001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.activemq.memory; 018 019public class CacheEntry { 020 021 public final Object key; 022 public final Object value; 023 024 public CacheEntry next; 025 public CacheEntry previous; 026 public CacheEntryList owner; 027 028 public CacheEntry(Object key, Object value) { 029 this.key = key; 030 this.value = value; 031 } 032 033 /** 034 * @return false if you are trying to remove the tail pointer. 035 */ 036 public boolean remove() { 037 038 // Cannot remove if this is a tail pointer. 039 // Or not linked. 040 if (owner == null || this.key == null || this.next == null) { 041 return false; 042 } 043 044 synchronized (owner.tail) { 045 this.next.previous = this.previous; 046 this.previous.next = this.next; 047 this.owner = null; 048 this.next = null; 049 this.previous = null; 050 } 051 052 return true; 053 } 054}