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.thread;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  
  import java.util.concurrent.Callable;
  import java.util.concurrent.CountDownLatch;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.Future;
  import java.util.concurrent.SynchronousQueue;
  import java.util.concurrent.ThreadFactory;
  import java.util.concurrent.ThreadPoolExecutor;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.junit.After;
  import org.junit.Before;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.TestName;
  
  public class PooledTaskRunnerTest {
  
      @Rule public TestName name = new TestName();
  
      private ExecutorService executor;
  
      @Before
      public void setUp() throws Exception {
          executor = Executors.newCachedThreadPool(new IgnoreUncaughtExceptionThreadFactory());
      }
  
      @After
      public void tearDown() throws Exception {
          executor.shutdownNow();
      }
  
      @Test
      public void testNormalBehavior() throws Exception {
          final CountDownLatch latch = new CountDownLatch( 1 );
  
          PooledTaskRunner runner = new PooledTaskRunner( executor, new Task() {
              @Override
              public boolean iterate() {
                  latch.countDown();
  
                  return false;
              }
          }, 1 );
  
          runner.wakeup();
  
          assertTrue( latch.await( 1, TimeUnit.SECONDS ) );
  
          runner.shutdown();
      }
  
      @Test
      public void testWakeupResultsInThreadSafeCalls() throws Exception {
  
          ThreadPoolExecutor executor = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 10, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), new ThreadFactory() {
              @Override
              public Thread newThread(Runnable runnable) {
                  Thread thread = new Thread(runnable, name.getMethodName());
                  thread.setDaemon(true);
                  thread.setPriority(Thread.NORM_PRIORITY);
                  return thread;
              }
          });
          final CountDownLatch doneLatch = new CountDownLatch( 100 );
          final AtomicInteger clashCount = new AtomicInteger();
          final AtomicInteger count = new AtomicInteger();
  
  
          final PooledTaskRunner runner = new PooledTaskRunner(executor, new Task() {
              String threadUnSafeVal = null;
              @Override
              public boolean iterate() {
                  if (threadUnSafeVal != null) {
                      clashCount.incrementAndGet();
                  }
                  threadUnSafeVal = Thread.currentThread().getName();
                  count.incrementAndGet();
                  doneLatch.countDown();
                  if (!threadUnSafeVal.equals(Thread.currentThread().getName())) {
                      clashCount.incrementAndGet();
                  }
                  threadUnSafeVal = null;
                  return false;
              }
          }, 1 );
  
          Runnable doWakeup = new Runnable() {
              @Override
              public void run() {
                  try {
                      runner.wakeup();
                  } catch (InterruptedException ignored) {
                  }
              }
          };
  
          final int iterations = 1000;
          for (int i=0; i< iterations; i++) {
              if (i%100 == 0) {
                  Thread.sleep(10);
              }
              executor.execute(doWakeup);
          }
  
          doneLatch.await(20, TimeUnit.SECONDS);
          assertEquals("thread safety clash", 0, clashCount.get());
          assertTrue("called more than once", count.get() > 1);
          runner.shutdown();
      }
  
      @Test
      public void testShutsDownAfterRunnerFailure() throws Exception {
          Future<Object> future = executor.submit( new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  final CountDownLatch latch = new CountDownLatch( 1 );
  
                  PooledTaskRunner runner = new PooledTaskRunner( executor, new Task() {
                      @Override
                      public boolean iterate() {
                          latch.countDown();
  
                          throw new RuntimeException();
                      }
                  }, 1 );
  
                  runner.wakeup();
  
                  assertTrue( latch.await( 1, TimeUnit.SECONDS ) );
  
                  runner.shutdown();
  
                  return null;
              }
          } );
  
          try {
              future.get( 5, TimeUnit.SECONDS );
          } catch( TimeoutException e ) {
              fail( "TaskRunner did not shut down cleanly" );
          }
      }
  
      private class IgnoreUncaughtExceptionThreadFactory implements ThreadFactory, Thread.UncaughtExceptionHandler {
  
          ThreadFactory threadFactory = Executors.defaultThreadFactory();
  
          @Override
          public Thread newThread(Runnable r) {
              Thread thread = threadFactory.newThread(r);
              thread.setUncaughtExceptionHandler(this);
              return thread;
          }
  
          @Override
          public void uncaughtException(Thread t, Throwable e) {
              // ignore ie: no printStackTrace that would sully the test console
           }
      }
  }