Java tutorial
/************************************************************************* * Copyright 2009-2012 Eucalyptus Systems, Inc. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 3 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see http://www.gnu.org/licenses/. * * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need * additional information or have any questions. * * This file may incorporate work covered under the following copyright * and permission notice: * * Software License Agreement (BSD License) * * Copyright (c) 2008, Regents of the University of California * All rights reserved. * * Redistribution and use of this software in source and binary forms, * with or without modification, are permitted provided that the * following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. USERS OF THIS SOFTWARE ACKNOWLEDGE * THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE LICENSED MATERIAL, * COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS SOFTWARE, * AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING * IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, * SANTA BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, * WHICH IN THE REGENTS' DISCRETION MAY INCLUDE, WITHOUT LIMITATION, * REPLACEMENT OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO * IDENTIFIED, OR WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT * NEEDED TO COMPLY WITH ANY SUCH LICENSES OR RIGHTS. ************************************************************************/ package com.eucalyptus.cluster.callback; import java.util.concurrent.ConcurrentMap; import java.util.concurrent.atomic.AtomicBoolean; import org.apache.log4j.Logger; import com.eucalyptus.cluster.Cluster; import com.eucalyptus.event.ClockTick; import com.eucalyptus.event.Event; import com.eucalyptus.event.EventListener; import com.eucalyptus.records.EventRecord; import com.eucalyptus.records.EventType; import com.eucalyptus.util.async.MessageCallback; import com.eucalyptus.util.async.RemoteCallback; import com.google.common.base.Predicate; import com.google.common.collect.Iterables; import com.google.common.collect.Maps; public class StateUpdateHandler implements EventListener { private static Logger LOG = Logger.getLogger(StateUpdateHandler.class); private static final ConcurrentMap<String, StateUpdateHandler> clusterMap = Maps.newConcurrentMap(); private final ConcurrentMap<Class, AtomicBoolean> inflightMap = Maps.newConcurrentMap(); private final ConcurrentMap<Class, MessageCallback> callbackMap = Maps.newConcurrentMap(); private final Cluster cluster; public static void create(Cluster cluster, RemoteCallback callback) { StateUpdateHandler handler = new StateUpdateHandler(cluster); StateUpdateHandler.clusterMap.putIfAbsent(cluster.getName(), handler); handler = StateUpdateHandler.clusterMap.get(cluster.getName()); EventRecord.here(StateUpdateHandler.class, EventType.CLUSTER_STATE_HANDLER_REGISTERED, cluster.getName(), callback.getClass().getCanonicalName()); } private StateUpdateHandler(Cluster cluster) { this.cluster = cluster; } public boolean timedTrigger(Event c) { if (c instanceof ClockTick) { return ((ClockTick) c).isBackEdge(); } else { return false; } } public void addCallback(MessageCallback cb) { if (this.callbackMap.putIfAbsent(cb.getClass(), cb) == null) { this.inflightMap.put(cb.getClass(), new AtomicBoolean(false)); } else { LOG.debug("Ignoring addition of timed callback for cluster " + this.cluster.getName() + " which is already configured: " + cb.getClass()); } } @Override public void fireEvent(Event event) { if (this.timedTrigger(event)) { Iterables.all(callbackMap.keySet(), new Predicate<Class>() { @Override public boolean apply(Class arg0) { if (StateUpdateHandler.this.inflightMap.get(arg0).compareAndSet(false, true)) { //TODO: RELEASE: wrap this up here. } return false; } }); } } }