/*
* JBoss, Home of Professional Open Source.
* Copyright 2009, 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.web.tomcat.service.session;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletResponse;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.valves.ValveBase;
import org.jboss.servlet.http.HttpEvent;
/**
* Generic valve that applies a given lock to a request.
*
* @author Paul Ferraro
*/
public class LockingValve extends ValveBase
{
private final Lock lock;
public LockingValve(Lock lock)
{
this.lock = lock;
}
/**
* {@inheritDoc}
*/
@Override
public void invoke(Request request, Response response) throws IOException, ServletException
{
try
{
if (this.lock.tryLock(0, TimeUnit.SECONDS))
{
try
{
this.next.invoke(request, response);
}
finally
{
this.lock.unlock();
}
}
else
{
response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
}
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
}
}
/**
* {@inheritDoc}
*/
@Override
public void event(Request request, Response response, HttpEvent event) throws IOException, ServletException
{
try
{
if (this.lock.tryLock(0, TimeUnit.SECONDS))
{
try
{
this.next.event(request, response, event);
}
finally
{
this.lock.unlock();
}
}
else
{
response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
}
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
}
}
}