| /* |
| * Copyright (c) 2016, 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 8159244 |
| * @summary Verifies that no partially initialized String object escapes from |
| * C2's String concat optimization in a highly concurrent setting. |
| * This test triggers the bug in about 1 out of 10 runs. |
| * @requires vm.gc == "Parallel" | vm.gc == "null" |
| * |
| * @compile -XDstringConcat=inline TestStringObjectInitialization.java |
| * @run main/othervm/timeout=300 -XX:+IgnoreUnrecognizedVMOptions -XX:-UseCompressedOops -XX:-CompactStrings |
| * -XX:-UseG1GC -XX:+UseParallelGC |
| * compiler.stringopts.TestStringObjectInitialization |
| */ |
| |
| package compiler.stringopts; |
| |
| import java.util.Arrays; |
| |
| public class TestStringObjectInitialization { |
| |
| String myString; |
| |
| public static void main(String[] args) throws Exception { |
| TestStringObjectInitialization t = new TestStringObjectInitialization(); |
| // Create some threads that concurrently update 'myString' |
| for (int i = 0; i < 100; ++i) { |
| (new Thread(new Runner(t))).start(); |
| } |
| Thread last = new Thread(new Runner(t)); |
| last.start(); |
| last.join(); |
| } |
| |
| private void add(String message) { |
| // String escapes to other threads here |
| myString += message; |
| } |
| |
| public void run(String s, String[] sArray) { |
| // Trigger C2's string concatenation optimization |
| add(s + Arrays.toString(sArray) + " const "); |
| } |
| |
| public void reset() { |
| // Reset string to avoid OOMEs |
| myString = ""; |
| } |
| |
| private static class Runner implements Runnable { |
| private TestStringObjectInitialization test; |
| |
| public Runner(TestStringObjectInitialization t) { |
| test = t; |
| } |
| |
| public void run() { |
| String[] array = {"a", "b", "c"}; |
| for (int i = 0; i < 100_000; ++i) { |
| test.run("a", array); |
| test.reset(); |
| } |
| } |
| } |
| } |
| |