0N/A/*
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0N/A * published by the Free Software Foundation.
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0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
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0N/A * 2 along with this work; if not, write to the Free Software Foundation,
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0N/A *
2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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0N/A */
0N/A
0N/A/* @test
0N/A * @bug 6482247
0N/A * @summary Test that creating MXBeans does not introduce memory leaks.
0N/A * @author Eamonn McManus
469N/A * @run build LeakTest RandomMXBeanTest
0N/A * @run main LeakTest
0N/A */
0N/A
0N/A/* In this test we create a ClassLoader, then use it to load and run another
0N/A * jtreg test. When the other test has completed, we wait for the ClassLoader
0N/A * to be garbage-collected. If it has not been gc'd after a reasonable
0N/A * amount of time, then something is keeping a reference to the ClassLoader,
0N/A * which implies a memory leak.
0N/A *
0N/A * This test can be applied to any jtreg test, not just the MXBean tests.
0N/A */
0N/A
0N/Aimport java.lang.ref.Reference;
0N/Aimport java.lang.ref.ReferenceQueue;
0N/Aimport java.lang.ref.WeakReference;
0N/Aimport java.lang.reflect.Method;
0N/Aimport java.net.URL;
0N/Aimport java.net.URLClassLoader;
0N/A
0N/Apublic class LeakTest {
0N/A /* Ideally we would include MXBeanTest in the list of tests, since it
0N/A * has fairly complete coverage. However, the ClassLoader fails to be
0N/A * gc'd when we do that, and I am unable to figure out why. Examining
0N/A * a heap dump shows only weak references to the ClassLoader. I suspect
0N/A * something is wrong in the internals of the reflection classes, used
0N/A * quite heavily by MXBeanTest.
0N/A */
0N/A// private static Class<?>[] otherTests = {MXBeanTest.class};
0N/A
0N/A private static Class<?>[] otherTests = {RandomMXBeanTest.class};
0N/A
0N/A // This class just makes it easier for us to spot our loader in heap dumps
0N/A private static class ShadowClassLoader extends URLClassLoader {
0N/A ShadowClassLoader(URL[] urls, ClassLoader parent) {
0N/A super(urls, parent);
0N/A }
0N/A }
0N/A
0N/A public static void main(String[] args) throws Exception {
0N/A System.out.println("Testing that no references are held to ClassLoaders " +
0N/A "by caches in the MXBean infrastructure");
0N/A for (Class<?> testClass : otherTests)
0N/A test(testClass);
0N/A if (failure != null)
0N/A throw new Exception("CLASSLOADER LEAK TEST FAILED: " + failure);
0N/A System.out.println("CLASSLOADER LEAK TEST PASSED");
0N/A if (args.length > 0) {
0N/A System.out.println("Waiting for input");
0N/A System.in.read();
0N/A }
0N/A }
0N/A
0N/A private static void test(Class<?> originalTestClass) throws Exception {
0N/A System.out.println();
0N/A System.out.println("TESTING " + originalTestClass.getName());
0N/A WeakReference<ClassLoader> wr = testShadow(originalTestClass);
0N/A System.out.println("Test passed, waiting for ClassLoader to disappear");
0N/A long deadline = System.currentTimeMillis() + 20*1000;
0N/A Reference<? extends ClassLoader> ref;
0N/A while (wr.get() != null && System.currentTimeMillis() < deadline) {
0N/A System.gc();
0N/A Thread.sleep(100);
0N/A }
0N/A if (wr.get() != null)
0N/A fail(originalTestClass.getName() + " kept ClassLoader reference");
0N/A }
0N/A
0N/A private static WeakReference<ClassLoader>
0N/A testShadow(Class<?> originalTestClass) throws Exception {
0N/A URLClassLoader originalLoader =
0N/A (URLClassLoader) originalTestClass.getClassLoader();
0N/A URL[] urls = originalLoader.getURLs();
0N/A URLClassLoader shadowLoader =
0N/A new ShadowClassLoader(urls, originalLoader.getParent());
0N/A System.out.println("Shadow loader is " + shadowLoader);
0N/A String className = originalTestClass.getName();
0N/A Class<?> testClass = Class.forName(className, false, shadowLoader);
0N/A if (testClass.getClassLoader() != shadowLoader) {
0N/A throw new IllegalArgumentException("Loader didn't work: " +
0N/A testClass.getClassLoader() + " != " + shadowLoader);
0N/A }
0N/A Method main = testClass.getMethod("main", String[].class);
0N/A main.invoke(null, (Object) new String[0]);
0N/A return new WeakReference<ClassLoader>(shadowLoader);
0N/A }
0N/A
0N/A private static void fail(String why) {
0N/A System.out.println("FAILED: " + why);
0N/A failure = why;
0N/A }
0N/A
0N/A private static String failure;
0N/A}