/*
 * Copyright 2011 LMAX Ltd.
 *
 * 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.lmax.disruptor.dsl;

import com.lmax.disruptor.BatchEventProcessor;
import com.lmax.disruptor.BlockingWaitStrategy;
import com.lmax.disruptor.EventHandler;
import com.lmax.disruptor.EventProcessor;
import com.lmax.disruptor.EventTranslator;
import com.lmax.disruptor.EventTranslatorOneArg;
import com.lmax.disruptor.ExceptionHandler;
import com.lmax.disruptor.FatalExceptionHandler;
import com.lmax.disruptor.RingBuffer;
import com.lmax.disruptor.Sequence;
import com.lmax.disruptor.SequenceBarrier;
import com.lmax.disruptor.TimeoutException;
import com.lmax.disruptor.dsl.stubs.DelayedEventHandler;
import com.lmax.disruptor.dsl.stubs.EventHandlerStub;
import com.lmax.disruptor.dsl.stubs.EvilEqualsEventHandler;
import com.lmax.disruptor.dsl.stubs.ExceptionThrowingEventHandler;
import com.lmax.disruptor.dsl.stubs.SleepingEventHandler;
import com.lmax.disruptor.dsl.stubs.StubExceptionHandler;
import com.lmax.disruptor.dsl.stubs.StubPublisher;
import com.lmax.disruptor.dsl.stubs.StubThreadFactory;
import com.lmax.disruptor.dsl.stubs.TestWorkHandler;
import com.lmax.disruptor.support.TestEvent;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.util.ArrayList;
import java.util.Collection;
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

import static java.lang.Thread.yield;
import static java.util.concurrent.TimeUnit.SECONDS;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

@SuppressWarnings(value = {"unchecked"})
public class DisruptorTest
{
    private static final int TIMEOUT_IN_SECONDS = 2;

    private final Collection<DelayedEventHandler> delayedEventHandlers = new ArrayList<DelayedEventHandler>();
    private final Collection<TestWorkHandler> testWorkHandlers = new ArrayList<TestWorkHandler>();
    private Disruptor<TestEvent> disruptor;
    private StubThreadFactory executor;
    private RingBuffer<TestEvent> ringBuffer;
    private TestEvent lastPublishedEvent;

    @Before
    public void setUp() throws Exception
    {
        createDisruptor();
    }

    @After
    public void tearDown() throws Exception
    {
        for (DelayedEventHandler delayedEventHandler : delayedEventHandlers)
        {
            delayedEventHandler.stopWaiting();
        }
        for (TestWorkHandler testWorkHandler : testWorkHandlers)
        {
            testWorkHandler.stopWaiting();
        }

        disruptor.halt();
        executor.joinAllThreads();
    }

    @Test
    public void shouldProcessMessagesPublishedBeforeStartIsCalled() throws Exception
    {
        final CountDownLatch eventCounter = new CountDownLatch(2);
        disruptor.handleEventsWith(new EventHandler<TestEvent>()
        {
            @Override
            public void onEvent(final TestEvent event, final long sequence, final boolean endOfBatch) throws Exception
            {
                eventCounter.countDown();
            }
        });

        disruptor.publishEvent(
         new EventTranslator<TestEvent>()
         {
             @Override
             public void translateTo(final TestEvent event, final long sequence)
             {
                 lastPublishedEvent = event;
             }
         });

        disruptor.start();

        disruptor.publishEvent(
         new EventTranslator<TestEvent>()
         {
             @Override
             public void translateTo(final TestEvent event, final long sequence)
             {
                 lastPublishedEvent = event;
             }
         });

        if (!eventCounter.await(5, TimeUnit.SECONDS))
        {
            fail("Did not process event published before start was called. Missed events: " + eventCounter.getCount());
        }
    }


    @Test
    public void shouldBatchOfEvents() throws Exception
    {
        final CountDownLatch eventCounter = new CountDownLatch(2);
        disruptor.handleEventsWith(new EventHandler<TestEvent>()
        {
            @Override
            public void onEvent(final TestEvent event, final long sequence, final boolean endOfBatch) throws Exception
            {
                eventCounter.countDown();
            }
        });

        disruptor.start();

        disruptor.publishEvents(
            new EventTranslatorOneArg<TestEvent, Object>()
            {
                @Override
                public void translateTo(final TestEvent event, final long sequence, Object arg)
                {
                    lastPublishedEvent = event;
                }
            },
            new Object[] { "a", "b" }
        );

        if (!eventCounter.await(5, TimeUnit.SECONDS))
        {
            fail("Did not process event published before start was called. Missed events: " + eventCounter.getCount());
        }
    }

