Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/sys/queue.h
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)queue.h 8.5 (Berkeley) 8/20/94 34 * $FreeBSD$ 35 */ 36 37 #ifndef _SYS_QUEUE_H_ 38 #define _SYS_QUEUE_H_ 39 40 /* 41 * This file defines five types of data structures: singly-linked lists, 42 * singly-linked tail queues, lists, tail queues, and circular queues. 43 * 44 * A singly-linked list is headed by a single forward pointer. The elements 45 * are singly linked for minimum space and pointer manipulation overhead at 46 * the expense of O(n) removal for arbitrary elements. New elements can be 47 * added to the list after an existing element or at the head of the list. 48 * Elements being removed from the head of the list should use the explicit 49 * macro for this purpose for optimum efficiency. A singly-linked list may 50 * only be traversed in the forward direction. Singly-linked lists are ideal 51 * for applications with large datasets and few or no removals or for 52 * implementing a LIFO queue. 53 * 54 * A singly-linked tail queue is headed by a pair of pointers, one to the 55 * head of the list and the other to the tail of the list. The elements are 56 * singly linked for minimum space and pointer manipulation overhead at the 57 * expense of O(n) removal for arbitrary elements. New elements can be added 58 * to the list after an existing element, at the head of the list, or at the 59 * end of the list. Elements being removed from the head of the tail queue 60 * should use the explicit macro for this purpose for optimum efficiency. 61 * A singly-linked tail queue may only be traversed in the forward direction. 62 * Singly-linked tail queues are ideal for applications with large datasets 63 * and few or no removals or for implementing a FIFO queue. 64 * 65 * A list is headed by a single forward pointer (or an array of forward 66 * pointers for a hash table header). The elements are doubly linked 67 * so that an arbitrary element can be removed without a need to 68 * traverse the list. New elements can be added to the list before 69 * or after an existing element or at the head of the list. A list 70 * may only be traversed in the forward direction. 71 * 72 * A tail queue is headed by a pair of pointers, one to the head of the 73 * list and the other to the tail of the list. The elements are doubly 74 * linked so that an arbitrary element can be removed without a need to 75 * traverse the list. New elements can be added to the list before or 76 * after an existing element, at the head of the list, or at the end of 77 * the list. A tail queue may be traversed in either direction. 78 * 79 * A circle queue is headed by a pair of pointers, one to the head of the 80 * list and the other to the tail of the list. The elements are doubly 81 * linked so that an arbitrary element can be removed without a need to 82 * traverse the list. New elements can be added to the list before or after 83 * an existing element, at the head of the list, or at the end of the list. 84 * A circle queue may be traversed in either direction, but has a more 85 * complex end of list detection. 86 * 87 * For details on the use of these macros, see the queue(3) manual page. 88 * 89 * 90 * SLIST LIST STAILQ TAILQ CIRCLEQ 91 * _HEAD + + + + + 92 * _ENTRY + + + + + 93 * _INIT + + + + + 94 * _EMPTY + + + + + 95 * _FIRST + + + + + 96 * _NEXT + + + + + 97 * _PREV - - - + + 98 * _LAST - - + + + 99 * _FOREACH + + + + + 100 * _FOREACH_REVERSE - - - + + 101 * _INSERT_HEAD + + + + + 102 * _INSERT_BEFORE - + - + + 103 * _INSERT_AFTER + + + + + 104 * _INSERT_TAIL - - + + + 105 * _REMOVE_HEAD + - + - - 106 * _REMOVE + + + + + 107 * 108 */ 109 110 /* 111 * Singly-linked List definitions. 112 */ 113 #define SLIST_HEAD(name, type) \ 114 struct name { \ 115 struct type *slh_first; /* first element */ \ 116 } 117 118 #define SLIST_HEAD_INITIALIZER(head) \ 119 { NULL } 120 121 #define SLIST_ENTRY(type) \ 122 struct { \ 123 struct type *sle_next; /* next element */ \ 124 } 125 126 /* 127 * Singly-linked List functions. 