/*

 * Copyright (c) 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.  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.

 *

 * 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 jdk.jfr.api.consumer.recordingstream;

import java.util.concurrent.CompletableFuture;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.atomic.AtomicBoolean;

import jdk.jfr.Event;

import jdk.jfr.consumer.RecordingStream;

/**

 * @test

 * @summary Tests RecordingStream::start()

 * @key jfr

 * @requires vm.hasJFR

 * @library /test/lib

 * @run main/othervm jdk.jfr.api.consumer.recordingstream.TestStart

 */

public class TestStart {

    static class StartEvent extends Event {

    }

    static class EventProducer extends Thread {

        private boolean killed = false;

        public void run() {

            while (true) {

                StartEvent s = new StartEvent();

                s.commit();

                    try {

                        if (killed) {

                            return; // end thread

                        }

                    } catch (InterruptedException e) {

                        // ignore

                    }

                }

            }

        }

        public void kill() {

                this.killed = true;

            }

        }

    }

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

        testStart();

        testStartOnEvent();

        testStartTwice();

        testStartClosed();

    }

    private static void testStartTwice() throws Exception {

        log("Entering testStartTwice()");

        CountDownLatch started = new CountDownLatch(1);

        try (RecordingStream rs = new RecordingStream()) {

            EventProducer t = new EventProducer();

            t.start();

            CompletableFuture.runAsync(() -> {

                rs.start();

            });

            rs.onEvent(e -> {

                if (started.getCount() > 0) {

                    started.countDown();

                }

            });

            started.await();

            t.kill();

            try {

                rs.start();

                throw new AssertionError("Expected IllegalStateException if started twice");

            } catch (IllegalStateException ise) {

                // OK, as expected

            }

        }

        log("Leaving testStartTwice()");

    }

    static void testStart() throws Exception {

        log("Entering testStart()");

        CountDownLatch started = new CountDownLatch(1);

        try (RecordingStream rs = new RecordingStream()) {

            rs.onEvent(e -> {

                started.countDown();

            });

            EventProducer t = new EventProducer();

            t.start();

            CompletableFuture.runAsync(() -> {

                rs.start();

            });

            started.await();

            t.kill();

        }

        log("Leaving testStart()");

    }

    static void testStartOnEvent() throws Exception {

        log("Entering testStartOnEvent()");

        AtomicBoolean ISE = new AtomicBoolean(false);

        CountDownLatch startedTwice = new CountDownLatch(1);

        try (RecordingStream rs = new RecordingStream()) {

            rs.onEvent(e -> {

                try {

                    rs.start(); // must not deadlock

                } catch (IllegalStateException ise) {

                    if (!ISE.get())  {

                        ISE.set(true);

                        startedTwice.countDown();

                    }

                }

            });

            EventProducer t = new EventProducer();

            t.start();

            CompletableFuture.runAsync(() -> {

                rs.start();

            });

            startedTwice.await();

            t.kill();

            if (!ISE.get()) {

                throw new AssertionError("Expected IllegalStateException");

            }

        }

        log("Leaving testStartOnEvent()");

    }

    static void testStartClosed() {

        log("Entering testStartClosed()");

        RecordingStream rs = new RecordingStream();

        rs.close();

        try {

            rs.start();

            throw new AssertionError("Expected IllegalStateException");

        } catch (IllegalStateException ise) {

            // OK, as expected.

        }

        log("Leaving testStartClosed()");

    }

    private static void log(String msg) {

        System.out.println(msg);

    }

}