Java example source code file (Uninterruptibles.java)

This example Java source code file (Uninterruptibles.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

canignorereturnvalue, consider, executionexception, gwtcompatible, gwtincompatible, interruptedexception, nanoseconds, semaphore, threading, threads, timeoutexception, timeunit, todo, uninterruptibles

The Uninterruptibles.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 java.util.concurrent.TimeUnit.NANOSECONDS;

import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * Utilities for treating interruptible operations as uninterruptible. In all cases, if a thread is
 * interrupted during such a call, the call continues to block until the result is available or the
 * timeout elapses, and only then re-interrupts the thread.
 *
 * @author Anthony Zana
 * @since 10.0
 */
@Beta
@GwtCompatible(emulated = true)
public final class Uninterruptibles {

  // Implementation Note: As of 3-7-11, the logic for each blocking/timeout
  // methods is identical, save for method being invoked.

  /**
   * Invokes {@code latch.}{@link CountDownLatch#await() await()} uninterruptibly.
   */
  @GwtIncompatible // concurrency
  public static void awaitUninterruptibly(CountDownLatch latch) {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          latch.await();
          return;
        } catch (InterruptedException e) {
          interrupted = true;
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code latch.}{@link CountDownLatch#await(long, TimeUnit) await(timeout, unit)}
   * uninterruptibly.
   */
  @CanIgnoreReturnValue // TODO(cpovirk): Consider being more strict.
  @GwtIncompatible // concurrency
  public static boolean awaitUninterruptibly(CountDownLatch latch, long timeout, TimeUnit unit) {
    boolean interrupted = false;
    try {
      long remainingNanos = unit.toNanos(timeout);
      long end = System.nanoTime() + remainingNanos;

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

  /**
   * Invokes {@code toJoin.}{@link Thread#join() join()} uninterruptibly.
   */
  @GwtIncompatible // concurrency
  public static void joinUninterruptibly(Thread toJoin) {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          toJoin.join();
          return;
        } catch (InterruptedException e) {
          interrupted = true;
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code future.}{@link Future#get() get()} uninterruptibly.
   *
   * <p>Similar methods:
   *
   * <ul>
   * <li>To retrieve a result from a {@code Future} that is already done, use
   *     {@link Futures#getDone Futures.getDone}.
   * <li>To treat {@link InterruptedException} uniformly with other exceptions, use
   *     {@link Futures#getChecked(Future, Class) Futures.getChecked}.
   * <li>To get uninterruptibility and remove checked exceptions, use {@link Futures#getUnchecked}.
   * </ul>
   *
   * @throws ExecutionException if the computation threw an exception
   * @throws CancellationException if the computation was cancelled
   */
  @CanIgnoreReturnValue
  public static <V> V getUninterruptibly(Future future) throws ExecutionException {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          return future.get();
        } catch (InterruptedException e) {
          interrupted = true;
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code future.}{@link Future#get(long, TimeUnit) get(timeout, unit)} uninterruptibly.
   *
   * <p>Similar methods:
   *
   * <ul>
   * <li>To retrieve a result from a {@code Future} that is already done, use
   *     {@link Futures#getDone Futures.getDone}.
   * <li>To treat {@link InterruptedException} uniformly with other exceptions, use
   *     {@link Futures#getChecked(Future, Class, long, TimeUnit) Futures.getChecked}.
   * <li>To get uninterruptibility and remove checked exceptions, use {@link Futures#getUnchecked}.
   * </ul>
   *
   * @throws ExecutionException if the computation threw an exception
   * @throws CancellationException if the computation was cancelled
   * @throws TimeoutException if the wait timed out
   */
  @CanIgnoreReturnValue
  @GwtIncompatible // TODO
  public static <V> V getUninterruptibly(Future future, long timeout, TimeUnit unit)
      throws ExecutionException, TimeoutException {
    boolean interrupted = false;
    try {
      long remainingNanos = unit.toNanos(timeout);
      long end = System.nanoTime() + remainingNanos;

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

  /**
   * Invokes {@code unit.}{@link TimeUnit#timedJoin(Thread, long) timedJoin(toJoin, timeout)}
   * uninterruptibly.
   */
  @GwtIncompatible // concurrency
  public static void joinUninterruptibly(Thread toJoin, long timeout, TimeUnit unit) {
    Preconditions.checkNotNull(toJoin);
    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(toJoin, remainingNanos);
          return;
        } catch (InterruptedException e) {
          interrupted = true;
          remainingNanos = end - System.nanoTime();
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code queue.}{@link BlockingQueue#take() take()} uninterruptibly.
   */
  @GwtIncompatible // concurrency
  public static <E> E takeUninterruptibly(BlockingQueue queue) {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          return queue.take();
        } catch (InterruptedException e) {
          interrupted = true;
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code queue.}{@link BlockingQueue#put(Object) put(element)} uninterruptibly.
   *
   * @throws ClassCastException if the class of the specified element prevents it from being added
   *     to the given queue
   * @throws IllegalArgumentException if some property of the specified element prevents it from
   *     being added to the given queue
   */
  @GwtIncompatible // concurrency
  public static <E> void putUninterruptibly(BlockingQueue queue, E element) {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          queue.put(element);
          return;
        } catch (InterruptedException e) {
          interrupted = true;
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  // TODO(user): Support Sleeper somehow (wrapper or interface method)?
  /**
   * Invokes {@code unit.}{@link TimeUnit#sleep(long) sleep(sleepFor)} uninterruptibly.
   */
  @GwtIncompatible // concurrency
  public static void sleepUninterruptibly(long sleepFor, TimeUnit unit) {
    boolean interrupted = false;
    try {
      long remainingNanos = unit.toNanos(sleepFor);
      long end = System.nanoTime() + remainingNanos;
      while (true) {
        try {
          // TimeUnit.sleep() treats negative timeouts just like zero.
          NANOSECONDS.sleep(remainingNanos);
          return;
        } catch (InterruptedException e) {
          interrupted = true;
          remainingNanos = end - System.nanoTime();
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code semaphore.}{@link Semaphore#tryAcquire(int, long, TimeUnit) tryAcquire(1,
   * timeout, unit)} uninterruptibly.
   *
   * @since 18.0
   */
  @GwtIncompatible // concurrency
  public static boolean tryAcquireUninterruptibly(
      Semaphore semaphore, long timeout, TimeUnit unit) {
    return tryAcquireUninterruptibly(semaphore, 1, timeout, unit);
  }

  /**
   * Invokes {@code semaphore.}{@link Semaphore#tryAcquire(int, long, TimeUnit) tryAcquire(permits,
   * timeout, unit)} uninterruptibly.
   *
   * @since 18.0
   */
  @GwtIncompatible // concurrency
  public static boolean tryAcquireUninterruptibly(
      Semaphore semaphore, int permits, long timeout, TimeUnit unit) {
    boolean interrupted = false;
    try {
      long remainingNanos = unit.toNanos(timeout);
      long end = System.nanoTime() + remainingNanos;

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

  // TODO(user): Add support for waitUninterruptibly.

  private Uninterruptibles() {}
}