128 */ 129 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 130 131 #define SLIST_FIRST(head) ((head)->slh_first) 132 133 #define SLIST_FOREACH(var, head, field) \ 134 for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next) 135 136 #define SLIST_INIT(head) { \ 137 (head)->slh_first = NULL; \ 138 } 139 140 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 141 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 142 (slistelm)->field.sle_next = (elm); \ 143 } while (0) 144 145 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 146 (elm)->field.sle_next = (head)->slh_first; \ 147 (head)->slh_first = (elm); \ 148 } while (0) 149 150 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 151 152 #define SLIST_REMOVE_HEAD(head, field) do { \ 153 (head)->slh_first = (head)->slh_first->field.sle_next; \ 154 } while (0) 155 156 #define SLIST_REMOVE(head, elm, type, field) do { \ 157 if ((head)->slh_first == (elm)) { \ 158 SLIST_REMOVE_HEAD((head), field); \ 159 } \ 160 else { \ 161 struct type *curelm = (head)->slh_first; \ 162 while( curelm->field.sle_next != (elm) ) \ 163 curelm = curelm->field.sle_next; \ 164 curelm->field.sle_next = \ 165 curelm->field.sle_next->field.sle_next; \ 166 } \ 167 } while (0) 168 169 /* 170 * Singly-linked Tail queue definitions. 171 */ 172 #define STAILQ_HEAD(name, type) \ 173 struct name { \ 174 struct type *stqh_first;/* first element */ \ 175 struct type **stqh_last;/* addr of last next element */ \ 176 } 177 178 #define STAILQ_HEAD_INITIALIZER(head) \ 179 { NULL, &(head).stqh_first } 180 181 #define STAILQ_ENTRY(type) \ 182 struct { \ 183 struct type *stqe_next; /* next element */ \ 184 } 185 186 /* 187 * Singly-linked Tail queue functions. 188 */ 189 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 190 191 #define STAILQ_INIT(head) do { \ 192 (head)->stqh_first = NULL; \ 193 (head)->stqh_last = &(head)->stqh_first; \ 194 } while (0) 195 196 #define STAILQ_FIRST(head) ((head)->stqh_first) 197 #define STAILQ_LAST(head) (*(head)->stqh_last) 198 199 #define STAILQ_FOREACH(var, head, field) \ 200 for((var) = (head)->stqh_first; (var); (var) = (var)->field.stqe_next) 201 202 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 203 if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \ 204 (head)->stqh_last = &(elm)->field.stqe_next; \ 205 (head)->stqh_first = (elm); \ 206 } while (0) 207 208 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 209 (elm)->field.stqe_next = NULL; \ 210 *(head)->stqh_last = (elm); \ 211 (head)->stqh_last = &(elm)->field.stqe_next; \ 212 } while (0) 213 214 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 215 if (((elm)->field.stqe_next = (tqelm)->field.stqe_next) == NULL)\ 216 (head)->stqh_last = &(elm)->field.stqe_next; \ 217 (tqelm)->field.stqe_next = (elm); \ 218 } while (0) 219 220 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 221 222 #define STAILQ_REMOVE_HEAD(head, field) do { \ 223 if (((head)->stqh_first = \ 224 (head)->stqh_first->field.stqe_next) == NULL) \ 225 (head)->stqh_last = &(head)->stqh_first; \ 226 } while (0) 227 228 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \ 229 if (((head)->stqh_first = (elm)->field.stqe_next) == NULL) \ 230 (head)->stqh_last = &(head)->stqh_first; \ 231 } while (0) 232 233 #define STAILQ_REMOVE(head, elm, type, field) do { \ 234 if ((head)->stqh_first == (elm)) { \ 235 STAILQ_REMOVE_HEAD(head, field); \ 236 } \ 237 else { \ 238 struct type *curelm = (head)->stqh_first; \ 239 while( curelm->field.stqe_next != (elm) ) \ 240 curelm = curelm->field.stqe_next; \ 241 if((curelm->field.stqe_next = \ 242 curelm->field.stqe_next->field.stqe_next) == NULL) \ 243 (head)->stqh_last = &(curelm)->field.stqe_next; \ 244 } \ 245 } while (0) 246 247 /* 248 * List definitions. 249 */ 250 #define LIST_HEAD(name, type) \ 251 struct name { \ 252 struct type *lh_first; /* first element */ \ 253 } 254 255 #define LIST_HEAD_INITIALIZER(head) \ 256 { NULL } 257 258 #define LIST_ENTRY(type) \ 259 struct { \ 260 struct type *le_next; /* next element */ \ 261 struct type **le_prev; /* address of previous next element */ \ 262 } 263 264 /* 265 * List functions. 