| /* |
| * Copyright (c) 2014, 2016, 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 TestAnonymousClassUnloading |
| * @bug 8054402 |
| * @summary "Tests unloading of anonymous classes." |
| * @library /test/lib / |
| * @modules java.base/jdk.internal.misc |
| * |
| * @run main/othervm/bootclasspath -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI |
| * -XX:-BackgroundCompilation |
| * compiler.classUnloading.anonymousClass.TestAnonymousClassUnloading |
| */ |
| |
| package compiler.classUnloading.anonymousClass; |
| |
| import jdk.internal.misc.Unsafe; |
| import sun.hotspot.WhiteBox; |
| |
| import java.io.IOException; |
| import java.lang.reflect.Method; |
| import java.net.URL; |
| import java.net.URLConnection; |
| |
| public class TestAnonymousClassUnloading { |
| private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox(); |
| private static final Unsafe UNSAFE = Unsafe.getUnsafe(); |
| private static int COMP_LEVEL_SIMPLE = 1; |
| private static int COMP_LEVEL_FULL_OPTIMIZATION = 4; |
| |
| /** |
| * We override hashCode here to be able to access this implementation |
| * via an Object reference (we cannot cast to TestAnonymousClassUnloading). |
| */ |
| @Override |
| public int hashCode() { |
| return 42; |
| } |
| |
| /** |
| * Does some work by using the anonymousClass. |
| * @param anonymousClass Class performing some work (will be unloaded) |
| */ |
| static private void doWork(Class<?> anonymousClass) throws InstantiationException, IllegalAccessException { |
| // Create a new instance |
| Object anon = anonymousClass.newInstance(); |
| // We would like to call a method of anonymousClass here but we cannot cast because the class |
| // was loaded by a different class loader. One solution would be to use reflection but since |
| // we want C2 to implement the call as an IC we call Object::hashCode() here which actually |
| // calls anonymousClass::hashCode(). C2 will then implement this call as an IC. |
| if (anon.hashCode() != 42) { |
| new RuntimeException("Work not done"); |
| } |
| } |
| |
| /** |
| * Makes sure that method is compiled by forcing compilation if not yet compiled. |
| * @param m Method to be checked |
| */ |
| static private void makeSureIsCompiled(Method m) { |
| // Make sure background compilation is disabled |
| if (WHITE_BOX.getBooleanVMFlag("BackgroundCompilation")) { |
| throw new RuntimeException("Background compilation enabled"); |
| } |
| |
| // Check if already compiled |
| if (!WHITE_BOX.isMethodCompiled(m)) { |
| // If not, try to compile it with C2 |
| if(!WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_FULL_OPTIMIZATION)) { |
| // C2 compiler not available, try to compile with C1 |
| WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_SIMPLE); |
| } |
| // Because background compilation is disabled, method should now be compiled |
| if(!WHITE_BOX.isMethodCompiled(m)) { |
| throw new RuntimeException(m + " not compiled"); |
| } |
| } |
| } |
| |
| /** |
| * This test creates stale Klass* metadata referenced by a compiled IC. |
| * |
| * The following steps are performed: |
| * (1) An anonymous version of TestAnonymousClassUnloading is loaded by a custom class loader |
| * (2) The method doWork that calls a method of the anonymous class is compiled. The call |
| * is implemented as an IC referencing Klass* metadata of the anonymous class. |
| * (3) Unloading of the anonymous class is enforced. The IC now references dead metadata. |
| */ |
| static public void main(String[] args) throws Exception { |
| // (1) Load an anonymous version of this class using the corresponding Unsafe method |
| URL classUrl = TestAnonymousClassUnloading.class.getResource( |
| TestAnonymousClassUnloading.class.getName().replace('.', '/') + ".class"); |
| URLConnection connection = classUrl.openConnection(); |
| |
| int length = connection.getContentLength(); |
| byte[] classBytes = connection.getInputStream().readAllBytes(); |
| if (length != -1 && classBytes.length != length) { |
| throw new IOException("Expected:" + length + ", actual: " + classBytes.length); |
| } |
| |
| Class<?> anonymousClass = UNSAFE.defineAnonymousClass(TestAnonymousClassUnloading.class, classBytes, null); |
| |
| // (2) Make sure all paths of doWork are profiled and compiled |
| for (int i = 0; i < 100000; ++i) { |
| doWork(anonymousClass); |
| } |
| |
| // Make sure doWork is compiled now |
| Method doWork = TestAnonymousClassUnloading.class.getDeclaredMethod("doWork", Class.class); |
| makeSureIsCompiled(doWork); |
| |
| // (3) Throw away reference to anonymousClass to allow unloading |
| anonymousClass = null; |
| |
| // Force garbage collection to trigger unloading of anonymousClass |
| // Dead metadata reference to anonymousClass triggers JDK-8054402 |
| WHITE_BOX.fullGC(); |
| } |
| } |