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: src/sys/sys/queue.h,v 1.32.2.7 2002/04/17 14:21:02 des Exp $ 35 * $DragonFly: src/sys/sys/queue.h,v 1.11 2008/08/28 08:42:29 hasso Exp $ 36 */ 37 38 #ifndef _SYS_QUEUE_H_ 39 #define _SYS_QUEUE_H_ 40 41 #ifndef _MACHINE_STDINT_H_ 42 #include <machine/stdint.h> /* for __offsetof */ 43 #endif 44 45 /* 46 * This file defines five types of data structures: singly-linked lists, 47 * singly-linked tail queues, lists, tail queues, and circular queues. 48 * 49 * A singly-linked list is headed by a single forward pointer. The elements 50 * are singly linked for minimum space and pointer manipulation overhead at 51 * the expense of O(n) removal for arbitrary elements. New elements can be 52 * added to the list after an existing element or at the head of the list. 53 * Elements being removed from the head of the list should use the explicit 54 * macro for this purpose for optimum efficiency. A singly-linked list may 55 * only be traversed in the forward direction. Singly-linked lists are ideal 56 * for applications with large datasets and few or no removals or for 57 * implementing a LIFO queue. 58 * 59 * A singly-linked tail queue is headed by a pair of pointers, one to the 60 * head of the list and the other to the tail of the list. The elements are 61 * singly linked for minimum space and pointer manipulation overhead at the 62 * expense of O(n) removal for arbitrary elements. New elements can be added 63 * to the list after an existing element, at the head of the list, or at the 64 * end of the list. Elements being removed from the head of the tail queue 65 * should use the explicit macro for this purpose for optimum efficiency. 66 * A singly-linked tail queue may only be traversed in the forward direction. 67 * Singly-linked tail queues are ideal for applications with large datasets 68 * and few or no removals or for implementing a FIFO queue. 69 * 70 * A list is headed by a single forward pointer (or an array of forward 71 * pointers for a hash table header). The elements are doubly linked 72 * so that an arbitrary element can be removed without a need to 73 * traverse the list. New elements can be added to the list before 74 * or after an existing element or at the head of the list. A list 75 * may only be traversed in the forward direction. 76 * 77 * A tail queue is headed by a pair of pointers, one to the head of the 78 * list and the other to the tail of the list. The elements are doubly 79 * linked so that an arbitrary element can be removed without a need to 80 * traverse the list. New elements can be added to the list before or 81 * after an existing element, at the head of the list, or at the end of 82 * the list. A tail queue may be traversed in either direction. 83 * 84 * A circle queue is headed by a pair of pointers, one to the head of the 85 * list and the other to the tail of the list. The elements are doubly 86 * linked so that an arbitrary element can be removed without a need to 87 * traverse the list. New elements can be added to the list before or after 88 * an existing element, at the head of the list, or at the end of the list. 89 * A circle queue may be traversed in either direction, but has a more 90 * complex end of list detection. 91 * 92 * For details on the use of these macros, see the queue(3) manual page. 93 * 94 * 95 * SLIST LIST STAILQ TAILQ CIRCLEQ 96 * _HEAD + + + + + 97 * _HEAD_INITIALIZER + + + + + 98 * _ENTRY + + + + + 99 * _INIT + + + + + 100 * _EMPTY + + + + + 101 * _FIRST + + + + + 102 * _NEXT + + + + + 103 * _PREV - - - + + 104 * _LAST - - + + + 105 * _FOREACH + + + + + 106 * _FOREACH_MUTABLE - + + + - 107 * _FOREACH_REVERSE - - - + + 108 * _INSERT_HEAD + + + + + 109 * _INSERT_BEFORE - + - + + 110 * _INSERT_AFTER + + + + + 111 * _INSERT_TAIL - - + + + 112 * _CONCAT - - + + - 113 * _REMOVE_HEAD + - + - - 114 * _REMOVE + + + + + 115 * 116 */ 117 118 /* 119 * Singly-linked List declarations. 