/**
* Copyright 2014 Netflix, Inc.
*
* 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 rx.subscriptions;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.fail;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import static org.mockito.Mockito.verifyZeroInteractions;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.runners.MockitoJUnitRunner;
import rx.Subscription;
@RunWith(MockitoJUnitRunner.class)
public class SerialSubscriptionTests {
private SerialSubscription serialSubscription;
@Before
public void setUp() {
serialSubscription = new SerialSubscription();
}
@Test
public void unsubscribingWithoutUnderlyingDoesNothing() {
serialSubscription.unsubscribe();
}
@Test
public void getSubscriptionShouldReturnset() {
final Subscription underlying = mock(Subscription.class);
serialSubscription.set(underlying);
assertSame(underlying, serialSubscription.get());
final Subscription another = mock(Subscription.class);
serialSubscription.set(another);
assertSame(another, serialSubscription.get());
}
@Test
public void unsubscribingTwiceDoesUnsubscribeOnce() {
Subscription underlying = mock(Subscription.class);
serialSubscription.set(underlying);
serialSubscription.unsubscribe();
verify(underlying).unsubscribe();
serialSubscription.unsubscribe();
verifyNoMoreInteractions(underlying);
}
@Test
public void settingSameSubscriptionTwiceDoesUnsubscribeIt() {
Subscription underlying = mock(Subscription.class);
serialSubscription.set(underlying);
verifyZeroInteractions(underlying);
serialSubscription.set(underlying);
verify(underlying).unsubscribe();
}
@Test
public void unsubscribingWithSingleUnderlyingUnsubscribes() {
Subscription underlying = mock(Subscription.class);
serialSubscription.set(underlying);
underlying.unsubscribe();
verify(underlying).unsubscribe();
}
@Test
public void replacingFirstUnderlyingCausesUnsubscription() {
Subscription first = mock(Subscription.class);
serialSubscription.set(first);
Subscription second = mock(Subscription.class);
serialSubscription.set(second);
verify(first).unsubscribe();
}
@Test
public void whenUnsubscribingSecondUnderlyingUnsubscribed() {
Subscription first = mock(Subscription.class);
serialSubscription.set(first);
Subscription second = mock(Subscription.class);
serialSubscription.set(second);
serialSubscription.unsubscribe();
verify(second).unsubscribe();
}
@Test
public void settingUnderlyingWhenUnsubscribedCausesImmediateUnsubscription() {
serialSubscription.unsubscribe();
Subscription underlying = mock(Subscription.class);
serialSubscription.set(underlying);
verify(underlying).unsubscribe();
}
@Test(timeout = 1000)
public void settingUnderlyingWhenUnsubscribedCausesImmediateUnsubscriptionConcurrently()
throws InterruptedException {
final Subscription firstSet = mock(Subscription.class);
serialSubscription.set(firstSet);
final CountDownLatch start = new CountDownLatch(1);
final int count = 10;
final CountDownLatch end = new CountDownLatch(count);
final List<Thread> threads = new ArrayList<Thread>();
for (int i = 0; i < count; i++) {
final Thread t = new Thread() {
@Override
public void run() {
try {
start.await();
serialSubscription.unsubscribe();
} catch (InterruptedException e) {
fail(e.getMessage());
} finally {
end.countDown();
}
}
};
t.start();
threads.add(t);
}
final Subscription underlying = mock(Subscription.class);
start.countDown();
serialSubscription.set(underlying);
end.await();
verify(firstSet).unsubscribe();
verify(underlying).unsubscribe();
for (final Thread t : threads) {
t.join();
}
}
@Test
public void concurrentSetSubscriptionShouldNotInterleave()
throws InterruptedException {
final int count = 10;
final List<Subscription> subscriptions = new ArrayList<Subscription>();
final CountDownLatch start = new CountDownLatch(1);
final CountDownLatch end = new CountDownLatch(count);
final List<Thread> threads = new ArrayList<Thread>();
for (int i = 0; i < count; i++) {
final Subscription subscription = mock(Subscription.class);
subscriptions.add(subscription);
final Thread t = new Thread() {
@Override
public void run() {
try {
start.await();
serialSubscription.set(subscription);
} catch (InterruptedException e) {
fail(e.getMessage());
} finally {
end.countDown();
}
}
};
t.start();
threads.add(t);
}
start.countDown();
end.await();
serialSubscription.unsubscribe();
for (final Subscription subscription : subscriptions) {
verify(subscription).unsubscribe();
}
for (final Thread t : threads) {
t.join();
}
}
}