/*

 * 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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 */

/**

 * @test

 * @bug 4176355 7181748

 * @summary Suspending a ThreadGroup that contains the current thread has

 *          unpredictable results.

 */

public class Suspend implements Runnable {

    private static volatile int count = 0;

    private static final ThreadGroup group = new ThreadGroup("");

    private static final Thread first = new Thread(group, new Suspend());

    private static final Thread second = new Thread(group, new Suspend());

    public void run() {

        while (true) {

            try {

                Thread.sleep(100);

                if (Thread.currentThread() == first) {

                    if (second.isAlive()) {

                        group.suspend();

                    }

                } else {

                    count++;

                }

            } catch (InterruptedException e) {

            }

        }

    }

    public static void main(String[] args) throws Exception {

        // Launch two threads as part of the same thread group

        first.start();

        second.start();

        // Wait for the thread group suspend to be issued

        while (!first.isAlive() || !second.isAlive()) {

            Thread.sleep(100);

        }

        Thread.sleep(1000);

        // Suppose, the thread group is now suspended

        count = 0;

        Thread.sleep(1000);

        // Increment of the count indicates that the second thread is still running

        boolean failed = (count > 1);

        first.stop();

        second.stop();

        if (failed) {

            throw new RuntimeException("Failure.");

        }

    }

}