/*

 * 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

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 * questions.

 */

/*

 * @test

 * @bug 7122142

 * @summary Test deadlock situation when recursive annotations are parsed

 */

import java.lang.annotation.Retention;

import java.lang.management.ManagementFactory;

import java.lang.management.ThreadInfo;

import java.lang.management.ThreadMXBean;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.atomic.AtomicInteger;

import static java.lang.annotation.RetentionPolicy.RUNTIME;

public class AnnotationTypeDeadlockTest {

    @Retention(RUNTIME)

    @AnnB

    public @interface AnnA {

    }

    @Retention(RUNTIME)

    @AnnA

    public @interface AnnB {

    }

    static class Task extends Thread {

        final CountDownLatch prepareLatch;

        final AtomicInteger goLatch;

        final Class<?> clazz;

        Task(CountDownLatch prepareLatch, AtomicInteger goLatch, Class<?> clazz) {

            super(clazz.getSimpleName());

            setDaemon(true); // in case it deadlocks

            this.prepareLatch = prepareLatch;

            this.goLatch = goLatch;

            this.clazz = clazz;

        }

        @Override

        public void run() {

            prepareLatch.countDown();  // notify we are prepared

            while (goLatch.get() > 0); // spin-wait before go

            clazz.getDeclaredAnnotations();

        }

    }

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

        CountDownLatch prepareLatch = new CountDownLatch(2);

        AtomicInteger goLatch = new AtomicInteger(1);

        Task taskA = new Task(prepareLatch, goLatch, AnnA.class);

        Task taskB = new Task(prepareLatch, goLatch, AnnB.class);

        taskA.start();

        taskB.start();

        // wait until both threads start-up

        prepareLatch.await();

        // let them go

        goLatch.set(0);

        // obtain ThreadMXBean

        ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();

        // wait for threads to finish or dead-lock

        while (taskA.isAlive() || taskB.isAlive()) {

            // attempt to join threads

            taskA.join(500L);

            taskB.join(500L);

            // detect dead-lock

            long[] deadlockedIds = threadBean.findMonitorDeadlockedThreads();

            if (deadlockedIds != null && deadlockedIds.length > 0) {

                StringBuilder sb = new StringBuilder("deadlock detected:\n\n");

                for (ThreadInfo ti : threadBean.getThreadInfo(deadlockedIds, Integer.MAX_VALUE)) {

                    sb.append(ti);

                }

                throw new IllegalStateException(sb.toString());

            }

        }

    }

}