1 /*
   2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 8032011
  27  * @summary biased locking's revoke_bias locks monitor in compiled frame with eliminated lock
  28  *
  29  * @run main/othervm -XX:-UseOnStackReplacement
  30  *      -XX:CompileCommand=dontinline,compiler.uncommontrap.TestLockEliminatedAtDeopt$A::m2
  31  *      -XX:-BackgroundCompilation -XX:BiasedLockingStartupDelay=0
  32  *      compiler.uncommontrap.TestLockEliminatedAtDeopt
  33  */
  34 
  35 package compiler.uncommontrap;
  36 
  37 public class TestLockEliminatedAtDeopt {
  38 
  39     static class A {
  40         void m() {
  41         }
  42 
  43         // This lock is not eliminated but biased to main thread on
  44         // first call
  45         synchronized void m2(boolean trap) {
  46             if (trap) {
  47                 new B();
  48             }
  49         }
  50     }
  51 
  52     static class B extends A {
  53         void m() {
  54         }
  55     }
  56 
  57     static void m1(boolean trap) {
  58         A a = new A();
  59         // This lock is eliminated by c2
  60         synchronized(a) {
  61             a.m2(trap);
  62             a.m();
  63         }
  64     }
  65 
  66      public static void main(String[] args) {
  67         for (int i = 0; i < 20000; i++) {
  68             m1(false);
  69         }
  70         // Trigger uncommon trap in A.m2() (class unloaded) and
  71         // deoptimization of m1() (CHA invalidated). Uncommon trap
  72         // code locks monitor in m1's frame where's it's eliminated.
  73         m1(true);
  74     }
  75 }