Author: ggregory Date: Wed Nov 9 14:34:43 2011 New Revision: 1199773 URL: http://svn.apache.org/viewvc?rev=1199773&view=rev Log: [LANG-762] Handle or document ReflectionToStringBuilder and ToStringBuilder for collections that are not thread safe.
Added: commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/builder/ToStringStyleConcurrencyTest.java Added: commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/builder/ToStringStyleConcurrencyTest.java URL: http://svn.apache.org/viewvc/commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/builder/ToStringStyleConcurrencyTest.java?rev=1199773&view=auto ============================================================================== --- commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/builder/ToStringStyleConcurrencyTest.java (added) +++ commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/builder/ToStringStyleConcurrencyTest.java Wed Nov 9 14:34:43 2011 @@ -0,0 +1,108 @@ +/* + * 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 org.junit.Test; + +/** + * Tests concurrent access for the default {@link ToStringStyle}. + * <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> + * This test passes but only tests one aspect of the issue. + * </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 3.0.2 + */ +public class ToStringStyleConcurrencyTest { + + static class CollectionHolder<T extends Collection<?>> { + T collection; + + CollectionHolder(T collection) { + this.collection = collection; + } + } + + private static final List<Integer> LIST; + private static final int LIST_SIZE = 100000; + private static final int REPEAT = 100; + + static { + LIST = new ArrayList<Integer>(LIST_SIZE); + for (int i = 0; i < LIST_SIZE; i++) { + LIST.add(Integer.valueOf(i)); + } + } + + @Test + public void testLinkedList() throws InterruptedException, ExecutionException { + this.testConcurrency(new CollectionHolder<List<Integer>>(new LinkedList<Integer>())); + } + + @Test + public void testArrayList() throws InterruptedException, ExecutionException { + this.testConcurrency(new CollectionHolder<List<Integer>>(new ArrayList<Integer>())); + } + + @Test + public void testCopyOnWriteArrayList() throws InterruptedException, ExecutionException { + this.testConcurrency(new CollectionHolder<List<Integer>>(new CopyOnWriteArrayList<Integer>())); + } + + private void testConcurrency(final CollectionHolder<List<Integer>> holder) throws InterruptedException, + ExecutionException { + final List<Integer> list = holder.collection; + // make a big array that takes a long time to toString() + list.addAll(LIST); + // Create a thread pool with two threads to cause the most contention on the underlying resource. + final ExecutorService threadPool = Executors.newFixedThreadPool(2); + // Consumes toStrings + Callable<Integer> consumer = new Callable<Integer>() { + public Integer call() { + for (int i = 0; i < REPEAT; i++) { + // Calls ToStringStyle + new ToStringBuilder(holder).append(holder.collection); + } + return REPEAT; + } + }; + Collection<Callable<Integer>> tasks = new ArrayList<Callable<Integer>>(); + tasks.add(consumer); + tasks.add(consumer); + final List<Future<Integer>> futures = threadPool.invokeAll(tasks); + for (Future<Integer> future : futures) { + future.get(); + } + } +}