/*
* JBoss, Home of Professional Open Source.
* Copyright 2006, 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.resource.adapter.jms.inflow;
import java.util.ArrayList;
import javax.jms.Connection;
import javax.jms.ConnectionConsumer;
import javax.jms.JMSException;
import javax.jms.Queue;
import javax.jms.ServerSession;
import javax.jms.ServerSessionPool;
import javax.jms.Topic;
import org.jboss.logging.Logger;
/**
* A generic jms session pool.
*
* @author <a href="adrian@jboss.com">Adrian Brock</a>
* @version $Revision: 100217 $
*/
public class JmsServerSessionPool implements ServerSessionPool
{
/** The logger */
private static final Logger log = Logger.getLogger(JmsServerSessionPool.class);
/** The activation */
JmsActivation activation;
/** The consumer */
ConnectionConsumer consumer;
/** The server sessions */
ArrayList serverSessions = new ArrayList();
/** Whether the pool is stopped */
boolean stopped = false;
/** The number of sessions */
int sessionCount = 0;
/**
* Create a new session pool
*
* @param activation the jms activation
*/
public JmsServerSessionPool(JmsActivation activation)
{
this.activation = activation;
}
/**
* @return the activation
*/
public JmsActivation getActivation()
{
return activation;
}
/**
* Start the server session pool
*
* @throws Exeption for any error
*/
public void start() throws Exception
{
setupSessions();
setupConsumer();
}
/**
* Stop the server session pool
*/
public void stop()
{
teardownConsumer();
teardownSessions();
}
public ServerSession getServerSession() throws JMSException
{
boolean trace = log.isTraceEnabled();
if (trace)
log.trace("getServerSession");
ServerSession result = null;
try
{
synchronized (serverSessions)
{
while (true)
{
int sessionsSize = serverSessions.size();
if (stopped)
throw new Exception("Cannot get a server session after the pool is stopped");
else if (sessionsSize > 0)
{
result = (ServerSession) serverSessions.remove(sessionsSize-1);
break;
}
else
{
try
{
serverSessions.wait();
}
catch (InterruptedException ignored)
{
}
}
}
}
}
catch (Throwable t)
{
throw new JMSException("Unable to get a server session " + t);
}
if (trace)
log.trace("Returning server session " + result);
return result;
}
/**
* Return the server session
*
* @param session the session
*/
protected void returnServerSession(JmsServerSession session)
{
synchronized (serverSessions)
{
if (stopped)
{
session.teardown();
--sessionCount;
}
else
serverSessions.add(session);
serverSessions.notifyAll();
}
}
/**
* Setup the sessions
*
* @throws Exeption for any error
*/
protected void setupSessions() throws Exception
{
JmsActivationSpec spec = activation.getActivationSpec();
ArrayList clonedSessions = null;
// Create the sessions
synchronized (serverSessions)
{
for (int i = 0; i < spec.getMaxSessionInt(); ++i)
{
JmsServerSession session = new JmsServerSession(this);
serverSessions.add(session);
}
sessionCount = serverSessions.size();
clonedSessions = (ArrayList) serverSessions.clone();
}
// Start the sessions
for (int i = 0; i < clonedSessions.size(); ++ i)
{
JmsServerSession session = (JmsServerSession) clonedSessions.get(i);
session.setup();
}
}
/**
* Stop the sessions
*/
protected void teardownSessions()
{
synchronized (serverSessions)
{
// Disallow any new sessions
stopped = true;
serverSessions.notifyAll();
// Stop inactive sessions
for (int i = 0; i < serverSessions.size(); ++i)
{
JmsServerSession session = (JmsServerSession) serverSessions.get(i);
session.teardown();
--sessionCount;
}
serverSessions.clear();
if (activation.getActivationSpec().isForceClearOnShutdown())
{
int attempts = 0;
int forceClearAttempts = activation.getActivationSpec().getForceClearAttempts();
long forceClearInterval = activation.getActivationSpec().getForceClearOnShutdownInterval();
log.trace(this + " force clear behavior in effect. Waiting for " + forceClearInterval + " milliseconds for " + forceClearAttempts + " attempts.");
while((sessionCount > 0) && (attempts < forceClearAttempts))
{
try
{
int currentSessions = sessionCount;
serverSessions.wait(forceClearInterval);
// Number of session didn't change
if (sessionCount == currentSessions)
{
++attempts;
log.trace(this + " clear attempt failed " + attempts);
}
}
catch(InterruptedException ignore)
{
}
}
}
else
{
// Wait for inuse sessions
while (sessionCount > 0)
{
try
{
serverSessions.wait();
}
catch (InterruptedException ignore)
{
}
}
}
}
}
/**
* Setup the connection consumer
*
* @throws Exeption for any error
*/
protected void setupConsumer() throws Exception
{
Connection connection = activation.getConnection();
JmsActivationSpec spec = activation.getActivationSpec();
String selector = spec.getMessageSelector();
int maxMessages = spec.getMaxMessagesInt();
if (activation.isTopic())
{
Topic topic = (Topic) activation.getDestination();
String subscriptionName = spec.getSubscriptionName();
if (spec.isDurable())
consumer = connection.createDurableConnectionConsumer(topic, subscriptionName, selector, this, maxMessages);
else
consumer = connection.createConnectionConsumer(topic, selector, this, maxMessages);
}
else
{
Queue queue = (Queue) activation.getDestination();
consumer = connection.createConnectionConsumer(queue, selector, this, maxMessages);
}
log.debug("Created consumer " + consumer);
if (consumer == null)
throw new JMSException("Consumer is null");
}
/**
* Stop the connection consumer
*/
protected void teardownConsumer()
{
try
{
if (consumer != null)
{
log.debug("Closing the " + consumer);
consumer.close();
}
}
catch (Throwable t)
{
log.debug("Error closing the consumer " + consumer, t);
}
}
}