org/objectweb/proactive/loadbalancing/LoadBalancing.java

/* 
 * ################################################################
 * 
 * ProActive: The Java(TM) library for Parallel, Distributed, 
 *            Concurrent computing with Security and Mobility
 * 
 * Copyright (C) 1997-2007 INRIA/University of Nice-Sophia Antipolis
 * Contact: proactive@objectweb.org
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *  
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *  
 *  Initial developer(s):               The ProActive Team
 *                        http://www.inria.fr/oasis/ProActive/contacts.html
 *  Contributor(s): 
 * 
 * ################################################################
 */ 
package org.objectweb.proactive.loadbalancing;

import java.util.Iterator;
import java.util.ArrayList;

import org.objectweb.proactive.ActiveObjectCreationException;
import org.objectweb.proactive.ProActive;
import org.objectweb.proactive.core.node.Node;
import org.objectweb.proactive.core.node.NodeException;
import org.objectweb.proactive.loadbalancing.metrics.MetricFactory;

public class LoadBalancing {
        private static ArrayList<LoadBalancer> loadBalancers = new ArrayList<LoadBalancer>();
        private static MetricFactory mf;
        private static boolean activated = false;
        private static InformationRecover ir;
        
        public static void activateOn(Node[] nodes, MetricFactory mf) {
                LoadBalancing.mf = mf;
                activated = true;
                LoadBalancer lb = null;

                try {
                        ir = (InformationRecover) ProActive.newActive(
                                        InformationRecover.class.getName(), null);

                        for (int i = 0; i < nodes.length; i++) {
                                lb = (LoadBalancer) ProActive.newActive(LoadBalancer.class
                                                .getName(), new Object[]{mf}, nodes[i]);
                                loadBalancers.add(lb);

                                lb = null;
                        }

                        Iterator<LoadBalancer> it = loadBalancers.iterator();
                        while (it.hasNext()) {
                                lb = it.next();
                                lb.init(loadBalancers,ir);
                                lb = null;

                        }
                } 
                catch (ActiveObjectCreationException e)         {e.printStackTrace();}
                catch (NodeException e)                                         {e.printStackTrace();}

        }
        
        public static void activate(MetricFactory mf) {
                LoadBalancing.mf = mf;
                activated = true;

                try {
                        ir = (InformationRecover) ProActive.newActive(
                                        InformationRecover.class.getName(), null);

                        
                } 
                catch (ActiveObjectCreationException e)         {e.printStackTrace();}
                catch (NodeException e)                                         {e.printStackTrace();}

        }
        
        public static void kill() {
                activated = false;

                ProActive.terminateActiveObject(ir,true);
                LoadBalancer lb;
                Iterator<LoadBalancer> it = loadBalancers.iterator();
                while (it.hasNext()) {
                        lb = it.next();
                        ProActive.terminateActiveObject(lb,true);
                }
        }
        
        public static void addNode(Node node){
                if(! activated)
                        return; // TO DO : it's better to throw an exception
                
                try {
                        LoadBalancer lb = (LoadBalancer) ProActive.newActive(LoadBalancer.class
                                        .getName(), new Object[]{mf}, node);
                        loadBalancers.add(lb);
                        lb.init(loadBalancers,ir);
                        lb.notifyLoadBalancers();
                        
                }
                catch (ActiveObjectCreationException e)         {e.printStackTrace();}
                catch (NodeException e)                                         {e.printStackTrace();}
                
        }
}

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