Bugs item #1070309, was opened at 2004-11-20 23:38 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=116035&aid=1070309&group_id=16035
Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Guillaume Poirier (gpoirier) Assigned to: Nobody/Anonymous (nobody) Summary: ThreadLocal cache Initial Comment: There's a problem with the use of ThreadLocals for caching, it's never cleaned up. If the ClassLoader is thrown away (e.g. if a webapp is reloaded), then the ThreadLocal stuff hold until the Thread dies, which might take a while in a Servlet container where the Threads are pooled. In such situation, DOM4J would prevent the webapp's ClassLoader to be garbage collected, which would creates a a memory leak and eventually an OOM if the webapp is reloaded too many times. To fix the problem, the use of ThreadLocal could be avoided completly by using thread-safe singleton instead. There's three places it's used. There's the getInstance() method from DOMDocumentFactory and DocumentFactory. In that situation, it doesn't seem an appropriate use to me. First, the DOM spec doesn't mandate for that implementation to be thread safe, and anyway returning a different instance per thread is no help there, each instance can still be used in different threads. And you would usually expect a getInstance() method to always return the same object. Also, DOMDocumentFactory already seems perfectly thread safe. The last use of ThreadLocal I identified is in QName, basically for ThreadLocal caching, which doesn't really seem needed, QNameCache seems thread-safe as far as I can see, unless the content of the HashMaps are not meant to be shared by differents calls to DocumentFactory? But anyway, I don't really thing it would too hard to get rid of the ThreadLocal there. http://article.gmane.org/gmane.comp.java.springframework.devel/6216 ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=116035&aid=1070309&group_id=16035 ------------------------------------------------------- This SF.Net email is sponsored by: InterSystems CACHE FREE OODBMS DOWNLOAD - A multidimensional database that combines robust object and relational technologies, making it a perfect match for Java, C++,COM, XML, ODBC and JDBC. www.intersystems.com/match8 _______________________________________________ dom4j-dev mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dom4j-dev
