/*

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 *

 * 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).

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 * 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.

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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 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/

 */

/*

 * @test

 * @bug 6445158

 * @key intermittent

 * @summary Basic tests for Phaser

 * @author Chris Hegarty

 */

import static java.util.concurrent.TimeUnit.MILLISECONDS;

import static java.util.concurrent.TimeUnit.NANOSECONDS;

import static java.util.concurrent.TimeUnit.SECONDS;

import java.lang.management.ManagementFactory;

import java.lang.management.ThreadInfo;

import java.lang.management.ThreadMXBean;

import java.util.Iterator;

import java.util.LinkedList;

import java.util.concurrent.Phaser;

import java.util.concurrent.TimeUnit;

import java.util.concurrent.TimeoutException;

import java.util.concurrent.atomic.AtomicInteger;

public class Basic {

    private static void checkTerminated(final Phaser phaser) {

        check(phaser.isTerminated());

        int unarriverParties = phaser.getUnarrivedParties();

        int registeredParties = phaser.getRegisteredParties();

        int phase = phaser.getPhase();

        check(phase < 0);

        equal(phase, phaser.arrive());

        equal(phase, phaser.arriveAndDeregister());

        equal(phase, phaser.arriveAndAwaitAdvance());

        equal(phase, phaser.bulkRegister(10));

        equal(phase, phaser.register());

        try {

            equal(phase, phaser.awaitAdvanceInterruptibly(0));

            equal(phase, phaser.awaitAdvanceInterruptibly(0, 10, SECONDS));

        } catch (Exception ie) {

            unexpected(ie);

        }

        equal(phaser.getUnarrivedParties(), unarriverParties);

        equal(phaser.getRegisteredParties(), registeredParties);

    }

    private static void checkResult(Arriver a, Class<? extends Throwable> c) {

        Throwable t = a.result();

        if (! ((t == null && c == null) || (c != null && c.isInstance(t)))) {

            //      t.printStackTrace();

            fail("Mismatch in thread " +

                 a.getName() + ": " +

                 t + ", " +

                 (c == null ? "<null>" : c.getName()));

        } else {

            pass();

        }

    }

    //----------------------------------------------------------------

    // Mechanism to get all test threads into "running" mode.

    //----------------------------------------------------------------

    private static Phaser startingGate = new Phaser(3);

    private static void toTheStartingGate() {

        try {

            boolean expectNextPhase = (startingGate.getUnarrivedParties() == 1);

            int phase = startingGate.getPhase();

            equal(phase, startingGate.arrive());

            int awaitPhase;

            for (boolean interrupted = false;;) {

                try {

                    awaitPhase = startingGate.awaitAdvanceInterruptibly

                        (phase, 30, SECONDS);

                    if (interrupted) Thread.currentThread().interrupt();

                    break;

                } catch (InterruptedException ie) {

                    interrupted = true;

                }

            }

            if (expectNextPhase) check(awaitPhase == phase + 1);

            else check(awaitPhase == phase || awaitPhase == phase + 1);

            pass();

        } catch (Throwable t) {

            unexpected(t);

            // reset(startingGate);

            throw new Error(t);

        }

    }

    //----------------------------------------------------------------

    // Convenience methods for creating threads that call arrive,

    // awaitAdvance, arriveAndAwaitAdvance, awaitAdvanceInterruptibly

    //----------------------------------------------------------------

    private abstract static class Arriver extends Thread {

        static AtomicInteger count = new AtomicInteger(1);

        Arriver() {

            this("Arriver");

        }

        Arriver(String name) {

            this.setName(name + ":" + count.getAndIncrement());

            this.setDaemon(true);

