// The contents of this file are subject to the Mozilla Public License
// Version 1.1 (the "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of the License
// at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
// the License for the specific language governing rights and
// limitations under the License.
//
// The Original Code is RabbitMQ.
//
// The Initial Developer of the Original Code is GoPivotal, Inc.
// Copyright (c) 2007-2014 GoPivotal, Inc. All rights reserved.
//
package com.rabbitmq.client.impl;
import java.util.ArrayList;
import java.util.List;
import com.rabbitmq.client.ShutdownListener;
import com.rabbitmq.client.ShutdownNotifier;
import com.rabbitmq.client.ShutdownSignalException;
/**
* A class that manages {@link ShutdownListener}s and remembers the reason for a shutdown. Both
* {@link com.rabbitmq.client.Channel Channel}s and {@link com.rabbitmq.client.Connection
* Connection}s have shutdown listeners.
*/
public class ShutdownNotifierComponent implements ShutdownNotifier {
/** Monitor for shutdown listeners and shutdownCause */
private final Object monitor = new Object();
/** List of all shutdown listeners associated with the component */
private final List<ShutdownListener> shutdownListeners = new ArrayList<ShutdownListener>();
/**
* When this value is null, the component is in an "open"
* state. When non-null, the component is in "closed" state, and
* this value indicates the circumstances of the shutdown.
*/
private volatile ShutdownSignalException shutdownCause = null;
public void addShutdownListener(ShutdownListener listener)
{
ShutdownSignalException sse = null;
synchronized(this.monitor) {
sse = this.shutdownCause;
this.shutdownListeners.add(listener);
}
if (sse != null) // closed
listener.shutdownCompleted(sse);
}
public ShutdownSignalException getCloseReason() {
synchronized(this.monitor) {
return this.shutdownCause;
}
}
public void notifyListeners()
{
ShutdownSignalException sse = null;
ShutdownListener[] sdls = null;
synchronized(this.monitor) {
sdls = this.shutdownListeners
.toArray(new ShutdownListener[this.shutdownListeners.size()]);
sse = this.shutdownCause;
}
for (ShutdownListener l: sdls) {
try {
l.shutdownCompleted(sse);
} catch (Exception e) {
// FIXME: proper logging
}
}
}
public void removeShutdownListener(ShutdownListener listener)
{
synchronized(this.monitor) {
this.shutdownListeners.remove(listener);
}
}
public boolean isOpen() {
synchronized(this.monitor) {
return this.shutdownCause == null;
}
}
/**
* Internal: this is the means of registering shutdown.
* @param sse the reason for the shutdown
* @return <code>true</code> if the component is open; <code>false</code> otherwise.
*/
public boolean setShutdownCauseIfOpen(ShutdownSignalException sse) {
synchronized (this.monitor) {
if (isOpen()) {
this.shutdownCause = sse;
return true;
}
return false;
}
}
}