| /* |
| * 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. |
| */ |
| |
| /** |
| * @test |
| * @bug 8042235 |
| * @summary redefining method used by multiple MethodHandles crashes VM |
| * @compile -XDignore.symbol.file RedefineMethodUsedByMultipleMethodHandles.java |
| * @run main RedefineMethodUsedByMultipleMethodHandles |
| */ |
| |
| import java.io.*; |
| import java.lang.instrument.*; |
| import java.lang.invoke.*; |
| import java.lang.invoke.MethodHandles.Lookup; |
| import java.lang.management.*; |
| import java.lang.reflect.*; |
| import java.nio.file.*; |
| import java.security.*; |
| import java.util.jar.*; |
| |
| import javax.tools.*; |
| |
| import jdk.internal.org.objectweb.asm.*; |
| |
| public class RedefineMethodUsedByMultipleMethodHandles { |
| |
| static class Foo { |
| public static Object getName() { |
| return "foo"; |
| } |
| } |
| |
| public static void main(String[] args) throws Throwable { |
| |
| Lookup lookup = MethodHandles.lookup(); |
| Method fooMethod = Foo.class.getDeclaredMethod("getName"); |
| |
| // fooMH2 displaces fooMH1 from the MemberNamesTable |
| MethodHandle fooMH1 = lookup.unreflect(fooMethod); |
| MethodHandle fooMH2 = lookup.unreflect(fooMethod); |
| |
| System.out.println("fooMH1.invoke = " + fooMH1.invokeExact()); |
| System.out.println("fooMH2.invoke = " + fooMH2.invokeExact()); |
| |
| // Redefining Foo.getName() causes vmtarget to be updated |
| // in fooMH2 but not fooMH1 |
| redefineFoo(); |
| |
| // Full GC causes fooMH1.vmtarget to be deallocated |
| System.gc(); |
| |
| // Calling fooMH1.vmtarget crashes the VM |
| System.out.println("fooMH1.invoke = " + fooMH1.invokeExact()); |
| } |
| |
| /** |
| * Adds the class file bytes for {@code c} to {@code jar}. |
| */ |
| static void add(JarOutputStream jar, Class<?> c) throws IOException { |
| String classAsPath = c.getName().replace('.', '/') + ".class"; |
| jar.putNextEntry(new JarEntry(classAsPath)); |
| InputStream stream = c.getClassLoader().getResourceAsStream(classAsPath); |
| |
| int b; |
| while ((b = stream.read()) != -1) { |
| jar.write(b); |
| } |
| } |
| |
| static 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(); |
| runAgent(jar); |
| } finally { |
| Files.deleteIfExists(jar); |
| } |
| } |
| |
| public static void runAgent(Path agent) throws Exception { |
| String vmName = ManagementFactory.getRuntimeMXBean().getName(); |
| int p = vmName.indexOf('@'); |
| assert p != -1 : "VM name not in <pid>@<host> format: " + vmName; |
| String pid = vmName.substring(0, p); |
| ClassLoader cl = ToolProvider.getSystemToolClassLoader(); |
| 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); |
| 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 { |
| assert inst.isRedefineClassesSupported(); |
| assert inst.isRetransformClassesSupported(); |
| inst.addTransformer(new FooTransformer(), true); |
| Class<?>[] classes = inst.getAllLoadedClasses(); |
| for (int i = 0; i < classes.length; i++) { |
| Class<?> c = classes[i]; |
| if (c == Foo.class) { |
| inst.retransformClasses(new Class[]{c}); |
| } |
| } |
| } |
| } |
| |
| 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)) { |
| System.out.println("redefining " + classBeingRedefined); |
| ClassReader cr = new ClassReader(classfileBuffer); |
| ClassWriter cw = new ClassWriter(cr, ClassWriter.COMPUTE_FRAMES); |
| ClassVisitor adapter = new ClassVisitor(Opcodes.ASM5, cw) { |
| @Override |
| public MethodVisitor visitMethod(int access, String base, String desc, String signature, String[] exceptions) { |
| MethodVisitor mv = cv.visitMethod(access, base, desc, signature, exceptions); |
| if (mv != null) { |
| mv = new MethodVisitor(Opcodes.ASM5, mv) { |
| @Override |
| public void visitLdcInsn(Object cst) { |
| System.out.println("replacing \"" + cst + "\" with \"bar\""); |
| mv.visitLdcInsn("bar"); |
| } |
| }; |
| } |
| return mv; |
| } |
| }; |
| |
| cr.accept(adapter, ClassReader.SKIP_FRAMES); |
| cw.visitEnd(); |
| return cw.toByteArray(); |
| } |
| return classfileBuffer; |
| } |
| } |
| } |