| /* |
| * Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* @test |
| * @bug 6482247 |
| * @summary Test that creating MXBeans does not introduce memory leaks. |
| * @author Eamonn McManus |
| * @modules java.management |
| * @run build LeakTest RandomMXBeanTest MerlinMXBean TigerMXBean |
| * @run main LeakTest |
| */ |
| |
| /* In this test we create a ClassLoader, then use it to load and run another |
| * jtreg test. When the other test has completed, we wait for the ClassLoader |
| * to be garbage-collected. If it has not been gc'd after a reasonable |
| * amount of time, then something is keeping a reference to the ClassLoader, |
| * which implies a memory leak. |
| * |
| * This test can be applied to any jtreg test, not just the MXBean tests. |
| */ |
| |
| import java.io.File; |
| import java.lang.ref.Reference; |
| import java.lang.ref.ReferenceQueue; |
| import java.lang.ref.WeakReference; |
| import java.lang.reflect.Method; |
| import java.net.URL; |
| import java.net.URLClassLoader; |
| import java.nio.file.Paths; |
| |
| public class LeakTest { |
| /* Ideally we would include MXBeanTest in the list of tests, since it |
| * has fairly complete coverage. However, the ClassLoader fails to be |
| * gc'd when we do that, and I am unable to figure out why. Examining |
| * a heap dump shows only weak references to the ClassLoader. I suspect |
| * something is wrong in the internals of the reflection classes, used |
| * quite heavily by MXBeanTest. |
| */ |
| // private static Class<?>[] otherTests = {MXBeanTest.class}; |
| |
| private static Class<?>[] otherTests = {RandomMXBeanTest.class}; |
| |
| // This class just makes it easier for us to spot our loader in heap dumps |
| private static class ShadowClassLoader extends URLClassLoader { |
| ShadowClassLoader(URL[] urls, ClassLoader parent) { |
| super(urls, parent); |
| } |
| } |
| |
| public static void main(String[] args) throws Exception { |
| System.out.println("Testing that no references are held to ClassLoaders " + |
| "by caches in the MXBean infrastructure"); |
| for (Class<?> testClass : otherTests) |
| test(testClass); |
| if (failure != null) |
| throw new Exception("CLASSLOADER LEAK TEST FAILED: " + failure); |
| System.out.println("CLASSLOADER LEAK TEST PASSED"); |
| if (args.length > 0) { |
| System.out.println("Waiting for input"); |
| System.in.read(); |
| } |
| } |
| |
| private static void test(Class<?> originalTestClass) throws Exception { |
| System.out.println(); |
| System.out.println("TESTING " + originalTestClass.getName()); |
| WeakReference<ClassLoader> wr = testShadow(originalTestClass); |
| System.out.println("Test passed, waiting for ClassLoader to disappear"); |
| long deadline = System.currentTimeMillis() + 20*1000; |
| Reference<? extends ClassLoader> ref; |
| while (wr.get() != null && System.currentTimeMillis() < deadline) { |
| System.gc(); |
| Thread.sleep(100); |
| } |
| if (wr.get() != null) |
| fail(originalTestClass.getName() + " kept ClassLoader reference"); |
| } |
| |
| private static WeakReference<ClassLoader> |
| testShadow(Class<?> originalTestClass) throws Exception { |
| String[] cpaths = System.getProperty("test.classes", ".") |
| .split(File.pathSeparator); |
| URL[] urls = new URL[cpaths.length]; |
| for (int i=0; i < cpaths.length; i++) { |
| urls[i] = Paths.get(cpaths[i]).toUri().toURL(); |
| } |
| |
| URLClassLoader shadowLoader = |
| new ShadowClassLoader(urls, originalTestClass.getClassLoader().getParent()); |
| System.out.println("Shadow loader is " + shadowLoader); |
| String className = originalTestClass.getName(); |
| Class<?> testClass = Class.forName(className, false, shadowLoader); |
| if (testClass.getClassLoader() != shadowLoader) { |
| throw new IllegalArgumentException("Loader didn't work: " + |
| testClass.getClassLoader() + " != " + shadowLoader); |
| } |
| Method main = testClass.getMethod("main", String[].class); |
| main.invoke(null, (Object) new String[0]); |
| return new WeakReference<ClassLoader>(shadowLoader); |
| } |
| |
| private static void fail(String why) { |
| System.out.println("FAILED: " + why); |
| failure = why; |
| } |
| |
| private static String failure; |
| } |