| /* |
| * Copyright 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; |
| |
| /** |
| * 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> extends ConcurrentLinkedQueue<T> implements Pool<T> { |
| /** |
| * 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 = super.poll(); |
| if(t==null) |
| return create(); |
| return t; |
| } |
| |
| /** |
| * Returns an object back to the pool. |
| */ |
| public final void recycle(T t) { |
| super.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 @NotNull T create(); |
| } |
| } |