com.groupbyinc.common.apache.commons.io.ThreadMonitor Maven / Gradle / Ivy
/*
* 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.commons.io;
/**
* Monitors a thread, interrupting it if it reaches the specified timeout.
*
* This works by sleeping until the specified timeout amount and then
* interrupting the thread being monitored. If the thread being monitored
* completes its work before being interrupted, it should interrupt()
* the monitor thread.
*
*
*
* long timeoutInMillis = 1000;
* try {
* Thread monitor = ThreadMonitor.start(timeoutInMillis);
* // do some work here
* ThreadMonitor.stop(monitor);
* } catch (InterruptedException e) {
* // timed amount was reached
* }
*
*
*/
class ThreadMonitor implements Runnable {
private final Thread thread;
private final long timeout;
/**
* Start monitoring the current thread.
*
* @param timeout The timeout amount in milliseconds
* or no timeout if the value is zero or less
* @return The monitor thread or {@code null}
* if the timeout amount is not greater than zero
*/
public static Thread start(final long timeout) {
return start(Thread.currentThread(), timeout);
}
/**
* Start monitoring the specified thread.
*
* @param thread The thread The thread to monitor
* @param timeout The timeout amount in milliseconds
* or no timeout if the value is zero or less
* @return The monitor thread or {@code null}
* if the timeout amount is not greater than zero
*/
public static Thread start(final Thread thread, final long timeout) {
Thread monitor = null;
if (timeout > 0) {
final ThreadMonitor timout = new ThreadMonitor(thread, timeout);
monitor = new Thread(timout, ThreadMonitor.class.getSimpleName());
monitor.setDaemon(true);
monitor.start();
}
return monitor;
}
/**
* Stop monitoring the specified thread.
*
* @param thread The monitor thread, may be {@code null}
*/
public static void stop(final Thread thread) {
if (thread != null) {
thread.interrupt();
}
}
/**
* Construct and new monitor.
*
* @param thread The thread to monitor
* @param timeout The timeout amount in milliseconds
*/
private ThreadMonitor(final Thread thread, final long timeout) {
this.thread = thread;
this.timeout = timeout;
}
/**
* Sleep until the specified timeout amount and then
* interrupt the thread being monitored.
*
* @see Runnable#run()
*/
@Override
public void run() {
try {
sleep(timeout);
thread.interrupt();
} catch (final InterruptedException e) {
// timeout not reached
}
}
/**
* Sleep for a guaranteed minimum number of milliseconds unless interrupted.
*
* This method exists because Thread.sleep(100) can sleep for 0, 70, 100 or 200ms or anything else
* it deems appropriate. Read the docs on Thread.sleep for further interesting details.
*
* @param ms the number of milliseconds to sleep for
* @throws InterruptedException if interrupted
*/
private static void sleep(final long ms) throws InterruptedException {
final long finishAt = System.currentTimeMillis() + ms;
long remaining = ms;
do {
Thread.sleep(remaining);
remaining = finishAt - System.currentTimeMillis();
} while (remaining > 0);
}
}