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* 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.
*
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*/
/**
* @test
* @bug 8042235
* @summary redefining method used by multiple MethodHandles crashes VM
* @library /
* @modules java.base/jdk.internal.org.objectweb.asm
* java.compiler
* java.instrument
* java.management
* jdk.attach
*
* @run main/othervm compiler.jsr292.RedefineMethodUsedByMultipleMethodHandles
*/
package compiler.jsr292;
import jdk.internal.org.objectweb.asm.ClassReader;
import jdk.internal.org.objectweb.asm.ClassVisitor;
import jdk.internal.org.objectweb.asm.ClassWriter;
import jdk.internal.org.objectweb.asm.MethodVisitor;
import jdk.internal.org.objectweb.asm.Opcodes;
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.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodHandles.Lookup;
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.jar.Attributes;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;
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 = 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);
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;
}
}
}