1 /* $OpenBSD: queue.h,v 1.25 2004/04/08 16:08:21 henning Exp $ */ 2 /* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ 3 4 /* 5 * Copyright (c) 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)queue.h 8.5 (Berkeley) 8/20/94 33 */ 34 35 /* OPENBSD ORIGINAL: sys/sys/queue.h */ 36 37 #ifndef _FAKE_QUEUE_H_ 38 #define _FAKE_QUEUE_H_ 39 40 /* 41 * Require for OS/X and other platforms that have old/broken/incomplete 42 * <sys/queue.h>. 43 */ 44 #undef SLIST_HEAD 45 #undef SLIST_HEAD_INITIALIZER 46 #undef SLIST_ENTRY 47 #undef SLIST_FOREACH_PREVPTR 48 #undef SLIST_FIRST 49 #undef SLIST_END 50 #undef SLIST_EMPTY 51 #undef SLIST_NEXT 52 #undef SLIST_FOREACH 53 #undef SLIST_INIT 54 #undef SLIST_INSERT_AFTER 55 #undef SLIST_INSERT_HEAD 56 #undef SLIST_REMOVE_HEAD 57 #undef SLIST_REMOVE 58 #undef SLIST_REMOVE_NEXT 59 #undef LIST_HEAD 60 #undef LIST_HEAD_INITIALIZER 61 #undef LIST_ENTRY 62 #undef LIST_FIRST 63 #undef LIST_END 64 #undef LIST_EMPTY 65 #undef LIST_NEXT 66 #undef LIST_FOREACH 67 #undef LIST_INIT 68 #undef LIST_INSERT_AFTER 69 #undef LIST_INSERT_BEFORE 70 #undef LIST_INSERT_HEAD 71 #undef LIST_REMOVE 72 #undef LIST_REPLACE 73 #undef SIMPLEQ_HEAD 74 #undef SIMPLEQ_HEAD_INITIALIZER 75 #undef SIMPLEQ_ENTRY 76 #undef SIMPLEQ_FIRST 77 #undef SIMPLEQ_END 78 #undef SIMPLEQ_EMPTY 79 #undef SIMPLEQ_NEXT 80 #undef SIMPLEQ_FOREACH 81 #undef SIMPLEQ_INIT 82 #undef SIMPLEQ_INSERT_HEAD 83 #undef SIMPLEQ_INSERT_TAIL 84 #undef SIMPLEQ_INSERT_AFTER 85 #undef SIMPLEQ_REMOVE_HEAD 86 #undef TAILQ_HEAD 87 #undef TAILQ_HEAD_INITIALIZER 88 #undef TAILQ_ENTRY 89 #undef TAILQ_FIRST 90 #undef TAILQ_END 91 #undef TAILQ_NEXT 92 #undef TAILQ_LAST 93 #undef TAILQ_PREV 94 #undef TAILQ_EMPTY 95 #undef TAILQ_FOREACH 96 #undef TAILQ_FOREACH_REVERSE 97 #undef TAILQ_INIT 98 #undef TAILQ_INSERT_HEAD 99 #undef TAILQ_INSERT_TAIL 100 #undef TAILQ_INSERT_AFTER 101 #undef TAILQ_INSERT_BEFORE 102 #undef TAILQ_REMOVE 103 #undef TAILQ_REPLACE 104 #undef CIRCLEQ_HEAD 105 #undef CIRCLEQ_HEAD_INITIALIZER 106 #undef CIRCLEQ_ENTRY 107 #undef CIRCLEQ_FIRST 108 #undef CIRCLEQ_LAST 109 #undef CIRCLEQ_END 110 #undef CIRCLEQ_NEXT 111 #undef CIRCLEQ_PREV 112 #undef CIRCLEQ_EMPTY 113 #undef CIRCLEQ_FOREACH 114 #undef CIRCLEQ_FOREACH_REVERSE 115 #undef CIRCLEQ_INIT 116 #undef CIRCLEQ_INSERT_AFTER 117 #undef CIRCLEQ_INSERT_BEFORE 118 #undef CIRCLEQ_INSERT_HEAD 119 #undef CIRCLEQ_INSERT_TAIL 120 #undef CIRCLEQ_REMOVE 121 #undef CIRCLEQ_REPLACE 122 123 /* 124 * This file defines five types of data structures: singly-linked lists, 125 * lists, simple queues, tail queues, and circular queues. 126 * 127 * 128 * A singly-linked list is headed by a single forward pointer. The elements 129 * are singly linked for minimum space and pointer manipulation overhead at 130 * the expense of O(n) removal for arbitrary elements. New elements can be 131 * added to the list after an existing element or at the head of the list. 132 * Elements being removed from the head of the list should use the explicit 133 * macro for this purpose for optimum efficiency. A singly-linked list may 134 * only be traversed in the forward direction. Singly-linked lists are ideal 135 * for applications with large datasets and few or no removals or for 136 * implementing a LIFO queue. 137 * 138 * A list is headed by a single forward pointer (or an array of forward 139 * pointers for a hash table header). The elements are doubly linked 140 * so that an arbitrary element can be removed without a need to 141 * traverse the list. New elements can be added to the list before 142 * or after an existing element or at the head of the list. A list 143 * may only be traversed in the forward direction. 