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1 /* $NetBSD: queue.h,v 1.45.14.1 2007/07/18 20:13:24 liamjfoy Exp $ */ |
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2 |
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3 /* |
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4 * Qemu version: Copy from netbsd, removed debug code, removed some of |
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5 * the implementations. Left in lists, tail queues and circular queues. |
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6 */ |
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7 |
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8 /* |
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9 * Copyright (c) 1991, 1993 |
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10 * The Regents of the University of California. All rights reserved. |
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11 * |
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12 * Redistribution and use in source and binary forms, with or without |
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13 * modification, are permitted provided that the following conditions |
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14 * are met: |
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15 * 1. Redistributions of source code must retain the above copyright |
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16 * notice, this list of conditions and the following disclaimer. |
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17 * 2. Redistributions in binary form must reproduce the above copyright |
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18 * notice, this list of conditions and the following disclaimer in the |
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19 * documentation and/or other materials provided with the distribution. |
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20 * 3. Neither the name of the University nor the names of its contributors |
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21 * may be used to endorse or promote products derived from this software |
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22 * without specific prior written permission. |
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23 * |
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24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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34 * SUCH DAMAGE. |
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35 * |
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36 * @(#)queue.h 8.5 (Berkeley) 8/20/94 |
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37 */ |
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38 |
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39 #ifndef _SYS_QUEUE_H_ |
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40 #define _SYS_QUEUE_H_ |
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41 |
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42 /* |
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43 * This file defines three types of data structures: |
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44 * lists, tail queues, and circular queues. |
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45 * |
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46 * A list is headed by a single forward pointer (or an array of forward |
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47 * pointers for a hash table header). The elements are doubly linked |
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48 * so that an arbitrary element can be removed without a need to |
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49 * traverse the list. New elements can be added to the list before |
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50 * or after an existing element or at the head of the list. A list |
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51 * may only be traversed in the forward direction. |
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52 * |
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53 * A tail queue is headed by a pair of pointers, one to the head of the |
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54 * list and the other to the tail of the list. The elements are doubly |
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55 * linked so that an arbitrary element can be removed without a need to |
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56 * traverse the list. New elements can be added to the list before or |
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57 * after an existing element, at the head of the list, or at the end of |
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58 * the list. A tail queue may be traversed in either direction. |
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59 * |
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60 * A circle queue is headed by a pair of pointers, one to the head of the |
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61 * list and the other to the tail of the list. The elements are doubly |
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62 * linked so that an arbitrary element can be removed without a need to |
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63 * traverse the list. New elements can be added to the list before or after |
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64 * an existing element, at the head of the list, or at the end of the list. |
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65 * A circle queue may be traversed in either direction, but has a more |
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66 * complex end of list detection. |
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67 * |
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68 * For details on the use of these macros, see the queue(3) manual page. |
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69 */ |
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70 |
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71 /* |
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72 * List definitions. |
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73 */ |
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74 #define LIST_HEAD(name, type) \ |
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75 struct name { \ |
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76 struct type *lh_first; /* first element */ \ |
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77 } |
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78 |
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79 #define LIST_HEAD_INITIALIZER(head) \ |
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80 { NULL } |
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81 |
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82 #define LIST_ENTRY(type) \ |
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83 struct { \ |
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84 struct type *le_next; /* next element */ \ |
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85 struct type **le_prev; /* address of previous next element */ \ |
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86 } |
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87 |
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88 /* |
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89 * List functions. |
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90 */ |
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91 #define LIST_INIT(head) do { \ |
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92 (head)->lh_first = NULL; \ |
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93 } while (/*CONSTCOND*/0) |
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94 |
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95 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ |
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96 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ |
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97 (listelm)->field.le_next->field.le_prev = \ |
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98 &(elm)->field.le_next; \ |
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99 (listelm)->field.le_next = (elm); \ |
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100 (elm)->field.le_prev = &(listelm)->field.le_next; \ |
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101 } while (/*CONSTCOND*/0) |
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102 |
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103 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ |
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104 (elm)->field.le_prev = (listelm)->field.le_prev; \ |
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105 (elm)->field.le_next = (listelm); \ |
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106 *(listelm)->field.le_prev = (elm); \ |
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107 (listelm)->field.le_prev = &(elm)->field.le_next; \ |
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108 } while (/*CONSTCOND*/0) |
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109 |
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110 #define LIST_INSERT_HEAD(head, elm, field) do { \ |
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111 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ |
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112 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ |
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113 (head)->lh_first = (elm); \ |
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114 (elm)->field.le_prev = &(head)->lh_first; \ |
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115 } while (/*CONSTCOND*/0) |
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116 |
