/**
 * 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.vm;

import java.net.URI;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import javax.jms.Connection;

import junit.framework.TestCase;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.bugs.embedded.ThreadExplorer;
import org.apache.activemq.network.NetworkConnector;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class VmTransportNetworkBrokerTest extends TestCase {

   private static final Logger LOG = LoggerFactory.getLogger(VmTransportNetworkBrokerTest.class);

   private static final String VM_BROKER_URI = "vm://localhost?create=false";

   CountDownLatch started = new CountDownLatch(1);
   CountDownLatch gotConnection = new CountDownLatch(1);

   public void testNoThreadLeak() throws Exception {

      // with VMConnection and simple discovery network connector
      int originalThreadCount = Thread.activeCount();
      LOG.debug(ThreadExplorer.show("threads at beginning"));

      BrokerService broker = new BrokerService();
      broker.setDedicatedTaskRunner(true);
      broker.setPersistent(false);
      broker.addConnector("tcp://localhost:61616");
      NetworkConnector networkConnector = broker.addNetworkConnector("static:(tcp://wrongHostname1:61617,tcp://wrongHostname2:61618)?useExponentialBackOff=false");
      networkConnector.setDuplex(true);
      broker.start();

      ActiveMQConnectionFactory cf = new ActiveMQConnectionFactory(new URI(VM_BROKER_URI));
      Connection connection = cf.createConnection("system", "manager");
      connection.start();

      // let it settle
      TimeUnit.SECONDS.sleep(5);

      int threadCountAfterStart = Thread.activeCount();
      TimeUnit.SECONDS.sleep(30);
      int threadCountAfterSleep = Thread.activeCount();

      assertTrue("Threads are leaking: " + ThreadExplorer.show("active sleep") + ", threadCount=" + threadCountAfterStart + " threadCountAfterSleep=" + threadCountAfterSleep, threadCountAfterSleep < threadCountAfterStart + 8);

      connection.close();
      broker.stop();
      broker.waitUntilStopped();

      // testNoDanglingThreadsAfterStop with tcp transport
      broker = new BrokerService();
      broker.setSchedulerSupport(true);
      broker.setDedicatedTaskRunner(true);
      broker.setPersistent(false);
      broker.addConnector("tcp://localhost:61616?wireFormat.maxInactivityDuration=1000&wireFormat.maxInactivityDurationInitalDelay=1000");
      broker.start();

      cf = new ActiveMQConnectionFactory("tcp://localhost:61616?wireFormat.maxInactivityDuration=1000&wireFormat.maxInactivityDurationInitalDelay=1000");
      connection = cf.createConnection("system", "manager");
      connection.start();
      connection.close();
      broker.stop();
      broker.waitUntilStopped();

      // let it settle
      TimeUnit.SECONDS.sleep(5);

      // get final threads but filter out any daemon threads that the JVM may have created.
      Thread[] threads = filterDaemonThreads(ThreadExplorer.listThreads());
      int threadCountAfterStop = threads.length;

      // lets see the thread counts at INFO level so they are always in the test log
      LOG.info(ThreadExplorer.show("active after stop"));
      LOG.info("originalThreadCount=" + originalThreadCount + " threadCountAfterStop=" + threadCountAfterStop);

      assertTrue("Threads are leaking: " +
                    ThreadExplorer.show("active after stop") +
                    ". originalThreadCount=" +
                    originalThreadCount +
                    " threadCountAfterStop=" +
                    threadCountAfterStop, threadCountAfterStop <= originalThreadCount);
   }

   /**
    * Filters any daemon threads from the thread list.
    *
    * Thread counts before and after the test should ideally be equal.
    * However there is no guarantee that the JVM does not create any
    * additional threads itself.
    * E.g. on Mac OSX there is a JVM internal thread called
    * "Poller SunPKCS11-Darwin" created after the test go started and
    * under the main thread group.
    * When debugging tests in Eclipse another so called "Reader" thread
    * is created by Eclipse.
    * So we cannot assume that the JVM does not create additional threads
    * during the test. However for the time being we assume that any such
    * additionally created threads are daemon threads.
    *
    * @param threads - the array of threads to parse
    * @return a new array with any daemon threads removed
    */
   public Thread[] filterDaemonThreads(Thread[] threads) throws Exception {

      List<Thread> threadList = new ArrayList<Thread>(Arrays.asList(threads));

      // Can't use an Iterator as it would raise a
      // ConcurrentModificationException when trying to remove an element
      // from the list, so using standard walk through
      for (int i = 0; i < threadList.size(); i++) {

         Thread thread = threadList.get(i);
         LOG.debug("Inspecting thread " + thread.getName());
         if (thread.isDaemon()) {
            LOG.debug("Removing deamon thread.");
            threadList.remove(thread);
            Thread.sleep(100);

         }
      }
      LOG.debug("Converting list back to Array");
      return threadList.toArray(new Thread[0]);
   }
}
