content: /*
   * 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.activemq.transport.amqp.interop;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertTrue;
  
  import java.util.concurrent.TimeUnit;
  
  import org.apache.activemq.broker.BrokerService;
  import org.apache.activemq.broker.jmx.QueueViewMBean;
  import org.apache.activemq.broker.region.policy.PolicyEntry;
  import org.apache.activemq.broker.region.policy.PolicyMap;
  import org.apache.activemq.broker.region.policy.VMPendingQueueMessageStoragePolicy;
  import org.apache.activemq.broker.region.policy.VMPendingSubscriberMessageStoragePolicy;
  import org.apache.activemq.transport.amqp.client.AmqpClient;
  import org.apache.activemq.transport.amqp.client.AmqpClientTestSupport;
  import org.apache.activemq.transport.amqp.client.AmqpConnection;
  import org.apache.activemq.transport.amqp.client.AmqpMessage;
  import org.apache.activemq.transport.amqp.client.AmqpReceiver;
  import org.apache.activemq.transport.amqp.client.AmqpSender;
  import org.apache.activemq.transport.amqp.client.AmqpSession;
  import org.apache.activemq.util.Wait;
  import org.junit.Test;
  
  public class AmqpFlowControlTest extends AmqpClientTestSupport {
  
      @Override
      protected void performAdditionalConfiguration(BrokerService brokerService) throws Exception {
          // Setup a destination policy where it takes only 1 message at a time.
          PolicyMap policyMap = new PolicyMap();
          PolicyEntry policy = new PolicyEntry();
          policy.setMemoryLimit(1);
          policy.setPendingSubscriberPolicy(new VMPendingSubscriberMessageStoragePolicy());
          policy.setPendingQueuePolicy(new VMPendingQueueMessageStoragePolicy());
          policy.setProducerFlowControl(true);
          policyMap.setDefaultEntry(policy);
  
          brokerService.setDestinationPolicy(policyMap);
      }
  
      @Test(timeout = 60000)
      public void testCreditNotGrantedUntilBacklogClears() throws Exception {
          final int MSG_COUNT = 1000;
  
          AmqpClient client = createAmqpClient();
          AmqpConnection connection = trackConnection(client.connect());
          AmqpSession session = connection.createSession();
  
          AmqpReceiver receiver = session.createReceiver("queue://" + getTestName());
          AmqpSender sender = session.createSender("queue://" + getTestName(), true);
  
          for (int i = 1; i <= MSG_COUNT; ++i) {
              AmqpMessage message = new AmqpMessage();
              message.setText("Test-Message: " + i);
              sender.send(message);
  
              if (i % 1000 == 0) {
                  LOG.info("Sent message: {}", i);
              }
          }
  
          // Should only accept one message
          final QueueViewMBean queue = getProxyToQueue(getTestName());
          assertTrue("All messages should arrive", Wait.waitFor(new Wait.Condition() {
  
              @Override
              public boolean isSatisified() throws Exception {
                  return queue.getQueueSize() == 1;
              }
          }));
  
          assertEquals(0, sender.getEndpoint().getRemoteCredit());
  
          receiver.flow(1);
          AmqpMessage received = receiver.receive(5, TimeUnit.SECONDS);
          assertNotNull(received);
          received.accept();
  
          // Should not grant any credit until backlog starts to clear
          assertEquals(0, sender.getEndpoint().getRemoteCredit());
  
          receiver.flow(MSG_COUNT - 1);
          for (int i = 0; i < MSG_COUNT - 1; ++i) {
              received = receiver.receive(5, TimeUnit.SECONDS);
              assertNotNull(received);
              received.accept();
          }
  
          // Should have been granted credit once backlog was cleared.
          assertTrue(sender.getEndpoint().getRemoteCredit() > 0);
  
          sender.close();
          connection.close();
      }
  }
  