1 /* 2 * Copyright (c) 2011, 2015, 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 /** 25 * @test 26 * @requires (os.simpleArch == "x64" | os.simpleArch == "sparcv9") & os.arch != "aarch64" 27 * @compile RedefineClassTest.java TypeUniverse.java TestMetaAccessProvider.java 28 * @run junit/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI jdk.vm.ci.runtime.test.RedefineClassTest 29 */ 30 31 package jdk.vm.ci.runtime.test; 32 33 import static org.junit.Assume.*; 34 35 import java.io.*; 36 import java.lang.instrument.*; 37 import java.lang.management.*; 38 import java.lang.reflect.*; 39 import java.nio.file.*; 40 import java.security.*; 41 import java.util.*; 42 import java.util.jar.*; 43 44 import javax.tools.*; 45 46 import jdk.vm.ci.meta.*; 47 48 import org.junit.*; 49 50 /** 51 * Tests that {@link ResolvedJavaMethod}s are safe in the context of class redefinition being used 52 * to redefine the method to which they refer. 53 */ 54 public class RedefineClassTest extends TypeUniverse { 55 56 static class Foo { 57 public static Object getName() { 58 return "foo"; 59 } 60 } 61 62 @Test 63 public void test() throws Throwable { 64 65 Method fooMethod = Foo.class.getDeclaredMethod("getName"); 66 67 ResolvedJavaMethod foo1 = metaAccess.lookupJavaMethod(fooMethod); 68 ResolvedJavaMethod foo2 = metaAccess.lookupJavaMethod(fooMethod); 69 70 String foo1Code = Arrays.toString(foo1.getCode()); 71 String foo2Code = Arrays.toString(foo2.getCode()); 72 73 Assert.assertEquals("foo", Foo.getName()); 74 75 redefineFoo(); 76 System.gc(); 77 78 // Make sure the transformation happened 79 Assert.assertEquals("bar", Foo.getName()); 80 81 Assert.assertEquals(foo1Code, Arrays.toString(foo1.getCode())); 82 Assert.assertEquals(foo2Code, Arrays.toString(foo1.getCode())); 83 } 84 85 /** 86 * Adds the class file bytes for a given class to a JAR stream. 87 */ 88 static void add(JarOutputStream jar, Class<?> c) throws IOException { 89 String name = c.getName(); 90 String classAsPath = name.replace('.', '/') + ".class"; 91 jar.putNextEntry(new JarEntry(classAsPath)); 92 93 InputStream stream = c.getClassLoader().getResourceAsStream(classAsPath); 94 95 int nRead; 96 byte[] buf = new byte[1024]; 97 while ((nRead = stream.read(buf, 0, buf.length)) != -1) { 98 jar.write(buf, 0, nRead); 99 } 100 101 jar.closeEntry(); 102 } 103 104 protected void redefineFoo() throws Exception { 105 Manifest manifest = new Manifest(); 106 manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0"); 107 Attributes mainAttrs = manifest.getMainAttributes(); 108 mainAttrs.putValue("Agent-Class", FooAgent.class.getName()); 109 mainAttrs.putValue("Can-Redefine-Classes", "true"); 110 mainAttrs.putValue("Can-Retransform-Classes", "true"); 111 112 Path jar = Files.createTempFile("myagent", ".jar"); 113 try { 114 JarOutputStream jarStream = new JarOutputStream(new FileOutputStream(jar.toFile()), manifest); 115 add(jarStream, FooAgent.class); 116 add(jarStream, FooTransformer.class); 117 jarStream.close(); 118 119 loadAgent(jar); 120 } finally { 121 Files.deleteIfExists(jar); 122 } 123 } 124 125 public static void loadAgent(Path agent) throws Exception { 126 String vmName = ManagementFactory.getRuntimeMXBean().getName(); 127 int p = vmName.indexOf('@'); 128 assumeTrue(p != -1); 129 String pid = vmName.substring(0, p); 130 ClassLoader cl = ToolProvider.getSystemToolClassLoader(); 131 Class<?> c = Class.forName("com.sun.tools.attach.VirtualMachine", true, cl); 132 Method attach = c.getDeclaredMethod("attach", String.class); 133 Method loadAgent = c.getDeclaredMethod("loadAgent", String.class, String.class); 134 Method detach = c.getDeclaredMethod("detach"); 135 Object vm = attach.invoke(null, pid); 136 loadAgent.invoke(vm, agent.toString(), ""); 137 detach.invoke(vm); 138 } 139 140 public static class FooAgent { 141 142 public static void agentmain(@SuppressWarnings("unused") String args, Instrumentation inst) throws Exception { 143 if (inst.isRedefineClassesSupported() && inst.isRetransformClassesSupported()) { 144 inst.addTransformer(new FooTransformer(), true); 145 Class<?>[] allClasses = inst.getAllLoadedClasses(); 146 for (int i = 0; i < allClasses.length; i++) { 147 Class<?> c = allClasses[i]; 148 if (c == Foo.class) { 149 inst.retransformClasses(new Class<?>[]{c}); 150 } 151 } 152 } 153 } 154 } 155 156 /** 157 * This transformer replaces the first instance of the constant "foo" in the class file for 158 * {@link Foo} with "bar". 159 */ 160 static class FooTransformer implements ClassFileTransformer { 161 162 @Override 163 public byte[] transform(ClassLoader cl, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException { 164 if (Foo.class.equals(classBeingRedefined)) { 165 String cf = new String(classfileBuffer); 166 int i = cf.indexOf("foo"); 167 Assert.assertTrue("cannot find \"foo\" constant in " + Foo.class.getSimpleName() + "'s class file", i > 0); 168 classfileBuffer[i] = 'b'; 169 classfileBuffer[i + 1] = 'a'; 170 classfileBuffer[i + 2] = 'r'; 171 } 172 return classfileBuffer; 173 } 174 } 175 }