        }

        private volatile Throwable result;

        private volatile int phase;

        protected void result(Throwable result) { this.result = result; }

        public Throwable result() { return this.result; }

        protected void phase(int phase) { this.phase = phase; }

        public int phase() { return this.phase; }

    }

    private abstract static class Awaiter extends Arriver {

        Awaiter() { super("Awaiter"); }

        Awaiter(String name) { super(name); }

    }

    private static Arriver arriver(final Phaser phaser) {

        return new Arriver() { public void run() {

            toTheStartingGate();

            try { phase(phaser.arrive()); }

            catch (Throwable result) { result(result); }}};

    }

    private static AtomicInteger cycleArriveAwaitAdvance = new AtomicInteger(1);

    private static Awaiter awaiter(final Phaser phaser) {

        return new Awaiter() { public void run() {

            toTheStartingGate();

            try {

                if (cycleArriveAwaitAdvance.getAndIncrement() % 2 == 0)

                    phase(phaser.awaitAdvance(phaser.arrive()));

                else

                    phase(phaser.arriveAndAwaitAdvance());

            } catch (Throwable result) { result(result); }}};

    }

    private static Awaiter awaiter(final Phaser phaser,

                                   final long timeout,

                                   final TimeUnit unit) {

        return new Awaiter("InterruptibleWaiter") { public void run() {

            toTheStartingGate();

            try {

                if (timeout < 0)

                    phase(phaser.awaitAdvanceInterruptibly(phaser.arrive()));

                else

                    phase(phaser.awaitAdvanceInterruptibly(phaser.arrive(),

                                                     timeout,

                                                     unit));

            } catch (Throwable result) { result(result); }}};

    }

    // Returns an infinite lazy list of all possible arriver/awaiter combinations.

    private static Iterator<Arriver> arriverIterator(final Phaser phaser) {

        return new Iterator<Arriver>() {

            int i = 0;

            public boolean hasNext() { return true; }

            public Arriver next() {

                switch ((i++)&7) {

                    case 0: case 4:

                        return arriver(phaser);

                    case 1: case 5:

                        return awaiter(phaser);

                    case 2: case 6: case 7:

                        return awaiter(phaser, -1, SECONDS);

                    default:

                        return awaiter(phaser, 30, SECONDS); }}

            public void remove() {throw new UnsupportedOperationException();}};

    }

    // Returns an infinite lazy list of all possible awaiter only combinations.

    private static Iterator<Awaiter> awaiterIterator(final Phaser phaser) {

        return new Iterator<Awaiter>() {

            int i = 0;

            public boolean hasNext() { return true; }

            public Awaiter next() {

                switch ((i++)&7) {

                    case 1: case 4: case 7:

                        return awaiter(phaser);

                    case 2: case 5:

                        return awaiter(phaser, -1, SECONDS);

                    default:

                        return awaiter(phaser, 30, SECONDS); }}

            public void remove() {throw new UnsupportedOperationException();}};

    }

    static class SimpleTimer {

        long startTime = System.nanoTime();

        long elapsedMillis() {

            long now = System.nanoTime();

            long elapsed = NANOSECONDS.toMillis(now - startTime);

            startTime = now;

            return elapsed;

        }

        void printElapsed() { System.out.println(elapsedMillis() + " ms"); }

    }

    private static void realMain(String[] args) throws Throwable {

        SimpleTimer timer = new SimpleTimer();

        Thread.currentThread().setName("mainThread");

        //----------------------------------------------------------------

        System.out.print("Normal use: ");

        //----------------------------------------------------------------

        try {

            Phaser phaser = new Phaser(3);

            equal(phaser.getRegisteredParties(), 3);

            equal(phaser.getArrivedParties(), 0);

            equal(phaser.getPhase(), 0);

            check(phaser.getRoot().equals(phaser));

            equal(phaser.getParent(), null);

            check(!phaser.isTerminated());

            Iterator<Arriver> arrivers = arriverIterator(phaser);

            int phase = 0;

            for (int i = 0; i < 10; i++) {

                equal(phaser.getPhase(), phase++);

                Arriver a1 = arrivers.next(); a1.start();

