1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/jaxws_classes/com/sun/xml/internal/ws/util/Pool.java Tue Mar 06 16:09:35 2012 -0800
1.3 @@ -0,0 +1,162 @@
1.4 +/*
1.5 + * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package com.sun.xml.internal.ws.util;
1.30 +
1.31 +import com.sun.xml.internal.ws.api.pipe.Tube;
1.32 +import com.sun.xml.internal.ws.api.pipe.TubeCloner;
1.33 +
1.34 +import javax.xml.bind.JAXBContext;
1.35 +import javax.xml.bind.JAXBException;
1.36 +import java.util.concurrent.ConcurrentLinkedQueue;
1.37 +import java.lang.ref.WeakReference;
1.38 +
1.39 +/**
1.40 + * General-purpose object pool.
1.41 + *
1.42 + * <p>
1.43 + * In many parts of the runtime, we need to pool instances of objects that
1.44 + * are expensive to create (such as JAXB objects, StAX parsers, {@link Tube} instances.)
1.45 + *
1.46 + * <p>
1.47 + * This class provides a default implementation of such a pool.
1.48 + *
1.49 + * TODO: improve the implementation
1.50 + *
1.51 + * @author Kohsuke Kawaguchi
1.52 + */
1.53 +public abstract class Pool<T> {
1.54 +
1.55 + // volatile since multiple threads may access queue reference
1.56 + private volatile WeakReference<ConcurrentLinkedQueue<T>> queue;
1.57 +
1.58 + /**
1.59 + * Gets a new object from the pool.
1.60 + *
1.61 + * <p>
1.62 + * If no object is available in the pool, this method creates a new one.
1.63 + *
1.64 + * @return
1.65 + * always non-null.
1.66 + */
1.67 + public final T take() {
1.68 + T t = getQueue().poll();
1.69 + if(t==null)
1.70 + return create();
1.71 + return t;
1.72 + }
1.73 +
1.74 + private ConcurrentLinkedQueue<T> getQueue() {
1.75 + WeakReference<ConcurrentLinkedQueue<T>> q = queue;
1.76 + if (q != null) {
1.77 + ConcurrentLinkedQueue<T> d = q.get();
1.78 + if (d != null)
1.79 + return d;
1.80 + }
1.81 +
1.82 + // overwrite the queue
1.83 + ConcurrentLinkedQueue<T> d = new ConcurrentLinkedQueue<T>();
1.84 + queue = new WeakReference<ConcurrentLinkedQueue<T>>(d);
1.85 +
1.86 + return d;
1.87 + }
1.88 +
1.89 + /**
1.90 + * Returns an object back to the pool.
1.91 + */
1.92 + public final void recycle(T t) {
1.93 + getQueue().offer(t);
1.94 + }
1.95 +
1.96 + /**
1.97 + * Creates a new instance of object.
1.98 + *
1.99 + * <p>
1.100 + * This method is used when someone wants to
1.101 + * {@link #take() take} an object from an empty pool.
1.102 + *
1.103 + * <p>
1.104 + * Also note that multiple threads may call this method
1.105 + * concurrently.
1.106 + */
1.107 + protected abstract T create();
1.108 +
1.109 +
1.110 + /**
1.111 + * JAXB {@link javax.xml.bind.Marshaller} pool.
1.112 + */
1.113 + public static final class Marshaller extends Pool<javax.xml.bind.Marshaller> {
1.114 + private final JAXBContext context;
1.115 +
1.116 + public Marshaller(JAXBContext context) {
1.117 + this.context = context;
1.118 + }
1.119 +
1.120 + protected javax.xml.bind.Marshaller create() {
1.121 + try {
1.122 + return context.createMarshaller();
1.123 + } catch (JAXBException e) {
1.124 + // impossible
1.125 + throw new AssertionError(e);
1.126 + }
1.127 + }
1.128 + }
1.129 +
1.130 + /**
1.131 + * JAXB {@link javax.xml.bind.Marshaller} pool.
1.132 + */
1.133 + public static final class Unmarshaller extends Pool<javax.xml.bind.Unmarshaller> {
1.134 + private final JAXBContext context;
1.135 +
1.136 + public Unmarshaller(JAXBContext context) {
1.137 + this.context = context;
1.138 + }
1.139 +
1.140 + protected javax.xml.bind.Unmarshaller create() {
1.141 + try {
1.142 + return context.createUnmarshaller();
1.143 + } catch (JAXBException e) {
1.144 + // impossible
1.145 + throw new AssertionError(e);
1.146 + }
1.147 + }
1.148 + }
1.149 +
1.150 + /**
1.151 + * {@link Tube} pool.
1.152 + */
1.153 + public static final class TubePool extends Pool<Tube> {
1.154 + private final Tube master;
1.155 +
1.156 + public TubePool(Tube master) {
1.157 + this.master = master;
1.158 + recycle(master); // we'll use master as a part of the pool, too.
1.159 + }
1.160 +
1.161 + protected Tube create() {
1.162 + return TubeCloner.clone(master);
1.163 + }
1.164 + }
1.165 +}
