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* 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.codehaus.groovy.reflection;
import groovy.lang.GroovyClassLoader;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.groovy.stress.util.GCUtils;
import org.apache.groovy.stress.util.ThreadUtils;
import org.junit.Test;
import static org.junit.Assert.*;
/**
* Tests for deadlocks in the ClassInfo caching.
*
*/
public class ClassInfoDeadlockStressTest {
private static final int DEADLOCK_TRIES = 8;
private static final int THREAD_COUNT = 8;
private final CountDownLatch startLatch = new CountDownLatch(1);
private final CountDownLatch completeLatch = new CountDownLatch(THREAD_COUNT);
private final GroovyClassLoader gcl = new GroovyClassLoader();
private final AtomicInteger counter = new AtomicInteger();
/**
* We first generate a large number of ClassInfo instances for classes
* that are no longer reachable. Then queue up threads to all request
* ClassInfo instances for new classes simultaneously to ensure that
* clearing the old references wont deadlock the creation of new
* instances.
* <p>
* GROOVY-8067
*/
@Test
public void testDeadlock() throws Exception {
for (int i = 1; i <= DEADLOCK_TRIES; i++) {
System.out.println("Test Number: " + i);
generateGarbage();
GCUtils.gc();
attemptDeadlock(null);
}
}
@Test
public void testRequestsForSameClassInfo() throws Exception {
Class<?> newClass = createRandomClass();
for (int i = 1; i <= DEADLOCK_TRIES; i++) {
System.out.println("Test Number: " + i);
generateGarbage();
GCUtils.gc();
attemptDeadlock(newClass);
}
ClassInfo newClassInfo = ClassInfo.getClassInfo(newClass);
for (ClassInfo ci : ClassInfo.getAllClassInfo()) {
if (ci.getTheClass() == newClass && ci != newClassInfo) {
fail("Found multiple ClassInfo instances for class");
}
}
}
private void attemptDeadlock(final Class<?> cls) throws Exception {
for (int i = 0; i < THREAD_COUNT; i++) {
Runnable runnable = new Runnable() {
@Override
public void run() {
Class<?> newClass = (cls == null) ? createRandomClass() : cls;
ThreadUtils.await(startLatch);
ClassInfo ci = ClassInfo.getClassInfo(newClass);
assertEquals(newClass, ci.getTheClass());
completeLatch.countDown();
}
};
Thread t = new Thread(runnable);
t.setDaemon(true);
t.start();
}
startLatch.countDown();
completeLatch.await(10L, TimeUnit.SECONDS);
if (completeLatch.getCount() != 0) {
System.err.println("Possible deadlock, grab a thread dump now");
completeLatch.await(1L, TimeUnit.MINUTES);
if (completeLatch.getCount() == 0) {
System.out.println("No deadlock, but took longer than expected");
} else {
fail("Deadlock occurred");
}
} else {
System.out.println("No deadlock detected");
}
}
// This may deadlock so run in a separate thread
private void generateGarbage() throws Exception {
System.out.println("Generating garbage");
Runnable runnable = new Runnable() {
@Override
public void run() {
for (int i = 0; i < 5000; i++) {
Class<?> c = createRandomClass();
ClassInfo ci = ClassInfo.getClassInfo(c);
}
}
};
Thread t = new Thread(runnable, "GenerateGarbageThread");
t.setDaemon(true);
t.start();
t.join(TimeUnit.SECONDS.toMillis(120L));
if (t.isAlive()) {
fail("Deadlock detected while generating garbage");
}
}
private Class<?> createRandomClass() {
return gcl.parseClass("println foo-" + counter.incrementAndGet(), "Script1.groovy");
}
}