    @Test
    public void shouldAddEventProcessorsAfterPublishing() throws Exception
    {
        RingBuffer<TestEvent> rb = disruptor.getRingBuffer();
        BatchEventProcessor<TestEvent> b1 = new BatchEventProcessor<TestEvent>(
            rb, rb.newBarrier(), new SleepingEventHandler());
        BatchEventProcessor<TestEvent> b2 = new BatchEventProcessor<TestEvent>(
            rb, rb.newBarrier(b1.getSequence()), new SleepingEventHandler());
        BatchEventProcessor<TestEvent> b3 = new BatchEventProcessor<TestEvent>(
            rb, rb.newBarrier(b2.getSequence()), new SleepingEventHandler());

        assertThat(b1.getSequence().get(), is(-1L));
        assertThat(b2.getSequence().get(), is(-1L));
        assertThat(b3.getSequence().get(), is(-1L));

        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());

        disruptor.handleEventsWith(b1, b2, b3);

        assertThat(b1.getSequence().get(), is(5L));
        assertThat(b2.getSequence().get(), is(5L));
        assertThat(b3.getSequence().get(), is(5L));
    }

    @Test
    public void shouldSetSequenceForHandlerIfAddedAfterPublish() throws Exception
    {
        RingBuffer<TestEvent> rb = disruptor.getRingBuffer();
        EventHandler<TestEvent> b1 = new SleepingEventHandler();
        EventHandler<TestEvent> b2 = new SleepingEventHandler();
        EventHandler<TestEvent> b3 = new SleepingEventHandler();

        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());

        disruptor.handleEventsWith(b1, b2, b3);

        assertThat(disruptor.getSequenceValueFor(b1), is(5L));
        assertThat(disruptor.getSequenceValueFor(b2), is(5L));
        assertThat(disruptor.getSequenceValueFor(b3), is(5L));
    }

    @Test
    public void shouldSetSequenceForWorkProcessorIfAddedAfterPublish() throws Exception
    {
        RingBuffer<TestEvent> rb = disruptor.getRingBuffer();
        TestWorkHandler wh1 = createTestWorkHandler();
        TestWorkHandler wh2 = createTestWorkHandler();
        TestWorkHandler wh3 = createTestWorkHandler();

        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());
        rb.publish(rb.next());

        disruptor.handleEventsWithWorkerPool(wh1, wh2, wh3);

        assertThat(disruptor.getRingBuffer().getMinimumGatingSequence(), is(5L));
    }


    @Test
    public void shouldCreateEventProcessorGroupForFirstEventProcessors()
        throws Exception
    {
        executor.ignoreExecutions();
        final EventHandler<TestEvent> eventHandler1 = new SleepingEventHandler();
        EventHandler<TestEvent> eventHandler2 = new SleepingEventHandler();

        final EventHandlerGroup<TestEvent> eventHandlerGroup =
            disruptor.handleEventsWith(eventHandler1, eventHandler2);
        disruptor.start();

        assertNotNull(eventHandlerGroup);
        assertThat(Integer.valueOf(executor.getExecutionCount()), equalTo(Integer.valueOf(2)));
    }

    @Test
    public void shouldMakeEntriesAvailableToFirstHandlersImmediately() throws Exception
    {
        CountDownLatch countDownLatch = new CountDownLatch(2);
        EventHandler<TestEvent> eventHandler = new EventHandlerStub<TestEvent>(countDownLatch);

        disruptor.handleEventsWith(createDelayedEventHandler(), eventHandler);

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch);
    }

    @Test
    public void shouldWaitUntilAllFirstEventProcessorsProcessEventBeforeMakingItAvailableToDependentEventProcessors()
        throws Exception
    {
        DelayedEventHandler eventHandler1 = createDelayedEventHandler();

        CountDownLatch countDownLatch = new CountDownLatch(2);
        EventHandler<TestEvent> eventHandler2 = new EventHandlerStub<TestEvent>(countDownLatch);

        disruptor.handleEventsWith(eventHandler1).then(eventHandler2);

