Missing element in WeakRefVFSCache
Just something I noticed, which I didn't expect.
I'm running JBossAS with WeakRefVFSCache: -Djboss.vfs.cache=org.jboss.virtual.plugins.cache.WeakRefVFSCache
Hence every VFSContext that doesn't have strong ref should be GCed.
In order to prevent some of them from being GCed too soon,
I've added the following bean:
public class PreInitializeVFSContexts
{
private Logger log = Logger.getLogger(PreInitializeVFSContexts.class);
private List<URL> initializedVFSContexts;
private boolean holdReference;
private List<VFS> references;
/**
* Start initializer.
*
* @throws Exception for any exception
*/
public void start() throws Exception
{
if (initializedVFSContexts != null && initializedVFSContexts.isEmpty() == false)
{
if (holdReference)
references = new ArrayList<VFS>();
for (URL url : initializedVFSContexts)
{
VFS vfs = VFS.getVFS(url);
log.debug("Initialized Virtual File: " + vfs.getRoot());
if (holdReference)
{
references.add(vfs);
}
}
}
}
/**
* Clear possible references.
*/
public void stop()
{
if (references != null)
references.clear();
}
/**
* Get VFS references.
*
* @return the VFS references
*/
public List<VFS> getReferences()
{
return references;
}
/**
* Set URLs that need to be initialized before anything else.
*
* @param initializedVFSContexts the URLs to be initialized
*/
public void setInitializedVFSContexts(List<URL> initializedVFSContexts)
{
this.initializedVFSContexts = initializedVFSContexts;
}
/**
* Should we hold the reference to initialized VFSs.
*
* @param holdReference the hold reference flag
*/
public void setHoldReference(boolean holdReference)
{
this.holdReference = holdReference;
}
}
So, if you mark this bean as holdReference, it's gonna put VFS into List,
hence keeping the strong ref; VFS --> VFSContext
See JBossAS/initialize.xml:
<bean name="JBossVFSInitializer" class="org.jboss.virtual.plugins.cache.PreInitializeVFSContexts">
<property name="initializedVFSContexts">
<list elementClass="java.net.URL">
<value>${jboss.lib.url}</value>
<value>${jboss.shared.lib.url}</value>
<value>${jboss.server.lib.url}</value>
</list>
</property>
<property name="holdReference">true</property>
</bean>
But when inspecting jmx-console VFSCacheStatistics,
I'm missing jboss.server.lib.url (it's real value) in VFSContext list.
Where did I go wrong? :-)
