/*

 * Copyright (c) 2006, 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

 * @summary deadlock occurs in LogManager initialization and JVM termination

 * @author  Serguei Spitsyn / Hitachi / Martin Buchholz

 *

 * @build    LoggingDeadlock2

 * @run  main LoggingDeadlock2

 * @key randomness

 */

/*

 *

 * There is a clear deadlock between LogManager.<clinit> and

 * Cleaner.run() methods.

 * T1 thread:

 *   The LogManager.<clinit> creates LogManager.manager object,

 *   sets shutdown hook with the Cleaner class and then waits

 *   to lock the LogManager.manager monitor.

 * T2 thread:

 *   It is started by the System.exit() as shutdown hook thread.

 *   It locks the LogManager.manager monitor and then calls the

 *   static methods of the LogManager class (in this particular

 *   case it is a trick of the inner classes implementation).

 *   It is waits when the LogManager.<clinit> is completed.

 *

 * This is a regression test for this bug.

 */

import java.util.Arrays;

import java.util.List;

import java.util.Random;

import java.util.concurrent.CyclicBarrier;

import java.util.concurrent.atomic.AtomicInteger;

import java.util.logging.LogManager;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.Reader;

import java.util.concurrent.TimeUnit;

public class LoggingDeadlock2 {

    // ask child process to dumpstack after 60secs

    public static final long DUMP_STACK_FREQUENCY_MS = 60000;

    // A marker that allows to validate the subprocess output.

    public static final String MARKER = "$";

    public static void realMain(String arg[]) throws Throwable {

        try {

            System.out.println(javaChildArgs);

            ProcessBuilder pb = new ProcessBuilder(javaChildArgs);

            ProcessResults r = run(pb.start());

            equal(r.exitValue(), 99);

            // output of subprocess should end with "$"

            final String out = r.out();

            final String trailingOutput = out.indexOf(MARKER) > -1

                    ? out.substring(out.indexOf(MARKER)+MARKER.length())

                    : out;

            equal(trailingOutput, "");

            equal(r.err(), "");

            equal(out.startsWith("JavaChild started"), true);

            equal(out.endsWith("$"), true);

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

    }

    public static class JavaChild {

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

            System.out.println("JavaChild started");

            final CyclicBarrier startingGate = new CyclicBarrier(2);

            final Throwable[] thrown = new Throwable[1];

            // Some random variation, to help tickle races.

            final Random rnd = new Random();

            final long seed = rnd.nextLong();

            rnd.setSeed(seed);

            System.out.println("seed=" + seed);

            final boolean dojoin = rnd.nextBoolean();

            final int JITTER = 1024;

            final int iters1 = rnd.nextInt(JITTER);

            final int iters2 = JITTER - iters1;

            final AtomicInteger counter = new AtomicInteger(0);

            System.out.println("dojoin=" + dojoin);

            System.out.println("iters1=" + iters1);

            System.out.println("iters2=" + iters2);

            Thread exiter = new Thread() {

                public void run() {

                    try {

                        startingGate.await();

                        for (int i = 0; i < iters1; i++)

                            counter.getAndIncrement();

                        System.exit(99);

                    } catch (Throwable t) {

                        t.printStackTrace();

                        System.exit(86);

                    }

                }};

            exiter.start();

            System.out.println("exiter started");

            // signal end of verbose output

            System.out.print(MARKER);

            System.out.flush();

            startingGate.await();

            for (int i = 0; i < iters2; i++)

                counter.getAndIncrement();

            // This may or may not result in a first call to

            // Runtime.addShutdownHook after shutdown has already

            // commenced.

            LogManager.getLogManager();

            if (dojoin) {

                exiter.join();

                if (thrown[0] != null)

                    throw new Error(thrown[0]);

                check(counter.get() == JITTER);

            }

        }

    }

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

    // The rest of this test is copied from ProcessBuilder/Basic.java

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

    private static final String javaExe =

        System.getProperty("java.home") +

        File.separator + "bin" + File.separator + "java";

    private static final String jstackExe =

        System.getProperty("java.home") +

        File.separator + "bin" + File.separator + "jstack";

    private static final String classpath =

        System.getProperty("java.class.path");

    private static final List<String> javaChildArgs =

        Arrays.asList(new String[]

