1 /*
   2  * Copyright (c) 2002, 2018, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 package gc.gctests.WeakReferenceGC;
  25 
  26 class node {
  27     byte [] arr;
  28     node next;
  29     node prev;
  30     node(){ arr = new byte[100]; }
  31 }
  32 
  33 public class CircularLinkedList implements Cloneable {
  34     private node Root;
  35 
  36     public void addElement() {
  37        node newnode;
  38 
  39        newnode = new node();
  40        if (Root == null){
  41           Root = newnode;
  42           Root.next = Root;
  43           Root.prev = Root;
  44        } else{
  45           newnode.next = Root.next;
  46           Root.next.prev = newnode;
  47           Root.next = newnode;
  48           newnode.prev = Root;
  49        }
  50     }
  51 
  52     public void addNelements(int n) {
  53        for (int i = 0; i < n ; i++)
  54           addElement();
  55     }
  56 
  57     public int elementCount() {
  58        node p;
  59        int count;
  60 
  61        p = Root;
  62        count = 0;
  63 
  64        do {
  65           p = p.prev;
  66           count++;
  67        }while(p != Root);
  68        return count;
  69     }
  70 
  71     public Object clone() {
  72        node p;
  73        p = Root;
  74 
  75        if ( p == null ) return null;
  76        CircularLinkedList clone = new CircularLinkedList();
  77        do {
  78           clone.addElement();
  79           p = p.prev;
  80        } while(p != Root);
  81        return clone;
  82     }
  83 }