org.commonjava.util.partyline.ConcurrentReadErrorsClearLocksTest.java Source code

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Here is the source code for org.commonjava.util.partyline.ConcurrentReadErrorsClearLocksTest.java

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/**
 * Copyright (C) 2015 Red Hat, Inc. (jdcasey@commonjava.org)
 *
 * Licensed 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.commonjava.util.partyline;

import org.apache.commons.io.FileUtils;
import org.jboss.byteman.contrib.bmunit.BMRule;
import org.jboss.byteman.contrib.bmunit.BMRules;
import org.jboss.byteman.contrib.bmunit.BMUnitConfig;
import org.jboss.byteman.contrib.bmunit.BMUnitRunner;
import org.junit.Test;
import org.junit.runner.RunWith;

import java.io.File;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import static org.commonjava.util.partyline.UtilThreads.reader;
import static org.commonjava.util.partyline.UtilThreads.writer;

@RunWith(BMUnitRunner.class)
public class ConcurrentReadErrorsClearLocksTest extends AbstractBytemanTest {
    /**
     * Test that locks for mutiple reads clear correctly. This will setup an script of events for
     * a single file, where:
     * <ol>
     *     <li>Multiple reads happen simultaneously, read the content, and close</li>
     *     <li>A single write at the end ensures the other locks are clear</li>
     * </ol>
     * @throws Exception
     */
    /*@formatter:off*/
    @BMRules(rules = {
            // When we try to init a new JoinableFile for INPUT, simulate an IOException from somewhere deeper in the stack.
            @BMRule(name = "new JoinableFile error", targetClass = "JoinableFile", targetMethod = "<init>", targetLocation = "ENTRY", condition = "$4 == false", action = "debug(\"Throwing test exception.\"); "
                    + "throw new java.io.IOException(\"Test exception\")") })
    /*@formatter:on*/
    @BMUnitConfig(debug = true)
    @Test
    public void run() throws Exception {
        final ExecutorService execs = Executors.newFixedThreadPool(5);
        final File f = temp.newFile("child.txt");
        FileUtils.write(f, "test data");

        final CountDownLatch latch = new CountDownLatch(4);

        CountDownLatch readBeginLatch = new CountDownLatch(3);
        CountDownLatch readEndLatch = new CountDownLatch(3);

        final JoinableFileManager manager = new JoinableFileManager();
        final long start = System.currentTimeMillis();

        execs.execute(writer(manager, f, latch, readEndLatch));

        for (int i = 0; i < 3; i++) {
            final int k = i;
            execs.execute(reader(k, manager, f, latch, readBeginLatch, readEndLatch, null));
        }

        latch.await();
    }

}