| /* |
| * 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. |
| */ |
| |
| package compiler.profiling.spectrapredefineclass; |
| |
| import com.sun.tools.attach.VirtualMachine; |
| import jdk.test.lib.Utils; |
| |
| import java.lang.instrument.ClassFileTransformer; |
| import java.lang.instrument.Instrumentation; |
| import java.lang.management.ManagementFactory; |
| import java.nio.file.Paths; |
| import java.security.ProtectionDomain; |
| |
| class A { |
| void m() { |
| } |
| } |
| |
| class B extends A { |
| void m() { |
| } |
| } |
| |
| class C extends A { |
| void m() { |
| } |
| } |
| |
| class Test { |
| |
| static public void m() throws Exception { |
| for (int i = 0; i < 20000; i++) { |
| m1(a); |
| } |
| for (int i = 0; i < 4; i++) { |
| m1(b); |
| } |
| } |
| |
| static boolean m1(A a) { |
| boolean res = Agent.m2(a); |
| return res; |
| } |
| |
| static public A a = new A(); |
| static public B b = new B(); |
| static public C c = new C(); |
| } |
| |
| public class Agent implements ClassFileTransformer { |
| public static final String AGENT_JAR = Paths.get(Utils.TEST_CLASSES, "agent.jar").toString(); |
| static public boolean m2(A a) { |
| boolean res = false; |
| if (a.getClass() == B.class) { |
| a.m(); |
| } else { |
| res = true; |
| } |
| return res; |
| } |
| |
| static public void main(String[] args) throws Exception { |
| // Create speculative trap entries |
| Test.m(); |
| |
| String nameOfRunningVM = ManagementFactory.getRuntimeMXBean().getName(); |
| int p = nameOfRunningVM.indexOf('@'); |
| String pid = nameOfRunningVM.substring(0, p); |
| |
| // Make the nmethod go away |
| for (int i = 0; i < 10; i++) { |
| System.gc(); |
| } |
| |
| // Redefine class |
| try { |
| VirtualMachine vm = VirtualMachine.attach(pid); |
| vm.loadAgent(AGENT_JAR, ""); |
| vm.detach(); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| |
| Test.m(); |
| // GC will hit dead method pointer |
| for (int i = 0; i < 10; i++) { |
| System.gc(); |
| } |
| } |
| |
| public synchronized byte[] transform(final ClassLoader classLoader, |
| final String className, |
| Class<?> classBeingRedefined, |
| ProtectionDomain protectionDomain, |
| byte[] classfileBuffer) { |
| System.out.println("Transforming class " + className); |
| return classfileBuffer; |
| } |
| |
| public static void redefine(String agentArgs, Instrumentation instrumentation, Class to_redefine) { |
| |
| try { |
| instrumentation.retransformClasses(to_redefine); |
| } catch (Exception e) { |
| e.printStackTrace(); |
| } |
| |
| } |
| |
| public static void agentmain(String agentArgs, Instrumentation instrumentation) throws Exception { |
| Agent transformer = new Agent(); |
| instrumentation.addTransformer(transformer, true); |
| |
| redefine(agentArgs, instrumentation, Test.class); |
| } |
| } |