/*
* 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.base.Preconditions;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
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
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.
*/
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.
*/
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.
*/
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.
* To get uninterruptibility and remove checked exceptions, see
* {@link Futures#getUnchecked}.
*
* <p>If instead, you wish to treat {@link InterruptedException} uniformly
* with other exceptions, see {@link Futures#get(Future, Class) Futures.get}
* or {@link Futures#makeChecked}.
*/
public static <V> V getUninterruptibly(Future<V> 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>If instead, you wish to treat {@link InterruptedException} uniformly
* with other exceptions, see {@link Futures#get(Future, Class) Futures.get}
* or {@link Futures#makeChecked}.
*/
public static <V> V getUninterruptibly(
Future<V> 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.
*/
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.
*/
public static <E> E takeUninterruptibly(BlockingQueue<E> 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.
*/
public static <E> void putUninterruptibly(BlockingQueue<E> 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.
*/
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();
}
}
}
// TODO(user): Add support for waitUninterruptibly.
private Uninterruptibles() {}
}
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