1 /* $NetBSD: queue.h,v 1.45.14.1 2007/07/18 20:13:24 liamjfoy Exp $ */ 2 3 /* 4 * Qemu version: Copy from netbsd, removed debug code, removed some of 5 * the implementations. Left in lists, tail queues and circular queues. 6 */ 7 8 /* 9 * Copyright (c) 1991, 1993 10 * The Regents of the University of California. All rights reserved. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)queue.h 8.5 (Berkeley) 8/20/94 37 */ 38 39 #ifndef _SYS_QUEUE_H_ 40 #define _SYS_QUEUE_H_ 41 42 /* 43 * This file defines three types of data structures: 44 * lists, tail queues, and circular queues. 45 * 46 * A list is headed by a single forward pointer (or an array of forward 47 * pointers for a hash table header). The elements are doubly linked 48 * so that an arbitrary element can be removed without a need to 49 * traverse the list. New elements can be added to the list before 50 * or after an existing element or at the head of the list. A list 51 * may only be traversed in the forward direction. 52 * 53 * A tail queue is headed by a pair of pointers, one to the head of the 54 * list and the other to the tail of the list. The elements are doubly 55 * linked so that an arbitrary element can be removed without a need to 56 * traverse the list. New elements can be added to the list before or 57 * after an existing element, at the head of the list, or at the end of 58 * the list. A tail queue may be traversed in either direction. 59 * 60 * A circle queue is headed by a pair of pointers, one to the head of the 61 * list and the other to the tail of the list. The elements are doubly 62 * linked so that an arbitrary element can be removed without a need to 63 * traverse the list. New elements can be added to the list before or after 64 * an existing element, at the head of the list, or at the end of the list. 65 * A circle queue may be traversed in either direction, but has a more 66 * complex end of list detection. 67 * 68 * For details on the use of these macros, see the queue(3) manual page. 69 */ 70 71 /* 72 * List definitions. 73 */ 74 #define LIST_HEAD(name, type) \ 75 struct name { \ 76 struct type *lh_first; /* first element */ \ 77 } 78 79 #define LIST_HEAD_INITIALIZER(head) \ 80 { NULL } 81 82 #define LIST_ENTRY(type) \ 83 struct { \ 84 struct type *le_next; /* next element */ \ 85 struct type **le_prev; /* address of previous next element */ \ 86 } 87 88 /* 89 * List functions. 90 */ 91 #define LIST_INIT(head) do { \ 92 (head)->lh_first = NULL; \ 93 } while (/*CONSTCOND*/0) 94 95 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 96 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 97 (listelm)->field.le_next->field.le_prev = \ 98 &(elm)->field.le_next; \ 99 (listelm)->field.le_next = (elm); \ 100 (elm)->field.le_prev = &(listelm)->field.le_next; \ 101 } while (/*CONSTCOND*/0) 102 103 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 104 (elm)->field.le_prev = (listelm)->field.le_prev; \ 105 (elm)->field.le_next = (listelm); \ 106 *(listelm)->field.le_prev = (elm); \ 107 (listelm)->field.le_prev = &(elm)->field.le_next; \ 108 } while (/*CONSTCOND*/0) 109 110 #define LIST_INSERT_HEAD(head, elm, field) do { \ 111 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 112 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 113 (head)->lh_first = (elm); \ 114 (elm)->field.le_prev = &(head)->lh_first; \ 115 } while (/*CONSTCOND*/0) 116 117 #define LIST_REMOVE(elm, field) do { \ 118 if ((elm)->field.le_next != NULL) \ 119 (elm)->field.le_next->field.le_prev = \ 120 (elm)->field.le_prev; \ 121 *(elm)->field.le_prev = (elm)->field.le_next; \ 122 } while (/*CONSTCOND*/0) 123 124 #define LIST_FOREACH(var, head, field) \ 125 for ((var) = ((head)->lh_first); \ 126 (var); \ 127 (var) = ((var)->field.le_next)) 128 129 /* 130 * List access methods. 