120 */ 121 #define SLIST_HEAD(name, type) \ 122 struct name { \ 123 struct type *slh_first; /* first element */ \ 124 } 125 126 #define SLIST_HEAD_INITIALIZER(head) \ 127 { NULL } 128 129 #define SLIST_ENTRY(type) \ 130 struct { \ 131 struct type *sle_next; /* next element */ \ 132 } 133 134 #define SLIST_ENTRY_INITIALIZER { NULL } 135 136 /* 137 * Singly-linked List functions. 138 */ 139 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 140 141 #define SLIST_FIRST(head) ((head)->slh_first) 142 143 #define SLIST_FOREACH(var, head, field) \ 144 for ((var) = SLIST_FIRST((head)); \ 145 (var); \ 146 (var) = SLIST_NEXT((var), field)) 147 148 #define SLIST_INIT(head) do { \ 149 SLIST_FIRST((head)) = NULL; \ 150 } while (0) 151 152 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 153 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 154 SLIST_NEXT((slistelm), field) = (elm); \ 155 } while (0) 156 157 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 158 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 159 SLIST_FIRST((head)) = (elm); \ 160 } while (0) 161 162 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 163 164 #define SLIST_REMOVE(head, elm, type, field) do { \ 165 if (SLIST_FIRST((head)) == (elm)) { \ 166 SLIST_REMOVE_HEAD((head), field); \ 167 } \ 168 else { \ 169 struct type *curelm = SLIST_FIRST((head)); \ 170 while (SLIST_NEXT(curelm, field) != (elm)) \ 171 curelm = SLIST_NEXT(curelm, field); \ 172 SLIST_NEXT(curelm, field) = \ 173 SLIST_NEXT(SLIST_NEXT(curelm, field), field); \ 174 } \ 175 } while (0) 176 177 #define SLIST_REMOVE_HEAD(head, field) do { \ 178 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 179 } while (0) 180 181 /* 182 * Singly-linked Tail queue declarations. 183 */ 184 #define STAILQ_HEAD(name, type) \ 185 struct name { \ 186 struct type *stqh_first;/* first element */ \ 187 struct type **stqh_last;/* addr of last next element */ \ 188 } 189 190 #define STAILQ_HEAD_INITIALIZER(head) \ 191 { NULL, &(head).stqh_first } 192 193 #define STAILQ_ENTRY(type) \ 194 struct { \ 195 struct type *stqe_next; /* next element */ \ 196 } 197 198 /* 199 * Singly-linked Tail queue functions. 200 */ 201 #define STAILQ_CONCAT(head1, head2) do { \ 202 if (!STAILQ_EMPTY((head2))) { \ 203 *(head1)->stqh_last = (head2)->stqh_first; \ 204 (head1)->stqh_last = (head2)->stqh_last; \ 205 STAILQ_INIT((head2)); \ 206 } \ 207 } while (0) 208 209 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 210 211 #define STAILQ_FIRST(head) ((head)->stqh_first) 212 213 #define STAILQ_FOREACH(var, head, field) \ 214 for((var) = STAILQ_FIRST((head)); \ 215 (var); \ 216 (var) = STAILQ_NEXT((var), field)) 217 218 #define STAILQ_FOREACH_MUTABLE(var, head, field, tvar) \ 219 for ((var) = STAILQ_FIRST((head)); \ 220 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 221 (var) = (tvar)) 222 223 #define STAILQ_INIT(head) do { \ 224 STAILQ_FIRST((head)) = NULL; \ 225 (head)->stqh_last = &STAILQ_FIRST((head)); \ 226 } while (0) 227 228 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 229 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 230 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 231 STAILQ_NEXT((tqelm), field) = (elm); \ 232 } while (0) 233 234 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 235 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 236 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 237 STAILQ_FIRST((head)) = (elm); \ 238 } while (0) 239 240 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 241 STAILQ_NEXT((elm), field) = NULL; \ 242 *(head)->stqh_last = (elm); \ 243 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 