/*
* Copyright 2004-2006 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.sf.cindy.session.dispatcher;
import net.sf.cindy.Session;
import net.sf.cindy.util.LogThreadGroup;
import edu.emory.mathcs.backport.java.util.LinkedList;
import edu.emory.mathcs.backport.java.util.Queue;
/**
* Direct dispatcher implementation, do not support block operation such as
* Future.complete.
*
* @author <a href="chenrui@gmail.com">Roger Chen</a>
* @version $id$
*/
public class DirectDispatcher implements Dispatcher {
private final ThreadLocal local = new ThreadLocal();
public void block() {
if (LogThreadGroup.CINDY_THREAD_GROUP.parentOf(Thread.currentThread()
.getThreadGroup()))// can't block kernel thread
throw new IllegalStateException("can't block kernel thread");
}
private Queue getQueue() {
Queue queue = (Queue) local.get();
if (queue == null) {
queue = new LinkedList();
local.set(queue);
}
return queue;
}
public void dispatch(Session session, Runnable event) {
Queue queue = getQueue();
queue.add(event); // enqueue
if (queue.size() == 1) {
event.run();
queue.poll(); // dequeue current runnable
for (Runnable task = null; (task = (Runnable) queue.peek()) != null; queue
.poll())
task.run();
}
}
}