/**
 *
 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
 *
 * 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 (at your option) 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, see <http://www.gnu.org/licenses/>.
 * 
 **/
package lucee.commons.management;

import java.lang.management.ManagementFactory;
import java.lang.management.MemoryMXBean;
import java.lang.management.MemoryPoolMXBean;
import java.lang.management.MemoryType;
import java.util.HashMap;
import java.util.Map;

import javax.management.NotificationEmitter;

import lucee.runtime.config.ConfigServer;


public class MemoryControler {
	private final static Map<String,MemoryType> types=new HashMap<String, MemoryType>();
	private static boolean init;
	public synchronized static void init(ConfigServer cs){
	      if(init) return;
			// set level
	      for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {
	    	  types.put(pool.getName(), pool.getType());
	        // I don't know whether this approach is better, or whether
	        // we should rather check for the pool name "Tenured Gen"?
	    	  if (pool.getType() == MemoryType.HEAP && pool.isUsageThresholdSupported()) {
	    		  long maxMemory = pool.getUsage().getMax();
	    		  long warningThreshold = (long) (maxMemory * 0.9);
	    		  //long warningThreshold = maxMemory -(10*1024*1024);
	    		  pool.setUsageThreshold(warningThreshold);
	    	  }
	      }
	      
	      MemoryMXBean mbean = ManagementFactory.getMemoryMXBean();
	      NotificationEmitter emitter = (NotificationEmitter) mbean;
	      MemoryNotificationListener listener = new MemoryNotificationListener(types);
	      emitter.addNotificationListener(listener, null, cs);
	      init=true;
	}
}