244 } while (0) 245 246 #define STAILQ_LAST(head, type, field) \ 247 (STAILQ_EMPTY(head) ? \ 248 NULL : \ 249 ((struct type *) \ 250 ((char *)((head)->stqh_last) - __offsetof(struct type, field)))) 251 252 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 253 254 #define STAILQ_REMOVE(head, elm, type, field) do { \ 255 if (STAILQ_FIRST((head)) == (elm)) { \ 256 STAILQ_REMOVE_HEAD(head, field); \ 257 } \ 258 else { \ 259 struct type *curelm = STAILQ_FIRST((head)); \ 260 while (STAILQ_NEXT(curelm, field) != (elm)) \ 261 curelm = STAILQ_NEXT(curelm, field); \ 262 if ((STAILQ_NEXT(curelm, field) = \ 263 STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\ 264 (head)->stqh_last = &STAILQ_NEXT((curelm), field);\ 265 } \ 266 } while (0) 267 268 #define STAILQ_REMOVE_HEAD(head, field) do { \ 269 if ((STAILQ_FIRST((head)) = \ 270 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 271 (head)->stqh_last = &STAILQ_FIRST((head)); \ 272 } while (0) 273 274 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \ 275 if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \ 276 (head)->stqh_last = &STAILQ_FIRST((head)); \ 277 } while (0) 278 279 /* 280 * List declarations. 281 */ 282 #define LIST_HEAD(name, type) \ 283 struct name { \ 284 struct type *lh_first; /* first element */ \ 285 } 286 287 #define LIST_HEAD_INITIALIZER(head) \ 288 { NULL } 289 290 #define LIST_ENTRY(type) \ 291 struct { \ 292 struct type *le_next; /* next element */ \ 293 struct type **le_prev; /* address of previous next element */ \ 294 } 295 296 /* 297 * List functions. 298 */ 299 300 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 301 302 #define LIST_FIRST(head) ((head)->lh_first) 303 304 #define LIST_FOREACH(var, head, field) \ 305 for ((var) = LIST_FIRST((head)); \ 306 (var); \ 307 (var) = LIST_NEXT((var), field)) 308 309 #define LIST_FOREACH_MUTABLE(var, head, field, nvar) \ 310 for ((var) = LIST_FIRST((head)); \ 311 (var) && ((nvar) = LIST_NEXT((var), field), 1); \ 312 (var) = (nvar)) 313 314 #define LIST_INIT(head) do { \ 315 LIST_FIRST((head)) = NULL; \ 316 } while (0) 317 318 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 319 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 320 LIST_NEXT((listelm), field)->field.le_prev = \ 321 &LIST_NEXT((elm), field); \ 322 LIST_NEXT((listelm), field) = (elm); \ 323 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 324 } while (0) 325 326 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 327 (elm)->field.le_prev = (listelm)->field.le_prev; \ 328 LIST_NEXT((elm), field) = (listelm); \ 329 *(listelm)->field.le_prev = (elm); \ 330 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 331 } while (0) 332 333 #define LIST_INSERT_HEAD(head, elm, field) do { \ 334 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 335 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 336 LIST_FIRST((head)) = (elm); \ 337 (elm)->field.le_prev = &LIST_FIRST((head)); \ 338 } while (0) 339 340 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 341 342 #define LIST_REMOVE(elm, field) do { \ 343 if (LIST_NEXT((elm), field) != NULL) \ 344 LIST_NEXT((elm), field)->field.le_prev = \ 345 (elm)->field.le_prev; \ 346 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 347 } while (0) 348 349 /* 350 * Tail queue declarations. 351 */ 352 #define TAILQ_HEAD(name, type) \ 353 struct name { \ 354 struct type *tqh_first; /* first element */ \ 355 struct type **tqh_last; /* addr of last next element */ \ 356 } 357 358 #define TAILQ_HEAD_INITIALIZER(head) \ 359 { NULL, &(head).tqh_first } 360 361 #define TAILQ_ENTRY(type) \ 362 struct { \ 363 struct type *tqe_next; /* next element */ \ 364 struct type **tqe_prev; /* address of previous next element */ \ 365 } 366 367 /* 368 * Tail queue functions. 