SingletonStatelessSessionInstancePool

[olegnitz]

Hi!

Looks like org.jboss.ejb.plugins.SingletonStatelessSessionInstancePool in JBoss 4.0.1 wasn't updated for a while, at it doesn't work properly.
Below I give the fixed version, as far as I can guess how it should be fixed.

Regards,
Oleg

-----------------------------------------------------------------------------------

/*
* JBoss, the OpenSource J2EE webOS
*
* Distributable under LGPL license.
* See terms of license at gnu.org.
*/
package org.jboss.ejb.plugins;

import java.rmi.RemoteException;
import java.util.Map;
import java.util.HashMap;

import javax.ejb.EJBException;

import org.jboss.deployment.DeploymentException;
import org.jboss.ejb.Container;
import org.jboss.ejb.InstancePool;
import org.jboss.ejb.EnterpriseContext;
import org.jboss.ejb.StatelessSessionEnterpriseContext;

import org.jboss.metadata.XmlLoadable;
import org.jboss.metadata.MetaData;
import org.w3c.dom.Element;

/**
* Singleton pool for session beans. This lets you have
* singletons in EJB!
*
* @see
* @author <a href="mailto:[e-mail]">Rickard Oberg</a>
* @version $Revision: 1.23 $
*/
public class SingletonStatelessSessionInstancePool extends AbstractInstancePool
{
// Constants -----------------------------------------------------

// Attributes ----------------------------------------------------
EnterpriseContext ctx;
boolean inUse = false;
boolean isSynchronized = true;

// Static --------------------------------------------------------

// Constructors --------------------------------------------------

// Public --------------------------------------------------------

public void create()
throws Exception
{
}

public void start()
throws Exception
{
}

public void stop()
{
}

public void destroy()
{
}

/**
* Get the singleton instance
*
* @return Context /w instance
* @exception Exception
*/
public synchronized EnterpriseContext get()
throws Exception
{
// Wait while someone else is using it
while(inUse && isSynchronized)
{
try { this.wait(); } catch (InterruptedException e) {}
}

// Create if not already created (or it has been discarded)
if (ctx == null)
{
try
{
ctx = create(getContainer().createBeanClassInstance());
} catch (InstantiationException e)
{
throw new EJBException("Could not instantiate bean", e);
} catch (IllegalAccessException e)
{
throw new EJBException("Could not instantiate bean", e);
}
}
else
{
}

// Lock and return instance
inUse = true;
return ctx;
}

/**
* Return an instance after invocation.
*
* Called in 2 cases:
* a) Done with finder method
* b) Just removed
*
* @param ctx
*/
public synchronized void free(EnterpriseContext ctx)
{
// Notify waiters
inUse = false;
this.notifyAll();
}

public synchronized void discard(EnterpriseContext ctx)
{
// Throw away
try
{
ctx.discard();
} catch (RemoteException e)
{
// DEBUG Logger.exception(e);
}

// Notify waiters
inUse = false;
this.notifyAll();
}

/**
* Add a instance in the pool
*/
public void add()
throws Exception
{
// Empty
}

public int getCurrentSize()
{
return 1;
}

public int getMaxSize()
{
return 1;
}

// Z implementation ----------------------------------------------

// XmlLoadable implementation
public void importXml(Element element) throws DeploymentException
{
Element synch = MetaData.getUniqueChild(element, "Synchronized");
isSynchronized = Boolean.valueOf(MetaData.getElementContent(synch)).booleanValue();
}

// Package protected ---------------------------------------------

// Protected -----------------------------------------------------
protected EnterpriseContext create(Object instance)
throws Exception
{
// The instance is created by the caller and is a newInstance();
return new StatelessSessionEnterpriseContext(instance, getContainer());
}
// Private -------------------------------------------------------

// Inner classes -------------------------------------------------

}

[starksm64]

Please submit a patch as a context diff to jira for this:

http://jira.jboss.com/jira/browse/JBAS