/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.ejb.plugins;
import java.util.HashSet;
import java.util.Map;
import java.util.Iterator;
import java.rmi.RemoteException;
import javax.transaction.Status;
import javax.transaction.SystemException;
import org.jboss.ejb.Container;
import org.jboss.ejb.StatefulSessionContainer;
import org.jboss.ejb.EnterpriseContext;
import org.jboss.ejb.StatefulSessionEnterpriseContext;
import org.jboss.ejb.StatefulSessionPersistenceManager;
import EDU.oswego.cs.dl.util.concurrent.ConcurrentReaderHashMap;
/**
* Cache for stateful session beans.
*
* @author <a href="mailto:simone.bordet@compaq.com">Simone Bordet</a>
* @author <a href="mailto:sebastien.alborini@m4x.org">Sebastien Alborini</a>
* @version $Revision: 81030 $
*/
public class StatefulSessionInstanceCache extends AbstractInstanceCache
{
// Constants -----------------------------------------------------
// Attributes ----------------------------------------------------
/* The container */
private StatefulSessionContainer m_container;
/** The map<id, Long> that holds passivated bean ids that have been removed
* from the cache and passivated to the pm along with the time of passivation
*/
private ConcurrentReaderHashMap passivatedIDs = new ConcurrentReaderHashMap();
/* Ids that are currently being activated */
private HashSet activating = new HashSet();
/* Used for logging */
private StringBuffer buffer = new StringBuffer();
// Static --------------------------------------------------------
// Constructors --------------------------------------------------
// Public --------------------------------------------------------
/** Get the passivated count.
* @jmx:managed-attribute
* @return the number of passivated instances.
*/
public long getPassivatedCount()
{
return passivatedIDs.size();
}
/* From ContainerPlugin interface */
public void setContainer(Container c)
{
m_container = (StatefulSessionContainer) c;
}
public void destroy()
{
synchronized (this)
{
this.m_container = null;
}
passivatedIDs.clear();
super.destroy();
}
// Z implementation ----------------------------------------------
// Y overrides ---------------------------------------------------
protected synchronized Container getContainer()
{
return m_container;
}
protected void passivate(EnterpriseContext ctx) throws RemoteException
{
m_container.getPersistenceManager().passivateSession((StatefulSessionEnterpriseContext) ctx);
passivatedIDs.put(ctx.getId(), new Long(System.currentTimeMillis()));
}
protected void activate(EnterpriseContext ctx) throws RemoteException
{
m_container.getPersistenceManager().activateSession((StatefulSessionEnterpriseContext) ctx);
passivatedIDs.remove(ctx.getId());
}
protected boolean doActivate(EnterpriseContext ctx) throws RemoteException
{
Object id = ctx.getId();
synchronized (activating)
{
// This is a recursive invocation
if (activating.contains(id))
return false;
activating.add(id);
}
try
{
return super.doActivate(ctx);
}
finally
{
synchronized (activating)
{
activating.remove(id);
}
}
}
protected EnterpriseContext acquireContext() throws Exception
{
return m_container.getInstancePool().get();
}
protected void freeContext(EnterpriseContext ctx)
{
m_container.getInstancePool().free(ctx);
}
protected Object getKey(EnterpriseContext ctx)
{
return ctx.getId();
}
protected void setKey(Object id, EnterpriseContext ctx)
{
ctx.setId(id);
}
protected boolean canPassivate(EnterpriseContext ctx)
{
if (ctx.isLocked())
{
// The context is in the interceptor chain
return false;
}
else if (m_container.getLockManager().canPassivate(ctx.getId()) == false)
{
return false;
}
else
{
if (ctx.getTransaction() != null)
{
try
{
return (ctx.getTransaction().getStatus() == Status.STATUS_NO_TRANSACTION);
}
catch (SystemException e)
{
// SA FIXME: not sure what to do here
return false;
}
}
}
return true;
}
/** Remove all passivated instances that have been inactive too long.
* @param maxLifeAfterPassivation the upper bound in milliseconds that an
* inactive session will be kept.
*/
protected void removePassivated(long maxLifeAfterPassivation)
{
StatefulSessionPersistenceManager store = m_container.getPersistenceManager();
long now = System.currentTimeMillis();
log.debug("removePassivated, now="+now+", maxLifeAfterPassivation="+maxLifeAfterPassivation);
boolean trace = log.isTraceEnabled();
Iterator entries = passivatedIDs.entrySet().iterator();
while (entries.hasNext())
{
Map.Entry entry = (Map.Entry) entries.next();
Object key = entry.getKey();
Long value = (Long) entry.getValue();
if (value != null)
{
long passivationTime = value.longValue();
if (now - passivationTime > maxLifeAfterPassivation)
{
preRemovalPreparation(key);
store.removePassivated(key);
if (trace)
log(key, passivationTime);
// Must use iterator to avoid ConcurrentModificationException
entries.remove();
postRemovalCleanup(key);
}
}
}
}
// Protected -----------------------------------------------------
protected void preRemovalPreparation(Object key)
{
// no-op...extending classes may add prep
}
protected void postRemovalCleanup(Object key)
{
// no-op...extending classes may add cleanup
}
// Private -------------------------------------------------------
private void log(Object key, long passivationTime)
{
if (log.isTraceEnabled())
{
buffer.setLength(0);
buffer.append("Removing from storage bean '");
buffer.append(m_container.getBeanMetaData().getEjbName());
buffer.append("' with id = ");
buffer.append(key);
buffer.append(", passivationTime=");
buffer.append(passivationTime);
log.trace(buffer.toString());
}
}
// Inner classes -------------------------------------------------
}