/*

 * Copyright (c) 2015, 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

 * questions.

 */

import java.util.concurrent.CountDownLatch;

import jdk.test.lib.dcmd.CommandExecutor;

import jdk.test.lib.dcmd.JMXExecutor;

public class FinalizationRunner {

    public static final String FAILED = "Failed";

    public static final String PASSED = "Passed";

    static volatile boolean wasFinalized = false;

    private static final CountDownLatch finRunLatch = new CountDownLatch(1);

    private static final CountDownLatch finBlockLatch = new CountDownLatch(1);

    static class MyObject {

        @Override

        protected void finalize() {

            if (Thread.currentThread().getName().equals("Finalizer")) {

                try {

                    System.out.println("inside the regular finalizer thread; blocking");

                    // 'regular' finalizer thread is ready to be effectively blocked -

                    //    we can continue with the GC.run_finalization test

                    finRunLatch.countDown();

                    // prevent the 'regular' finalizer from finalizing this instance

                    // until the GC.run_finalization has had its chance to do so

                    finBlockLatch.await();

                } catch (InterruptedException e) {

                }

            } else {

                if (Thread.currentThread().getName().equals("Secondary finalizer")) {

                    System.out.println("finalizing the test instance");

                    // finalizing on behalf of GC.run_finalization -

                    //   unblock the 'regular' finalizer and the test main method

                    wasFinalized = true;

                } else {

                    fail("Unexpected finalizer thread name: " +

                            Thread.currentThread().getName());

                }

                finBlockLatch.countDown();

            }

        }

    }

    // this instance will be used to provoke the regular finalization

    // so the finalizer thread can be blocked for the duration of

    // GC.run_finalization test

    public static MyObject o1;

    // this instance will be used to perform the GC.run_finalization test

    public static MyObject o2;

    private static void run(CommandExecutor executor) {

        o2 = new MyObject();

        o2 = null;

        System.out.println("running GC.run_finalization");

        System.gc();

        executor.execute("GC.run_finalization");

        System.out.println("Waiting for finalization");

        try {

            finBlockLatch.await();

            if (wasFinalized) {

                System.out.println(PASSED + ": Object was finalized");

            } else {

                fail("Object was not finalized");

            }

        } catch (InterruptedException e) {

            fail("Interrupted while waiting for finalization", e);

        }

    }

    public static void main(String ... args) {

        System.out.println("\n=== FinalizationRunner");

        try {

            blockFinalizerThread();

            Runtime.getRuntime().addShutdownHook(new Thread(()->{

                run(new JMXExecutor());

            }));

        } catch (InterruptedException e) {

            fail("Interrupted while trying to block the finalizer thread", e);

        }

    }

    private static void blockFinalizerThread() throws InterruptedException {

        System.out.println("trying to block the finalizer thread");

        o1 = new MyObject();

        o1 = null;

        System.gc();

        finRunLatch.await();

    }

    private static void fail(String msg, Exception e) {

        fail(msg);

        e.printStackTrace(System.err);

    }

    private static void fail(String msg) {

        System.err.println(FAILED + ": " + msg);

    }

}