Mercurial > hg > release > icedtea7-forest-2.1 > jaxws
view sources/jaxws_src/src/com/sun/xml/internal/ws/util/Pool.java @ 282:78c175236707
Update to jdk7-jaxws-2009_09_28.zip
author | andrew |
---|---|
date | Thu, 22 Sep 2011 02:57:13 +0100 |
parents | c608b38af726 |
children | 4f4a2cd249d8 |
line wrap: on
line source
/* * Copyright 2005-2006 Sun Microsystems, Inc. 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. Sun designates this * particular file as subject to the "Classpath" exception as provided * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. */ package com.sun.xml.internal.ws.util; import com.sun.xml.internal.ws.api.pipe.Tube; import com.sun.xml.internal.ws.api.pipe.TubeCloner; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import java.util.concurrent.ConcurrentLinkedQueue; import java.lang.ref.WeakReference; /** * General-purpose object pool. * * <p> * In many parts of the runtime, we need to pool instances of objects that * are expensive to create (such as JAXB objects, StAX parsers, {@link Tube} instances.) * * <p> * This class provides a default implementation of such a pool. * * TODO: improve the implementation * * @author Kohsuke Kawaguchi */ public abstract class Pool<T> { // volatile since multiple threads may access queue reference private volatile WeakReference<ConcurrentLinkedQueue<T>> queue; /** * Gets a new object from the pool. * * <p> * If no object is available in the pool, this method creates a new one. * * @return * always non-null. */ public final T take() { T t = getQueue().poll(); if(t==null) return create(); return t; } private ConcurrentLinkedQueue<T> getQueue() { WeakReference<ConcurrentLinkedQueue<T>> q = queue; if (q != null) { ConcurrentLinkedQueue<T> d = q.get(); if (d != null) return d; } // overwrite the queue ConcurrentLinkedQueue<T> d = new ConcurrentLinkedQueue<T>(); queue = new WeakReference<ConcurrentLinkedQueue<T>>(d); return d; } /** * Returns an object back to the pool. */ public final void recycle(T t) { getQueue().offer(t); } /** * Creates a new instance of object. * * <p> * This method is used when someone wants to * {@link #take() take} an object from an empty pool. * * <p> * Also note that multiple threads may call this method * concurrently. */ protected abstract T create(); /** * JAXB {@link javax.xml.bind.Marshaller} pool. */ public static final class Marshaller extends Pool<javax.xml.bind.Marshaller> { private final JAXBContext context; public Marshaller(JAXBContext context) { this.context = context; } protected javax.xml.bind.Marshaller create() { try { return context.createMarshaller(); } catch (JAXBException e) { // impossible throw new AssertionError(e); } } } /** * JAXB {@link javax.xml.bind.Marshaller} pool. */ public static final class Unmarshaller extends Pool<javax.xml.bind.Unmarshaller> { private final JAXBContext context; public Unmarshaller(JAXBContext context) { this.context = context; } protected javax.xml.bind.Unmarshaller create() { try { return context.createUnmarshaller(); } catch (JAXBException e) { // impossible throw new AssertionError(e); } } } /** * {@link Tube} pool. */ public static final class TubePool extends Pool<Tube> { private final Tube master; public TubePool(Tube master) { this.master = master; recycle(master); // we'll use master as a part of the pool, too. } protected Tube create() { return TubeCloner.clone(master); } } }