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch, eventHandler1);
    }

    @Test
    public void should()
        throws Exception
    {
        RingBuffer<TestEvent> rb = disruptor.getRingBuffer();
        BatchEventProcessor<TestEvent> b1 = new BatchEventProcessor<TestEvent>(
            rb, rb.newBarrier(), new SleepingEventHandler());
        EventProcessorFactory<TestEvent> b2 = new EventProcessorFactory<TestEvent>()
        {
            @Override
            public EventProcessor createEventProcessor(
                RingBuffer<TestEvent> ringBuffer, Sequence[] barrierSequences)
            {
                return new BatchEventProcessor<TestEvent>(
                    ringBuffer, ringBuffer.newBarrier(barrierSequences), new SleepingEventHandler());
            }
        };

        disruptor.handleEventsWith(b1).then(b2);

        disruptor.start();
    }

    @Test
    public void shouldAllowSpecifyingSpecificEventProcessorsToWaitFor()
        throws Exception
    {
        DelayedEventHandler handler1 = createDelayedEventHandler();
        DelayedEventHandler handler2 = createDelayedEventHandler();

        CountDownLatch countDownLatch = new CountDownLatch(2);
        EventHandler<TestEvent> handlerWithBarrier = new EventHandlerStub<TestEvent>(countDownLatch);

        disruptor.handleEventsWith(handler1, handler2);
        disruptor.after(handler1, handler2).handleEventsWith(handlerWithBarrier);

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch, handler1, handler2);
    }

    @Test
    public void shouldWaitOnAllProducersJoinedByAnd()
        throws Exception
    {
        DelayedEventHandler handler1 = createDelayedEventHandler();
        DelayedEventHandler handler2 = createDelayedEventHandler();

        CountDownLatch countDownLatch = new CountDownLatch(2);
        EventHandler<TestEvent> handlerWithBarrier = new EventHandlerStub<TestEvent>(countDownLatch);

        disruptor.handleEventsWith(handler1);
        final EventHandlerGroup<TestEvent> handler2Group = disruptor.handleEventsWith(handler2);
        disruptor.after(handler1).and(handler2Group).handleEventsWith(handlerWithBarrier);

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch, handler1, handler2);
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldThrowExceptionIfHandlerIsNotAlreadyConsuming()
        throws Exception
    {
        disruptor.after(createDelayedEventHandler()).handleEventsWith(createDelayedEventHandler());
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldTrackEventHandlersByIdentityNotEquality()
        throws Exception
    {
        EvilEqualsEventHandler handler1 = new EvilEqualsEventHandler();
        EvilEqualsEventHandler handler2 = new EvilEqualsEventHandler();

        disruptor.handleEventsWith(handler1);

        // handler2.equals(handler1) but it hasn't yet been registered so should throw exception.
        disruptor.after(handler2);
    }

    @SuppressWarnings("deprecation")
    @Test
    public void shouldSupportSpecifyingAExceptionHandlerForEventProcessors()
        throws Exception
    {
        AtomicReference<Throwable> eventHandled = new AtomicReference<Throwable>();
        ExceptionHandler exceptionHandler = new StubExceptionHandler(eventHandled);
        RuntimeException testException = new RuntimeException();
        ExceptionThrowingEventHandler handler = new ExceptionThrowingEventHandler(testException);

        disruptor.handleExceptionsWith(exceptionHandler);
        disruptor.handleEventsWith(handler);

        publishEvent();

        final Throwable actualException = waitFor(eventHandled);
        assertSame(testException, actualException);
    }

    @SuppressWarnings("deprecation")
    @Test
    public void shouldOnlyApplyExceptionsHandlersSpecifiedViaHandleExceptionsWithOnNewEventProcessors()
        throws Exception
    {
        AtomicReference<Throwable> eventHandled = new AtomicReference<Throwable>();
        ExceptionHandler exceptionHandler = new StubExceptionHandler(eventHandled);
        RuntimeException testException = new RuntimeException();
        ExceptionThrowingEventHandler handler = new ExceptionThrowingEventHandler(testException);

        disruptor.handleExceptionsWith(exceptionHandler);
        disruptor.handleEventsWith(handler);
        disruptor.handleExceptionsWith(new FatalExceptionHandler());

        publishEvent();

        final Throwable actualException = waitFor(eventHandled);
        assertSame(testException, actualException);
    }

