| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.beam.sdk.fn.stream; |
| |
| import static org.junit.Assert.assertEquals; |
| import static org.junit.Assert.assertFalse; |
| import static org.junit.Assert.assertTrue; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.Future; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| import org.apache.beam.sdk.fn.test.TestExecutors; |
| import org.apache.beam.sdk.fn.test.TestExecutors.TestExecutorService; |
| import org.apache.beam.sdk.fn.test.TestStreams; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.util.concurrent.Uninterruptibles; |
| import org.junit.Rule; |
| import org.junit.Test; |
| import org.junit.runner.RunWith; |
| import org.junit.runners.JUnit4; |
| |
| /** Tests for {@link DirectStreamObserver}. */ |
| @RunWith(JUnit4.class) |
| public class DirectStreamObserverTest { |
| @Rule public TestExecutorService executor = TestExecutors.from(Executors.newCachedThreadPool()); |
| |
| @Test |
| public void testThreadSafety() throws Exception { |
| final List<String> onNextValues = new ArrayList<>(); |
| AdvancingPhaser phaser = new AdvancingPhaser(1); |
| final AtomicBoolean isCriticalSectionShared = new AtomicBoolean(); |
| final DirectStreamObserver<String> streamObserver = |
| new DirectStreamObserver<>( |
| phaser, |
| TestStreams.withOnNext( |
| (String t) -> { |
| // Use the atomic boolean to detect if multiple threads are in this |
| // critical section. Any thread that enters purposefully blocks by sleeping |
| // to increase the contention between threads artificially. |
| assertFalse(isCriticalSectionShared.getAndSet(true)); |
| Uninterruptibles.sleepUninterruptibly(50, TimeUnit.MILLISECONDS); |
| onNextValues.add(t); |
| assertTrue(isCriticalSectionShared.getAndSet(false)); |
| }) |
| .build()); |
| |
| List<String> prefixes = ImmutableList.of("0", "1", "2", "3", "4"); |
| List<Callable<String>> tasks = new ArrayList<>(); |
| for (final String prefix : prefixes) { |
| tasks.add( |
| () -> { |
| for (int i = 0; i < 10; i++) { |
| streamObserver.onNext(prefix + i); |
| } |
| return prefix; |
| }); |
| } |
| executor.invokeAll(tasks); |
| streamObserver.onCompleted(); |
| |
| // Check that order was maintained. |
| int[] prefixesIndex = new int[prefixes.size()]; |
| assertEquals(50, onNextValues.size()); |
| for (String onNextValue : onNextValues) { |
| int prefix = Integer.parseInt(onNextValue.substring(0, 1)); |
| int suffix = Integer.parseInt(onNextValue.substring(1, 2)); |
| assertEquals(prefixesIndex[prefix], suffix); |
| prefixesIndex[prefix] += 1; |
| } |
| } |
| |
| @Test |
| public void testIsReadyIsHonored() throws Exception { |
| AdvancingPhaser phaser = new AdvancingPhaser(1); |
| final AtomicBoolean elementsAllowed = new AtomicBoolean(); |
| final DirectStreamObserver<String> streamObserver = |
| new DirectStreamObserver<>( |
| phaser, |
| TestStreams.withOnNext((String t) -> assertTrue(elementsAllowed.get())) |
| .withIsReady(elementsAllowed::get) |
| .build(), |
| 0); |
| |
| // Start all the tasks |
| List<Future<String>> results = new ArrayList<>(); |
| for (final String prefix : ImmutableList.of("0", "1", "2", "3", "4")) { |
| results.add( |
| executor.submit( |
| () -> { |
| for (int i = 0; i < 10; i++) { |
| streamObserver.onNext(prefix + i); |
| } |
| return prefix; |
| })); |
| } |
| |
| // Have them wait and then flip that we do allow elements and wake up those awaiting |
| Uninterruptibles.sleepUninterruptibly(500, TimeUnit.MILLISECONDS); |
| elementsAllowed.set(true); |
| phaser.arrive(); |
| |
| for (Future<String> result : results) { |
| result.get(); |
| } |
| streamObserver.onCompleted(); |
| } |
| |
| /** |
| * This test specifically covers the case if the outbound observer is being invoked on the same |
| * thread that the inbound observer is. gRPC documentation states: |
| * |
| * <p><i>Note: the onReadyHandler's invocation is serialized on the same thread pool as the |
| * incoming StreamObserver's onNext(), onError(), and onComplete() handlers. Blocking the |
| * onReadyHandler will prevent additional messages from being processed by the incoming |
| * StreamObserver. The onReadyHandler must return in a timely manor or else message processing |
| * throughput will suffer. </i> |
| */ |
| @Test |
| public void testIsReadyCheckDoesntBlockIfPhaserCallbackNeverHappens() throws Exception { |
| // Note that we never advance the phaser in this test. |
| final AtomicBoolean elementsAllowed = new AtomicBoolean(); |
| final DirectStreamObserver<String> streamObserver = |
| new DirectStreamObserver<>( |
| new AdvancingPhaser(1), |
| TestStreams.withOnNext((String t) -> assertTrue(elementsAllowed.get())) |
| .withIsReady(elementsAllowed::get) |
| .build(), |
| 0); |
| |
| // Start all the tasks |
| List<Future<String>> results = new ArrayList<>(); |
| for (final String prefix : ImmutableList.of("0", "1", "2", "3", "4")) { |
| results.add( |
| executor.submit( |
| () -> { |
| for (int i = 0; i < 10; i++) { |
| streamObserver.onNext(prefix + i); |
| } |
| return prefix; |
| })); |
| } |
| |
| // Have them wait and then flip that we do allow elements and wake up those awaiting |
| Uninterruptibles.sleepUninterruptibly(500, TimeUnit.MILLISECONDS); |
| elementsAllowed.set(true); |
| |
| for (Future<String> result : results) { |
| result.get(); |
| } |
| streamObserver.onCompleted(); |
| } |
| } |