/hudson-remoting/src/main/java/hudson/remoting/PingThread.java
http://github.com/hudson/hudson · Java · 125 lines · 61 code · 15 blank · 49 comment · 1 complexity · 2fe20d3b549889d6b5e617bead9a297a MD5 · raw file
- /*
- * The MIT License
- *
- * Copyright (c) 2004-2010, Sun Microsystems, Inc., Kohsuke Kawaguchi
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
- package hudson.remoting;
- import java.io.IOException;
- import java.util.concurrent.ExecutionException;
- import static java.util.concurrent.TimeUnit.MILLISECONDS;
- import java.util.concurrent.TimeoutException;
- import java.util.logging.Logger;
- /**
- * Periodically perform a ping.
- *
- * <p>
- * Useful when a connection needs to be kept alive by sending data,
- * or when the disconnection is not properly detected.
- *
- * <p>
- * {@link #onDead()} method needs to be overrided to define
- * what to do when a connection appears to be dead.
- *
- * @author Kohsuke Kawaguchi
- * @since 1.170
- */
- public abstract class PingThread extends Thread {
- private final Channel channel;
- /**
- * Time out in milliseconds.
- * If the response doesn't come back by then, the channel is considered dead.
- */
- private final long timeout;
- /**
- * Performs a check every this milliseconds.
- */
- private final long interval;
- public PingThread(Channel channel, long timeout, long interval) {
- super("Ping thread for channel "+channel);
- this.channel = channel;
- this.timeout = timeout;
- this.interval = interval;
- setDaemon(true);
- }
- public PingThread(Channel channel, long interval) {
- this(channel, 4*60*1000/*4 mins*/, interval);
- }
- public PingThread(Channel channel) {
- this(channel,10*60*1000/*10 mins*/);
- }
- public void run() {
- try {
- while(true) {
- long nextCheck = System.currentTimeMillis()+interval;
- ping();
- // wait until the next check
- long diff;
- while((diff=nextCheck-System.currentTimeMillis())>0)
- Thread.sleep(diff);
- }
- } catch (ChannelClosedException e) {
- LOGGER.fine(getName()+" is closed. Terminating");
- } catch (IOException e) {
- onDead();
- } catch (InterruptedException e) {
- // use interruption as a way to terminate the ping thread.
- LOGGER.fine(getName()+" is interrupted. Terminating");
- }
- }
- private void ping() throws IOException, InterruptedException {
- Future<?> f = channel.callAsync(new Ping());
- try {
- f.get(timeout,MILLISECONDS);
- } catch (ExecutionException e) {
- if (e.getCause() instanceof RequestAbortedException)
- return; // connection has shut down orderly.
- onDead();
- } catch (TimeoutException e) {
- onDead();
- }
- }
- /**
- * Called when ping failed.
- */
- protected abstract void onDead();
- private static final class Ping implements Callable<Void, IOException> {
- private static final long serialVersionUID = 1L;
- public Void call() throws IOException {
- return null;
- }
- }
- private static final Logger LOGGER = Logger.getLogger(PingThread.class.getName());
- }