131 */ 132 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 133 #define LIST_FIRST(head) ((head)->lh_first) 134 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 135 136 137 /* 138 * Tail queue definitions. 139 */ 140 #define _TAILQ_HEAD(name, type, qual) \ 141 struct name { \ 142 qual type *tqh_first; /* first element */ \ 143 qual type *qual *tqh_last; /* addr of last next element */ \ 144 } 145 #define TAILQ_HEAD(name, type) _TAILQ_HEAD(name, struct type,) 146 147 #define TAILQ_HEAD_INITIALIZER(head) \ 148 { NULL, &(head).tqh_first } 149 150 #define _TAILQ_ENTRY(type, qual) \ 151 struct { \ 152 qual type *tqe_next; /* next element */ \ 153 qual type *qual *tqe_prev; /* address of previous next element */\ 154 } 155 #define TAILQ_ENTRY(type) _TAILQ_ENTRY(struct type,) 156 157 /* 158 * Tail queue functions. 159 */ 160 #define TAILQ_INIT(head) do { \ 161 (head)->tqh_first = NULL; \ 162 (head)->tqh_last = &(head)->tqh_first; \ 163 } while (/*CONSTCOND*/0) 164 165 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 166 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 167 (head)->tqh_first->field.tqe_prev = \ 168 &(elm)->field.tqe_next; \ 169 else \ 170 (head)->tqh_last = &(elm)->field.tqe_next; \ 171 (head)->tqh_first = (elm); \ 172 (elm)->field.tqe_prev = &(head)->tqh_first; \ 173 } while (/*CONSTCOND*/0) 174 175 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 176 (elm)->field.tqe_next = NULL; \ 177 (elm)->field.tqe_prev = (head)->tqh_last; \ 178 *(head)->tqh_last = (elm); \ 179 (head)->tqh_last = &(elm)->field.tqe_next; \ 180 } while (/*CONSTCOND*/0) 181 182 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 183 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 184 (elm)->field.tqe_next->field.tqe_prev = \ 185 &(elm)->field.tqe_next; \ 186 else \ 187 (head)->tqh_last = &(elm)->field.tqe_next; \ 188 (listelm)->field.tqe_next = (elm); \ 189 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 190 } while (/*CONSTCOND*/0) 191 192 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 193 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 194 (elm)->field.tqe_next = (listelm); \ 195 *(listelm)->field.tqe_prev = (elm); \ 196 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 197 } while (/*CONSTCOND*/0) 198 199 #define TAILQ_REMOVE(head, elm, field) do { \ 200 if (((elm)->field.tqe_next) != NULL) \ 201 (elm)->field.tqe_next->field.tqe_prev = \ 202 (elm)->field.tqe_prev; \ 203 else \ 204 (head)->tqh_last = (elm)->field.tqe_prev; \ 205 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 206 } while (/*CONSTCOND*/0) 207 208 #define TAILQ_FOREACH(var, head, field) \ 209 for ((var) = ((head)->tqh_first); \ 210 (var); \ 211 (var) = ((var)->field.tqe_next)) 212 213 #define TAILQ_FOREACH_SAFE(var, head, field, next_var) \ 214 for ((var) = ((head)->tqh_first); \ 215 (var) && ((next_var) = ((var)->field.tqe_next), 1); \ 216 (var) = (next_var)) 217 218 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 219 for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \ 220 (var); \ 221 (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last))) 222 223 /* 224 * Tail queue access methods. 225 */ 226 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 227 #define TAILQ_FIRST(head) ((head)->tqh_first) 228 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 229 230 #define TAILQ_LAST(head, headname) \ 231 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 232 #define TAILQ_PREV(elm, headname, field) \ 233 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 234 235 236 /* 237 * Circular queue definitions. 