This is a real problem in cases where you want to perform a "hot redeploy" of a webapp within Tomcat or other application servers. Single JVM, multiple classloaders. A classloader (and all its classes) can only get GC'ed if everything is cleaned up (including running threads). If you don't, after a couple of deploys you get a PermGen: Out of Memory error.
GeoTools basically has the identical problem [http://jira.codehaus.org/browse/GEOT-2742]. I will investigate how to apply a similar approach and submit a patch. cheers, Joel Carranza j...@gatekeeper.com Gatekeeper Systems thomas.deweese wrote: > > Hi Joel, > > Joel Carranza <j...@gatekeeper.com> wrote on 02/17/2010 05:57:50 PM: > >> We are using Batik in a webapp context and the thread >> org.apache.batik.util.CleanerThread never terminates. > > Correct, it is a daemon thread. My understanding is > that this signals the JVM that it can terminate it if > there is nothing else of interest in it's context. > >> This is a serious problem as it prevents the webapp's classloader >> from being garbage collected. > > Why is that a particularly serious problem? It seems to > me that generally speaking the classloader isn't GCed unless > the JVM goes away anyway. > >> Am I doing something wrong? Is there a way to "clean up" and >> stop this thread when my webapp exits? > > Batik doesn't provide one currently. It's a little > tricky since you shouldn't kill that thread until all objects that > have been registered with the associated ReferenceQueue have been > dequeued. > > You might be able to do something with TheadGroups and 'stop'. > You could also register a PhantomWeakReference and have it's > 'cleared()' method throw a ThreadDeath exception. > > You also have access to the source and contributions are always > welcome ;) > > -- View this message in context: http://old.nabble.com/CleanerThread-never-terminates%2C-causes-leaks-in-webapp-tp27631790p27642863.html Sent from the Batik - Users mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: batik-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: batik-users-h...@xmlgraphics.apache.org