266 */ 267 268 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 269 270 #define LIST_FIRST(head) ((head)->lh_first) 271 272 #define LIST_FOREACH(var, head, field) \ 273 for((var) = (head)->lh_first; (var); (var) = (var)->field.le_next) 274 275 #define LIST_INIT(head) do { \ 276 (head)->lh_first = NULL; \ 277 } while (0) 278 279 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 280 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 281 (listelm)->field.le_next->field.le_prev = \ 282 &(elm)->field.le_next; \ 283 (listelm)->field.le_next = (elm); \ 284 (elm)->field.le_prev = &(listelm)->field.le_next; \ 285 } while (0) 286 287 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 288 (elm)->field.le_prev = (listelm)->field.le_prev; \ 289 (elm)->field.le_next = (listelm); \ 290 *(listelm)->field.le_prev = (elm); \ 291 (listelm)->field.le_prev = &(elm)->field.le_next; \ 292 } while (0) 293 294 #define LIST_INSERT_HEAD(head, elm, field) do { \ 295 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 296 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 297 (head)->lh_first = (elm); \ 298 (elm)->field.le_prev = &(head)->lh_first; \ 299 } while (0) 300 301 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 302 303 #define LIST_REMOVE(elm, field) do { \ 304 if ((elm)->field.le_next != NULL) \ 305 (elm)->field.le_next->field.le_prev = \ 306 (elm)->field.le_prev; \ 307 *(elm)->field.le_prev = (elm)->field.le_next; \ 308 } while (0) 309 310 /* 311 * Tail queue definitions. 312 */ 313 #define TAILQ_HEAD(name, type) \ 314 struct name { \ 315 struct type *tqh_first; /* first element */ \ 316 struct type **tqh_last; /* addr of last next element */ \ 317 } 318 319 #define TAILQ_HEAD_INITIALIZER(head) \ 320 { NULL, &(head).tqh_first } 321 322 #define TAILQ_ENTRY(type) \ 323 struct { \ 324 struct type *tqe_next; /* next element */ \ 325 struct type **tqe_prev; /* address of previous next element */ \ 326 } 327 328 /* 329 * Tail queue functions. 330 */ 331 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 332 333 #define TAILQ_FOREACH(var, head, field) \ 334 for (var = TAILQ_FIRST(head); var; var = TAILQ_NEXT(var, field)) 335 336 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 337 for ((var) = TAILQ_LAST((head), headname); \ 338 (var); \ 339 (var) = TAILQ_PREV((var), headname, field)) 340 341 #define TAILQ_FIRST(head) ((head)->tqh_first) 342 343 #define TAILQ_LAST(head, headname) \ 344 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 345 346 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 347 348 #define TAILQ_PREV(elm, headname, field) \ 349 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 350 351 #define TAILQ_INIT(head) do { \ 352 (head)->tqh_first = NULL; \ 353 (head)->tqh_last = &(head)->tqh_first; \ 354 } while (0) 355 356 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 357 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 358 (head)->tqh_first->field.tqe_prev = \ 359 &(elm)->field.tqe_next; \ 360 else \ 361 (head)->tqh_last = &(elm)->field.tqe_next; \ 362 (head)->tqh_first = (elm); \ 363 (elm)->field.tqe_prev = &(head)->tqh_first; \ 364 } while (0) 365 366 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 367 (elm)->field.tqe_next = NULL; \ 368 (elm)->field.tqe_prev = (head)->tqh_last; \ 369 *(head)->tqh_last = (elm); \ 370 (head)->tqh_last = &(elm)->field.tqe_next; \ 371 } while (0) 372 373 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 374 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 375 (elm)->field.tqe_next->field.tqe_prev = \ 376 &(elm)->field.tqe_next; \ 377 else \ 378 (head)->tqh_last = &(elm)->field.tqe_next; \ 379 (listelm)->field.tqe_next = (elm); \ 380 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 381 } while (0) 382 383 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 384 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 385 (elm)->field.tqe_next = (listelm); \ 386 *(listelm)->field.tqe_prev = (elm); \ 387 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 388 } while (0) 389 390 #define TAILQ_REMOVE(head, elm, field) do { \ 391 if (((elm)->field.tqe_next) != NULL) \ 392 (elm)->field.tqe_next->field.tqe_prev = \ 393 (elm)->field.tqe_prev; \ 394 else \ 395 (head)->tqh_last = (elm)->field.tqe_prev; \ 396 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 397 } while (0) 398 399 /* 400 * Circular queue definitions. 