                Arriver a2 = arrivers.next(); a2.start();

                toTheStartingGate();

                phaser.arriveAndAwaitAdvance();

                a1.join();

                a2.join();

                checkResult(a1, null);

                checkResult(a2, null);

                check(!phaser.isTerminated());

                equal(phaser.getRegisteredParties(), 3);

                equal(phaser.getArrivedParties(), 0);

            }

        } catch (Throwable t) { unexpected(t); }

        timer.printElapsed();

        //----------------------------------------------------------------

        System.out.print("One thread interrupted: ");

        //----------------------------------------------------------------

        try {

            Phaser phaser = new Phaser(3);

            Iterator<Arriver> arrivers = arriverIterator(phaser);

            int phase = phaser.getPhase();

            for (int i = 0; i < 10; i++) {

                check(phaser.getPhase() == phase);

                Awaiter a1 = awaiter(phaser, 30, SECONDS); a1.start();

                Arriver a2 = arrivers.next(); a2.start();

                toTheStartingGate();

                a1.interrupt();

                a1.join();

                phaser.arriveAndAwaitAdvance();

                a2.join();

                checkResult(a1, InterruptedException.class);

                checkResult(a2, null);

                check(!phaser.isTerminated());

                equal(phaser.getRegisteredParties(), 3);

                equal(phaser.getArrivedParties(), 0);

                phase++;

            }

        } catch (Throwable t) { unexpected(t); }

        timer.printElapsed();

        //----------------------------------------------------------------

        System.out.print("Phaser is terminated while threads are waiting: ");

        //----------------------------------------------------------------

        try {

            for (int i = 0; i < 10; i++) {

                Phaser phaser = new Phaser(3);

                Iterator<Awaiter> awaiters = awaiterIterator(phaser);

                Arriver a1 = awaiters.next(); a1.start();

                Arriver a2 = awaiters.next(); a2.start();

                toTheStartingGate();

                while (phaser.getArrivedParties() < 2) Thread.yield();

                equal(0, phaser.getPhase());

                phaser.forceTermination();

                a1.join();

                a2.join();

                equal(0 + Integer.MIN_VALUE, a1.phase);

                equal(0 + Integer.MIN_VALUE, a2.phase);

                int arrivedParties = phaser.getArrivedParties();

                checkTerminated(phaser);

                equal(phaser.getArrivedParties(), arrivedParties);

            }

        } catch (Throwable t) { unexpected(t); }

        timer.printElapsed();

        //----------------------------------------------------------------

        System.out.print("Adds new unarrived parties to this phaser: ");

        //----------------------------------------------------------------

        try {

            Phaser phaser = new Phaser(1);

            Iterator<Arriver> arrivers = arriverIterator(phaser);

            LinkedList<Arriver> arriverList = new LinkedList<Arriver>();

            int phase = phaser.getPhase();

            for (int i = 1; i < 5; i++) {

                startingGate = new Phaser(1+(3*i));

                check(phaser.getPhase() == phase);

                // register 3 more

                phaser.register(); phaser.register(); phaser.register();

                for (int z=0; z<(3*i); z++) {

                   arriverList.add(arrivers.next());

                }

                for (Arriver arriver : arriverList)

                    arriver.start();

                toTheStartingGate();

                phaser.arriveAndAwaitAdvance();

                for (Arriver arriver : arriverList) {

                    arriver.join();

                    checkResult(arriver, null);

                }

                equal(phaser.getRegisteredParties(), 1 + (3*i));

                equal(phaser.getArrivedParties(), 0);

                arriverList.clear();

                phase++;

            }

            startingGate = new Phaser(3);

        } catch (Throwable t) { unexpected(t); }

        timer.printElapsed();

        //----------------------------------------------------------------

        System.out.print("One thread timed out: ");

        //----------------------------------------------------------------

        try {

            Phaser phaser = new Phaser(3);

