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 * 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

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 */

import java.util.Arrays;

/*

 * @test

 * @bug 8159244

 * @requires vm.gc == "Parallel" | vm.gc == "null"

 * @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.

 * @compile -XDstringConcat=inline TestStringObjectInitialization.java

 * @run main/othervm/timeout=300 -XX:+IgnoreUnrecognizedVMOptions -XX:-UseCompressedOops -XX:-CompactStrings

 *                               -XX:-UseG1GC -XX:+UseParallelGC TestStringObjectInitialization

 */

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 ");

    }

}

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 < 10000; ++i) {

            test.run("a", array);

        }

    }

}