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/*
*
* 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.qpid.server.protocol.v0_8;
import junit.framework.TestCase;
import org.apache.qpid.AMQException;
import org.apache.qpid.server.message.MessageInstance;
import org.apache.qpid.server.message.ServerMessage;
import org.apache.qpid.server.queue.AMQQueue;
import org.apache.qpid.server.queue.QueueEntry;
import org.apache.qpid.server.consumer.Consumer;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.Map;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
/**
* QPID-1385 : Race condition between added to unacked map and resending due to a rollback.
*
* In AMQChannel _unackedMap.clear() was done after the visit. This meant that the clear was not in the same
* synchronized block as as the preparation to resend.
*
* This clearing/prep for resend was done as a result of the rollback call. HOWEVER, the delivery thread was still
* in the process of sending messages to the client. It is therefore possible that a message could block on the
* _unackedMap lock waiting for the visit to complete so that it can add the new message to the unackedMap....
* which is then cleared by the resend/rollback thread.
*
* This problem was encountered by the testSend2ThenRollback test.
*
* To try and increase the chance of the race condition occurring this test will send multiple messages so that the
* delivery thread will be in progress while the rollback method is called. Hopefully this will cause the
* deliveryTag to be lost
*/
public class ExtractResendAndRequeueTest extends TestCase
{
private UnacknowledgedMessageMapImpl _unacknowledgedMessageMap;
private static final int INITIAL_MSG_COUNT = 10;
private AMQQueue _queue;
private LinkedList<QueueEntry> _referenceList = new LinkedList<QueueEntry>();
private Consumer _consumer;
private boolean _queueDeleted;
@Override
public void setUp() throws AMQException
{
_queueDeleted = false;
_unacknowledgedMessageMap = new UnacknowledgedMessageMapImpl(100);
_queue = mock(AMQQueue.class);
when(_queue.getName()).thenReturn(getName());
when(_queue.isDeleted()).thenReturn(_queueDeleted);
_consumer = mock(Consumer.class);
when(_consumer.getId()).thenReturn(Consumer.SUB_ID_GENERATOR.getAndIncrement());
long id = 0;
// Add initial messages to QueueEntryList
for (int count = 0; count < INITIAL_MSG_COUNT; count++)
{
ServerMessage msg = mock(ServerMessage.class);
when(msg.getMessageNumber()).thenReturn(id);
final QueueEntry entry = mock(QueueEntry.class);
when(entry.getMessage()).thenReturn(msg);
when(entry.getQueue()).thenReturn(_queue);
when(entry.isQueueDeleted()).thenReturn(_queueDeleted);
doAnswer(new Answer()
{
@Override
public Object answer(final InvocationOnMock invocation) throws Throwable
{
when(entry.isDeleted()).thenReturn(true);
return null;
}
}).when(entry).delete();
_unacknowledgedMessageMap.add(id, entry);
_referenceList.add(entry);
//Increment ID;
id++;
}
assertEquals("Map does not contain correct setup data", INITIAL_MSG_COUNT, _unacknowledgedMessageMap.size());
}
/**
* Helper method to create a new subscription and acquire the given messages.
*
* @param messageList The messages to acquire
*
* @return Subscription that performed the acquire
*/
private void acquireMessages(LinkedList<QueueEntry> messageList)
{
// Acquire messages in subscription
for(QueueEntry entry : messageList)
{
when(entry.getDeliveredConsumer()).thenReturn(_consumer);
}
}
/**
* This is the normal consumer rollback method.
*
* An active consumer that has acquired messages expects those messages to be reset when rollback is requested.
*
* This test validates that the msgToResend map includes all the messages and none are left behind.
*
* @throws AMQException the visit interface throws this
*/
public void testResend() throws AMQException
{
//We don't need the subscription object here.
acquireMessages(_referenceList);
final Map<Long, MessageInstance> msgToRequeue = new LinkedHashMap<Long, MessageInstance>();
final Map<Long, MessageInstance> msgToResend = new LinkedHashMap<Long, MessageInstance>();
// requeueIfUnableToResend doesn't matter here.
_unacknowledgedMessageMap.visit(new ExtractResendAndRequeue(_unacknowledgedMessageMap, msgToRequeue,
msgToResend));
assertEquals("Message count for resend not correct.", INITIAL_MSG_COUNT, msgToResend.size());
assertEquals("Message count for requeue not correct.", 0, msgToRequeue.size());
assertEquals("Map was not emptied", 0, _unacknowledgedMessageMap.size());
}
/**
* This is the normal consumer close method.
*
* When a consumer that has acquired messages expects closes the messages that it has acquired should be removed from
* the unacknowledgedMap and placed in msgToRequeue
*
* This test validates that the msgToRequeue map includes all the messages and none are left behind.
*
* @throws AMQException the visit interface throws this
*/
public void testRequeueDueToSubscriptionClosure() throws AMQException
{
acquireMessages(_referenceList);
// Close subscription
when(_consumer.isClosed()).thenReturn(true);
final Map<Long, MessageInstance> msgToRequeue = new LinkedHashMap<Long, MessageInstance>();
final Map<Long, MessageInstance> msgToResend = new LinkedHashMap<Long, MessageInstance>();
// requeueIfUnableToResend doesn't matter here.
_unacknowledgedMessageMap.visit(new ExtractResendAndRequeue(_unacknowledgedMessageMap, msgToRequeue,
msgToResend));
assertEquals("Message count for resend not correct.", 0, msgToResend.size());
assertEquals("Message count for requeue not correct.", INITIAL_MSG_COUNT, msgToRequeue.size());
assertEquals("Map was not emptied", 0, _unacknowledgedMessageMap.size());
}
}
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