On 30/08/2010 22:08, Caldarale, Charles R wrote: >> From: Bill Davidson [mailto:bill...@gmail.com] >> The iCal4j author assures me that this isn't really a memory leak. > > I suppose it depends on your definition of memory leak, but I'd certainly > consider it one. It adds to the heap, and doesn't go away automatically when > the application is undeployed (and likely prevents complete undeployment). > Furthermore, when the application is redeployed, you'll get an additional set > per thread, since the net.fortuna.ical4j.* classes will be loaded from a new > classloader.
It is going to pin every class loaded by your web application in memory when the app is reloaded. By pretty much any definition of the term, that is a memory leak in PermGen. >> Is there no way for me to kill these? > > Not easily. Most uses of ThreadLocal seem to be blissfully (sometimes > arrogantly) unaware of thread-pooling mechanisms and app servers. Ideally, > these ThreadLocal instances would instead be created in a pool for the webapp > to use, rather than being tied to individual threads. 6.0.26 removes those by default. 6.0.29, removing them is optional - see the clearReferencesThreadLocals attribute on the context. The only way to get rid of the messages is to fix the memory leak. >> Alternatively, if it really is harmless, is there a way to >> turn off these messages? > > It's not harmless. I think you can inhibit the checks by disabling the > JreMemoryLeakPreventionListener: 'Fraid not. The right solution here is for the iCal4j library to fix the leak or provide a mechanism to enable clients to trigger clean-up on shutdown (which can then be called from a Servlet context listener). Generally, library authors have moved quickly to fix the leaks when reported. log4j, Spring Batch, commons-lang are the ones I can recall and I am sure there have been others. Mark --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
