001 //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.3_testing/src/org/deegree/framework/util/ObjectPool.java $
002 /*----------------------------------------------------------------------------
003 This file is part of deegree, http://deegree.org/
004 Copyright (C) 2001-2009 by:
005 Department of Geography, University of Bonn
006 and
007 lat/lon GmbH
008
009 This library is free software; you can redistribute it and/or modify it under
010 the terms of the GNU Lesser General Public License as published by the Free
011 Software Foundation; either version 2.1 of the License, or (at your option)
012 any later version.
013 This library is distributed in the hope that it will be useful, but WITHOUT
014 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
015 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
016 details.
017 You should have received a copy of the GNU Lesser General Public License
018 along with this library; if not, write to the Free Software Foundation, Inc.,
019 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020
021 Contact information:
022
023 lat/lon GmbH
024 Aennchenstr. 19, 53177 Bonn
025 Germany
026 http://lat-lon.de/
027
028 Department of Geography, University of Bonn
029 Prof. Dr. Klaus Greve
030 Postfach 1147, 53001 Bonn
031 Germany
032 http://www.geographie.uni-bonn.de/deegree/
033
034 e-mail: info@deegree.org
035 ----------------------------------------------------------------------------*/
036 package org.deegree.framework.util;
037
038 import java.io.IOException;
039 import java.io.InputStream;
040 import java.util.ArrayList;
041 import java.util.Collections;
042 import java.util.HashMap;
043 import java.util.List;
044 import java.util.Map;
045 import java.util.Properties;
046 import java.util.Timer;
047 import java.util.TimerTask;
048
049 import org.deegree.framework.log.ILogger;
050 import org.deegree.framework.log.LoggerFactory;
051
052 /**
053 * class to manage the object pool. this is part of the combination of the object pool pattern an the singelton pattern.
054 *
055 * @version $Revision: 20107 $
056 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
057 * @author last edited by: $Author: aschmitz $
058 *
059 * @version $Revision: 20107 $, $Date: 2009-10-13 13:15:16 +0200 (Di, 13. Okt 2009) $
060 */
061 public abstract class ObjectPool extends TimerTask {
062
063 private static final ILogger LOG = LoggerFactory.getLogger( ObjectPool.class );
064
065 /**
066 * all available objects
067 */
068 protected List<Object> available = null;
069
070 /**
071 * all objects in use
072 */
073 protected List<Object> in_use = null;
074
075 /**
076 * the start life time for each object
077 */
078 protected Map<Object, Long> startLifeTime = null;
079
080 /**
081 * the start usage time for each object
082 */
083 protected Map<Object, Long> startUsageTime = null;
084
085 /**
086 * number of existing instances
087 */
088 protected int existingInstances = 0;
089
090 private int maxInstances = 50;
091
092 // min * sec * millisec. example: 15*60*1000 = 15 minutes
093 private int maxLifeTime = 15 * 60 * 1000;
094
095 // min * sec * millisec. example: 5*60*1000 = 5 minutes
096 private int maxUsageTime = 5 * 60 * 1000;
097
098 // milliseconds
099 private int updateInterval = 15000;
100
101 /**
102 * Creates a new ObjectPool object.
103 */
104 protected ObjectPool() {
105 available = Collections.synchronizedList( new ArrayList<Object>( maxInstances ) );
106 in_use = Collections.synchronizedList( new ArrayList<Object>( maxInstances ) );
107 startLifeTime = Collections.synchronizedMap( new HashMap<Object, Long>( maxInstances ) );
108 startUsageTime = Collections.synchronizedMap( new HashMap<Object, Long>( maxInstances ) );
109 Timer timer = new Timer();
110 timer.scheduleAtFixedRate( this, 10000, updateInterval );
111 InputStream is = ObjectPool.class.getResourceAsStream( "pool.properties" );
112 if ( is != null ) {
113 Properties props = new Properties();
114 try {
115 props.load( is );
116 is.close();
117 } catch ( IOException e ) {
118 LOG.logInfo( "could not load pool properties" );
119 return;
120 }
121 maxInstances = Integer.parseInt( props.getProperty( "maxInstances" ) );
122 maxLifeTime = Integer.parseInt( props.getProperty( "maxLifeTime" ) );
123 maxUsageTime = Integer.parseInt( props.getProperty( "maxUsageTime" ) );
124 updateInterval = Integer.parseInt( props.getProperty( "updateInterval" ) );
125 LOG.logInfo( "pool configuration read from pool.properties" );
126 LOG.logDebug( "pool properties", this.toString() );
127 }
128 }
129
130 /**
131 * dummy
132 *
133 * @return null
134 */
135 public static ObjectPool getInstance() {
136 return null;
137 }
138
139 /**
140 * clears the complete pool. objects in used while the clear() method has been called won't be put back to the pool
141 * if released back through the <tt>releaseObject</tt> method.
