/*
* Copyright (C) 2009 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.checkState;
import static com.google.common.util.concurrent.Futures.immediateFuture;
import static com.google.common.util.concurrent.JdkFutureAdapters.listenInPoolThread;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static java.util.concurrent.Executors.newCachedThreadPool;
import static java.util.concurrent.TimeUnit.SECONDS;
import com.google.common.testing.ClassSanityTester;
import com.google.common.util.concurrent.FuturesTest.ExecutorSpy;
import com.google.common.util.concurrent.FuturesTest.SingleCallListener;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
* Unit tests for {@link JdkFutureAdapters}.
*
* @author Sven Mawson
* @author Kurt Alfred Kluever
*/
public class JdkFutureAdaptersTest extends TestCase {
private static final String DATA1 = "data";
public void testListenInPoolThreadReturnsSameFuture() throws Exception {
ListenableFuture<String> listenableFuture = immediateFuture(DATA1);
assertSame(listenableFuture, listenInPoolThread(listenableFuture));
}
public void testListenInPoolThreadIgnoresExecutorWhenDelegateIsDone()
throws Exception {
NonListenableSettableFuture<String> abstractFuture =
NonListenableSettableFuture.create();
abstractFuture.set(DATA1);
ExecutorSpy spy = new ExecutorSpy(directExecutor());
ListenableFuture<String> listenableFuture =
listenInPoolThread(abstractFuture, spy);
SingleCallListener singleCallListener = new SingleCallListener();
singleCallListener.expectCall();
assertFalse(spy.wasExecuted);
assertFalse(singleCallListener.wasCalled());
assertTrue(listenableFuture.isDone()); // We call AbstractFuture#set above.
// #addListener() will run the listener immediately because the Future is
// already finished (we explicitly set the result of it above).
listenableFuture.addListener(singleCallListener, directExecutor());
assertEquals(DATA1, listenableFuture.get());
// 'spy' should have been ignored since 'abstractFuture' was done before
// a listener was added.
assertFalse(spy.wasExecuted);
assertTrue(singleCallListener.wasCalled());
assertTrue(listenableFuture.isDone());
}
public void testListenInPoolThreadUsesGivenExecutor() throws Exception {
ExecutorService executorService = newCachedThreadPool(
new ThreadFactoryBuilder().setDaemon(true).build());
NonListenableSettableFuture<String> abstractFuture =
NonListenableSettableFuture.create();
ExecutorSpy spy = new ExecutorSpy(executorService);
ListenableFuture<String> listenableFuture =
listenInPoolThread(abstractFuture, spy);
SingleCallListener singleCallListener = new SingleCallListener();
singleCallListener.expectCall();
assertFalse(spy.wasExecuted);
assertFalse(singleCallListener.wasCalled());
assertFalse(listenableFuture.isDone());
listenableFuture.addListener(singleCallListener, executorService);
abstractFuture.set(DATA1);
assertEquals(DATA1, listenableFuture.get());
singleCallListener.waitForCall();
assertTrue(spy.wasExecuted);
assertTrue(singleCallListener.wasCalled());
assertTrue(listenableFuture.isDone());
}
public void testListenInPoolThreadCustomExecutorInterrupted()
throws Exception {
final CountDownLatch submitSuccessful = new CountDownLatch(1);
ExecutorService executorService = new ThreadPoolExecutor(
0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS,
new SynchronousQueue<Runnable>(),
new ThreadFactoryBuilder().setDaemon(true).build()) {
@Override
protected void beforeExecute(Thread t, Runnable r) {
submitSuccessful.countDown();
}
};
NonListenableSettableFuture<String> abstractFuture =
NonListenableSettableFuture.create();
ListenableFuture<String> listenableFuture =
listenInPoolThread(abstractFuture, executorService);
SingleCallListener singleCallListener = new SingleCallListener();
singleCallListener.expectCall();
assertFalse(singleCallListener.wasCalled());
assertFalse(listenableFuture.isDone());
listenableFuture.addListener(singleCallListener, directExecutor());
/*
* Don't shut down until the listenInPoolThread task has been accepted to
* run. We want to see what happens when it's interrupted, not when it's
* rejected.
*/
submitSuccessful.await();
executorService.shutdownNow();
abstractFuture.set(DATA1);
assertEquals(DATA1, listenableFuture.get());
singleCallListener.waitForCall();
assertTrue(singleCallListener.wasCalled());
assertTrue(listenableFuture.isDone());
}
/**
* A Future that doesn't implement ListenableFuture, useful for testing
* listenInPoolThread.
*/
private static final class NonListenableSettableFuture<V>
extends ForwardingFuture<V> {
static <V> NonListenableSettableFuture<V> create() {
return new NonListenableSettableFuture<V>();
}
final SettableFuture<V> delegate = SettableFuture.create();
@Override protected Future<V> delegate() {
return delegate;
}
void set(V value) {
delegate.set(value);
}
}
private static final class RuntimeExceptionThrowingFuture<V>
implements Future<V> {
final CountDownLatch allowGetToComplete = new CountDownLatch(1);
@Override
public boolean cancel(boolean mayInterruptIfRunning) {
throw new AssertionFailedError();
}
@Override
public V get() throws InterruptedException {
/*
* Wait a little to give us time to call addListener before the future's
* value is set in addition to the call we'll make after then.
*/
allowGetToComplete.await(1, SECONDS);
throw new RuntimeException("expected, should be caught");
}
@Override
public V get(long timeout, TimeUnit unit) {
throw new AssertionFailedError();
}
@Override
public boolean isCancelled() {
throw new AssertionFailedError();
}
@Override
public boolean isDone() {
/*
* If isDone is true during the call to listenInPoolThread,
* listenInPoolThread doesn't start a thread. Make sure it's false the
* first time through (and forever after, since no one else cares about
* it).
*/
return false;
}
}
private static final class RecordingRunnable implements Runnable {
final CountDownLatch wasRun = new CountDownLatch(1);
// synchronized so that checkState works as expected.
@Override
public synchronized void run() {
checkState(wasRun.getCount() > 0);
wasRun.countDown();
}
}
public void testListenInPoolThreadRunsListenerAfterRuntimeException()
throws Exception {
RuntimeExceptionThrowingFuture<String> input =
new RuntimeExceptionThrowingFuture<String>();
/*
* The compiler recognizes that "input instanceof ListenableFuture" is
* impossible. We want the test, though, in case that changes in the future,
* so we use isInstance instead.
*/
assertFalse("Can't test the main listenInPoolThread path "
+ "if the input is already a ListenableFuture",
ListenableFuture.class.isInstance(input));
ListenableFuture<String> listenable = listenInPoolThread(input);
/*
* This will occur before the waiting get() in the
* listenInPoolThread-spawned thread completes:
*/
RecordingRunnable earlyListener = new RecordingRunnable();
listenable.addListener(earlyListener, directExecutor());
input.allowGetToComplete.countDown();
// Now give the get() thread time to finish:
assertTrue(earlyListener.wasRun.await(1, SECONDS));
// Now test an additional addListener call, which will be run in-thread:
RecordingRunnable lateListener = new RecordingRunnable();
listenable.addListener(lateListener, directExecutor());
assertTrue(lateListener.wasRun.await(1, SECONDS));
}
public void testAdapters_nullChecks() throws Exception {
new ClassSanityTester()
.forAllPublicStaticMethods(JdkFutureAdapters.class)
.thatReturn(Future.class)
.testNulls();
}
}