            Iterator<Arriver> arrivers = arriverIterator(phaser);

            for (long timeout : new long[] { 0L, 12L }) {

                Awaiter a1 = awaiter(phaser, timeout, MILLISECONDS);

                a1.start();

                Arriver a2 = arrivers.next();

                a2.start();

                toTheStartingGate();

                a1.join();

                checkResult(a1, TimeoutException.class);

                phaser.arrive();

                a2.join();

                checkResult(a2, null);

                check(!phaser.isTerminated());

            }

        } catch (Throwable t) { unexpected(t); }

        timer.printElapsed();

        //----------------------------------------------------------------

        System.out.print("Barrier action completed normally: ");

        //----------------------------------------------------------------

        try {

            final AtomicInteger count = new AtomicInteger(0);

            final Phaser[] kludge = new Phaser[1];

            Phaser phaser = new Phaser(3) {

                @Override

                protected boolean onAdvance(int phase, int registeredParties) {

                    int countPhase = count.getAndIncrement();

                    equal(countPhase, phase);

                    equal(kludge[0].getPhase(), phase);

                    equal(kludge[0].getRegisteredParties(), registeredParties);

                    if (phase >= 3)

                        return true; // terminate

                    return false;

                }

            };

            kludge[0] = phaser;

            equal(phaser.getRegisteredParties(), 3);

            Iterator<Awaiter> awaiters = awaiterIterator(phaser);

            for (int i = 0; i < 4; i++) {

                Awaiter a1 = awaiters.next(); a1.start();

                Awaiter a2 = awaiters.next(); a2.start();

                toTheStartingGate();

                while (phaser.getArrivedParties() < 2) Thread.yield();

                phaser.arrive();

                a1.join();

                a2.join();

                checkResult(a1, null);

                checkResult(a2, null);

                equal(count.get(), i+1);

                if (i < 3) {

                    check(!phaser.isTerminated());

                    equal(phaser.getRegisteredParties(), 3);

                    equal(phaser.getArrivedParties(), 0);

                    equal(phaser.getUnarrivedParties(), 3);

                    equal(phaser.getPhase(), count.get());

                } else

                    checkTerminated(phaser);

            }

        } catch (Throwable t) { unexpected(t); }

        timer.printElapsed();

    }

    //--------------------- Infrastructure ---------------------------

    /**

     * A debugging tool to print stack traces of most threads, as jstack does.

     * Uninteresting threads are filtered out.

     */

    static void dumpTestThreads() {

        ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();

        System.err.println("------ stacktrace dump start ------");

        for (ThreadInfo info : threadMXBean.dumpAllThreads(true, true)) {

            String name = info.getThreadName();

            if ("Signal Dispatcher".equals(name))

                continue;

            if ("Reference Handler".equals(name)

                && info.getLockName().startsWith("java.lang.ref.Reference$Lock"))

                continue;

            if ("Finalizer".equals(name)

                && info.getLockName().startsWith("java.lang.ref.ReferenceQueue$Lock"))

                continue;

            if ("process reaper".equals(name))

                continue;

            if (name != null && name.startsWith("ForkJoinPool.commonPool-worker"))

                continue;

            System.err.print(info);

        }

        System.err.println("------ stacktrace dump end ------");

    }

    static volatile int passed = 0, failed = 0;

    static void pass() {passed++;}

    static void fail() {failed++; Thread.dumpStack();}

    static void fail(String msg) {System.out.println(msg); fail();}

    static void unexpected(Throwable t) {failed++; t.printStackTrace(); dumpTestThreads();}

    static void check(boolean cond) {if (cond) pass(); else fail();}

    static void equal(Object x, Object y) {

        if (x == null ? y == null : x.equals(y)) pass();

        else fail(x + " not equal to " + y);}

    public static void main(String[] args) throws Throwable {

        try {realMain(args);} catch (Throwable t) {unexpected(t);}

        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);

        if (failed > 0) throw new AssertionError("Some tests failed");}

}