Hi,
I've been running into an issue where an exception is thrown when undeploying
an application on Glassfish 3.1 (b43). The stack trace looks like this:
java.lang.IllegalStateException: WEB9031: WebappClassLoader unable to load
resource [net.sf.ehcache.transaction.xa.processor.XARequestProcessor],
because it has not yet been started, or was already stopped at
org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1410)
at
org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1368)
at net.sf.ehcache.CacheManager.shutdown(CacheManager.java:1174) at
net.sf.ehcache.hibernate.EhCacheRegionFactory.stop(EhCacheRegionFactory.java:101)
at org.hibernate.impl.SessionFactoryImpl.close(SessionFactoryImpl.java:958)
at
org.hibernate.ejb.EntityManagerFactoryImpl.close(EntityManagerFactoryImpl.java:127)
at org.glassfish.persistence.jpa.JPADeployer.closeEMFs(JPADeployer.java:404)
at org.glassfish.persistence.jpa.JPADeployer.event(JPADeployer.java:395) at
org.glassfish.kernel.event.EventsImpl$1.run(EventsImpl.java:120) at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441) at
java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at
java.util.concurrent.FutureTask.run(FutureTask.java:138) at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Using the -XX:+TraceClassLoading flag shows that the XARequestProcessor class
isn't loaded prior to being referenced from CacheManager#shutdown, meaning
that the shutdown method is making a request for the class to be loaded.
However, the WebappClassLoader instance is already stopped when that request
is made, leading to this exception. It just so happens that this also
prevents the WebappClassLoader instance from being garbage collected, which
causes all the libraries in the web application to remain in memory
indefinitely.
I've attached a simple test case that I've been using to reproduce this
exception - simply deploying and undeploying the application gives the
exception (note that you will need to add a JVM flag to get around the NPE
obscuring the actual exception:
-Dorg.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES=false).
I've also tried deploying/undeploying on Glassfish 3.0.1 - no exception is
thrown there.
Does anyone have any experience with this? It looks like the lifecycle of the
class loader isn't properly coordinated with the lifecycle of the JPA
subsystem. Any ideas?
Thanks in advance.
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