401 */ 402 #define CIRCLEQ_HEAD(name, type) \ 403 struct name { \ 404 struct type *cqh_first; /* first element */ \ 405 struct type *cqh_last; /* last element */ \ 406 } 407 408 #define CIRCLEQ_ENTRY(type) \ 409 struct { \ 410 struct type *cqe_next; /* next element */ \ 411 struct type *cqe_prev; /* previous element */ \ 412 } 413 414 /* 415 * Circular queue functions. 416 */ 417 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) 418 419 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 420 421 #define CIRCLEQ_FOREACH(var, head, field) \ 422 for((var) = (head)->cqh_first; \ 423 (var) != (void *)(head); \ 424 (var) = (var)->field.cqe_next) 425 426 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 427 for((var) = (head)->cqh_last; \ 428 (var) != (void *)(head); \ 429 (var) = (var)->field.cqe_prev) 430 431 #define CIRCLEQ_INIT(head) do { \ 432 (head)->cqh_first = (void *)(head); \ 433 (head)->cqh_last = (void *)(head); \ 434 } while (0) 435 436 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 437 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 438 (elm)->field.cqe_prev = (listelm); \ 439 if ((listelm)->field.cqe_next == (void *)(head)) \ 440 (head)->cqh_last = (elm); \ 441 else \ 442 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 443 (listelm)->field.cqe_next = (elm); \ 444 } while (0) 445 446 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 447 (elm)->field.cqe_next = (listelm); \ 448 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 449 if ((listelm)->field.cqe_prev == (void *)(head)) \ 450 (head)->cqh_first = (elm); \ 451 else \ 452 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 453 (listelm)->field.cqe_prev = (elm); \ 454 } while (0) 455 456 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 457 (elm)->field.cqe_next = (head)->cqh_first; \ 458 (elm)->field.cqe_prev = (void *)(head); \ 459 if ((head)->cqh_last == (void *)(head)) \ 460 (head)->cqh_last = (elm); \ 461 else \ 462 (head)->cqh_first->field.cqe_prev = (elm); \ 463 (head)->cqh_first = (elm); \ 464 } while (0) 465 466 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 467 (elm)->field.cqe_next = (void *)(head); \ 468 (elm)->field.cqe_prev = (head)->cqh_last; \ 469 if ((head)->cqh_first == (void *)(head)) \ 470 (head)->cqh_first = (elm); \ 471 else \ 472 (head)->cqh_last->field.cqe_next = (elm); \ 473 (head)->cqh_last = (elm); \ 474 } while (0) 475 476 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 477 478 #define CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next) 479 480 #define CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev) 481 482 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 483 if ((elm)->field.cqe_next == (void *)(head)) \ 484 (head)->cqh_last = (elm)->field.cqe_prev; \ 485 else \ 486 (elm)->field.cqe_next->field.cqe_prev = \ 487 (elm)->field.cqe_prev; \ 488 if ((elm)->field.cqe_prev == (void *)(head)) \ 489 (head)->cqh_first = (elm)->field.cqe_next; \ 490 else \ 491 (elm)->field.cqe_prev->field.cqe_next = \ 492 (elm)->field.cqe_next; \ 493 } while (0) 494 495 #ifdef KERNEL 496 497 /* 498 * XXX insque() and remque() are an old way of handling certain queues. 499 * They bogusly assumes that all queue heads look alike. 500 */ 501 502 struct quehead { 503 struct quehead *qh_link; 504 struct quehead *qh_rlink; 505 }; 506 507 #ifdef __GNUC__ 508 509 static __inline void 510 insque(void *a, void *b) 511 { 512 struct quehead *element = a, *head = b; 513 514 element->qh_link = head->qh_link; 515 element->qh_rlink = head; 516 head->qh_link = element; 517 element->qh_link->qh_rlink = element; 518 } 519 520 static __inline void 521 remque(void *a) 522 { 523 struct quehead *element = a; 524 525 element->qh_link->qh_rlink = element->qh_rlink; 526 element->qh_rlink->qh_link = element->qh_link; 527 element->qh_rlink = 0; 528 } 529 530 #else /* !__GNUC__ */ 531 532 void insque __P((void *a, void *b)); 533 void remque __P((void *a)); 534 535 #endif /* __GNUC__ */ 536 537 #endif /* KERNEL */ 538 539 #endif /* !_SYS_QUEUE_H_ */
Cache object: 1949dc186ee05e0d862a3d55e53074f8
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]