io.grpc.netty.WriteQueueTest.java Source code

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Here is the source code for io.grpc.netty.WriteQueueTest.java

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/*
 * Copyright 2016 The gRPC 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 io.grpc.netty;

import static org.junit.Assert.fail;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.ArgumentMatchers.isA;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import io.grpc.netty.WriteQueue.QueuedCommand;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelPromise;
import io.netty.channel.EventLoop;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicBoolean;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.Timeout;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.MockitoAnnotations;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;

@RunWith(JUnit4.class)
public class WriteQueueTest {

    @Rule
    public final Timeout globalTimeout = Timeout.seconds(60);

    private final Object lock = new Object();

    @Mock
    public Channel channel;

    @Mock
    public ChannelPromise promise;

    private long writeCalledNanos;
    private long flushCalledNanos = writeCalledNanos;

    /**
     * Set up for test.
     */
    @Before
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);
        when(channel.newPromise()).thenReturn(promise);

        EventLoop eventLoop = Mockito.mock(EventLoop.class);
        doAnswer(new Answer<Void>() {
            @Override
            public Void answer(InvocationOnMock invocation) throws Throwable {
                Runnable r = (Runnable) invocation.getArguments()[0];
                r.run();
                return null;
            }
        }).when(eventLoop).execute(any(Runnable.class));
        when(eventLoop.inEventLoop()).thenReturn(true);
        when(channel.eventLoop()).thenReturn(eventLoop);

        when(channel.flush()).thenAnswer(new Answer<Channel>() {
            @Override
            public Channel answer(InvocationOnMock invocation) throws Throwable {
                synchronized (lock) {
                    flushCalledNanos = System.nanoTime();
                    if (flushCalledNanos == writeCalledNanos) {
                        flushCalledNanos += 1;
                    }
                }
                return channel;
            }
        });

        when(channel.write(any(QueuedCommand.class), eq(promise))).thenAnswer(new Answer<ChannelFuture>() {
            @Override
            public ChannelFuture answer(InvocationOnMock invocation) throws Throwable {
                synchronized (lock) {
                    writeCalledNanos = System.nanoTime();
                    if (writeCalledNanos == flushCalledNanos) {
                        writeCalledNanos += 1;
                    }
                }
                return promise;
            }
        });
    }

    @Test
    public void singleWriteShouldWork() {
        WriteQueue queue = new WriteQueue(channel);
        queue.enqueue(new CuteCommand(), true);

        verify(channel).write(isA(QueuedCommand.class), eq(promise));
        verify(channel).flush();
    }

    @Test
    public void multipleWritesShouldBeBatched() {
        WriteQueue queue = new WriteQueue(channel);
        for (int i = 0; i < 5; i++) {
            queue.enqueue(new CuteCommand(), false);
        }
        queue.scheduleFlush();

        verify(channel, times(5)).write(isA(QueuedCommand.class), eq(promise));
        verify(channel).flush();
    }

    @Test
    public void maxWritesBeforeFlushShouldBeEnforced() {
        WriteQueue queue = new WriteQueue(channel);
        int writes = WriteQueue.DEQUE_CHUNK_SIZE + 10;
        for (int i = 0; i < writes; i++) {
            queue.enqueue(new CuteCommand(), false);
        }
        queue.scheduleFlush();

        verify(channel, times(writes)).write(isA(QueuedCommand.class), eq(promise));
        verify(channel, times(2)).flush();
    }

    @Test
    public void concurrentWriteAndFlush() throws Throwable {
        final WriteQueue queue = new WriteQueue(channel);
        final CountDownLatch flusherStarted = new CountDownLatch(1);
        final AtomicBoolean doneWriting = new AtomicBoolean();
        Thread flusher = new Thread(new Runnable() {
            @Override
            public void run() {
                flusherStarted.countDown();
                while (!doneWriting.get()) {
                    queue.scheduleFlush();
                    assertFlushCalledAfterWrites();
                }
                // No more writes, so this flush should drain all writes from the queue
                queue.scheduleFlush();
                assertFlushCalledAfterWrites();
            }

            void assertFlushCalledAfterWrites() {
                synchronized (lock) {
                    if (flushCalledNanos - writeCalledNanos <= 0) {
                        fail("flush must be called after all writes");
                    }
                }
            }
        });

        class ExceptionHandler implements Thread.UncaughtExceptionHandler {
            private Throwable throwable;

            @Override
            public void uncaughtException(Thread t, Throwable e) {
                throwable = e;
            }

            void checkException() throws Throwable {
                if (throwable != null) {
                    throw throwable;
                }
            }
        }

        ExceptionHandler exHandler = new ExceptionHandler();
        flusher.setUncaughtExceptionHandler(exHandler);

        flusher.start();
        flusherStarted.await();
        int writes = 10 * WriteQueue.DEQUE_CHUNK_SIZE;
        for (int i = 0; i < writes; i++) {
            queue.enqueue(new CuteCommand(), false);
        }
        doneWriting.set(true);
        flusher.join();

        exHandler.checkException();
        verify(channel, times(writes)).write(isA(CuteCommand.class), eq(promise));
    }

    static class CuteCommand extends WriteQueue.AbstractQueuedCommand {

    }
}