/*

 * Copyright (c) 2004, 2019, 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.

 */

package nsk.jvmti.scenarios.contention.TC04;

import java.io.PrintStream;

import java.util.concurrent.*;

import nsk.share.*;

import nsk.share.jvmti.*;

public class tc04t001 extends DebugeeClass {

    final static int THREADS_LIMIT = 2;

    final static CountDownLatch threadsDoneSignal = new CountDownLatch(THREADS_LIMIT);

    // run test from command line

    public static void main(String argv[]) {

        argv = nsk.share.jvmti.JVMTITest.commonInit(argv);

        // JCK-compatible exit

        System.exit(run(argv, System.out) + Consts.JCK_STATUS_BASE);

    }

    // run test from JCK-compatible environment

    public static int run(String argv[], PrintStream out) {

        return new tc04t001().runIt(argv, out);

    }

    /* =================================================================== */

    // scaffold objects

    ArgumentHandler argHandler = null;

    Log log = null;

    int status = Consts.TEST_PASSED;

    long timeout = 0;

    // run debuggee

    public int runIt(String argv[], PrintStream out) {

        argHandler = new ArgumentHandler(argv);

        log = new Log(out, argHandler);

        timeout = argHandler.getWaitTime() * 60 * 1000;

        log.display("Timeout = " + timeout + " msc.");

        tc04t001Thread threads[] = new tc04t001Thread[THREADS_LIMIT];

        status = checkStatus(status);

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

            threads[i] = new tc04t001Thread(i);

            threads[i].start();

        }

        try {

            if (!threadsDoneSignal.await(timeout, TimeUnit.MILLISECONDS)) {

                throw new RuntimeException("Threads timeout");

            }

        } catch (InterruptedException e) {

            throw new Failure(e);

        }

        status = checkStatus(status);

        log.display("Debugee finished, value: " + tc04t001Thread.value);

        if (tc04t001Thread.value !=

                THREADS_LIMIT*tc04t001Thread.INCREMENT_LIMIT) {

            log.complain("Wrong value: " + tc04t001Thread.value +

                ", expected: " + THREADS_LIMIT*tc04t001Thread.INCREMENT_LIMIT);

            status = Consts.TEST_FAILED;

        }

        return status;

    }

}

/* =================================================================== */

class tc04t001Thread extends Thread {

    final static int INCREMENT_LIMIT = 100;

    final static int DELAY = 1000;

    static volatile int value = 0;

    static Flicker flicker = new Flicker();

    private int id;

    private static volatile int lastEnterEventsCount;

    private static native   int enterEventsCount();

    public tc04t001Thread(int i) {

        super("Debuggee Thread " + i);

        id = i;

    }

    public synchronized void run() {

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

            flicker.waitFor(id);

            increment(id);

            try {

                wait(1);

            } catch (InterruptedException e) {}

        }

        tc04t001.threadsDoneSignal.countDown();

    }

    static synchronized void increment(int i) {

        flicker.unlock(i);

        int temp = value;

        boolean done = false;

        // Wait in a loop for a MonitorContendedEnter event.

        // Timeout is: 20ms * DELAY.

        for (int j = 0; j < DELAY; j++) {

            try {

                sleep(20);

            } catch (InterruptedException e) {}

            done = (tc04t001.threadsDoneSignal.getCount() == 1);

            if (done) {

                break; // This thread is the only remaining thread, no more contention

            }

            if (enterEventsCount() > lastEnterEventsCount) {

                System.out.println("Thread-" + i + ": increment event: " + enterEventsCount());

                break; // Got an expected MonitorContendedEnter event

            }

        }

        if (!done && enterEventsCount() == lastEnterEventsCount) {

            String msg = "Timeout in waiting for a MonitorContendedEnter event";

            throw new RuntimeException(msg);

        }

        value = temp + 1;

        lastEnterEventsCount = enterEventsCount();

    }

}

class Flicker {

    private int owner = -1;

    public synchronized void waitFor(int owner) {

        while (this.owner == owner) {

            try {

                wait();

            } catch (InterruptedException e) {}

        }

    }

    public synchronized void unlock(int owner) {

        if (this.owner == owner)

            throw new IllegalStateException("the same owner: " + owner);

        this.owner = owner;

        notifyAll();

    }

}