/* * 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 8032011 * @summary biased locking's revoke_bias locks monitor in compiled frame with eliminated lock * @run main/othervm -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestLockEliminatedAtDeopt$A.m2 -XX:-BackgroundCompilation -XX:BiasedLockingStartupDelay=0 TestLockEliminatedAtDeopt * */ public class TestLockEliminatedAtDeopt { static class A { void m() { } // This lock is not eliminated but biased to main thread on // first call synchronized void m2(boolean trap) { if (trap) { new B(); } } } static class B extends A { void m() { } } static void m1(boolean trap) { A a = new A(); // This lock is eliminated by c2 synchronized(a) { a.m2(trap); a.m(); } } public static void main(String[] args) { for (int i = 0; i < 20000; i++) { m1(false); } // Trigger uncommon trap in A.m2() (class unloaded) and // deoptimization of m1() (CHA invalidated). Uncommon trap // code locks monitor in m1's frame where's it's eliminated. m1(true); } }