142 */
143 public synchronized void clear() {
144 in_use.clear();
145 available.clear();
146 startUsageTime.clear();
147 startLifeTime.clear();
148 }
149
150 /**
151 * release an object back to the pool so it is available for other requests.
152 *
153 * @param object
154 * @throws Exception
155 */
156 public void releaseObject( Object object )
157 throws Exception {
158
159 if ( in_use.contains( object ) ) {
160 // remove the object from the 'in use' container
161 in_use.remove( object );
162 // remove the objects entry from the 'usage star time' container
163 startUsageTime.remove( object );
164 // push the object to the list of available objects
165 available.add( object );
166 }
167 }
168
169 /**
170 * this method will be called when the submitted object will be removed from the pool
171 *
172 * @param o
173 */
174 public abstract void onObjectKill( Object o );
175
176 /**
177 * @return the max life time
178 */
179 public int getMaxLifeTime() {
180 return ( this.maxLifeTime );
181 }
182
183 /**
184 * @param maxLifeTime
185 */
186 public void setMaxLifeTime( int maxLifeTime ) {
187 this.maxLifeTime = maxLifeTime;
188 }
189
190 /**
191 * @return the max usage time
192 */
193 public int getMaxUsageTime() {
194 return ( this.maxUsageTime );
195 }
196
197 /**
198 * @param maxUsageTime
199 */
200 public void setMaxUsageTime( int maxUsageTime ) {
201 this.maxUsageTime = maxUsageTime;
202 }
203
204 /**
205 * @return the update interval
206 */
207 public int getUpdateInterval() {
208 return ( this.updateInterval );
209 }
210
211 /**
212 * @param updateInterval
213 */
214 public void setUpdateInterval( int updateInterval ) {
215 this.updateInterval = updateInterval;
216 }
217
218 /**
219 * @return max instances
220 */
221 public int getMaxInstances() {
222 return ( this.maxInstances );
223 }
224
225 /**
226 * @param maxInstances
227 */
228 public void setMaxInstances( int maxInstances ) {
229 this.maxInstances = maxInstances;
230 }
231
232 @Override
233 public String toString() {
234 String ret = getClass().getName() + "\n";
235 ret = "startLifeTime = " + startLifeTime + "\n";
236 ret += ( "startUsageTime = " + startUsageTime + "\n" );
237 ret += ( "maxLifeTime = " + maxLifeTime + "\n" );
238 ret += ( "maxUsageTime = " + maxUsageTime + "\n" );
239 ret += ( "updateInterval = " + updateInterval + "\n" );
240 ret += ( "maxInstances = " + maxInstances + "\n" );
241 return ret;
242 }
243
244 @Override
245 public void run() {
246 cleaner();
247 usage();
248 }
249
250 private synchronized void cleaner() {
251
252 try {
253 Object[] os = available.toArray();
254 for ( int i = 0; i < os.length; i++ ) {
255 Object o = os[i];
256 Long lng = startLifeTime.get( o );
257 long l = System.currentTimeMillis();
258 if ( lng == null || ( l - lng.longValue() ) > maxLifeTime ) {
259 if ( o != null ) {
260 available.remove( o );
261 startLifeTime.remove( o );
262 onObjectKill( o );
263 }
264 existingInstances--;
265 }
266 }
267
268 } catch ( Exception e ) {
269 LOG.logError( "ObjectPool Cleaner ", e );
270 }
271
272 }
273
274 private synchronized void usage() {
275 try {
276 Object[] os = in_use.toArray();
277 for ( int i = 0; i < os.length; i++ ) {
278 Object o = os[i];
279 Long lng = startUsageTime.get( o );
280 long l = System.currentTimeMillis();
281 if ( lng == null || ( l - lng.longValue() ) > maxUsageTime ) {
282 if ( o != null ) {
283 in_use.remove( o );
284 startUsageTime.remove( o );
285 startLifeTime.remove( o );
286 onObjectKill( o );
287 }
288 }
289 }
290 } catch ( Exception e ) {
291 LOG.logError( "UsageChecker ", e );
292 }
293
294 }
295
296 }