Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * 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;

         }

     }

 }