369 */ 370 #define TAILQ_CONCAT(head1, head2, field) do { \ 371 if (!TAILQ_EMPTY(head2)) { \ 372 *(head1)->tqh_last = (head2)->tqh_first; \ 373 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 374 (head1)->tqh_last = (head2)->tqh_last; \ 375 TAILQ_INIT((head2)); \ 376 } \ 377 } while (0) 378 379 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 380 381 #define TAILQ_FIRST(head) ((head)->tqh_first) 382 383 #define TAILQ_FOREACH(var, head, field) \ 384 for ((var) = TAILQ_FIRST((head)); \ 385 (var); \ 386 (var) = TAILQ_NEXT((var), field)) 387 388 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 389 for ((var) = TAILQ_FIRST((head)); \ 390 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 391 (var) = (tvar)) 392 393 394 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 395 for ((var) = TAILQ_LAST((head), headname); \ 396 (var); \ 397 (var) = TAILQ_PREV((var), headname, field)) 398 399 #define TAILQ_FOREACH_MUTABLE(var, head, field, nvar) \ 400 for ((var) = TAILQ_FIRST((head)); \ 401 (var) && ((nvar) = TAILQ_NEXT((var), field), (var)); \ 402 (var) = (nvar)) 403 404 #define TAILQ_INIT(head) do { \ 405 TAILQ_FIRST((head)) = NULL; \ 406 (head)->tqh_last = &TAILQ_FIRST((head)); \ 407 } while (0) 408 409 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 410 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 411 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 412 &TAILQ_NEXT((elm), field); \ 413 else \ 414 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 415 TAILQ_NEXT((listelm), field) = (elm); \ 416 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 417 } while (0) 418 419 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 420 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 421 TAILQ_NEXT((elm), field) = (listelm); \ 422 *(listelm)->field.tqe_prev = (elm); \ 423 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 424 } while (0) 425 426 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 427 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 428 TAILQ_FIRST((head))->field.tqe_prev = \ 429 &TAILQ_NEXT((elm), field); \ 430 else \ 431 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 432 TAILQ_FIRST((head)) = (elm); \ 433 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 434 } while (0) 435 436 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 437 TAILQ_NEXT((elm), field) = NULL; \ 438 (elm)->field.tqe_prev = (head)->tqh_last; \ 439 *(head)->tqh_last = (elm); \ 440 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 441 } while (0) 442 443 #define TAILQ_LAST(head, headname) \ 444 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 445 446 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 447 448 #define TAILQ_PREV(elm, headname, field) \ 449 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 450 451 #define TAILQ_REMOVE(head, elm, field) do { \ 452 if ((TAILQ_NEXT((elm), field)) != NULL) \ 453 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 454 (elm)->field.tqe_prev; \ 455 else \ 456 (head)->tqh_last = (elm)->field.tqe_prev; \ 457 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 458 } while (0) 459 460 /* 461 * Circular queue declarations. 462 */ 463 #define CIRCLEQ_HEAD(name, type) \ 464 struct name { \ 465 struct type *cqh_first; /* first element */ \ 466 struct type *cqh_last; /* last element */ \ 467 } 468 469 #define CIRCLEQ_HEAD_INITIALIZER(head) \ 470 { (void *)&(head), (void *)&(head) } 471 472 #define CIRCLEQ_ENTRY(type) \ 473 struct { \ 474 struct type *cqe_next; /* next element */ \ 475 struct type *cqe_prev; /* previous element */ \ 476 } 477 478 /* 479 * Circular queue functions. 