1 /*
   2  * Copyright (c) 2015, 2016, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  * @test TestStableMemoryBarrier
  28  * @bug 8139758
  29  * @summary tests memory barrier correctly inserted for stable fields
  30  * @modules java.base/jdk.internal.vm.annotation
  31  *
  32  * @run main/bootclasspath/othervm -Xcomp -XX:CompileOnly=::testCompile
  33  *                                 compiler.stable.TestStableMemoryBarrier
  34  *
  35  * @author hui.shi@linaro.org
  36  */
  37 
  38 package compiler.stable;
  39 
  40 import jdk.internal.vm.annotation.Stable;
  41 
  42 public class TestStableMemoryBarrier {
  43     public static void main(String[] args) throws Exception {
  44         for (int i = 0; i < 1000000; i++) {
  45             NotDominate.testCompile(i);
  46         }
  47     }
  48     /* ====================================================
  49      * Stable field initialized in method, but its allocation
  50      * doesn't dominate MemBar Release at the end of method.
  51      */
  52     private static class NotDominate {
  53         public @Stable int v;
  54         public static int[] array = new int[100];
  55 
  56         public static NotDominate testCompile(int n) {
  57             if ((n % 2) == 0) return null;
  58             // add a loop here, trigger PhaseIdealLoop::verify_dominance
  59             for (int i = 0; i < 100; i++) {
  60                 array[i] = n;
  61             }
  62             NotDominate nm = new NotDominate();
  63             nm.v = n;
  64             return nm;
  65         }
  66 
  67 
  68     }
  69 }
  70