[jbossws-dev] Reflection Injector for Optimisation Loosing Previously Defined Classes

[ https://jira.jboss.org/jira/browse/JBWS-2317?page=com.atlassian.jira.plug... ] Darran Lofthouse commented on JBWS-2317: ---------------------------------------- Modified file submitted to JAXB project : https://jaxb.dev.java.net/issues/show_bug.cgi?id=564 > $JAXBAccessorF_ and $JAXBAccessorM_ cache loosing classes and failing to re-create classes. > ------------------------------------------------------------------------------------------- > > Key: JBWS-2317 > URL: https://jira.jboss.org/jira/browse/JBWS-2317 > Project: JBoss Web Services > Issue Type: Bug > Security Level: Public(Everyone can see) > Components: jbossws-metro, jbossws-native > Affects Versions: jbossws-native-3.0.3, jbossws-metro-3.0.3 > Reporter: Darran Lofthouse > Assignee: Darran Lofthouse > Fix For: jbossws-native-3.0.5, jbossws-metro-3.0.5 > > Attachments: Injector.java > > > The JAXB implementation contains a package of classes to optimise field and method access by dynamically generating classes to avoid reflection, this has a start-up performance hit but then leads to an optimised runtime. > The package is: - > 'com.sun.xml.bind.v2.runtime.reflect.opt' > Within the Injector class is a HashMap to maintain a cache of these classes against the classloader they were created for: - > private static final Map<ClassLoader,WeakReference<Injector>> injectors = > Collections.synchronizedMap(new WeakHashMap<ClassLoader,WeakReference<Injector>>()); > A WeakReference has been used to wrap the value to prevent the value retaining a reference to the ClassLoader and then preventing garbage collection and leading to a leak. > The problem is that nothing retains a reference to the Injector so as this is wrapped with a WeakReference it is garbage collected. > I will attach to this case a new version of Injector.java. > The fix switches to using a Strong reference to the Injector so it is not garbage collected. > To maintain the original requirements the Injector will no longer hold a reference to the ClassLoader and will instead make use of the one passed in. > Within the Injector the HashMap of classes will reference the Class with a WeakReference. If we get a WeakReference with no class it means the class was previously loaded but garbage collected, in this case try to load the class by name from the classloader - if this fails then redefine the class. >