org.apache.hadoop.hbase.util.TestIdReadWriteLock.java Source code

Introduction

Here is the source code for org.apache.hadoop.hbase.util.TestIdReadWriteLock.java

Source

/*
 *
 * 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.hadoop.hbase.util;

import static org.junit.Assert.assertTrue;
import static org.junit.Assert.assertEquals;

import java.util.Map;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.testclassification.MiscTests;
import org.junit.Test;
import org.junit.experimental.categories.Category;

@Category({ MiscTests.class, MediumTests.class })
// Medium as it creates 100 threads; seems better to run it isolated
public class TestIdReadWriteLock {

    private static final Log LOG = LogFactory.getLog(TestIdReadWriteLock.class);

    private static final int NUM_IDS = 16;
    private static final int NUM_THREADS = 128;
    private static final int NUM_SECONDS = 15;

    private IdReadWriteLock idLock = new IdReadWriteLock();

    private Map<Long, String> idOwner = new ConcurrentHashMap<Long, String>();

    private class IdLockTestThread implements Callable<Boolean> {

        private String clientId;

        public IdLockTestThread(String clientId) {
            this.clientId = clientId;
        }

        @Override
        public Boolean call() throws Exception {
            Thread.currentThread().setName(clientId);
            Random rand = new Random();
            long endTime = System.currentTimeMillis() + NUM_SECONDS * 1000;
            while (System.currentTimeMillis() < endTime) {
                long id = rand.nextInt(NUM_IDS);
                boolean readLock = rand.nextBoolean();

                ReentrantReadWriteLock readWriteLock = idLock.getLock(id);
                Lock lock = readLock ? readWriteLock.readLock() : readWriteLock.writeLock();
                try {
                    lock.lock();
                    int sleepMs = 1 + rand.nextInt(4);
                    String owner = idOwner.get(id);
                    if (owner != null && LOG.isDebugEnabled()) {
                        LOG.debug((readLock ? "Read" : "Write") + "lock of Id " + id + " already taken by " + owner
                                + ", we are " + clientId);
                    }

                    idOwner.put(id, clientId);
                    Thread.sleep(sleepMs);
                    idOwner.remove(id);

                } finally {
                    lock.unlock();
                    if (LOG.isDebugEnabled()) {
                        LOG.debug("Release " + (readLock ? "Read" : "Write") + " lock of Id" + id + ", we are "
                                + clientId);
                    }
                }
            }
            return true;
        }

    }

    @Test(timeout = 60000)
    public void testMultipleClients() throws Exception {
        ExecutorService exec = Executors.newFixedThreadPool(NUM_THREADS);
        try {
            ExecutorCompletionService<Boolean> ecs = new ExecutorCompletionService<Boolean>(exec);
            for (int i = 0; i < NUM_THREADS; ++i)
                ecs.submit(new IdLockTestThread("client_" + i));
            for (int i = 0; i < NUM_THREADS; ++i) {
                Future<Boolean> result = ecs.take();
                assertTrue(result.get());
            }
            // make sure the entry pool will be cleared after GC and purge call
            int entryPoolSize = idLock.purgeAndGetEntryPoolSize();
            LOG.debug("Size of entry pool after gc and purge: " + entryPoolSize);
            assertEquals(0, entryPoolSize);
        } finally {
            exec.shutdown();
            exec.awaitTermination(5000, TimeUnit.MILLISECONDS);
        }
    }

}