers a configlistener that will receive events when there are changes to the config node.
* Don't do any heavy lifting in the callback and don't call cloudname from the callback as this
* might create a deadlock.
*
* @param trackedConfig
*/
public void registerTrackedConfig(final TrackedConfig trackedConfig) {
trackedConfigList.add(trackedConfig);
}
public void deregisterCoordinateListener(final CoordinateListener coordinateListener) {
coordinateListenerList.remove(coordinateListener);
}