    @Test
    public void shouldSupportSpecifyingADefaultExceptionHandlerForEventProcessors()
        throws Exception
    {
        AtomicReference<Throwable> eventHandled = new AtomicReference<Throwable>();
        ExceptionHandler exceptionHandler = new StubExceptionHandler(eventHandled);
        RuntimeException testException = new RuntimeException();
        ExceptionThrowingEventHandler handler = new ExceptionThrowingEventHandler(testException);

        disruptor.setDefaultExceptionHandler(exceptionHandler);
        disruptor.handleEventsWith(handler);

        publishEvent();

        final Throwable actualException = waitFor(eventHandled);
        assertSame(testException, actualException);
    }

    @Test
    public void shouldApplyDefaultExceptionHandlerToExistingEventProcessors()
        throws Exception
    {
        AtomicReference<Throwable> eventHandled = new AtomicReference<Throwable>();
        ExceptionHandler exceptionHandler = new StubExceptionHandler(eventHandled);
        RuntimeException testException = new RuntimeException();
        ExceptionThrowingEventHandler handler = new ExceptionThrowingEventHandler(testException);

        disruptor.handleEventsWith(handler);
        disruptor.setDefaultExceptionHandler(exceptionHandler);

        publishEvent();

        final Throwable actualException = waitFor(eventHandled);
        assertSame(testException, actualException);
    }

    @Test
    public void shouldBlockProducerUntilAllEventProcessorsHaveAdvanced()
        throws Exception
    {
        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();
        disruptor.handleEventsWith(delayedEventHandler);

        final RingBuffer<TestEvent> ringBuffer = disruptor.start();
        delayedEventHandler.awaitStart();

        final StubPublisher stubPublisher = new StubPublisher(ringBuffer);
        try
        {
            executor.newThread(stubPublisher).start();

            assertProducerReaches(stubPublisher, 4, true);

            delayedEventHandler.processEvent();
            delayedEventHandler.processEvent();
            delayedEventHandler.processEvent();
            delayedEventHandler.processEvent();
            delayedEventHandler.processEvent();

            assertProducerReaches(stubPublisher, 5, false);
        }
        finally
        {
            stubPublisher.halt();
        }
    }

    @Test
    public void shouldBeAbleToOverrideTheExceptionHandlerForAEventProcessor()
        throws Exception
    {
        final RuntimeException testException = new RuntimeException();
        final ExceptionThrowingEventHandler eventHandler = new ExceptionThrowingEventHandler(testException);
        disruptor.handleEventsWith(eventHandler);

        AtomicReference<Throwable> reference = new AtomicReference<Throwable>();
        StubExceptionHandler exceptionHandler = new StubExceptionHandler(reference);
        disruptor.handleExceptionsFor(eventHandler).with(exceptionHandler);

        publishEvent();

        waitFor(reference);
    }

    @Test(expected = IllegalStateException.class)
    public void shouldThrowExceptionWhenAddingEventProcessorsAfterTheProducerBarrierHasBeenCreated()
        throws Exception
    {
        executor.ignoreExecutions();
        disruptor.handleEventsWith(new SleepingEventHandler());
        disruptor.start();
        disruptor.handleEventsWith(new SleepingEventHandler());
    }

    @Test(expected = IllegalStateException.class)
    public void shouldThrowExceptionIfStartIsCalledTwice()
        throws Exception
    {
        executor.ignoreExecutions();
        disruptor.handleEventsWith(new SleepingEventHandler());
        disruptor.start();
        disruptor.start();
    }

    @Test
    public void shouldSupportCustomProcessorsAsDependencies()
        throws Exception
    {
        RingBuffer<TestEvent> ringBuffer = disruptor.getRingBuffer();

        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();

        CountDownLatch countDownLatch = new CountDownLatch(2);
        EventHandler<TestEvent> handlerWithBarrier = new EventHandlerStub<TestEvent>(countDownLatch);

        final BatchEventProcessor<TestEvent> processor =
            new BatchEventProcessor<TestEvent>(ringBuffer, ringBuffer.newBarrier(), delayedEventHandler);

        disruptor.handleEventsWith(processor).then(handlerWithBarrier);

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch, delayedEventHandler);
    }

    @Test
    public void shouldSupportHandlersAsDependenciesToCustomProcessors()
        throws Exception
    {
        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();
        disruptor.handleEventsWith(delayedEventHandler);


