/*
* 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.wicket.page;
import java.util.Random;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.wicket.MockPage;
import org.apache.wicket.core.util.lang.WicketObjects;
import org.apache.wicket.mock.MockPageManager;
import org.apache.wicket.page.PageAccessSynchronizer.PageLock;
import org.apache.wicket.util.SlowTests;
import org.apache.wicket.util.time.Duration;
import org.apache.wicket.util.time.Time;
import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.rules.Timeout;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*/
@Category(SlowTests.class)
public class PageAccessSynchronizerTest extends Assert
{
private static final Logger logger = LoggerFactory.getLogger(PageAccessSynchronizerTest.class);
/** */
@Rule
public Timeout globalTimeout = new Timeout(30, TimeUnit.SECONDS);
/**
* @throws Exception
*/
@Test
public void testReentrant() throws Exception
{
final PageAccessSynchronizer sync = new PageAccessSynchronizer(Duration.seconds(5));
sync.lockPage(0);
sync.lockPage(0);
}
/**
* @throws Exception
*/
@Test
public void testBlocking() throws Exception
{
final PageAccessSynchronizer sync = new PageAccessSynchronizer(Duration.seconds(5));
final Duration hold = Duration.seconds(1);
final Time t1locks[] = new Time[1];
final Time t2locks[] = new Time[1];
class T1 extends Thread
{
@Override
public void run()
{
sync.lockPage(1);
t1locks[0] = Time.now();
hold.sleep();
sync.unlockAllPages();
}
}
class T2 extends Thread
{
@Override
public void run()
{
sync.lockPage(1);
t2locks[0] = Time.now();
sync.unlockAllPages();
}
}
T1 t1 = new T1();
t1.setName("t1");
T2 t2 = new T2();
t2.setName("t2");
t1.start();
Duration.milliseconds(100).sleep();
t2.start();
t1.join();
t2.join();
assertTrue(!t2locks[0].before(t1locks[0].add(hold)));
}
/**
* @param pages
* @param workers
* @param duration
* @throws Exception
*/
public void runContentionTest(final int pages, final int workers, final Duration duration)
throws Exception
{
final PageAccessSynchronizer sync = new PageAccessSynchronizer(Duration.seconds(1));
final AtomicInteger[] counts = new AtomicInteger[pages];
for (int i = 0; i < counts.length; i++)
{
counts[i] = new AtomicInteger();
}
final AtomicInteger hits = new AtomicInteger();
final String[] error = new String[1];
class Worker extends Thread
{
@Override
public void run()
{
Random random = new Random();
Time start = Time.now();
while (start.elapsedSince().lessThan(duration) && error[0] == null)
{
logger.info("{} elapsed: {}, duration: {}", new Object[] {
Thread.currentThread().getName(), start.elapsedSince(), duration });
int page1 = random.nextInt(counts.length);
int page2 = random.nextInt(counts.length);
int count = 0;
while (page2 == page1 && count < 100)
{
page2 = random.nextInt(counts.length);
count++;
}
if (page2 == page1)
{
throw new RuntimeException("orly?");
}
try
{
sync.lockPage(page1);
sync.lockPage(page2);
// have locks, increment the count
counts[page1].incrementAndGet();
counts[page2].incrementAndGet();
hits.incrementAndGet();
// hold the lock for some time
try
{
Thread.sleep(50);
}
catch (InterruptedException e)
{
error[0] = "Worker :" + Thread.currentThread().getName() +
" interrupted";
}
// decrement the counts
counts[page1].decrementAndGet();
counts[page2].decrementAndGet();
// release lock
}
catch (CouldNotLockPageException e)
{
// ignore
}
finally
{
sync.unlockAllPages();
}
}
}
}
class Monitor extends Thread
{
volatile boolean stop = false;
@Override
public void run()
{
while (!stop && error[0] == null)
{
for (int i = 0; i < counts.length; i++)
{
int count = counts[i].get();
if (count < 0 || count > 1)
{
error[0] = "Detected count of: " + count + " for page: " + i;
return;
}
}
try
{
Thread.sleep(1);
}
catch (InterruptedException e)
{
