| /* |
| * Copyright (c) 2011, 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 |
| * @requires vm.jvmci |
| * @library ../../../../../ |
| * @modules jdk.internal.vm.ci/jdk.vm.ci.meta |
| * jdk.internal.vm.ci/jdk.vm.ci.runtime |
| * jdk.attach |
| * java.base/jdk.internal.misc |
| * @run junit/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI -Djvmci.Compiler=null jdk.vm.ci.runtime.test.RedefineClassTest |
| */ |
| |
| package jdk.vm.ci.runtime.test; |
| |
| import jdk.vm.ci.meta.ResolvedJavaMethod; |
| import org.junit.Assert; |
| import org.junit.Test; |
| |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.lang.instrument.ClassFileTransformer; |
| import java.lang.instrument.IllegalClassFormatException; |
| import java.lang.instrument.Instrumentation; |
| import java.lang.management.ManagementFactory; |
| import java.lang.reflect.Method; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| import java.security.ProtectionDomain; |
| import java.util.Arrays; |
| import java.util.jar.Attributes; |
| import java.util.jar.JarEntry; |
| import java.util.jar.JarOutputStream; |
| import java.util.jar.Manifest; |
| |
| import static org.junit.Assume.assumeTrue; |
| |
| /** |
| * Tests that {@link ResolvedJavaMethod}s are safe in the context of class redefinition being used |
| * to redefine the method to which they refer. |
| */ |
| public class RedefineClassTest extends TypeUniverse { |
| |
| static class Foo { |
| public static Object getName() { |
| return "foo"; |
| } |
| } |
| |
| @Test |
| public void test() throws Throwable { |
| |
| Method fooMethod = Foo.class.getDeclaredMethod("getName"); |
| |
| ResolvedJavaMethod foo1 = metaAccess.lookupJavaMethod(fooMethod); |
| ResolvedJavaMethod foo2 = metaAccess.lookupJavaMethod(fooMethod); |
| |
| String foo1Code = Arrays.toString(foo1.getCode()); |
| String foo2Code = Arrays.toString(foo2.getCode()); |
| |
| Assert.assertEquals("foo", Foo.getName()); |
| |
| redefineFoo(); |
| System.gc(); |
| |
| // Make sure the transformation happened |
| Assert.assertEquals("bar", Foo.getName()); |
| |
| Assert.assertEquals(foo1Code, Arrays.toString(foo1.getCode())); |
| Assert.assertEquals(foo2Code, Arrays.toString(foo1.getCode())); |
| } |
| |
| /** |
| * Adds the class file bytes for a given class to a JAR stream. |
| */ |
| static void add(JarOutputStream jar, Class<?> c) throws IOException { |
| String name = c.getName(); |
| String classAsPath = name.replace('.', '/') + ".class"; |
| jar.putNextEntry(new JarEntry(classAsPath)); |
| |
| InputStream stream = c.getClassLoader().getResourceAsStream(classAsPath); |
| |
| int nRead; |
| byte[] buf = new byte[1024]; |
| while ((nRead = stream.read(buf, 0, buf.length)) != -1) { |
| jar.write(buf, 0, nRead); |
| } |
| |
| jar.closeEntry(); |
| } |
| |
| protected void redefineFoo() throws Exception { |
| Manifest manifest = new Manifest(); |
| manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0"); |
| Attributes mainAttrs = manifest.getMainAttributes(); |
| mainAttrs.putValue("Agent-Class", FooAgent.class.getName()); |
| mainAttrs.putValue("Can-Redefine-Classes", "true"); |
| mainAttrs.putValue("Can-Retransform-Classes", "true"); |
| |
| Path jar = Files.createTempFile("myagent", ".jar"); |
| try { |
| JarOutputStream jarStream = new JarOutputStream(new FileOutputStream(jar.toFile()), manifest); |
| add(jarStream, FooAgent.class); |
| add(jarStream, FooTransformer.class); |
| jarStream.close(); |
| |
| loadAgent(jar); |
| } finally { |
| Files.deleteIfExists(jar); |
| } |
| } |
| |
| public static void loadAgent(Path agent) throws Exception { |
| String vmName = ManagementFactory.getRuntimeMXBean().getName(); |
| int p = vmName.indexOf('@'); |
| assumeTrue(p != -1); |
| String pid = vmName.substring(0, p); |
| ClassLoader cl = ClassLoader.getSystemClassLoader(); |
| Class<?> c = Class.forName("com.sun.tools.attach.VirtualMachine", true, cl); |
| Method attach = c.getDeclaredMethod("attach", String.class); |
| Method loadAgent = c.getDeclaredMethod("loadAgent", String.class, String.class); |
| Method detach = c.getDeclaredMethod("detach"); |
| Object vm = attach.invoke(null, pid); |
| loadAgent.invoke(vm, agent.toString(), ""); |
| detach.invoke(vm); |
| } |
| |
| public static class FooAgent { |
| |
| public static void agentmain(@SuppressWarnings("unused") String args, Instrumentation inst) throws Exception { |
| if (inst.isRedefineClassesSupported() && inst.isRetransformClassesSupported()) { |
| inst.addTransformer(new FooTransformer(), true); |
| Class<?>[] allClasses = inst.getAllLoadedClasses(); |
| for (int i = 0; i < allClasses.length; i++) { |
| Class<?> c = allClasses[i]; |
| if (c == Foo.class) { |
| inst.retransformClasses(new Class<?>[]{c}); |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * This transformer replaces the first instance of the constant "foo" in the class file for |
| * {@link Foo} with "bar". |
| */ |
| static class FooTransformer implements ClassFileTransformer { |
| |
| @Override |
| public byte[] transform(ClassLoader cl, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException { |
| if (Foo.class.equals(classBeingRedefined)) { |
| String cf = new String(classfileBuffer); |
| int i = cf.indexOf("foo"); |
| Assert.assertTrue("cannot find \"foo\" constant in " + Foo.class.getSimpleName() + "'s class file", i > 0); |
| classfileBuffer[i] = 'b'; |
| classfileBuffer[i + 1] = 'a'; |
| classfileBuffer[i + 2] = 'r'; |
| } |
| return classfileBuffer; |
| } |
| } |
| } |