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117 #define LIST_REMOVE(elm, field) do { \ |
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118 if ((elm)->field.le_next != NULL) \ |
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119 (elm)->field.le_next->field.le_prev = \ |
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120 (elm)->field.le_prev; \ |
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121 *(elm)->field.le_prev = (elm)->field.le_next; \ |
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122 } while (/*CONSTCOND*/0) |
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123 |
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124 #define LIST_FOREACH(var, head, field) \ |
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125 for ((var) = ((head)->lh_first); \ |
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126 (var); \ |
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127 (var) = ((var)->field.le_next)) |
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128 |
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129 /* |
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130 * List access methods. |
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131 */ |
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132 #define LIST_EMPTY(head) ((head)->lh_first == NULL) |
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133 #define LIST_FIRST(head) ((head)->lh_first) |
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134 #define LIST_NEXT(elm, field) ((elm)->field.le_next) |
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135 |
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136 |
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137 /* |
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138 * Tail queue definitions. |
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139 */ |
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140 #define _TAILQ_HEAD(name, type, qual) \ |
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141 struct name { \ |
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142 qual type *tqh_first; /* first element */ \ |
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143 qual type *qual *tqh_last; /* addr of last next element */ \ |
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144 } |
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145 #define TAILQ_HEAD(name, type) _TAILQ_HEAD(name, struct type,) |
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146 |
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147 #define TAILQ_HEAD_INITIALIZER(head) \ |
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148 { NULL, &(head).tqh_first } |
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149 |
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150 #define _TAILQ_ENTRY(type, qual) \ |
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151 struct { \ |
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152 qual type *tqe_next; /* next element */ \ |
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153 qual type *qual *tqe_prev; /* address of previous next element */\ |
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154 } |
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155 #define TAILQ_ENTRY(type) _TAILQ_ENTRY(struct type,) |
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156 |
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157 /* |
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158 * Tail queue functions. |
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159 */ |
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160 #define TAILQ_INIT(head) do { \ |
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161 (head)->tqh_first = NULL; \ |
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162 (head)->tqh_last = &(head)->tqh_first; \ |
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163 } while (/*CONSTCOND*/0) |
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164 |
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165 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ |
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166 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ |
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167 (head)->tqh_first->field.tqe_prev = \ |
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168 &(elm)->field.tqe_next; \ |
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169 else \ |
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170 (head)->tqh_last = &(elm)->field.tqe_next; \ |
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171 (head)->tqh_first = (elm); \ |
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172 (elm)->field.tqe_prev = &(head)->tqh_first; \ |
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173 } while (/*CONSTCOND*/0) |
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174 |
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175 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ |
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176 (elm)->field.tqe_next = NULL; \ |
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177 (elm)->field.tqe_prev = (head)->tqh_last; \ |
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178 *(head)->tqh_last = (elm); \ |
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179 (head)->tqh_last = &(elm)->field.tqe_next; \ |
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180 } while (/*CONSTCOND*/0) |
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181 |
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182 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ |
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183 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ |
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184 (elm)->field.tqe_next->field.tqe_prev = \ |
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185 &(elm)->field.tqe_next; \ |
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186 else \ |
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187 (head)->tqh_last = &(elm)->field.tqe_next; \ |
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188 (listelm)->field.tqe_next = (elm); \ |
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189 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ |
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190 } while (/*CONSTCOND*/0) |
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191 |
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192 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ |
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193 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ |
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194 (elm)->field.tqe_next = (listelm); \ |
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195 *(listelm)->field.tqe_prev = (elm); \ |
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196 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ |
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197 } while (/*CONSTCOND*/0) |
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198 |
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199 #define TAILQ_REMOVE(head, elm, field) do { \ |
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200 if (((elm)->field.tqe_next) != NULL) \ |
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201 (elm)->field.tqe_next->field.tqe_prev = \ |
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202 (elm)->field.tqe_prev; \ |
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203 else \ |
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204 (head)->tqh_last = (elm)->field.tqe_prev; \ |
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205 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ |
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206 } while (/*CONSTCOND*/0) |
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207 |
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208 #define TAILQ_FOREACH(var, head, field) \ |
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209 for ((var) = ((head)->tqh_first); \ |
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210 (var); \ |
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211 (var) = ((var)->field.tqe_next)) |
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212 |
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213 #define TAILQ_FOREACH_SAFE(var, head, field, next_var) \ |
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214 for ((var) = ((head)->tqh_first); \ |
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215 (var) && ((next_var) = ((var)->field.tqe_next), 1); \ |
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216 (var) = (next_var)) |
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217 |
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218 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ |
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219 for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \ |
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220 (var); \ |
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221 (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last))) |
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222 |
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223 /* |
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224 * Tail queue access methods. |
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225 */ |
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226 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) |
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227 #define TAILQ_FIRST(head) ((head)->tqh_first) |
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228 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) |
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229 |
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230 #define TAILQ_LAST(head, headname) \ |