        RingBuffer<TestEvent> ringBuffer = disruptor.getRingBuffer();
        CountDownLatch countDownLatch = new CountDownLatch(2);
        EventHandler<TestEvent> handlerWithBarrier = new EventHandlerStub<TestEvent>(countDownLatch);

        final SequenceBarrier sequenceBarrier = disruptor.after(delayedEventHandler).asSequenceBarrier();
        final BatchEventProcessor<TestEvent> processor =
            new BatchEventProcessor<TestEvent>(ringBuffer, sequenceBarrier, handlerWithBarrier);
        disruptor.handleEventsWith(processor);

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch, delayedEventHandler);
    }

    @Test
    public void shouldSupportCustomProcessorsAndHandlersAsDependencies() throws Exception
    {
        final DelayedEventHandler delayedEventHandler1 = createDelayedEventHandler();
        final DelayedEventHandler delayedEventHandler2 = createDelayedEventHandler();
        disruptor.handleEventsWith(delayedEventHandler1);


        RingBuffer<TestEvent> ringBuffer = disruptor.getRingBuffer();
        CountDownLatch countDownLatch = new CountDownLatch(2);
        EventHandler<TestEvent> handlerWithBarrier = new EventHandlerStub<TestEvent>(countDownLatch);

        final SequenceBarrier sequenceBarrier = disruptor.after(delayedEventHandler1).asSequenceBarrier();
        final BatchEventProcessor<TestEvent> processor =
            new BatchEventProcessor<TestEvent>(ringBuffer, sequenceBarrier, delayedEventHandler2);

        disruptor.after(delayedEventHandler1).and(processor).handleEventsWith(handlerWithBarrier);

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch, delayedEventHandler1, delayedEventHandler2);
    }

    @Test
    public void shouldProvideEventsToWorkHandlers() throws Exception
    {
        final TestWorkHandler workHandler1 = createTestWorkHandler();
        final TestWorkHandler workHandler2 = createTestWorkHandler();
        disruptor.handleEventsWithWorkerPool(workHandler1, workHandler2);

        publishEvent();
        publishEvent();

        workHandler1.processEvent();
        workHandler2.processEvent();
    }


    @Test
    public void shouldProvideEventsMultipleWorkHandlers() throws Exception
    {
        final TestWorkHandler workHandler1 = createTestWorkHandler();
        final TestWorkHandler workHandler2 = createTestWorkHandler();
        final TestWorkHandler workHandler3 = createTestWorkHandler();
        final TestWorkHandler workHandler4 = createTestWorkHandler();
        final TestWorkHandler workHandler5 = createTestWorkHandler();
        final TestWorkHandler workHandler6 = createTestWorkHandler();
        final TestWorkHandler workHandler7 = createTestWorkHandler();
        final TestWorkHandler workHandler8 = createTestWorkHandler();

        disruptor
            .handleEventsWithWorkerPool(workHandler1, workHandler2)
            .thenHandleEventsWithWorkerPool(workHandler3, workHandler4);
        disruptor
            .handleEventsWithWorkerPool(workHandler5, workHandler6)
            .thenHandleEventsWithWorkerPool(workHandler7, workHandler8);
    }


    @Test
    public void shouldSupportUsingWorkerPoolAsDependency() throws Exception
    {
        final TestWorkHandler workHandler1 = createTestWorkHandler();
        final TestWorkHandler workHandler2 = createTestWorkHandler();
        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();
        disruptor.handleEventsWithWorkerPool(workHandler1, workHandler2).then(delayedEventHandler);

        publishEvent();
        publishEvent();

        assertThat(disruptor.getBarrierFor(delayedEventHandler).getCursor(), equalTo(-1L));

        workHandler2.processEvent();
        workHandler1.processEvent();

        delayedEventHandler.processEvent();
    }

    @Test
    public void shouldSupportUsingWorkerPoolAsDependencyAndProcessFirstEventAsSoonAsItIsAvailable() throws Exception
    {
        final TestWorkHandler workHandler1 = createTestWorkHandler();
        final TestWorkHandler workHandler2 = createTestWorkHandler();
        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();
        disruptor.handleEventsWithWorkerPool(workHandler1, workHandler2).then(delayedEventHandler);

        publishEvent();
        publishEvent();

        workHandler1.processEvent();
        delayedEventHandler.processEvent();

