/*

 * 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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 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * Written by Doug Lea and Martin Buchholz with assistance from

 * members of JCP JSR-166 Expert Group and released to the public

 * domain, as explained at

 * http://creativecommons.org/publicdomain/zero/1.0/

 */

import java.lang.invoke.MethodHandles;

import java.lang.invoke.VarHandle;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.ForkJoinPool;

import java.util.concurrent.ForkJoinTask;

import java.util.concurrent.Future;

import java.util.stream.Stream;

import junit.framework.Test;

import junit.framework.TestSuite;

public class ForkJoinPool9Test extends JSR166TestCase {

    public static void main(String[] args) {

        main(suite(), args);

    }

    public static Test suite() {

        return new TestSuite(ForkJoinPool9Test.class);

    }

    /**

     * Check handling of common pool thread context class loader

     */

    public void testCommonPoolThreadContextClassLoader() throws Throwable {

        if (!testImplementationDetails) return;

        // Ensure common pool has at least one real thread

        String prop = System.getProperty(

            "java.util.concurrent.ForkJoinPool.common.parallelism");

        if ("0".equals(prop)) return;

        VarHandle CCL =

            MethodHandles.privateLookupIn(Thread.class, MethodHandles.lookup())

            .findVarHandle(Thread.class, "contextClassLoader", ClassLoader.class);

        ClassLoader systemClassLoader = ClassLoader.getSystemClassLoader();

        boolean haveSecurityManager = (System.getSecurityManager() != null);

        CountDownLatch runInCommonPoolStarted = new CountDownLatch(1);

        ClassLoader classLoaderDistinctFromSystemClassLoader

            = ClassLoader.getPlatformClassLoader();

        assertNotSame(classLoaderDistinctFromSystemClassLoader,

                      systemClassLoader);

        Runnable runInCommonPool = () -> {

            runInCommonPoolStarted.countDown();

            assertTrue(ForkJoinTask.inForkJoinPool());

            assertSame(ForkJoinPool.commonPool(), ForkJoinTask.getPool());

            Thread currentThread = Thread.currentThread();

            Stream.of(systemClassLoader, null).forEach(cl -> {

                    // should always be permitted, without effect

                    currentThread.setContextClassLoader(cl);

                });

            Stream.of(currentThread.getContextClassLoader(),

                      (ClassLoader) CCL.get(currentThread))

            .forEach(cl -> assertTrue(cl == systemClassLoader || cl == null));

            if (haveSecurityManager)

                assertThrows(

                    SecurityException.class,

                    () -> System.getProperty("foo"),

                    () -> currentThread.setContextClassLoader(

                        classLoaderDistinctFromSystemClassLoader));

            // TODO ?

//          if (haveSecurityManager

//              && Thread.currentThread().getClass().getSimpleName()

//                 .equals("InnocuousForkJoinWorkerThread"))

//              assertThrows(SecurityException.class, /* ?? */);

        };

        Future<?> f = ForkJoinPool.commonPool().submit(runInCommonPool);

        // Ensure runInCommonPool is truly running in the common pool,

        // by giving this thread no opportunity to "help" on get().

        await(runInCommonPoolStarted);

        assertNull(f.get());

    }

}