| /* |
| * 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 TestMemBarAcquire |
| * @bug 8048879 |
| * @summary "Tests optimization of MemBarAcquireNodes" |
| * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation TestMemBarAcquire |
| */ |
| public class TestMemBarAcquire { |
| private volatile static Object defaultObj = new Object(); |
| private Object obj; |
| |
| public TestMemBarAcquire(Object param) { |
| // Volatile load. MemBarAcquireNode is added after the |
| // load to prevent following loads from floating up past. |
| // StoreNode is added to store result of load in 'obj'. |
| this.obj = defaultObj; |
| // Overrides 'obj' and therefore makes previous StoreNode |
| // and the corresponding LoadNode useless. However, the |
| // LoadNode is still connected to the MemBarAcquireNode |
| // that should now release the reference. |
| this.obj = param; |
| } |
| |
| public static void main(String[] args) throws Exception { |
| // Make sure TestMemBarAcquire::<init> is compiled |
| for (int i = 0; i < 100000; ++i) { |
| TestMemBarAcquire p = new TestMemBarAcquire(new Object()); |
| } |
| } |
| } |
| |