| /* |
| * Copyright (c) 2014, 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. |
| */ |
| |
| import sun.hotspot.WhiteBox; |
| |
| import java.lang.reflect.Method; |
| import java.net.URL; |
| import java.net.URLClassLoader; |
| |
| /* |
| * @test MethodUnloadingTest |
| * @bug 8029443 |
| * @summary "Tests the unloading of methods to to class unloading" |
| * @library /testlibrary /testlibrary/whitebox |
| * @build TestMethodUnloading |
| * @build WorkerClass |
| * @run main ClassFileInstaller sun.hotspot.WhiteBox |
| * @run main/othervm -Xbootclasspath/a:. -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:-BackgroundCompilation -XX:-UseCompressedOops -XX:CompileOnly=TestMethodUnloading::doWork TestMethodUnloading |
| */ |
| public class TestMethodUnloading { |
| private static final String workerClassName = "WorkerClass"; |
| private static int work = -1; |
| |
| private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox(); |
| private static int COMP_LEVEL_SIMPLE = 1; |
| private static int COMP_LEVEL_FULL_OPTIMIZATION = 4; |
| |
| /** |
| * Does some work by either using the workerClass or locally producing values. |
| * @param workerClass Class performing some work (will be unloaded) |
| * @param useWorker If true the workerClass is used |
| */ |
| static private void doWork(Class<?> workerClass, boolean useWorker) throws InstantiationException, IllegalAccessException { |
| if (useWorker) { |
| // Create a new instance |
| Object worker = workerClass.newInstance(); |
| // We would like to call a method of WorkerClass here but we cannot cast to WorkerClass |
| // 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 optimized IC we call |
| // Object::hashCode() here which actually calls WorkerClass::hashCode(). |
| // C2 will then implement this call as an optimized IC that points to a to-interpreter stub |
| // referencing the Method* for WorkerClass::hashCode(). |
| work = worker.hashCode(); |
| if (work != 42) { |
| new RuntimeException("Work not done"); |
| } |
| } else { |
| // Do some important work here |
| work = 1; |
| } |
| } |
| |
| /** |
| * 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 Method* metadata in a to-interpreter stub of an optimized IC. |
| * |
| * The following steps are performed: |
| * (1) A workerClass is loaded by a custom class loader |
| * (2) The method doWork that calls a method of the workerClass is compiled. The call |
| * is implemented as an optimized IC calling a to-interpreted stub. The to-interpreter |
| * stub contains a Method* to a workerClass method. |
| * (3) Unloading of the workerClass is enforced. The to-interpreter stub now contains a dead Method*. |
| * (4) Depending on the implementation of the IC, the compiled version of doWork should still be |
| * valid. We call it again without using the workerClass. |
| */ |
| static public void main(String[] args) throws Exception { |
| // (1) Create a custom class loader with no parent class loader |
| URL url = TestMethodUnloading.class.getProtectionDomain().getCodeSource().getLocation(); |
| URLClassLoader loader = new URLClassLoader(new URL[] {url}, null); |
| |
| // Load worker class with custom class loader |
| Class<?> workerClass = Class.forName(workerClassName, true, loader); |
| |
| // (2) Make sure all paths of doWork are profiled and compiled |
| for (int i = 0; i < 100000; ++i) { |
| doWork(workerClass, true); |
| doWork(workerClass, false); |
| } |
| |
| // Make sure doWork is compiled now |
| Method doWork = TestMethodUnloading.class.getDeclaredMethod("doWork", Class.class, boolean.class); |
| makeSureIsCompiled(doWork); |
| |
| // (3) Throw away class loader and reference to workerClass to allow unloading |
| loader.close(); |
| loader = null; |
| workerClass = null; |
| |
| // Force garbage collection to trigger unloading of workerClass |
| // Dead reference to WorkerClass::hashCode triggers JDK-8029443 |
| WHITE_BOX.fullGC(); |
| |
| // (4) Depending on the implementation of the IC, the compiled version of doWork |
| // may still be valid here. Execute it without a workerClass. |
| doWork(null, false); |
| if (work != 1) { |
| throw new RuntimeException("Work not done"); |
| } |
| |
| doWork(Object.class, false); |
| } |
| } |