001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.util;
019
020import static org.junit.Assert.assertEquals;
021import static org.junit.Assert.assertTrue;
022
023import java.util.Arrays;
024import java.util.Map;
025import java.util.Random;
026import java.util.concurrent.Callable;
027import java.util.concurrent.ConcurrentHashMap;
028import java.util.concurrent.ExecutorCompletionService;
029import java.util.concurrent.ExecutorService;
030import java.util.concurrent.Executors;
031import java.util.concurrent.Future;
032import java.util.concurrent.TimeUnit;
033import java.util.concurrent.locks.Lock;
034import java.util.concurrent.locks.ReentrantReadWriteLock;
035import org.apache.hadoop.hbase.HBaseClassTestRule;
036import org.apache.hadoop.hbase.testclassification.MediumTests;
037import org.apache.hadoop.hbase.testclassification.MiscTests;
038import org.apache.hadoop.hbase.util.IdReadWriteLock.ReferenceType;
039import org.junit.ClassRule;
040import org.junit.Test;
041import org.junit.experimental.categories.Category;
042import org.junit.runner.RunWith;
043import org.junit.runners.Parameterized;
044import org.slf4j.Logger;
045import org.slf4j.LoggerFactory;
046
047@RunWith(Parameterized.class)
048@Category({MiscTests.class, MediumTests.class})
049// Medium as it creates 100 threads; seems better to run it isolated
050public class TestIdReadWriteLock {
051
052  @ClassRule
053  public static final HBaseClassTestRule CLASS_RULE =
054      HBaseClassTestRule.forClass(TestIdReadWriteLock.class);
055
056  private static final Logger LOG = LoggerFactory.getLogger(TestIdReadWriteLock.class);
057
058  private static final int NUM_IDS = 16;
059  private static final int NUM_THREADS = 128;
060  private static final int NUM_SECONDS = 15;
061
062  @Parameterized.Parameter
063  public IdReadWriteLock<Long> idLock;
064
065  @Parameterized.Parameters
066  public static Iterable<Object[]> data() {
067    return Arrays.asList(new Object[][] { { new IdReadWriteLock<Long>(ReferenceType.WEAK) },
068      { new IdReadWriteLock<Long>(ReferenceType.SOFT) } });
069  }
070
071  private Map<Long, String> idOwner = new ConcurrentHashMap<>();
072
073  private class IdLockTestThread implements Callable<Boolean> {
074
075    private String clientId;
076
077    public IdLockTestThread(String clientId) {
078      this.clientId = clientId;
079    }
080
081    @Override
082    public Boolean call() throws Exception {
083      Thread.currentThread().setName(clientId);
084      Random rand = new Random();
085      long endTime = System.currentTimeMillis() + NUM_SECONDS * 1000;
086      while (System.currentTimeMillis() < endTime) {
087        long id = rand.nextInt(NUM_IDS);
088        boolean readLock = rand.nextBoolean();
089
090        ReentrantReadWriteLock readWriteLock = idLock.getLock(id);
091        Lock lock = readLock ? readWriteLock.readLock() : readWriteLock.writeLock();
092        try {
093          lock.lock();
094          int sleepMs = 1 + rand.nextInt(4);
095          String owner = idOwner.get(id);
096          if (owner != null && LOG.isDebugEnabled()) {
097            LOG.debug((readLock ? "Read" : "Write") + "lock of Id " + id + " already taken by "
098                + owner + ", we are " + clientId);
099          }
100
101          idOwner.put(id, clientId);
102          Thread.sleep(sleepMs);
103          idOwner.remove(id);
104
105        } finally {
106          lock.unlock();
107          if (LOG.isDebugEnabled()) {
108            LOG.debug("Release " + (readLock ? "Read" : "Write") + " lock of Id" + id + ", we are "
109                + clientId);
110          }
111        }
112      }
113      return true;
114    }
115
116  }
117
118  @Test
119  public void testMultipleClients() throws Exception {
120    ExecutorService exec = Executors.newFixedThreadPool(NUM_THREADS);
121    try {
122      ExecutorCompletionService<Boolean> ecs = new ExecutorCompletionService<>(exec);
123      for (int i = 0; i < NUM_THREADS; ++i)
124        ecs.submit(new IdLockTestThread("client_" + i));
125      for (int i = 0; i < NUM_THREADS; ++i) {
126        Future<Boolean> result = ecs.take();
127        assertTrue(result.get());
128      }
129      int entryPoolSize = idLock.purgeAndGetEntryPoolSize();
130      LOG.debug("Size of entry pool after gc and purge: " + entryPoolSize);
131      ReferenceType refType = idLock.getReferenceType();
132      switch (refType) {
133      case WEAK:
134        // make sure the entry pool will be cleared after GC and purge call
135        assertEquals(0, entryPoolSize);
136        break;
137      case SOFT:
138        // make sure the entry pool won't be cleared when JVM memory is enough
139        // even after GC and purge call
140        assertEquals(NUM_IDS, entryPoolSize);
141        break;
142      default:
143        break;
144      }
145    } finally {
146      exec.shutdown();
147      exec.awaitTermination(5000, TimeUnit.MILLISECONDS);
148    }
149  }
150
151
152}
153