238 */ 239 #define CIRCLEQ_HEAD(name, type) \ 240 struct name { \ 241 struct type *cqh_first; /* first element */ \ 242 struct type *cqh_last; /* last element */ \ 243 } 244 245 #define CIRCLEQ_HEAD_INITIALIZER(head) \ 246 { (void *)&head, (void *)&head } 247 248 #define CIRCLEQ_ENTRY(type) \ 249 struct { \ 250 struct type *cqe_next; /* next element */ \ 251 struct type *cqe_prev; /* previous element */ \ 252 } 253 254 /* 255 * Circular queue functions. 256 */ 257 #define CIRCLEQ_INIT(head) do { \ 258 (head)->cqh_first = (void *)(head); \ 259 (head)->cqh_last = (void *)(head); \ 260 } while (/*CONSTCOND*/0) 261 262 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 263 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 264 (elm)->field.cqe_prev = (listelm); \ 265 if ((listelm)->field.cqe_next == (void *)(head)) \ 266 (head)->cqh_last = (elm); \ 267 else \ 268 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 269 (listelm)->field.cqe_next = (elm); \ 270 } while (/*CONSTCOND*/0) 271 272 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 273 (elm)->field.cqe_next = (listelm); \ 274 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 275 if ((listelm)->field.cqe_prev == (void *)(head)) \ 276 (head)->cqh_first = (elm); \ 277 else \ 278 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 279 (listelm)->field.cqe_prev = (elm); \ 280 } while (/*CONSTCOND*/0) 281 282 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 283 (elm)->field.cqe_next = (head)->cqh_first; \ 284 (elm)->field.cqe_prev = (void *)(head); \ 285 if ((head)->cqh_last == (void *)(head)) \ 286 (head)->cqh_last = (elm); \ 287 else \ 288 (head)->cqh_first->field.cqe_prev = (elm); \ 289 (head)->cqh_first = (elm); \ 290 } while (/*CONSTCOND*/0) 291 292 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 293 (elm)->field.cqe_next = (void *)(head); \ 294 (elm)->field.cqe_prev = (head)->cqh_last; \ 295 if ((head)->cqh_first == (void *)(head)) \ 296 (head)->cqh_first = (elm); \ 297 else \ 298 (head)->cqh_last->field.cqe_next = (elm); \ 299 (head)->cqh_last = (elm); \ 300 } while (/*CONSTCOND*/0) 301 302 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 303 if ((elm)->field.cqe_next == (void *)(head)) \ 304 (head)->cqh_last = (elm)->field.cqe_prev; \ 305 else \ 306 (elm)->field.cqe_next->field.cqe_prev = \ 307 (elm)->field.cqe_prev; \ 308 if ((elm)->field.cqe_prev == (void *)(head)) \ 309 (head)->cqh_first = (elm)->field.cqe_next; \ 310 else \ 311 (elm)->field.cqe_prev->field.cqe_next = \ 312 (elm)->field.cqe_next; \ 313 } while (/*CONSTCOND*/0) 314 315 #define CIRCLEQ_FOREACH(var, head, field) \ 316 for ((var) = ((head)->cqh_first); \ 317 (var) != (const void *)(head); \ 318 (var) = ((var)->field.cqe_next)) 319 320 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 321 for ((var) = ((head)->cqh_last); \ 322 (var) != (const void *)(head); \ 323 (var) = ((var)->field.cqe_prev)) 324 325 /* 326 * Circular queue access methods. 327 */ 328 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) 329 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 330 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 331 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 332 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 333 334 #define CIRCLEQ_LOOP_NEXT(head, elm, field) \ 335 (((elm)->field.cqe_next == (void *)(head)) \ 336 ? ((head)->cqh_first) \ 337 : (elm->field.cqe_next)) 338 #define CIRCLEQ_LOOP_PREV(head, elm, field) \ 339 (((elm)->field.cqe_prev == (void *)(head)) \ 340 ? ((head)->cqh_last) \ 341 : (elm->field.cqe_prev)) 342 343 #endif /* !_SYS_QUEUE_H_ */ 344
