/*
* Copyright 2007 Yusuke Yamamoto
*
* 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 twitter4j.internal.async;
import twitter4j.conf.Configuration;
import twitter4j.internal.logging.Logger;
import java.util.LinkedList;
import java.util.List;
/**
* @author Yusuke Yamamoto - yusuke at mac.com
* @since Twitter4J 2.1.2
*/
final class DispatcherImpl implements Dispatcher {
private ExecuteThread[] threads;
private final List<Runnable> q = new LinkedList<Runnable>();
public DispatcherImpl(Configuration conf) {
threads = new ExecuteThread[conf.getAsyncNumThreads()];
for (int i = 0; i < threads.length; i++) {
threads[i] = new ExecuteThread("Twitter4J Async Dispatcher", this, i);
threads[i].setDaemon(true);
threads[i].start();
}
Runtime.getRuntime().addShutdownHook(new Thread() {
public void run() {
if (active) {
shutdown();
}
}
});
}
@Override
public synchronized void invokeLater(Runnable task) {
synchronized (q) {
q.add(task);
}
synchronized (ticket) {
ticket.notify();
}
}
final Object ticket = new Object();
public Runnable poll() {
while (active) {
synchronized (q) {
if (q.size() > 0) {
Runnable task = q.remove(0);
if (task != null) {
return task;
}
}
}
synchronized (ticket) {
try {
ticket.wait();
} catch (InterruptedException ignore) {
}
}
}
return null;
}
private boolean active = true;
@Override
public synchronized void shutdown() {
if (active) {
active = false;
for (ExecuteThread thread : threads) {
thread.shutdown();
}
synchronized (ticket) {
ticket.notify();
}
}
}
}
class ExecuteThread extends Thread {
private static Logger logger = Logger.getLogger(ExecuteThread.class);
DispatcherImpl q;
ExecuteThread(String name, DispatcherImpl q, int index) {
super(name + "[" + index + "]");
this.q = q;
}
public void shutdown() {
alive = false;
}
private boolean alive = true;
public void run() {
while (alive) {
Runnable task = q.poll();
if (task != null) {
try {
task.run();
} catch (Exception ex) {
logger.error("Got an exception while running a task:", ex);
}
}
}
}
}