144 * 145 * A simple queue is headed by a pair of pointers, one the head of the 146 * list and the other to the tail of the list. The elements are singly 147 * linked to save space, so elements can only be removed from the 148 * head of the list. New elements can be added to the list before or after 149 * an existing element, at the head of the list, or at the end of the 150 * list. A simple queue may only be traversed in the forward direction. 151 * 152 * A tail queue is headed by a pair of pointers, one to the head of the 153 * list and the other to the tail of the list. The elements are doubly 154 * linked so that an arbitrary element can be removed without a need to 155 * traverse the list. New elements can be added to the list before or 156 * after an existing element, at the head of the list, or at the end of 157 * the list. A tail queue may be traversed in either direction. 158 * 159 * A circle queue is headed by a pair of pointers, one to the head of the 160 * list and the other to the tail of the list. The elements are doubly 161 * linked so that an arbitrary element can be removed without a need to 162 * traverse the list. New elements can be added to the list before or after 163 * an existing element, at the head of the list, or at the end of the list. 164 * A circle queue may be traversed in either direction, but has a more 165 * complex end of list detection. 166 * 167 * For details on the use of these macros, see the queue(3) manual page. 168 */ 169 170 /* 171 * Singly-linked List definitions. 172 */ 173 #define SLIST_HEAD(name, type) \ 174 struct name { \ 175 struct type *slh_first; /* first element */ \ 176 } 177 178 #define SLIST_HEAD_INITIALIZER(head) \ 179 { NULL } 180 181 #define SLIST_ENTRY(type) \ 182 struct { \ 183 struct type *sle_next; /* next element */ \ 184 } 185 186 /* 187 * Singly-linked List access methods. 188 */ 189 #define SLIST_FIRST(head) ((head)->slh_first) 190 #define SLIST_END(head) NULL 191 #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) 192 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 193 194 #define SLIST_FOREACH(var, head, field) \ 195 for((var) = SLIST_FIRST(head); \ 196 (var) != SLIST_END(head); \ 197 (var) = SLIST_NEXT(var, field)) 198 199 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 200 for ((varp) = &SLIST_FIRST((head)); \ 201 ((var) = *(varp)) != SLIST_END(head); \ 202 (varp) = &SLIST_NEXT((var), field)) 203 204 /* 205 * Singly-linked List functions. 206 */ 207 #define SLIST_INIT(head) { \ 208 SLIST_FIRST(head) = SLIST_END(head); \ 209 } 210 211 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 212 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 213 (slistelm)->field.sle_next = (elm); \ 214 } while (0) 215 216 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 217 (elm)->field.sle_next = (head)->slh_first; \ 218 (head)->slh_first = (elm); \ 219 } while (0) 220 221 #define SLIST_REMOVE_NEXT(head, elm, field) do { \ 222 (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \ 223 } while (0) 224 225 #define SLIST_REMOVE_HEAD(head, field) do { \ 226 (head)->slh_first = (head)->slh_first->field.sle_next; \ 227 } while (0) 228 229 #define SLIST_REMOVE(head, elm, type, field) do { \ 230 if ((head)->slh_first == (elm)) { \ 231 SLIST_REMOVE_HEAD((head), field); \ 232 } \ 233 else { \ 234 struct type *curelm = (head)->slh_first; \ 235 while( curelm->field.sle_next != (elm) ) \ 236 curelm = curelm->field.sle_next; \ 237 curelm->field.sle_next = \ 238 curelm->field.sle_next->field.sle_next; \ 239 } \ 240 } while (0) 241 242 /* 243 * List definitions. 