1 /* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import sun.hotspot.WhiteBox; 25 import sun.misc.IOUtils; 26 import sun.misc.Unsafe; 27 28 import java.io.IOException; 29 import java.lang.reflect.Method; 30 import java.net.URL; 31 import java.net.URLConnection; 32 33 /* 34 * @test TestAnonymousClassUnloading 35 * @bug 8054402 36 * @summary "Tests unloading of anonymous classes." 37 * @library /testlibrary /testlibrary/whitebox 38 * @compile TestAnonymousClassUnloading.java 39 * @run main ClassFileInstaller TestAnonymousClassUnloading 40 * sun.hotspot.WhiteBox 41 * sun.hotspot.WhiteBox$WhiteBoxPermission 42 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:-BackgroundCompilation TestAnonymousClassUnloading 43 */ 44 public class TestAnonymousClassUnloading { 45 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox(); 46 private static final Unsafe UNSAFE = Unsafe.getUnsafe(); 47 private static int COMP_LEVEL_SIMPLE = 1; 48 private static int COMP_LEVEL_FULL_OPTIMIZATION = 4; 49 50 /** 51 * We override hashCode here to be able to access this implementation 52 * via an Object reference (we cannot cast to TestAnonymousClassUnloading). 53 */ 54 @Override hashCode()55 public int hashCode() { 56 return 42; 57 } 58 59 /** 60 * Does some work by using the anonymousClass. 61 * @param anonymousClass Class performing some work (will be unloaded) 62 */ doWork(Class<?> anonymousClass)63 static private void doWork(Class<?> anonymousClass) throws InstantiationException, IllegalAccessException { 64 // Create a new instance 65 Object anon = anonymousClass.newInstance(); 66 // We would like to call a method of anonymousClass here but we cannot cast because the class 67 // was loaded by a different class loader. One solution would be to use reflection but since 68 // we want C2 to implement the call as an IC we call Object::hashCode() here which actually 69 // calls anonymousClass::hashCode(). C2 will then implement this call as an IC. 70 if (anon.hashCode() != 42) { 71 new RuntimeException("Work not done"); 72 } 73 } 74 75 /** 76 * Makes sure that method is compiled by forcing compilation if not yet compiled. 77 * @param m Method to be checked 78 */ makeSureIsCompiled(Method m)79 static private void makeSureIsCompiled(Method m) { 80 // Make sure background compilation is disabled 81 if (WHITE_BOX.getBooleanVMFlag("BackgroundCompilation")) { 82 throw new RuntimeException("Background compilation enabled"); 83 } 84 85 // Check if already compiled 86 if (!WHITE_BOX.isMethodCompiled(m)) { 87 // If not, try to compile it with C2 88 if(!WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_FULL_OPTIMIZATION)) { 89 // C2 compiler not available, try to compile with C1 90 WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_SIMPLE); 91 } 92 // Because background compilation is disabled, method should now be compiled 93 if(!WHITE_BOX.isMethodCompiled(m)) { 94 throw new RuntimeException(m + " not compiled"); 95 } 96 } 97 } 98 99 /** 100 * This test creates stale Klass* metadata referenced by a compiled IC. 101 * 102 * The following steps are performed: 103 * (1) An anonymous version of TestAnonymousClassUnloading is loaded by a custom class loader 104 * (2) The method doWork that calls a method of the anonymous class is compiled. The call 105 * is implemented as an IC referencing Klass* metadata of the anonymous class. 106 * (3) Unloading of the anonymous class is enforced. The IC now references dead metadata. 107 */ main(String[] args)108 static public void main(String[] args) throws Exception { 109 // (1) Load an anonymous version of this class using the corresponding Unsafe method 110 URL classUrl = TestAnonymousClassUnloading.class.getResource("TestAnonymousClassUnloading.class"); 111 URLConnection connection = classUrl.openConnection(); 112 113 int length = connection.getContentLength(); 114 byte[] classBytes = IOUtils.readAllBytes(connection.getInputStream()); 115 if (length != -1 && classBytes.length != length) { 116 throw new IOException("Expected:" + length + ", actual: " + classBytes.length); 117 } 118 119 Class<?> anonymousClass = UNSAFE.defineAnonymousClass(TestAnonymousClassUnloading.class, classBytes, null); 120 121 // (2) Make sure all paths of doWork are profiled and compiled 122 for (int i = 0; i < 100000; ++i) { 123 doWork(anonymousClass); 124 } 125 126 // Make sure doWork is compiled now 127 Method doWork = TestAnonymousClassUnloading.class.getDeclaredMethod("doWork", Class.class); 128 makeSureIsCompiled(doWork); 129 130 // (3) Throw away reference to anonymousClass to allow unloading 131 anonymousClass = null; 132 133 // Force garbage collection to trigger unloading of anonymousClass 134 // Dead metadata reference to anonymousClass triggers JDK-8054402 135 WHITE_BOX.fullGC(); 136 } 137 } 138