alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (ReflectionToStringBuilderConcurrencyTest.java)

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

Learn more about this Java project at its project page.

Java - Java tags/keywords

arraylist, callable, collectionholder, data_size, executionexception, executorservice, future, ignore, integer, interruptedexception, override, reflectiontostringbuilderconcurrencytest, repeat, test, threading, threads, util

The ReflectionToStringBuilderConcurrencyTest.java Java example 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.commons.lang3.builder;

import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

import org.junit.Assert;
import org.junit.Ignore;
import org.junit.Test;

/**
 * Tests concurrent access for {@link ReflectionToStringBuilder}.
 * <p>
 * The {@link ToStringStyle} class includes a registry to avoid infinite loops for objects with circular references. We
 * want to make sure that we do not get concurrency exceptions accessing this registry.
 * </p>
 * <p>
 * The tests on the non-thread-safe collections do not pass.
 * </p>
 * 
 * @see <a href="https://issues.apache.org/jira/browse/LANG-762">[LANG-762] Handle or document ReflectionToStringBuilder
 *      and ToStringBuilder for collections that are not thread safe</a>
 * @since 3.1
 */
public class ReflectionToStringBuilderConcurrencyTest {

    static class CollectionHolder<T extends Collection {
        T collection;

        CollectionHolder(final T collection) {
            this.collection = collection;
        }
    }

    private static final int DATA_SIZE = 100000;
    private static final int REPEAT = 100;

    @Test
    @Ignore
    public void testLinkedList() throws InterruptedException, ExecutionException {
        this.testConcurrency(new CollectionHolder<List(new LinkedList()));
    }

    @Test
    @Ignore
    public void testArrayList() throws InterruptedException, ExecutionException {
        this.testConcurrency(new CollectionHolder<List(new ArrayList()));
    }

    @Test
    @Ignore
    public void testCopyOnWriteArrayList() throws InterruptedException, ExecutionException {
        this.testConcurrency(new CollectionHolder<List(new CopyOnWriteArrayList()));
    }

    private void testConcurrency(final CollectionHolder<List holder) throws InterruptedException,
            ExecutionException {
        final List<Integer> list = holder.collection;
        // make a big array that takes a long time to toString()
        for (int i = 0; i < DATA_SIZE; i++) {
            list.add(Integer.valueOf(i));
        }
        // Create a thread pool with two threads to cause the most contention on the underlying resource.
        final ExecutorService threadPool = Executors.newFixedThreadPool(2);
        // Consumes toStrings
        final Callable<Integer> consumer = new Callable() {
            @Override
            public Integer call() {
                for (int i = 0; i < REPEAT; i++) {
                    final String s = ReflectionToStringBuilder.toString(holder);
                    Assert.assertNotNull(s);
                }
                return Integer.valueOf(REPEAT);
            }
        };
        // Produces changes in the list
        final Callable<Integer> producer = new Callable() {
            @Override
            public Integer call() {
                for (int i = 0; i < DATA_SIZE; i++) {
                    list.remove(list.get(0));
                }
                return Integer.valueOf(REPEAT);
            }
        };
        final Collection<Callable tasks = new ArrayList>();
        tasks.add(consumer);
        tasks.add(producer);
        final List<Future futures = threadPool.invokeAll(tasks);
        for (final Future<Integer> future : futures) {
            Assert.assertEquals(REPEAT, future.get().intValue());
        }
        threadPool.shutdown();
        threadPool.awaitTermination(1, TimeUnit.SECONDS);
    }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java ReflectionToStringBuilderConcurrencyTest.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.