/*
* Copyright 2010-2012 sshj contributors
*
* 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.
*
* This file may incorporate work covered by the following copyright and
* permission notice:
*
* 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 net.schmizz.sshj.transport;
import net.schmizz.sshj.common.Message;
import net.schmizz.sshj.common.SSHPacket;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
final class Heartbeater
extends Thread {
private final Logger log = LoggerFactory.getLogger(getClass());
private final TransportImpl trans;
private int interval;
Heartbeater(TransportImpl trans) {
this.trans = trans;
setName("heartbeater");
}
synchronized void setInterval(int interval) {
this.interval = interval;
if (interval > 0 && getState() == Thread.State.NEW)
start();
notify();
}
synchronized int getInterval() {
return interval;
}
synchronized private int getPositiveInterval()
throws InterruptedException {
while (interval <= 0)
wait();
return interval;
}
@Override
public void run() {
log.debug("Starting");
try {
while (!isInterrupted()) {
final int hi = getPositiveInterval();
if (trans.isRunning()) {
log.debug("Sending heartbeat since {} seconds elapsed", hi);
trans.write(new SSHPacket(Message.IGNORE));
}
Thread.sleep(hi * 1000);
}
} catch (Exception e) {
if (isInterrupted()) {
// We are meant to shut up and draw to a close if interrupted
} else
trans.die(e);
}
log.debug("Stopping");
}
}