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ActiveMQ example source code file (PooledTaskRunnerTest.java)

This example ActiveMQ source code file (PooledTaskRunnerTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - ActiveMQ tags/keywords

atomicinteger, countdownlatch, countdownlatch, exception, exception, ignoreuncaughtexceptionthreadfactory, override, pooledtaskrunner, pooledtaskrunner, task, thread, thread, threadfactory, threading, threadpoolexecutor, threads

The ActiveMQ PooledTaskRunnerTest.java source code

/**
 * 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 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 junit.framework.TestCase;

public class PooledTaskRunnerTest extends TestCase {
    private ExecutorService executor;

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        executor = Executors.newCachedThreadPool(new IgnoreUncaughtExceptionThreadFactory());
    }

    @Override
    protected void tearDown() throws Exception {
        executor.shutdownNow();

        super.tearDown();
    }

    public void testNormalBehavior() throws Exception {
        final CountDownLatch latch = new CountDownLatch( 1 );

        PooledTaskRunner runner = new PooledTaskRunner( executor, new Task() {
            public boolean iterate() {
                latch.countDown();

                return false;
            }
        }, 1 );

        runner.wakeup();

        assertTrue( latch.await( 1, TimeUnit.SECONDS ) );

        runner.shutdown();
    }

    
    public void testWakeupResultsInThreadSafeCalls() throws Exception {
        
        ThreadPoolExecutor executor = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 10, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), new ThreadFactory() {
            public Thread newThread(Runnable runnable) {
                Thread thread = new Thread(runnable, getName());
                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;
            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() {
            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();
    }

    public void testShutsDownAfterRunnerFailure() throws Exception {
        Future<Object> future = executor.submit( new Callable() {
            public Object call() throws Exception {
                final CountDownLatch latch = new CountDownLatch( 1 );

                PooledTaskRunner runner = new PooledTaskRunner( executor, new Task() {
                    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" );
        }
    }
    
    class IgnoreUncaughtExceptionThreadFactory implements ThreadFactory, Thread.UncaughtExceptionHandler {
        ThreadFactory threadFactory = Executors.defaultThreadFactory();
        public Thread newThread(Runnable r) {
            Thread thread = threadFactory.newThread(r);
            thread.setUncaughtExceptionHandler(this);
            return thread;
        }
        
        public void uncaughtException(Thread t, Throwable e) {
            // ignore ie: no printStackTrace that would sully the test console
         }
    }
}

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