Mercurial > hg > release > icedtea7-forest-2.0 > jaxws
view sources/jaxws_src/src/com/sun/istack/internal/Pool.java @ 282:78c175236707
Update to jdk7-jaxws-2009_09_28.zip
author | andrew |
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date | Thu, 22 Sep 2011 02:57:13 +0100 |
parents | c608b38af726 |
children | 4f4a2cd249d8 |
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/* * 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.istack.internal; import java.util.concurrent.ConcurrentLinkedQueue; import java.lang.ref.WeakReference; /** * Pool of reusable objects that are indistinguishable from each other, * such as JAXB marshallers. * * @author Kohsuke Kawaguchi */ public interface Pool<T> { /** * Gets a new object from the pool. * * <p> * If no object is available in the pool, this method creates a new one. */ @NotNull T take(); /** * Returns an object back to the pool. */ void recycle(@NotNull T t); /** * Default implementation that uses {@link ConcurrentLinkedQueue} * as the data store. * * <h2>Note for Implementors</h2> * <p> * Don't rely on the fact that this class extends from {@link ConcurrentLinkedQueue}. */ public abstract class Impl<T> implements Pool<T> { 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 @NotNull T take() { T t = getQueue().poll(); if(t==null) { return create(); } return t; } /** * Returns an object back to the pool. */ public final void recycle(T t) { getQueue().offer(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; } /** * 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 @NotNull T create(); } }