/*
* 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.flink.streaming.connectors.kafka.internals;
/**
* A watch dog thread that forcibly kills another thread, if that thread does not
* finish in time.
*
* <p>This uses the discouraged {@link Thread#stop()} method. While this is not
* advisable, this watch dog is only for extreme cases of thread that simply
* to not terminate otherwise.
*/
class KillerWatchDog extends Thread {
private final Thread toKill;
private final long timeout;
KillerWatchDog(Thread toKill, long timeout) {
super("KillerWatchDog");
setDaemon(true);
this.toKill = toKill;
this.timeout = timeout;
}
@SuppressWarnings("deprecation")
@Override
public void run() {
final long deadline = System.nanoTime() / 1_000_000L + timeout;
long now;
while (toKill.isAlive() && (now = (System.nanoTime() / 1_000_000L)) < deadline) {
try {
toKill.join(deadline - now);
}
catch (InterruptedException e) {
// ignore here, our job is important!
}
}
// this is harsh, but this watchdog is a last resort
if (toKill.isAlive()) {
toKill.stop();
}
}
}