com.netflix.curator.framework.recipes.locks.TestInterProcessReadWriteLock.java Source code

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/*
 * Copyright 2012 Netflix, Inc.
 *
 *    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 com.netflix.curator.framework.recipes.locks;

import java.util.Collection;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.commons.io.IOUtils;
import org.testng.Assert;
import org.testng.annotations.Test;

import com.google.common.collect.Lists;
import com.netflix.curator.framework.CuratorFramework;
import com.netflix.curator.framework.CuratorFrameworkFactory;
import com.netflix.curator.framework.recipes.BaseClassForTests;
import com.netflix.curator.retry.RetryOneTime;

public class TestInterProcessReadWriteLock extends BaseClassForTests {
    @Test
    public void testGetParticipantNodes() throws Exception {
        final int READERS = 20;
        final int WRITERS = 8;

        CuratorFramework client = CuratorFrameworkFactory.newClient(server.getConnectString(), new RetryOneTime(1));
        try {
            client.start();

            final CountDownLatch latch = new CountDownLatch(READERS + WRITERS);
            final CountDownLatch readLatch = new CountDownLatch(READERS);
            final InterProcessReadWriteLock lock = new InterProcessReadWriteLock(client, "/lock");

            ExecutorService service = Executors.newCachedThreadPool();
            for (int i = 0; i < READERS; ++i) {
                service.submit(new Callable<Void>() {
                    @Override
                    public Void call() throws Exception {
                        lock.readLock().acquire();
                        latch.countDown();
                        readLatch.countDown();
                        return null;
                    }
                });
            }
            for (int i = 0; i < WRITERS; ++i) {
                service.submit(new Callable<Void>() {
                    @Override
                    public Void call() throws Exception {
                        Assert.assertTrue(readLatch.await(10, TimeUnit.SECONDS));
                        latch.countDown(); // must be before as there can only be one writer
                        lock.writeLock().acquire();
                        return null;
                    }
                });
            }

            Assert.assertTrue(latch.await(10, TimeUnit.SECONDS));

            Collection<String> readers = lock.readLock().getParticipantNodes();
            Collection<String> writers = lock.writeLock().getParticipantNodes();

            Assert.assertEquals(readers.size(), READERS);
            Assert.assertEquals(writers.size(), WRITERS);
        } finally {
            IOUtils.closeQuietly(client);
        }
    }

    @Test
    public void testThatUpgradingIsDisallowed() throws Exception {
        CuratorFramework client = CuratorFrameworkFactory.newClient(server.getConnectString(), new RetryOneTime(1));
        try {
            client.start();

            InterProcessReadWriteLock lock = new InterProcessReadWriteLock(client, "/lock");
            lock.readLock().acquire();
            Assert.assertFalse(lock.writeLock().acquire(5, TimeUnit.SECONDS));

            lock.readLock().release();
        } finally {
            IOUtils.closeQuietly(client);
        }
    }

    @Test
    public void testThatDowngradingRespectsThreads() throws Exception {
        CuratorFramework client = CuratorFrameworkFactory.newClient(server.getConnectString(), new RetryOneTime(1));
        try {
            client.start();

            final InterProcessReadWriteLock lock = new InterProcessReadWriteLock(client, "/lock");
            ExecutorService t1 = Executors.newSingleThreadExecutor();
            ExecutorService t2 = Executors.newSingleThreadExecutor();

            final CountDownLatch latch = new CountDownLatch(1);

            Future<Object> f1 = t1.submit(new Callable<Object>() {
                @Override
                public Object call() throws Exception {
                    lock.writeLock().acquire();
                    latch.countDown();
                    return null;
                }
            });

            Future<Object> f2 = t2.submit(new Callable<Object>() {
                @Override
                public Object call() throws Exception {
                    Assert.assertTrue(latch.await(10, TimeUnit.SECONDS));
                    Assert.assertFalse(lock.readLock().acquire(5, TimeUnit.SECONDS));
                    return null;
                }
            });

            f1.get();
            f2.get();
        } finally {
            IOUtils.closeQuietly(client);
        }
    }

    @Test
    public void testDowngrading() throws Exception {
        CuratorFramework client = CuratorFrameworkFactory.newClient(server.getConnectString(), new RetryOneTime(1));
        try {
            client.start();

            InterProcessReadWriteLock lock = new InterProcessReadWriteLock(client, "/lock");
            lock.writeLock().acquire();
            Assert.assertTrue(lock.readLock().acquire(5, TimeUnit.SECONDS));
            lock.writeLock().release();

            lock.readLock().release();
        } finally {
            IOUtils.closeQuietly(client);
        }
    }

    @Test
    public void testBasic() throws Exception {
        final int CONCURRENCY = 8;
        final int ITERATIONS = 100;

        final Random random = new Random();
        final AtomicInteger concurrentCount = new AtomicInteger(0);
        final AtomicInteger maxConcurrentCount = new AtomicInteger(0);
        final AtomicInteger writeCount = new AtomicInteger(0);
        final AtomicInteger readCount = new AtomicInteger(0);

        List<Future<Void>> futures = Lists.newArrayList();
        ExecutorService service = Executors.newCachedThreadPool();
        for (int i = 0; i < CONCURRENCY; ++i) {
            Future<Void> future = service.submit(new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    CuratorFramework client = CuratorFrameworkFactory.newClient(server.getConnectString(),
                            new RetryOneTime(1));
                    client.start();
                    try {
                        InterProcessReadWriteLock lock = new InterProcessReadWriteLock(client, "/lock");
                        for (int i = 0; i < ITERATIONS; ++i) {
                            if (random.nextInt(100) < 10) {
                                doLocking(lock.writeLock(), concurrentCount, maxConcurrentCount, random, 1);
                                writeCount.incrementAndGet();
                            } else {
                                doLocking(lock.readLock(), concurrentCount, maxConcurrentCount, random,
                                        Integer.MAX_VALUE);
                                readCount.incrementAndGet();
                            }
                        }
                    } finally {
                        IOUtils.closeQuietly(client);
                    }
                    return null;
                }
            });
            futures.add(future);
        }

        for (Future<Void> future : futures) {
            future.get();
        }

        System.out.println("Writes: " + writeCount.get() + " - Reads: " + readCount.get() + " - Max Reads: "
                + maxConcurrentCount.get());

        Assert.assertTrue(writeCount.get() > 0);
        Assert.assertTrue(readCount.get() > 0);
        Assert.assertTrue(maxConcurrentCount.get() > 1);
    }

    private void doLocking(InterProcessLock lock, AtomicInteger concurrentCount, AtomicInteger maxConcurrentCount,
            Random random, int maxAllowed) throws Exception {
        try {
            Assert.assertTrue(lock.acquire(10, TimeUnit.SECONDS));
            int localConcurrentCount;
            synchronized (this) {
                localConcurrentCount = concurrentCount.incrementAndGet();
                if (localConcurrentCount > maxConcurrentCount.get()) {
                    maxConcurrentCount.set(localConcurrentCount);
                }
            }

            Assert.assertTrue(localConcurrentCount <= maxAllowed, "" + localConcurrentCount);

            Thread.sleep(random.nextInt(9) + 1);
        } finally {
            synchronized (this) {
                concurrentCount.decrementAndGet();
                lock.release();
            }
        }
    }
}