[jboss-user] [Persistence, JBoss/CMP, Hibernate, Database] - Hibernate3.1.3 ClassLoader Memory Leak

[i_n_g]

The Hibernate classes and the ClassLoader which loads them are not GCed. 

The following example has two classes, "CallJunk" creates a ClassLoader , loads Junk and hibernate classes, and call Junk.main().  Junk.main() opens a session and closes it.

The CallJunk program grows 1-2 MB in each loop step and finally run out of memory.
I profiled with JProfiler, found hibernate classes are duplicated, which is loaded by a new URLClassLoader in the Loop, but never GCed.



  | package calljunk;
  | 
  | import java.io.File;
  | import java.net.URL;
  | import java.net.URLClassLoader;
  | 
  | public class CallJunk {
  | 
  | 	static String[] dum=new String[0];
  | 	static Class[] parameterTypes = new Class[]{dum.getClass()};
  | 
  | 	public static void main(String[] args)throws Exception {
  | 		URL[] urls = new URL[]{
  | 				new File("../junk/cglib-2.1.3.jar").toURL(),
  | 				new File("../junk/commons-collections-2.1.1.jar").toURL(),
  | 				new File("../junk/dom4j-1.6.1.jar").toURL(),
  | 				new File("../junk/ehcache-1.1.jar").toURL(),
  | 				new File("../junk/hibernate3.jar").toURL(),
  | 				new File("../junk/jta.jar").toURL(),
  | 				new File("../junk/postgresql-8.0-311.jdbc3.jar").toURL(),
  | 				new File("../junk/commons-logging.jar").toURL(),
  | 				new File("../junk/bin").toURL()
  | 			};
  | 		
  | 		for (int i=0; i<100; i++) {
  | 			System.out.println("No "+i+": ");
  | 			System.in.read();
  | 			Class cls = new URLClassLoader(urls).loadClass("junk.Junk");
  | 			cls.getMethod("main", parameterTypes).invoke(null, new Object[]{dum});
  | 		}
  | 	}
  | }
  | 
  | 
  | package junk;
  | import org.hibernate.HibernateException;
  | import org.hibernate.Session;
  | import org.hibernate.SessionFactory;
  | import org.hibernate.cfg.Configuration;
  | import org.hibernate.cfg.Environment;
  | 
  | import javax.naming.InitialContext;
  | 
  | public class Junk {
  | 
  |     private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
  | 
  | 	public static void main(String[] args) throws Exception {
  | 		Configuration cfg = new Configuration();
  | 		SessionFactory sFactory = null;
  | 		try {
  | 			cfg.configure(CONFIG_FILE_LOCATION);
  | 			String sessionFactoryJndiName = cfg.getProperty(Environment.SESSION_FACTORY_NAME);
  | 			if (sessionFactoryJndiName != null) {
  | 				cfg.buildSessionFactory();
  | 				sFactory = (SessionFactory) (new InitialContext()).lookup(sessionFactoryJndiName);
  | 			} else {
  | 				sFactory = cfg.buildSessionFactory();
  | 			}
  | 		} catch (Exception e) {
  | 			throw new HibernateException("Could not initialize the Hibernate configuration");
  | 		}
  |     	Session s = sFactory.getCurrentSession();
  |     	s.close();
  |     	sFactory.close();
  | 	}
  | 	
  | }
  | 
  | 

View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3969822#3969822

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3969822