/*
 * Copyright (c) 2011-2014, Parallel Universe Software Co. All rights reserved.
 * 
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *  
 *   or (per the licensee's choosing)
 *  
 * under the terms of the GNU Lesser General Public License version 3.0
 * as published by the Free Software Foundation.
 */
package co.paralleluniverse.common.monitoring;

import java.lang.management.ManagementFactory;
import java.util.concurrent.ForkJoinPool;
import javax.management.InstanceAlreadyExistsException;
import javax.management.InstanceNotFoundException;
import javax.management.MBeanRegistrationException;
import javax.management.MBeanServer;
import javax.management.MalformedObjectNameException;
import javax.management.NotCompliantMBeanException;
import javax.management.ObjectName;

/**
 *
 * @author pron
 */
public class JMXForkJoinPoolMonitor extends ForkJoinPoolMonitor implements ForkJoinPoolMXBean {
    private final String mbeanName;
    private boolean registered;

    public JMXForkJoinPoolMonitor(String name, ForkJoinPool fjPool) {
        super(name, fjPool);
        //super(ForkJoinPoolMXBean.class, true, new NotificationBroadcasterSupport());
        this.mbeanName = "co.paralleluniverse:type=ForkJoinPool,name=" + name;
        registerMBean();
    }

    protected void registerMBean() {
        try {
            final MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
            final ObjectName mxbeanName = new ObjectName(mbeanName);
            mbs.registerMBean(this, mxbeanName);
            this.registered = true;
        } catch (InstanceAlreadyExistsException ex) {
            throw new RuntimeException(ex);
        } catch (MBeanRegistrationException ex) {
            ex.printStackTrace();
        } catch (NotCompliantMBeanException ex) {
            throw new AssertionError(ex);
        } catch (MalformedObjectNameException ex) {
            throw new AssertionError(ex);
        }
    }

    @Override
    public void unregister() {
        try {
            if (registered)
                ManagementFactory.getPlatformMBeanServer().unregisterMBean(new ObjectName(mbeanName));
            this.registered = false;
        } catch (InstanceNotFoundException ex) {
            ex.printStackTrace();
        } catch (MBeanRegistrationException ex) {
            ex.printStackTrace();
        } catch (MalformedObjectNameException ex) {
            throw new AssertionError(ex);
        }
    }

    public String getMbeanName() {
        return mbeanName;
    }

    public boolean isRegistered() {
        return registered;
    }

    @Override
    protected ForkJoinPool fjPool() {
        final ForkJoinPool fjPool = super.fjPool();
        if (fjPool == null) {
            unregister();
            throw new RuntimeException("Pool collected");
        }
        return fjPool;
    }

    @Override
    public ForkJoinPoolMonitor.Status getStatus() {
        final ForkJoinPool fjPool = fjPool();
        if (fjPool.isTerminated()) // Returns true if all tasks have completed following shut down.
            return ForkJoinPoolMonitor.Status.TERMINATED;
        if (fjPool.isTerminating()) // Returns true if the process of termination has commenced but not yet completed.
            return ForkJoinPoolMonitor.Status.TERMINATING;
        if (fjPool.isShutdown()) // Returns true if this pool has been shut down.
            return ForkJoinPoolMonitor.Status.SHUTDOWN;
        if (fjPool.isQuiescent()) // Returns true if all worker threads are currently idle.
            return ForkJoinPoolMonitor.Status.QUIESCENT;
        return ForkJoinPoolMonitor.Status.ACTIVE;
    }

    @Override
    public boolean getAsyncMode() {
        return fjPool().getAsyncMode(); // Returns true if this pool uses local first-in-first-out scheduling mode for forked tasks that are never joined.
    }

    @Override
    public int getParallelism() {
        return fjPool().getParallelism(); // Returns the targeted parallelism level of this pool.
    }

    @Override
    public int getPoolSize() {
        return fjPool().getPoolSize(); // Returns the number of worker threads that have started but not yet terminated.
    }

    @Override
    public int getActiveThreadCount() {
        return fjPool().getActiveThreadCount();
    }

    @Override
    public int getRunningThreadCount() {
        return fjPool().getRunningThreadCount();
    }

    @Override
    public int getQueuedSubmissionCount() {
        return fjPool().getQueuedSubmissionCount();
    }

    @Override
    public long getQueuedTaskCount() {
        return fjPool().getQueuedTaskCount();
    }

    @Override
    public long getStealCount() {
        return fjPool().getStealCount();
    }

    @Override
    public long[] getLatency() {
        return new ExecutorServiceLatencyProbe(fjPool(), 5).fire();
    }
    
    @Override
    public ForkJoinInfo getInfo() {
        final ForkJoinPool fjPool = fjPool();
        int activeThreadCount = fjPool.getActiveThreadCount(); // Returns an estimate of the number of threads that are currently stealing or executing tasks.
        int runningThreadCount = fjPool.getRunningThreadCount(); // Returns an estimate of the number of worker threads that are not blocked waiting to join tasks or for other managed synchronization.
        int queuedSumbmissionCount = fjPool.getQueuedSubmissionCount(); // Returns an estimate of the number of tasks submitted to this pool that have not yet begun executing.
        long queuedTaskCount = fjPool.getQueuedTaskCount(); // Returns an estimate of the total number of tasks currently held in queues by worker threads (but not including tasks submitted to the pool that have not begun executing).
        long stealCount = fjPool.getStealCount(); //  Returns an estimate of the total number of tasks stolen from one thread's work queue by another.

        return new ForkJoinInfo(activeThreadCount, runningThreadCount, queuedSumbmissionCount, queuedTaskCount, stealCount);
    }

    @Override
    public void shutdown() {
        fjPool().shutdown();
    }

    @Override
    public void shutdownNow() {
        fjPool().shutdownNow();
    }
}