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 * 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.
 *
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package jdk.jfr.api.consumer.filestream;

import java.nio.file.Files;
import java.nio.file.Path;
import java.time.Instant;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;

import jdk.jfr.Event;
import jdk.jfr.Recording;
import jdk.jfr.consumer.EventStream;

/**
 * @test
 * @summary Test EventStream::setOrdered(...)
 * @key jfr
 * @requires vm.hasJFR
 * @library /test/lib
 * @run main/othervm jdk.jfr.api.consumer.filestream.TestOrdered
 */
public class TestOrdered {

    static class OrderedEvent extends Event {
    }

    static class Emitter extends Thread {
        private final CyclicBarrier barrier;

        public Emitter(CyclicBarrier barrier) {
            this.barrier = barrier;
        }

        @Override
        public void run() {
            OrderedEvent e1 = new OrderedEvent();
            e1.commit();
            try {
                barrier.await();
            } catch (Exception e) {
                e.printStackTrace();
                throw new Error("Unexpected exception in barrier");
            }
            OrderedEvent e2 = new OrderedEvent();
            e2.commit();
        }
    }

    private static final int THREAD_COUNT = 4;

    public static void main(String... args) throws Exception {
        Path p = makeUnorderedRecording();

        testSetOrderedTrue(p);
        testSetOrderedFalse(p);
    }

    private static void testSetOrderedTrue(Path p) throws Exception {
        AtomicReference<Instant> timestamp = new AtomicReference<>(Instant.MIN);
        try (EventStream es = EventStream.openFile(p)) {
            es.setOrdered(true);
            es.onEvent(e -> {
                Instant endTime = e.getEndTime();
                if (endTime.isBefore(timestamp.get())) {
                    throw new Error("Events are not ordered!");
                }
                timestamp.set(endTime);
            });
            es.start();
        }
    }

    private static void testSetOrderedFalse(Path p) throws Exception {
        AtomicReference<Instant> timestamp = new AtomicReference<>(Instant.MIN);
        AtomicBoolean unoreded = new AtomicBoolean(false);
        try (EventStream es = EventStream.openFile(p)) {
            es.setOrdered(false);
            es.onEvent(e -> {
                Instant endTime = e.getEndTime();
                if (endTime.isBefore(timestamp.get())) {
                    unoreded.set(true);
                    es.close();
                }
                timestamp.set(endTime);
            });
            es.start();
            if (!unoreded.get()) {
                throw new Exception("Expected at least some events to be out of order");
            }
        }
    }

    private static Path makeUnorderedRecording() throws Exception {
        CyclicBarrier barrier = new CyclicBarrier(THREAD_COUNT + 1);

        try (Recording r = new Recording()) {
            r.start();
            List<Emitter> emitters = new ArrayList<>();
            for (int i = 0; i < THREAD_COUNT; i++) {
                Emitter e = new Emitter(barrier);
                e.start();
                emitters.add(e);
            }
            // Thread buffers should now have one event each
            barrier.await();
            // Add another event to each thread buffer, so
            // events are bound to come out of order when they
            // are flushed
            for (Emitter e : emitters) {
                e.join();
            }
            r.stop();
            Path p = Files.createTempFile("recording", ".jfr");
            r.dump(p);
            return p;
        }
    }
}