1 /*
   2  * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.xml.internal.stream.util;
  27 
  28 import java.lang.ref.*;
  29 
  30 /**
  31  * This is a Singleton class that allows you to allocate buffer that
  32  * are stored in ThreadLocal. This class stores 3 types of char
  33  * buffers - small (< 128 bytes), medium (<2K) and large (> 2K) as
  34  * well as three byte buffers - small, medium and large.
  35  * The local storage is activated on the return of the buffer.
  36  * The buffer returns null if it is already allocated.
  37  *
  38  * @author Binu.John@sun.com
  39  * @author Santiago.PericasGeertsen@sun.com
  40  */
  41 public class ThreadLocalBufferAllocator {
  42    private static ThreadLocal<SoftReference<BufferAllocator>> tlba = new ThreadLocal<>();
  43 
  44    public static BufferAllocator getBufferAllocator() {
  45         SoftReference<BufferAllocator> bAllocatorRef = tlba.get();
  46         if (bAllocatorRef == null || bAllocatorRef.get() == null) {
  47             bAllocatorRef = new SoftReference<>(new BufferAllocator());
  48             tlba.set(bAllocatorRef);
  49         }
  50 
  51         return bAllocatorRef.get();
  52    }
  53 }
--- EOF ---