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231 (*(((struct headname *)((head)->tqh_last))->tqh_last)) |
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232 #define TAILQ_PREV(elm, headname, field) \ |
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233 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) |
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234 |
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235 |
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236 /* |
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237 * Circular queue definitions. |
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238 */ |
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239 #define CIRCLEQ_HEAD(name, type) \ |
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240 struct name { \ |
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241 struct type *cqh_first; /* first element */ \ |
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242 struct type *cqh_last; /* last element */ \ |
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243 } |
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244 |
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245 #define CIRCLEQ_HEAD_INITIALIZER(head) \ |
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246 { (void *)&head, (void *)&head } |
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247 |
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248 #define CIRCLEQ_ENTRY(type) \ |
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249 struct { \ |
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250 struct type *cqe_next; /* next element */ \ |
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251 struct type *cqe_prev; /* previous element */ \ |
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252 } |
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253 |
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254 /* |
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255 * Circular queue functions. |
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256 */ |
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257 #define CIRCLEQ_INIT(head) do { \ |
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258 (head)->cqh_first = (void *)(head); \ |
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259 (head)->cqh_last = (void *)(head); \ |
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260 } while (/*CONSTCOND*/0) |
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261 |
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262 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ |
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263 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ |
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264 (elm)->field.cqe_prev = (listelm); \ |
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265 if ((listelm)->field.cqe_next == (void *)(head)) \ |
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266 (head)->cqh_last = (elm); \ |
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267 else \ |
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268 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ |
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269 (listelm)->field.cqe_next = (elm); \ |
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270 } while (/*CONSTCOND*/0) |
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271 |
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272 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ |
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273 (elm)->field.cqe_next = (listelm); \ |
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274 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ |
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275 if ((listelm)->field.cqe_prev == (void *)(head)) \ |
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276 (head)->cqh_first = (elm); \ |
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277 else \ |
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278 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ |
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279 (listelm)->field.cqe_prev = (elm); \ |
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280 } while (/*CONSTCOND*/0) |
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281 |
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282 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ |
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283 (elm)->field.cqe_next = (head)->cqh_first; \ |
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284 (elm)->field.cqe_prev = (void *)(head); \ |
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285 if ((head)->cqh_last == (void *)(head)) \ |
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286 (head)->cqh_last = (elm); \ |
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287 else \ |
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288 (head)->cqh_first->field.cqe_prev = (elm); \ |
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289 (head)->cqh_first = (elm); \ |
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290 } while (/*CONSTCOND*/0) |
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291 |
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292 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ |
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293 (elm)->field.cqe_next = (void *)(head); \ |
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294 (elm)->field.cqe_prev = (head)->cqh_last; \ |
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295 if ((head)->cqh_first == (void *)(head)) \ |
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296 (head)->cqh_first = (elm); \ |
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297 else \ |
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298 (head)->cqh_last->field.cqe_next = (elm); \ |
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299 (head)->cqh_last = (elm); \ |
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300 } while (/*CONSTCOND*/0) |
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301 |
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302 #define CIRCLEQ_REMOVE(head, elm, field) do { \ |
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303 if ((elm)->field.cqe_next == (void *)(head)) \ |
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304 (head)->cqh_last = (elm)->field.cqe_prev; \ |
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305 else \ |
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306 (elm)->field.cqe_next->field.cqe_prev = \ |
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307 (elm)->field.cqe_prev; \ |
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308 if ((elm)->field.cqe_prev == (void *)(head)) \ |
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309 (head)->cqh_first = (elm)->field.cqe_next; \ |
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310 else \ |
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311 (elm)->field.cqe_prev->field.cqe_next = \ |
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312 (elm)->field.cqe_next; \ |
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313 } while (/*CONSTCOND*/0) |
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314 |
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315 #define CIRCLEQ_FOREACH(var, head, field) \ |
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316 for ((var) = ((head)->cqh_first); \ |
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317 (var) != (const void *)(head); \ |
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318 (var) = ((var)->field.cqe_next)) |
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319 |
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320 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ |
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321 for ((var) = ((head)->cqh_last); \ |
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322 (var) != (const void *)(head); \ |
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323 (var) = ((var)->field.cqe_prev)) |
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324 |
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325 /* |
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326 * Circular queue access methods. |
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327 */ |
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328 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) |
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329 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) |
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330 #define CIRCLEQ_LAST(head) ((head)->cqh_last) |
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331 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) |
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332 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) |
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333 |
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334 #define CIRCLEQ_LOOP_NEXT(head, elm, field) \ |
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335 (((elm)->field.cqe_next == (void *)(head)) \ |
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336 ? ((head)->cqh_first) \ |
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337 : (elm->field.cqe_next)) |
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338 #define CIRCLEQ_LOOP_PREV(head, elm, field) \ |
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339 (((elm)->field.cqe_prev == (void *)(head)) \ |
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340 ? ((head)->cqh_last) \ |
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341 : (elm->field.cqe_prev)) |
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342 |
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343 #endif /* !_SYS_QUEUE_H_ */ |