| /* |
| * 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; |
| |
| import java.time.Duration; |
| |
| /** |
| * Monitors a thread, interrupting it if it reaches the specified timeout. |
| * <p> |
| * 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 {@code interrupt()} |
| * the <i>monitor</i> thread. |
| * </p> |
| * |
| * <pre> |
| * long timeoutInMillis = 1000; |
| * try { |
| * Thread monitor = ThreadMonitor.start(timeoutInMillis); |
| * // do some work here |
| * ThreadMonitor.stop(monitor); |
| * } catch (InterruptedException e) { |
| * // timed amount was reached |
| * } |
| * </pre> |
| * |
| */ |
| class ThreadMonitor implements Runnable { |
| |
| private final Thread thread; |
| private final Duration 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 |
| */ |
| static Thread start(final Duration 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 |
| */ |
| static Thread start(final Thread thread, final Duration timeout) { |
| if (timeout.isZero() || timeout.isNegative()) { |
| return null; |
| } |
| final ThreadMonitor timout = new ThreadMonitor(thread, timeout); |
| final Thread 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} |
| */ |
| static void stop(final Thread thread) { |
| if (thread != null) { |
| thread.interrupt(); |
| } |
| } |
| |
| /** |
| * Constructs a new monitor. |
| * |
| * @param thread The thread to monitor |
| * @param timeout The timeout amount in milliseconds |
| */ |
| private ThreadMonitor(final Thread thread, final Duration 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 |
| } |
| } |
| |
| /** |
| * Sleeps for a guaranteed minimum duration 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 duration the sleep duration. |
| * @throws InterruptedException if interrupted |
| */ |
| private static void sleep(final Duration duration) throws InterruptedException { |
| // Ignore nanos for now. |
| final long millis = duration.toMillis(); |
| final long finishAtMillis = System.currentTimeMillis() + millis; |
| long remainingMillis = millis; |
| do { |
| Thread.sleep(remainingMillis); |
| remainingMillis = finishAtMillis - System.currentTimeMillis(); |
| } while (remainingMillis > 0); |
| } |
| |
| |
| } |