alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (InterruptionUtil.java)

This example Java source code file (InterruptionUtil.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

assertionerror, interruptedexception, interruptenator, interruptenatortask, interruptionutil, log, logger, logging, milliseconds, override, runnable, teardownaccepter, thread, threading, threads, timeunit

The InterruptionUtil.java Java example source code

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * 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.
 */

package com.google.common.util.concurrent;

import static com.google.common.base.Preconditions.checkNotNull;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static junit.framework.Assert.fail;

import com.google.common.testing.TearDown;
import com.google.common.testing.TearDownAccepter;

import java.util.concurrent.TimeUnit;
import java.util.logging.Logger;

/**
 * Utilities for performing thread interruption in tests
 *
 * @author Kevin Bourrillion
 * @author Chris Povirk
 */
final class InterruptionUtil {
  private static final Logger logger =
      Logger.getLogger(InterruptionUtil.class.getName());

  /**
   * Runnable which will interrupt the target thread repeatedly when run.
   */
  private static final class Interruptenator implements Runnable {
    private final long everyMillis;
    private final Thread interruptee;
    private volatile boolean shouldStop = false;

    Interruptenator(Thread interruptee, long everyMillis) {
      this.everyMillis = everyMillis;
      this.interruptee = interruptee;
    }

    @Override
    public void run() {
      while (true) {
        try {
          Thread.sleep(everyMillis);
        } catch (InterruptedException e) {
          // ok. just stop sleeping.
        }
        if (shouldStop) {
          break;
        }
        interruptee.interrupt();
      }
    }

    void stopInterrupting() {
      shouldStop = true;
    }
  }

  /**
   * Interrupts the current thread after sleeping for the specified delay.
   */
  static void requestInterruptIn(final long time, final TimeUnit unit) {
    checkNotNull(unit);
    final Thread interruptee = Thread.currentThread();
    new Thread(new Runnable() {
      @Override
      public void run() {
        try {
          unit.sleep(time);
        } catch (InterruptedException wontHappen) {
          throw new AssertionError(wontHappen);
        }
        interruptee.interrupt();
      }
    }).start();
  }

  static void repeatedlyInterruptTestThread(
      long interruptPeriodMillis, TearDownAccepter tearDownAccepter) {
    final Interruptenator interruptingTask =
        new Interruptenator(Thread.currentThread(), interruptPeriodMillis);
    final Thread interruptingThread = new Thread(interruptingTask);
    interruptingThread.start();
    tearDownAccepter.addTearDown(new TearDown() {
      @Override public void tearDown() throws Exception {
        interruptingTask.stopInterrupting();
        interruptingThread.interrupt();
        joinUninterruptibly(interruptingThread, 2500, MILLISECONDS);
        Thread.interrupted();
        if (interruptingThread.isAlive()) {
          // This will be hidden by test-output redirection:
          logger.severe(
              "InterruptenatorTask did not exit; future tests may be affected");
          /*
           * This won't do any good under JUnit 3, but I'll leave it around in
           * case we ever switch to JUnit 4:
           */
          fail();
        }
      }
    });
  }

  // TODO(cpovirk): promote to Uninterruptibles, and add untimed version
  private static void joinUninterruptibly(
      Thread thread, long timeout, TimeUnit unit) {
    boolean interrupted = false;
    try {
      long remainingNanos = unit.toNanos(timeout);
      long end = System.nanoTime() + remainingNanos;

      while (true) {
        try {
          // TimeUnit.timedJoin() treats negative timeouts just like zero.
          NANOSECONDS.timedJoin(thread, remainingNanos);
          return;
        } catch (InterruptedException e) {
          interrupted = true;
          remainingNanos = end - System.nanoTime();
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java InterruptionUtil.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.