001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.geronimo.kernel.config;
019
020 import java.net.URI;
021 import java.net.URL;
022 import java.net.URLClassLoader;
023 import java.io.ObjectInputStream;
024 import java.io.ObjectOutputStream;
025 import java.io.ObjectStreamClass;
026 import java.util.Map;
027 import java.lang.reflect.Field;
028
029 import org.apache.commons.logging.LogFactory;
030
031 import org.apache.geronimo.kernel.util.ClassLoaderRegistry;
032
033 /**
034 *
035 * @version $Rev: 706640 $ $Date: 2008-10-21 14:44:05 +0000 (Tue, 21 Oct 2008) $
036 */
037 public class ConfigurationClassLoader extends URLClassLoader {
038 private final URI id;
039
040 public ConfigurationClassLoader(URI id, URL[] urls, ClassLoader parent) {
041 super(urls, parent);
042 ClassLoaderRegistry.add(this);
043 this.id = id;
044 }
045
046 public URI getID() {
047 return id;
048 }
049
050 public void destroy() {
051 LogFactory.release(this);
052 clearSoftCache(ObjectInputStream.class, "subclassAudits");
053 clearSoftCache(ObjectOutputStream.class, "subclassAudits");
054 clearSoftCache(ObjectStreamClass.class, "localDescs");
055 clearSoftCache(ObjectStreamClass.class, "reflectors");
056 ClassLoaderRegistry.remove(this);
057 }
058
059 public String toString() {
060 return "[Configuration ClassLoader id=" + id + "]";
061 }
062
063 private static Object lock = new Object();
064 private static boolean clearSoftCacheFailed = false;
065 private static void clearSoftCache(Class clazz, String fieldName) {
066 Map cache = null;
067 try {
068 Field f = clazz.getDeclaredField(fieldName);
069 f.setAccessible(true);
070 cache = (Map) f.get(null);
071 } catch (Throwable e) {
072 synchronized (lock) {
073 if (!clearSoftCacheFailed) {
074 clearSoftCacheFailed = true;
075 LogFactory.getLog(ConfigurationClassLoader.class).debug("Unable to clear SoftCache field " + fieldName + " in class " + clazz);
076 }
077 }
078 }
079
080 if (cache != null) {
081 synchronized (cache) {
082 cache.clear();
083 }
084 }
085 }
086 protected void finalize(){
087 ClassLoaderRegistry.remove(this);
088 }
089 }