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1 /* |
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2 * Copyright 2009 Sun Microsystems, Inc. All Rights Reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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20 * CA 95054 USA or visit www.sun.com if you need additional information or |
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21 * have any questions. |
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22 */ |
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23 |
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24 /* |
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25 * @test |
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26 * @bug 6843752 |
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27 * @summary missing code for an anti-dependent Phi in GCM |
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28 * @run main/othervm -Xbatch Test |
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29 */ |
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30 |
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31 public class Test { |
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32 |
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33 Item list; |
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34 |
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35 static class Item { |
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36 public Item next; |
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37 public Item prev; |
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38 public boolean remove; |
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39 |
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40 Item(boolean r) { remove = r; } |
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41 } |
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42 |
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43 private void linkIn(Item item) { |
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44 Item head = list; |
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45 if (head == null) { |
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46 item.next = item; |
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47 item.prev = item; |
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48 list = item; |
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49 } else { |
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50 item.next = head; |
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51 item.prev = head.prev; |
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52 head.prev.next = item; |
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53 head.prev = item; |
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54 } |
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55 } |
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56 |
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57 private void linkOut(Item item) { |
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58 Item head = list; |
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59 if (item.next == item) { |
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60 list = null; |
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61 } else { |
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62 item.prev.next = item.next; |
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63 item.next.prev = item.prev; |
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64 if (head == item) { |
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65 list = item.next; |
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66 } |
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67 } |
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68 item.next = null; |
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69 item.prev = null; // this is the null pointer we are seeing |
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70 } |
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71 |
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72 private void removeItems(int numItems) { |
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73 Item item = list; |
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74 if (item == null) { |
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75 return; |
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76 } |
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77 Item last = item.prev; |
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78 boolean done = false; |
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79 while (!done && numItems > 1) { |
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80 // the original code "done = (item == last);" triggered an infinite loop |
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81 // and was changed slightly in order to produce an exception instead. |
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82 done = (item.next == last.next); |
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83 item = item.next; |
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84 if (item.prev.remove) { |
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85 linkOut(item.prev); |
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86 } |
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87 } |
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88 } |
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89 |
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90 public void perform(int numItems) { |
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91 for (int i = 0; i < numItems; i++) { |
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92 linkIn(new Item(i == 0)); |
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93 } |
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94 removeItems(numItems); |
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95 list = null; |
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96 } |
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97 |
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98 static public void main(String[] args) { |
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99 int caseCnt = 0; |
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100 Test bj = new Test(); |
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101 try { |
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102 for (; caseCnt < 500000;) { |
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103 int numItems = (++caseCnt % 2); |
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104 if ((caseCnt % 64) == 0) { |
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105 numItems = 5; |
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106 } |
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107 bj.perform(numItems); |
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108 if ((caseCnt % 100000) == 0) { |
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109 System.out.println("successfully performed " + caseCnt + " cases"); |
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110 } |
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111 } |
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112 } catch (Exception e) { |
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113 System.out.println("ERROR: crashed during case " + caseCnt); |
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114 e.printStackTrace(System.out); |
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115 System.exit(97); |
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116 } |
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117 } |
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118 } |
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119 |