/*

 * 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

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 */

/*

 * @test

 * @bug 8019623

 * @summary Tests that AppContext.getAppContext() works correctly in multi-threads scenario.

 * @author Leonid Romanov

 */

import sun.awt.AppContext;

public class MultiThreadTest {

    private static final int NUM_THREADS = 2;

    private static AppContextGetter[] getters = new AppContextGetter[NUM_THREADS];

    public static void main(String[] args) {

        createAndStartThreads();

        compareAppContexts();

    }

    private static void createAndStartThreads() {

        ThreadGroup systemGroup = getSystemThreadGroup();

        for (int i = 0; i < NUM_THREADS; ++i) {

            ThreadGroup tg = new ThreadGroup(systemGroup, "AppContextGetter" + i);

            getters[i] = new AppContextGetter(tg);

        }

        for (int i = 0; i < NUM_THREADS; ++i) {

            getters[i].start();

        }

        for (int i = 0; i < NUM_THREADS; ++i) {

            try {

                getters[i].join();

            } catch (InterruptedException e) {

                // ignore

            }

        }

    }

    private static ThreadGroup getSystemThreadGroup() {

        ThreadGroup currentThreadGroup =

                Thread.currentThread().getThreadGroup();

        ThreadGroup parentThreadGroup = currentThreadGroup.getParent();

        while (parentThreadGroup != null) {

            currentThreadGroup = parentThreadGroup;

            parentThreadGroup = currentThreadGroup.getParent();

        }

        return currentThreadGroup;

    }

    private static void compareAppContexts() {

        AppContext ctx = getters[0].getAppContext();

        for (int i = 1; i < NUM_THREADS; ++i) {

            if (!ctx.equals(getters[i].getAppContext())) {

                throw new RuntimeException("Unexpected AppContexts difference, could be a race condition");

            }

        }

    }

    private static class AppContextGetter extends Thread {

        private AppContext appContext;

        public AppContextGetter(ThreadGroup tg) {

            super(tg, tg.getName());

        }

        AppContext getAppContext() {

            return appContext;

        }

        @Override

        public void run() {

            appContext = AppContext.getAppContext();

        }

    }

}