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/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.activemq.transport.nio;
import java.io.IOException;
import java.nio.channels.SocketChannel;
import java.util.LinkedList;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
* The SelectorManager will manage one Selector and the thread that checks the
* selector.
*
* We may need to consider running more than one thread to check the selector if
* servicing the selector takes too long.
*
* @version $Rev: 46019 $ $Date: 2004-09-14 05:56:06 -0400 (Tue, 14 Sep 2004) $
*/
public final class SelectorManager {
public static final SelectorManager SINGLETON = new SelectorManager();
private Executor selectorExecutor = createDefaultExecutor();
private Executor channelExecutor = selectorExecutor;
private LinkedList freeWorkers = new LinkedList();
private int maxChannelsPerWorker = 1024;
protected ExecutorService createDefaultExecutor() {
ThreadPoolExecutor rc = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 10, TimeUnit.MILLISECONDS, new SynchronousQueue(), new ThreadFactory() {
public Thread newThread(Runnable runnable) {
return new Thread(runnable, "ActiveMQ NIO Worker");
}
});
// rc.allowCoreThreadTimeOut(true);
return rc;
}
public static SelectorManager getInstance() {
return SINGLETON;
}
public interface Listener {
void onSelect(SelectorSelection selector);
void onError(SelectorSelection selection, Throwable error);
}
public synchronized SelectorSelection register(SocketChannel socketChannel, Listener listener)
throws IOException {
SelectorSelection selection = null;
while( selection == null ) {
if (freeWorkers.size() > 0) {
SelectorWorker worker = freeWorkers.getFirst();
if( worker.isReleased() ) {
freeWorkers.remove(worker);
} else {
worker.retain();
selection = new SelectorSelection(worker, socketChannel, listener);
}
} else {
// Worker starts /w retain count of 1
SelectorWorker worker = new SelectorWorker(this);
freeWorkers.addFirst(worker);
selection = new SelectorSelection(worker, socketChannel, listener);
}
}
return selection;
}
synchronized void onWorkerFullEvent(SelectorWorker worker) {
freeWorkers.remove(worker);
}
public synchronized void onWorkerEmptyEvent(SelectorWorker worker) {
freeWorkers.remove(worker);
}
public synchronized void onWorkerNotFullEvent(SelectorWorker worker) {
freeWorkers.addFirst(worker);
}
public Executor getChannelExecutor() {
return channelExecutor;
}
public void setChannelExecutor(Executor channelExecutor) {
this.channelExecutor = channelExecutor;
}
public int getMaxChannelsPerWorker() {
return maxChannelsPerWorker;
}
public void setMaxChannelsPerWorker(int maxChannelsPerWorker) {
this.maxChannelsPerWorker = maxChannelsPerWorker;
}
public Executor getSelectorExecutor() {
return selectorExecutor;
}
public void setSelectorExecutor(Executor selectorExecutor) {
this.selectorExecutor = selectorExecutor;
}
}