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 * 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

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package com.sun.corba.se.impl.orbutil.threadpool;

import java.util.LinkedList;

import com.sun.corba.se.spi.orbutil.threadpool.ThreadPool;

import com.sun.corba.se.spi.orbutil.threadpool.Work;

import com.sun.corba.se.spi.orbutil.threadpool.WorkQueue;

import com.sun.corba.se.impl.orbutil.ORBConstants;

import com.sun.corba.se.impl.orbutil.threadpool.ThreadPoolImpl;

import com.sun.corba.se.spi.monitoring.MonitoringConstants;

import com.sun.corba.se.spi.monitoring.MonitoringFactories;

import com.sun.corba.se.spi.monitoring.MonitoredObject;

import com.sun.corba.se.spi.monitoring.LongMonitoredAttributeBase;

public class WorkQueueImpl implements WorkQueue

{

    private ThreadPool workerThreadPool;

    private LinkedList theWorkQueue = new LinkedList();

    private long workItemsAdded = 0;

    // Initialized to 1 to avoid divide by zero in averageTimeInQueue()

    private long workItemsDequeued = 1;

    private long totalTimeInQueue = 0;

    // Name of the work queue

    private String name;

    // MonitoredObject for work queue

    private MonitoredObject workqueueMonitoredObject;

    public WorkQueueImpl() {

        name=ORBConstants.WORKQUEUE_DEFAULT_NAME;

        initializeMonitoring();

    }

    public WorkQueueImpl(ThreadPool workerThreadPool) {

        this(workerThreadPool, ORBConstants.WORKQUEUE_DEFAULT_NAME);

    }

    public WorkQueueImpl(ThreadPool workerThreadPool, String name) {

        this.workerThreadPool = workerThreadPool;

        this.name = name;

        initializeMonitoring();

    }

    // Setup monitoring for this workqueue

    private void initializeMonitoring() {

        workqueueMonitoredObject = MonitoringFactories.

                            getMonitoredObjectFactory().

                            createMonitoredObject(name,

                            MonitoringConstants.WORKQUEUE_MONITORING_DESCRIPTION);

        LongMonitoredAttributeBase b1 = new

            LongMonitoredAttributeBase(MonitoringConstants.WORKQUEUE_TOTAL_WORK_ITEMS_ADDED,

                    MonitoringConstants.WORKQUEUE_TOTAL_WORK_ITEMS_ADDED_DESCRIPTION) {

                public Object getValue() {

                    return new Long(WorkQueueImpl.this.totalWorkItemsAdded());

                }

            };

        workqueueMonitoredObject.addAttribute(b1);

        LongMonitoredAttributeBase b2 = new

            LongMonitoredAttributeBase(MonitoringConstants.WORKQUEUE_WORK_ITEMS_IN_QUEUE,

                    MonitoringConstants.WORKQUEUE_WORK_ITEMS_IN_QUEUE_DESCRIPTION) {

                public Object getValue() {

                    return new Long(WorkQueueImpl.this.workItemsInQueue());

                }

            };

        workqueueMonitoredObject.addAttribute(b2);

        LongMonitoredAttributeBase b3 = new

            LongMonitoredAttributeBase(MonitoringConstants.WORKQUEUE_AVERAGE_TIME_IN_QUEUE,

                    MonitoringConstants.WORKQUEUE_AVERAGE_TIME_IN_QUEUE_DESCRIPTION) {

                public Object getValue() {

                    return new Long(WorkQueueImpl.this.averageTimeInQueue());

                }

            };

        workqueueMonitoredObject.addAttribute(b3);

    }

    // Package private method to get the monitored object for this

    // class

    MonitoredObject getMonitoredObject() {

        return workqueueMonitoredObject;

    }

            workItemsAdded++;

            work.setEnqueueTime(System.currentTimeMillis());

            theWorkQueue.addLast(work);

            ((ThreadPoolImpl)workerThreadPool).notifyForAvailableWork(this);

    }

    {

        Work workItem;

            if (theWorkQueue.size() != 0) {

                workItem = (Work)theWorkQueue.removeFirst();

                totalTimeInQueue += System.currentTimeMillis() - workItem.getEnqueueTime();

                workItemsDequeued++;

                return workItem;

            }

            try {

                long remainingWaitTime = waitTime;

                long finishTime = System.currentTimeMillis() + waitTime;

                do {

                    this.wait(remainingWaitTime);

                    if (theWorkQueue.size() != 0) {

                        workItem = (Work)theWorkQueue.removeFirst();

                        totalTimeInQueue += System.currentTimeMillis() - workItem.getEnqueueTime();

                        workItemsDequeued++;

                        return workItem;

                    }

                    remainingWaitTime = finishTime - System.currentTimeMillis();

                } while (remainingWaitTime > 0);

                throw new TimeoutException();

            } catch (InterruptedException ie) {

                throw ie;

            }

    }

    public void setThreadPool(ThreadPool workerThreadPool) {

            this.workerThreadPool = workerThreadPool;

    }

    public ThreadPool getThreadPool() {

            return workerThreadPool;

    }

    /**

     * Returns the total number of Work items added to the Queue.

     * This method is unsynchronized and only gives a snapshot of the

     * state when it is called

     */

    public long totalWorkItemsAdded() {

        return workItemsAdded;

    }

    /**

     * Returns the total number of Work items in the Queue to be processed

     * This method is unsynchronized and only gives a snapshot of the

     * state when it is called

     */

    public int workItemsInQueue() {

        return theWorkQueue.size();

    }

    public synchronized long averageTimeInQueue() {

        return (totalTimeInQueue/workItemsDequeued);

    }

    public String getName() {

        return name;

    }

}

// End of file.