Wed, 27 Apr 2016 01:27:09 +0800
Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/jaxws/
changeset: 657:d47a47f961ee
tag: jdk8u25-b17
aoqi@0 | 1 | /* |
aoqi@0 | 2 | * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
aoqi@0 | 4 | * |
aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
aoqi@0 | 7 | * published by the Free Software Foundation. Oracle designates this |
aoqi@0 | 8 | * particular file as subject to the "Classpath" exception as provided |
aoqi@0 | 9 | * by Oracle in the LICENSE file that accompanied this code. |
aoqi@0 | 10 | * |
aoqi@0 | 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
aoqi@0 | 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
aoqi@0 | 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
aoqi@0 | 14 | * version 2 for more details (a copy is included in the LICENSE file that |
aoqi@0 | 15 | * accompanied this code). |
aoqi@0 | 16 | * |
aoqi@0 | 17 | * You should have received a copy of the GNU General Public License version |
aoqi@0 | 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
aoqi@0 | 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
aoqi@0 | 20 | * |
aoqi@0 | 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
aoqi@0 | 22 | * or visit www.oracle.com if you need additional information or have any |
aoqi@0 | 23 | * questions. |
aoqi@0 | 24 | */ |
aoqi@0 | 25 | |
aoqi@0 | 26 | package com.sun.istack.internal; |
aoqi@0 | 27 | |
aoqi@0 | 28 | import java.util.concurrent.ConcurrentLinkedQueue; |
aoqi@0 | 29 | import java.lang.ref.WeakReference; |
aoqi@0 | 30 | |
aoqi@0 | 31 | /** |
aoqi@0 | 32 | * Pool of reusable objects that are indistinguishable from each other, |
aoqi@0 | 33 | * such as JAXB marshallers. |
aoqi@0 | 34 | * |
aoqi@0 | 35 | * @author Kohsuke Kawaguchi |
aoqi@0 | 36 | */ |
aoqi@0 | 37 | public interface Pool<T> { |
aoqi@0 | 38 | |
aoqi@0 | 39 | /** |
aoqi@0 | 40 | * Gets a new object from the pool. |
aoqi@0 | 41 | * |
aoqi@0 | 42 | * <p> |
aoqi@0 | 43 | * If no object is available in the pool, this method creates a new one. |
aoqi@0 | 44 | */ |
aoqi@0 | 45 | @NotNull T take(); |
aoqi@0 | 46 | |
aoqi@0 | 47 | /** |
aoqi@0 | 48 | * Returns an object back to the pool. |
aoqi@0 | 49 | */ |
aoqi@0 | 50 | void recycle(@NotNull T t); |
aoqi@0 | 51 | |
aoqi@0 | 52 | /** |
aoqi@0 | 53 | * Default implementation that uses {@link ConcurrentLinkedQueue} |
aoqi@0 | 54 | * as the data store. |
aoqi@0 | 55 | * |
aoqi@0 | 56 | * <h2>Note for Implementors</h2> |
aoqi@0 | 57 | * <p> |
aoqi@0 | 58 | * Don't rely on the fact that this class extends from {@link ConcurrentLinkedQueue}. |
aoqi@0 | 59 | */ |
aoqi@0 | 60 | public abstract class Impl<T> implements Pool<T> { |
aoqi@0 | 61 | |
aoqi@0 | 62 | private volatile WeakReference<ConcurrentLinkedQueue<T>> queue; |
aoqi@0 | 63 | |
aoqi@0 | 64 | /** |
aoqi@0 | 65 | * Gets a new object from the pool. |
aoqi@0 | 66 | * |
aoqi@0 | 67 | * <p> |
aoqi@0 | 68 | * If no object is available in the pool, this method creates a new one. |
aoqi@0 | 69 | * |
aoqi@0 | 70 | * @return |
aoqi@0 | 71 | * always non-null. |
aoqi@0 | 72 | */ |
aoqi@0 | 73 | public final @NotNull T take() { |
aoqi@0 | 74 | T t = getQueue().poll(); |
aoqi@0 | 75 | if(t==null) { |
aoqi@0 | 76 | return create(); |
aoqi@0 | 77 | } |
aoqi@0 | 78 | return t; |
aoqi@0 | 79 | } |
aoqi@0 | 80 | |
aoqi@0 | 81 | /** |
aoqi@0 | 82 | * Returns an object back to the pool. |
aoqi@0 | 83 | */ |
aoqi@0 | 84 | public final void recycle(T t) { |
aoqi@0 | 85 | getQueue().offer(t); |
aoqi@0 | 86 | } |
aoqi@0 | 87 | |
aoqi@0 | 88 | private ConcurrentLinkedQueue<T> getQueue() { |
aoqi@0 | 89 | WeakReference<ConcurrentLinkedQueue<T>> q = queue; |
aoqi@0 | 90 | if (q != null) { |
aoqi@0 | 91 | ConcurrentLinkedQueue<T> d = q.get(); |
aoqi@0 | 92 | if (d != null) { |
aoqi@0 | 93 | return d; |
aoqi@0 | 94 | } |
aoqi@0 | 95 | } |
aoqi@0 | 96 | // overwrite the queue |
aoqi@0 | 97 | ConcurrentLinkedQueue<T> d = new ConcurrentLinkedQueue<T>(); |
aoqi@0 | 98 | queue = new WeakReference<ConcurrentLinkedQueue<T>>(d); |
aoqi@0 | 99 | |
aoqi@0 | 100 | return d; |
aoqi@0 | 101 | } |
aoqi@0 | 102 | |
aoqi@0 | 103 | /** |
aoqi@0 | 104 | * Creates a new instance of object. |
aoqi@0 | 105 | * |
aoqi@0 | 106 | * <p> |
aoqi@0 | 107 | * This method is used when someone wants to |
aoqi@0 | 108 | * {@link #take() take} an object from an empty pool. |
aoqi@0 | 109 | * |
aoqi@0 | 110 | * <p> |
aoqi@0 | 111 | * Also note that multiple threads may call this method |
aoqi@0 | 112 | * concurrently. |
aoqi@0 | 113 | */ |
aoqi@0 | 114 | protected abstract @NotNull T create(); |
aoqi@0 | 115 | } |
aoqi@0 | 116 | } |