/*

 * Copyright (c) 2018, 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

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 */

import java.io.IOException;

import java.lang.reflect.*;

import java.net.URL;

import java.net.URLConnection;

import java.net.URLStreamHandler;

import java.util.concurrent.CountDownLatch;

/*

 * @test

 * @bug 8213942

 * @summary URLStreamHandler initialization race

 * @run main/othervm RacyHandler

 * @run main/othervm RacyHandler

 * @run main/othervm RacyHandler

 */

/*

 * This test makes reasonable effort to reproduce the race.

 * Run repeatedly to ensure correctness.

 */

public class RacyHandler {

    static volatile boolean factorySet = false;

    static int NUM_THREADS = 2;

    static CountDownLatch cdl = new CountDownLatch(NUM_THREADS + 1);

    public static void main(String[] args) {

        RacyHandler tester = new RacyHandler();

        tester.runTest();

    }

    public void runTest() {

        new Thread(() -> {

            try {

                cdl.await();

                URL.setURLStreamHandlerFactory(proto -> new CustomHttpHandler());

                factorySet = true;

            } catch (Exception ignore) { }

        }).start();

        cdl.countDown();

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

            new Thread(() -> {

                try {

                    cdl.await();

                    while (!factorySet) {

                        // trigger URL class load

                        getURLStreamHandler();

                    }

                } catch (Exception ignore) { }

            }).start();

            cdl.countDown();

        }

        // wait for the factory to be set

        while (!factorySet) { }

        // The sleep seems to help trigger the failure

        try {

            Thread.sleep(500);

        } catch (InterruptedException ie) {

        }

        URLStreamHandler httpHandler = getURLStreamHandler();

        System.out.println("After setting factory URL handlers: http " + httpHandler);

        if (!(httpHandler instanceof CustomHttpHandler))

            throw new RuntimeException("FAILED: Incorrect handler type");

    }

    /*

     * This is just so we can see what we get for the URLStreamHandler back

     * from the factory to verify whether it really is using our Handler

     * or something else...

     */

    public URLStreamHandler getURLStreamHandler() {

        try {

            Method method = URL.class.getDeclaredMethod("getURLStreamHandler",

                    String.class);

            method.setAccessible(true);

            return (URLStreamHandler) method.invoke(null, "http");

        } catch (Exception e) {

            return null;

        }

    }

    class CustomHttpHandler extends URLStreamHandler {

        @Override

        protected URLConnection openConnection(URL u) throws IOException {

            return null;

        }

    }