480 */ 481 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) 482 483 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 484 485 #define CIRCLEQ_FOREACH(var, head, field) \ 486 for ((var) = CIRCLEQ_FIRST((head)); \ 487 (var) != (void *)(head) || ((var) = NULL); \ 488 (var) = CIRCLEQ_NEXT((var), field)) 489 490 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 491 for ((var) = CIRCLEQ_LAST((head)); \ 492 (var) != (void *)(head) || ((var) = NULL); \ 493 (var) = CIRCLEQ_PREV((var), field)) 494 495 #define CIRCLEQ_INIT(head) do { \ 496 CIRCLEQ_FIRST((head)) = (void *)(head); \ 497 CIRCLEQ_LAST((head)) = (void *)(head); \ 498 } while (0) 499 500 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 501 CIRCLEQ_NEXT((elm), field) = CIRCLEQ_NEXT((listelm), field); \ 502 CIRCLEQ_PREV((elm), field) = (listelm); \ 503 if (CIRCLEQ_NEXT((listelm), field) == (void *)(head)) \ 504 CIRCLEQ_LAST((head)) = (elm); \ 505 else \ 506 CIRCLEQ_PREV(CIRCLEQ_NEXT((listelm), field), field) = (elm);\ 507 CIRCLEQ_NEXT((listelm), field) = (elm); \ 508 } while (0) 509 510 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 511 CIRCLEQ_NEXT((elm), field) = (listelm); \ 512 CIRCLEQ_PREV((elm), field) = CIRCLEQ_PREV((listelm), field); \ 513 if (CIRCLEQ_PREV((listelm), field) == (void *)(head)) \ 514 CIRCLEQ_FIRST((head)) = (elm); \ 515 else \ 516 CIRCLEQ_NEXT(CIRCLEQ_PREV((listelm), field), field) = (elm);\ 517 CIRCLEQ_PREV((listelm), field) = (elm); \ 518 } while (0) 519 520 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 521 CIRCLEQ_NEXT((elm), field) = CIRCLEQ_FIRST((head)); \ 522 CIRCLEQ_PREV((elm), field) = (void *)(head); \ 523 if (CIRCLEQ_LAST((head)) == (void *)(head)) \ 524 CIRCLEQ_LAST((head)) = (elm); \ 525 else \ 526 CIRCLEQ_PREV(CIRCLEQ_FIRST((head)), field) = (elm); \ 527 CIRCLEQ_FIRST((head)) = (elm); \ 528 } while (0) 529 530 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 531 CIRCLEQ_NEXT((elm), field) = (void *)(head); \ 532 CIRCLEQ_PREV((elm), field) = CIRCLEQ_LAST((head)); \ 533 if (CIRCLEQ_FIRST((head)) == (void *)(head)) \ 534 CIRCLEQ_FIRST((head)) = (elm); \ 535 else \ 536 CIRCLEQ_NEXT(CIRCLEQ_LAST((head)), field) = (elm); \ 537 CIRCLEQ_LAST((head)) = (elm); \ 538 } while (0) 539 540 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 541 542 #define CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next) 543 544 #define CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev) 545 546 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 547 if (CIRCLEQ_NEXT((elm), field) == (void *)(head)) \ 548 CIRCLEQ_LAST((head)) = CIRCLEQ_PREV((elm), field); \ 549 else \ 550 CIRCLEQ_PREV(CIRCLEQ_NEXT((elm), field), field) = \ 551 CIRCLEQ_PREV((elm), field); \ 552 if (CIRCLEQ_PREV((elm), field) == (void *)(head)) \ 553 CIRCLEQ_FIRST((head)) = CIRCLEQ_NEXT((elm), field); \ 554 else \ 555 CIRCLEQ_NEXT(CIRCLEQ_PREV((elm), field), field) = \ 556 CIRCLEQ_NEXT((elm), field); \ 557 } while (0) 558 559 #ifdef _KERNEL 560 561 /* 562 * XXX insque() and remque() are an old way of handling certain queues. 563 * They bogusly assumes that all queue heads look alike. 564 */ 565 566 struct quehead { 567 struct quehead *qh_link; 568 struct quehead *qh_rlink; 569 }; 570 571 #ifdef __GNUC__ 572 573 static __inline void 574 insque(void *a, void *b) 575 { 576 struct quehead *element = (struct quehead *)a, 577 *head = (struct quehead *)b; 578 579 element->qh_link = head->qh_link; 580 element->qh_rlink = head; 581 head->qh_link = element; 582 element->qh_link->qh_rlink = element; 583 } 584 585 static __inline void 586 remque(void *a) 587 { 588 struct quehead *element = (struct quehead *)a; 589 590 element->qh_link->qh_rlink = element->qh_rlink; 591 element->qh_rlink->qh_link = element->qh_link; 592 element->qh_rlink = 0; 593 } 594 595 #else /* !__GNUC__ */ 596 597 void insque (void *a, void *b); 598 void remque (void *a); 599 600 #endif /* __GNUC__ */ 601 602 #endif /* _KERNEL */ 603 604 #endif /* !_SYS_QUEUE_H_ */ 605