        workHandler2.processEvent();
        delayedEventHandler.processEvent();
    }

    @Test
    public void shouldSupportUsingWorkerPoolWithADependency() throws Exception
    {
        final TestWorkHandler workHandler1 = createTestWorkHandler();
        final TestWorkHandler workHandler2 = createTestWorkHandler();
        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();
        disruptor.handleEventsWith(delayedEventHandler).thenHandleEventsWithWorkerPool(workHandler1, workHandler2);

        publishEvent();
        publishEvent();

        delayedEventHandler.processEvent();
        delayedEventHandler.processEvent();

        workHandler1.processEvent();
        workHandler2.processEvent();
    }

    @Test
    public void shouldSupportCombiningWorkerPoolWithEventHandlerAsDependencyWhenNotPreviouslyRegistered()
        throws Exception
    {
        final TestWorkHandler workHandler1 = createTestWorkHandler();
        final DelayedEventHandler delayedEventHandler1 = createDelayedEventHandler();
        final DelayedEventHandler delayedEventHandler2 = createDelayedEventHandler();
        disruptor
            .handleEventsWith(delayedEventHandler1)
            .and(disruptor.handleEventsWithWorkerPool(workHandler1))
            .then(delayedEventHandler2);

        publishEvent();
        publishEvent();

        delayedEventHandler1.processEvent();
        delayedEventHandler1.processEvent();

        workHandler1.processEvent();
        delayedEventHandler2.processEvent();

        workHandler1.processEvent();
        delayedEventHandler2.processEvent();
    }

    @Test(expected = TimeoutException.class, timeout = 2000)
    public void shouldThrowTimeoutExceptionIfShutdownDoesNotCompleteNormally() throws Exception
    {
        //Given
        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();
        disruptor.handleEventsWith(delayedEventHandler);
        publishEvent();

        //When
        disruptor.shutdown(1, SECONDS);

        //Then
    }

    @Test(timeout = 1000)
    public void shouldTrackRemainingCapacity() throws Exception
    {
        final long[] remainingCapacity = {-1};
        //Given
        final EventHandler<TestEvent> eventHandler = new EventHandler<TestEvent>()
        {
            @Override
            public void onEvent(final TestEvent event, final long sequence, final boolean endOfBatch) throws Exception
            {
                remainingCapacity[0] = disruptor.getRingBuffer().remainingCapacity();
            }
        };

        disruptor.handleEventsWith(eventHandler);

        //When
        publishEvent();

        //Then
        while (remainingCapacity[0] == -1)
        {
            Thread.sleep(100);
        }
        assertThat(remainingCapacity[0], is(ringBuffer.getBufferSize() - 1L));
        assertThat(disruptor.getRingBuffer().remainingCapacity(), is(ringBuffer.getBufferSize() - 0L));
    }

    @Test
    public void shouldAllowEventHandlerWithSuperType() throws Exception
    {
        final CountDownLatch latch = new CountDownLatch(2);
        final EventHandler<Object> objectHandler = new EventHandlerStub<Object>(latch);

        disruptor.handleEventsWith(objectHandler);

        ensureTwoEventsProcessedAccordingToDependencies(latch);
    }

    @Test
    public void shouldAllowChainingEventHandlersWithSuperType() throws Exception
    {
        final CountDownLatch latch = new CountDownLatch(2);
        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();
        final EventHandler<Object> objectHandler = new EventHandlerStub<Object>(latch);

        disruptor.handleEventsWith(delayedEventHandler).then(objectHandler);

        ensureTwoEventsProcessedAccordingToDependencies(latch, delayedEventHandler);
    }

    @Test
    public void shouldMakeEntriesAvailableToFirstCustomProcessorsImmediately() throws Exception
    {
        final CountDownLatch countDownLatch = new CountDownLatch(2);
        final EventHandler<TestEvent> eventHandler = new EventHandlerStub<TestEvent>(countDownLatch);

        disruptor.handleEventsWith(
            new EventProcessorFactory<TestEvent>()
            {
                @Override
                public EventProcessor createEventProcessor(
                    final RingBuffer<TestEvent> ringBuffer, final Sequence[] barrierSequences)
                {
                    assertEquals("Should not have had any barrier sequences", 0, barrierSequences.length);
                    return new BatchEventProcessor<TestEvent>(
                        disruptor.getRingBuffer(), ringBuffer.newBarrier(
                        barrierSequences), eventHandler);
                }
            });