error[0] = "Monitor thread interrupted";
}
}
}
}
Monitor monitor = new Monitor();
monitor.setName("monitor");
monitor.start();
Worker[] bots = new Worker[workers];
for (int i = 0; i < bots.length; i++)
{
bots[i] = new Worker();
bots[i].setName("worker " + i);
bots[i].start();
}
for (Worker bot : bots)
{
bot.join();
}
monitor.stop = true;
monitor.join();
assertNull(error[0], error[0]);
assertTrue(hits.get() >= counts.length);
}
/**
* @throws Exception
*/
@Test
public void testConcurrency() throws Exception
{
runContentionTest(20, 10, Duration.seconds(10));
}
/**
* @throws Exception
*/
@Test
public void testContention() throws Exception
{
runContentionTest(10, 20, Duration.seconds(10));
}
/**
* @throws Exception
*/
@Test
public void testSerialization() throws Exception
{
// a simple worker that acquires a lock on page 5
class Locker extends Thread
{
private final PageAccessSynchronizer sync;
public Locker(PageAccessSynchronizer sync)
{
this.sync = sync;
}
@Override
public void run()
{
sync.lockPage(5);
}
}
// set up a synchronizer and lock page 5 with locker1
final Duration timeout = Duration.seconds(30);
final PageAccessSynchronizer sync = new PageAccessSynchronizer(timeout);
Locker locker1 = new Locker(sync);
final long start = System.currentTimeMillis();
locker1.run();
// make sure we can serialize the synchronizer
final PageAccessSynchronizer sync2 = WicketObjects.cloneObject(sync);
assertTrue(sync != sync2);
// make sure the clone does not retain locks by attempting to lock page locked by locker1 in
// locker2
Locker locker2 = new Locker(sync2);
locker2.run();
assertTrue(Duration.milliseconds(System.currentTimeMillis() - start).lessThan(timeout));
}
/**
* https://issues.apache.org/jira/browse/WICKET-4009
*/
@Test
public void unlockIfNoSuchPage()
{
PageAccessSynchronizer synchronizer = new PageAccessSynchronizer(Duration.seconds(2));
IPageManager pageManager = new MockPageManager();
IPageManager synchronizedPageManager = synchronizer.adapt(pageManager);
synchronizedPageManager.getPage(0);
ConcurrentMap<Integer, PageLock> locks = synchronizer.getLocks().get();
PageLock pageLock = locks.get(Integer.valueOf(0));
assertNull(pageLock);
int pageId = 1;
IManageablePage page = new MockPage(pageId);
synchronizedPageManager.touchPage(page);
synchronizedPageManager.getPage(pageId);
PageLock pageLock2 = locks.get(Integer.valueOf(pageId));
assertNotNull(pageLock2);
}
/**
* https://issues.apache.org/jira/browse/WICKET-5316
*
* @throws Exception
*/
@Test
public void failToReleaseUnderLoad() throws Exception
{
final Duration duration = Duration.seconds(20); /* seconds */
final ConcurrentLinkedQueue<Exception> errors = new ConcurrentLinkedQueue<Exception>();
final long endTime = System.currentTimeMillis() + duration.getMilliseconds();
// set the synchronizer timeout one second longer than the test runs to prevent
// starvation to become an issue
final PageAccessSynchronizer sync = new PageAccessSynchronizer(duration.add(Duration.ONE_SECOND));
final CountDownLatch latch = new CountDownLatch(100);
for (int count = 0; count < 100; count++)
{
new Thread()
{
@Override
public void run()
{
try
{
while (System.currentTimeMillis() < endTime)
{
try
{
logger.debug(Thread.currentThread().getName() + " locking");
sync.lockPage(0);
Thread.sleep(1);
logger.debug(Thread.currentThread().getName() + " locked");
sync.unlockAllPages();
logger.debug(Thread.currentThread().getName() + " unlocked");
Thread.sleep(5);
}
catch (InterruptedException e)
{
throw new RuntimeException(e);
}
}
}
catch (Exception e)
{
logger.error(e.getMessage(), e);
errors.add(e);
}
finally
{
latch.countDown();
}
}
}.start();
}
latch.await();
if (!errors.isEmpty())
{
logger.error("Number of lock errors that occurred: {}", errors.size());
throw errors.remove();
}
}
}