/*

 * Copyright (c) 2012, 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.

 */

/*

 * @test

 * @bug     7194254

 * @summary Creates several threads with different java priorities and checks

 *      whether jstack reports correct priorities for them.

 *

 * @run main T7194254

 */

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.lang.management.ManagementFactory;

import java.lang.management.RuntimeMXBean;

import java.util.ArrayList;

import java.util.List;

import java.util.concurrent.CyclicBarrier;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class Test7194254 {

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

        final int NUMBER_OF_JAVA_PRIORITIES =

                Thread.MAX_PRIORITY - Thread.MIN_PRIORITY + 1;

        final CyclicBarrier barrier =

                new CyclicBarrier(NUMBER_OF_JAVA_PRIORITIES + 1);

        for (int p = Thread.MIN_PRIORITY; p <= Thread.MAX_PRIORITY; ++p) {

            final int priority = p;

            new Thread("Priority=" + p) {

                {

                    setPriority(priority);

                }

                public void run() {

                    try {

                        barrier.await(); // 1st

                        barrier.await(); // 2nd

                    } catch (Exception exc) {

                        // ignore

                    }

                }

            }.start();

        }

        barrier.await(); // 1st

        int matches = 0;

        List<String> failed = new ArrayList<>();

        try {

            String pid = getPid();

            String jstack = System.getProperty("java.home") + "/../bin/jstack";

            Process process = new ProcessBuilder(jstack, pid)

                    .redirectErrorStream(true).start();

            Pattern pattern = Pattern.compile(

                    "\\\"Priority=(\\d+)\\\".* prio=(\\d+).*");

            try (BufferedReader reader = new BufferedReader(

                    new InputStreamReader(process.getInputStream()))) {

                String line;

                while((line = reader.readLine()) != null) {

                    Matcher matcher = pattern.matcher(line);

                    if (matcher.matches()) {

                        matches += 1;

                        String expected = matcher.group(1);

                        String actual = matcher.group(2);

                        if (!expected.equals(actual)) {

                            failed.add(line);

                        }

                    }

                }

            }

            barrier.await(); // 2nd

        } finally {

            barrier.reset();

        }

        if (matches != NUMBER_OF_JAVA_PRIORITIES) {

            throw new AssertionError("matches: expected " +

                    NUMBER_OF_JAVA_PRIORITIES + ", but was " + matches);

        }

        if (!failed.isEmpty()) {

            throw new AssertionError(failed.size() + ":" + failed);

        }

        System.out.println("Test passes.");

    }

    static String getPid() {

        RuntimeMXBean runtimebean = ManagementFactory.getRuntimeMXBean();

        String vmname = runtimebean.getName();

        int i = vmname.indexOf('@');

        if (i != -1) {

            vmname = vmname.substring(0, i);

        }

        return vmname;

    }

}