            { javaExe, "-classpath", classpath,

              "LoggingDeadlock2$JavaChild"});

    private static class ProcessResults {

        private final String out;

        private final String err;

        private final int exitValue;

        private final Throwable throwable;

        public ProcessResults(String out,

                              String err,

                              int exitValue,

                              Throwable throwable) {

            this.out = out;

            this.err = err;

            this.exitValue = exitValue;

            this.throwable = throwable;

        }

        public String out()          { return out; }

        public String err()          { return err; }

        public int exitValue()       { return exitValue; }

        public String toString() {

            StringBuilder sb = new StringBuilder();

            sb.append("<STDOUT>\n" + out() + "</STDOUT>\n")

                .append("<STDERR>\n" + err() + "</STDERR>\n")

                .append("exitValue = " + exitValue + "\n");

            if (throwable != null)

                sb.append(throwable.getStackTrace());

            return sb.toString();

        }

    }

    private static class StreamAccumulator extends Thread {

        private final InputStream is;

        private final StringBuilder sb = new StringBuilder();

        private Throwable throwable = null;

        public String result () throws Throwable {

            if (throwable != null)

                throw throwable;

            return sb.toString();

        }

        StreamAccumulator (InputStream is) {

            this.is = is;

        }

        public void run() {

            try {

                Reader r = new InputStreamReader(is);

                int n;

                while ((n = r.read()) > 0) {

                    sb.append((char)n);

                    // prints everything immediately to System.out so that we can

                    // see the traces even in the event of a test timeout

                    System.out.write((char)n);

                    System.out.flush();

                }

            } catch (Throwable t) {

                throwable = t;

            } finally {

                try { is.close(); }

                catch (Throwable t) { throwable = t; }

            }

        }

    }

    /**

     * If the child process deadlocks, then the parent may fail in timeout.

     * In that case, we won't have any interesting traces, unless we manage

     * to get a thread dump from the child.

     * It is unsure whether obtaining a thread dump from a deadlocked child

     * will work - but maybe we could see something if the timeout is a false

     * positive (the child has not deadlocked but hasn't managed to fully start

     * yet, for instance).

     * The idea here is to periodically try to obtain a thread dump from the

     * child, every 60sec - which should be always less than the jtreg timeout.

     */

    private static class TimeoutThread extends Thread {

        final long ms;

        final Process process;

        TimeoutThread(long ms, Process p) {

            super("TimeoutThread");

            setDaemon(true);

            this.ms = ms;

            this.process = p;

        }

        @Override

        public void run() {

            long start = System.nanoTime();

            try {

                while (true) {

                    sleep(ms);

                    System.err.println("Timeout reached: " + ms);

                    if (process.isAlive()) {

                        long pid = process.getPid();

                        ProcessBuilder jstack = new ProcessBuilder(jstackExe, String.valueOf(pid));

                        System.err.println("Dumping subprocess stack: " + pid);

                        Process p = jstack.inheritIO().start();

                        p.waitFor(ms, TimeUnit.MILLISECONDS);

                    } else {

                        System.err.println("Process is not alive!");

                        break;

                    }

                }

            } catch (InterruptedException ex) {

                System.err.println("Interrupted: " + ex);

            } catch (IOException io) {

                System.err.println("Failed to get stack from subprocess");

                io.printStackTrace();

            }

        }

    }

    private static ProcessResults run(Process p) {

        Throwable throwable = null;

        int exitValue = -1;

        String out = "";

        String err = "";

        StreamAccumulator outAccumulator =

            new StreamAccumulator(p.getInputStream());

        StreamAccumulator errAccumulator =

            new StreamAccumulator(p.getErrorStream());

        try {

            System.out.println("Waiting for child process to exit");

            outAccumulator.start();

            errAccumulator.start();

            // ask subprocess to dump stack every 60 secs.

            new TimeoutThread(DUMP_STACK_FREQUENCY_MS, p).start();

            exitValue = p.waitFor();

            System.out.println("\nChild exited with status: " + exitValue);

            outAccumulator.join();

            errAccumulator.join();

            out = outAccumulator.result();

            err = errAccumulator.result();

        } catch (Throwable t) {

            throwable = t;

        }

        return new ProcessResults(out, err, exitValue, throwable);

    }

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

    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();}

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

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

    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");}

}