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch);
    }

    @Test
    public void shouldHonourDependenciesForCustomProcessors() throws Exception
    {
        final CountDownLatch countDownLatch = new CountDownLatch(2);
        final EventHandler<TestEvent> eventHandler = new EventHandlerStub<TestEvent>(countDownLatch);
        final DelayedEventHandler delayedEventHandler = createDelayedEventHandler();

        disruptor.handleEventsWith(delayedEventHandler).then(
            new EventProcessorFactory<TestEvent>()
            {
                @Override
                public EventProcessor createEventProcessor(
                    final RingBuffer<TestEvent> ringBuffer, final Sequence[] barrierSequences)
                {
                    assertSame("Should have had a barrier sequence", 1, barrierSequences.length);
                    return new BatchEventProcessor<TestEvent>(
                        disruptor.getRingBuffer(), ringBuffer.newBarrier(
                        barrierSequences), eventHandler);
                }
            });

        ensureTwoEventsProcessedAccordingToDependencies(countDownLatch, delayedEventHandler);
    }

    private TestWorkHandler createTestWorkHandler()
    {
        final TestWorkHandler testWorkHandler = new TestWorkHandler();
        testWorkHandlers.add(testWorkHandler);
        return testWorkHandler;
    }

    private void ensureTwoEventsProcessedAccordingToDependencies(
        final CountDownLatch countDownLatch,
        final DelayedEventHandler... dependencies)
        throws InterruptedException, BrokenBarrierException
    {
        publishEvent();
        publishEvent();

        for (DelayedEventHandler dependency : dependencies)
        {
            assertThatCountDownLatchEquals(countDownLatch, 2L);
            dependency.processEvent();
            dependency.processEvent();
        }

        assertThatCountDownLatchIsZero(countDownLatch);
    }

    private void assertProducerReaches(
        final StubPublisher stubPublisher,
        final int expectedPublicationCount,
        boolean strict)
    {
        long loopStart = System.currentTimeMillis();
        while (stubPublisher.getPublicationCount() < expectedPublicationCount && System
            .currentTimeMillis() - loopStart < 5000)
        {
            yield();
        }

        if (strict)
        {
            assertThat(stubPublisher.getPublicationCount(), equalTo(expectedPublicationCount));
        }
        else
        {
            final int actualPublicationCount = stubPublisher.getPublicationCount();
            assertTrue(
                "Producer reached unexpected count. Expected at least " + expectedPublicationCount +
                    " but only reached " + actualPublicationCount, actualPublicationCount >= expectedPublicationCount);
        }
    }

    private void createDisruptor()
    {
        executor = new StubThreadFactory();
        createDisruptor(executor);
    }

    private void createDisruptor(final ThreadFactory threadFactory)
    {
        disruptor = new Disruptor<TestEvent>(
            TestEvent.EVENT_FACTORY, 4, threadFactory,
            ProducerType.SINGLE, new BlockingWaitStrategy());
    }

    private TestEvent publishEvent() throws InterruptedException, BrokenBarrierException
    {
        if (ringBuffer == null)
        {
            ringBuffer = disruptor.start();

            for (DelayedEventHandler eventHandler : delayedEventHandlers)
            {
                eventHandler.awaitStart();
            }
        }

        disruptor.publishEvent(
            new EventTranslator<TestEvent>()
            {
                @Override
                public void translateTo(final TestEvent event, final long sequence)
                {
                    lastPublishedEvent = event;
                }
            });

        return lastPublishedEvent;
    }

    private Throwable waitFor(final AtomicReference<Throwable> reference)
    {
        while (reference.get() == null)
        {
            yield();
        }

        return reference.get();
    }

    private DelayedEventHandler createDelayedEventHandler()
    {
        final DelayedEventHandler delayedEventHandler = new DelayedEventHandler();
        delayedEventHandlers.add(delayedEventHandler);
        return delayedEventHandler;
    }

    private void assertThatCountDownLatchEquals(
        final CountDownLatch countDownLatch,
        final long expectedCountDownValue)
    {
        assertThat(Long.valueOf(countDownLatch.getCount()), equalTo(Long.valueOf(expectedCountDownValue)));
    }

    private void assertThatCountDownLatchIsZero(final CountDownLatch countDownLatch)
        throws InterruptedException
    {
        boolean released = countDownLatch.await(TIMEOUT_IN_SECONDS, SECONDS);
        assertTrue("Batch handler did not receive entries: " + countDownLatch.getCount(), released);
    }
}
