BlockingPool.java

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 * Copyright (c) 2016 Payara Foundation and/or its affiliates. All rights reserved.
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 * The contents of this file are subject to the terms of either the GNU
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 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://github.com/payara/Payara/blob/master/LICENSE.txt
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 * GPL Classpath Exception:
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 * exception as provided by the Payara Foundation in the GPL Version 2 section of the License
 * file that accompanied this code.
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package com.sun.ejb.containers.util.pool;

import static com.sun.ejb.containers.util.pool.AbstractPool._logger;
import java.util.logging.Level;

/**
 *
 * @author lprimak
 */
public class BlockingPool extends NonBlockingPool {
    public BlockingPool(long containerId, String name, ObjectFactory sessionCtxFactory, int steadyPoolSize,
            int poolResizeQuantity, int maxPoolSize, int poolIdleTimeoutInSeconds,
            ClassLoader loader, boolean singletonBeanPool, int maxWaitTimeInMillis) {
        super(containerId, name, sessionCtxFactory, steadyPoolSize, poolResizeQuantity, maxPoolSize,
                poolIdleTimeoutInSeconds, loader, singletonBeanPool);
        this.maxWaitTimeInMillis = maxWaitTimeInMillis;
    }


    @Override
    public Object getObject(Object param)
        throws PoolException
    {
        long t1, totalWaitTime = 0;
        synchronized (list) {
            while (singletonBeanPool == false) {
                if (list.size() > 0) {
                    return super.getObject(param);
                } else if ((createdCount - destroyedCount) < maxPoolSize) {
                    return super.getObject(param);
                }

                if (maxWaitTimeInMillis >= 0) {
                    waitCount++;
                    t1 = System.currentTimeMillis();
                    try {
                        _logger.log(Level.FINE, "[AbstractPool]: Waiting on" +
                                    " the pool to get a bean instance...");
                        list.wait(maxWaitTimeInMillis);
                    } catch (InterruptedException inEx) {
                        throw new PoolException("Thread interrupted.", inEx);
                    }
                    waitCount--;
                    totalWaitTime += System.currentTimeMillis() - t1;
                    if (list.size() > 0) {
                        return super.getObject(param);
                    } else if (maxWaitTimeInMillis == 0) {
                        // nothing special to do in this case
                    } else if (totalWaitTime >= maxWaitTimeInMillis) {
                        throw new PoolException("Pool Instance not obtained" +
                           " within given time interval.");
                    }
                } else {
                    throw new IllegalStateException("maxWaitTimeInMillis is negative with BlockingPool");
                }
            }
        }
        throw new IllegalStateException("Should never go here");
    }

    /**
     * Return an object back to the pool. An object that is obtained through
     *	getObject() must always be returned back to the pool using either
     *	returnObject(obj) or through destroyObject(obj).
     */
    @Override
    public void returnObject(Object object) {
        super.returnObject(object);
    	synchronized (list) {
            poolReturned++;
            if (waitCount > 0) {
                list.notify();
            }
    	}
    }

    /**
     * Destroys an Object. Note that applications should not ignore the
     * reference to the object that they got from getObject(). An object
     * that is obtained through getObject() must always be returned back to
     * the pool using either returnObject(obj) or through destroyObject(obj).
     * This method tells that the object should be destroyed and cannot
     * be reused.
     */
    @Override
    public void destroyObject(Object object) {
        super.destroyObject(object);
    	synchronized (list) {
            if (waitCount > 0) {
                list.notify();
            }
    	}
    }

    @Override
    protected void remove(int count) {
        super.remove(count);
        synchronized (list) {
            list.notifyAll();
        }
    }
}