244 */ 245 #define LIST_HEAD(name, type) \ 246 struct name { \ 247 struct type *lh_first; /* first element */ \ 248 } 249 250 #define LIST_HEAD_INITIALIZER(head) \ 251 { NULL } 252 253 #define LIST_ENTRY(type) \ 254 struct { \ 255 struct type *le_next; /* next element */ \ 256 struct type **le_prev; /* address of previous next element */ \ 257 } 258 259 /* 260 * List access methods 261 */ 262 #define LIST_FIRST(head) ((head)->lh_first) 263 #define LIST_END(head) NULL 264 #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) 265 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 266 267 #define LIST_FOREACH(var, head, field) \ 268 for((var) = LIST_FIRST(head); \ 269 (var)!= LIST_END(head); \ 270 (var) = LIST_NEXT(var, field)) 271 272 /* 273 * List functions. 274 */ 275 #define LIST_INIT(head) do { \ 276 LIST_FIRST(head) = LIST_END(head); \ 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_REMOVE(elm, field) do { \ 302 if ((elm)->field.le_next != NULL) \ 303 (elm)->field.le_next->field.le_prev = \ 304 (elm)->field.le_prev; \ 305 *(elm)->field.le_prev = (elm)->field.le_next; \ 306 } while (0) 307 308 #define LIST_REPLACE(elm, elm2, field) do { \ 309 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ 310 (elm2)->field.le_next->field.le_prev = \ 311 &(elm2)->field.le_next; \ 312 (elm2)->field.le_prev = (elm)->field.le_prev; \ 313 *(elm2)->field.le_prev = (elm2); \ 314 } while (0) 315 316 /* 317 * Simple queue definitions. 318 */ 319 #define SIMPLEQ_HEAD(name, type) \ 320 struct name { \ 321 struct type *sqh_first; /* first element */ \ 322 struct type **sqh_last; /* addr of last next element */ \ 323 } 324 325 #define SIMPLEQ_HEAD_INITIALIZER(head) \ 326 { NULL, &(head).sqh_first } 327 328 #define SIMPLEQ_ENTRY(type) \ 329 struct { \ 330 struct type *sqe_next; /* next element */ \ 331 } 332 333 /* 334 * Simple queue access methods. 335 */ 336 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) 337 #define SIMPLEQ_END(head) NULL 338 #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) 339 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 340 341 #define SIMPLEQ_FOREACH(var, head, field) \ 342 for((var) = SIMPLEQ_FIRST(head); \ 343 (var) != SIMPLEQ_END(head); \ 344 (var) = SIMPLEQ_NEXT(var, field)) 345 346 /* 347 * Simple queue functions. 348 */ 349 #define SIMPLEQ_INIT(head) do { \ 350 (head)->sqh_first = NULL; \ 351 (head)->sqh_last = &(head)->sqh_first; \ 352 } while (0) 353 354 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 355 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 356 (head)->sqh_last = &(elm)->field.sqe_next; \ 357 (head)->sqh_first = (elm); \ 358 } while (0) 359 360 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 361 (elm)->field.sqe_next = NULL; \ 362 *(head)->sqh_last = (elm); \ 363 (head)->sqh_last = &(elm)->field.sqe_next; \ 364 } while (0) 365 366 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 367 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ 368 (head)->sqh_last = &(elm)->field.sqe_next; \ 369 (listelm)->field.sqe_next = (elm); \ 370 } while (0) 371 372 #define SIMPLEQ_REMOVE_HEAD(head, elm, field) do { \ 373 if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) \ 374 (head)->sqh_last = &(head)->sqh_first; \ 375 } while (0) 376 377 /* 378 * Tail queue definitions. 379 */ 380 #define TAILQ_HEAD(name, type) \ 381 struct name { \ 382 struct type *tqh_first; /* first element */ \ 383 struct type **tqh_last; /* addr of last next element */ \ 384 } 385 386 #define TAILQ_HEAD_INITIALIZER(head) \ 387 { NULL, &(head).tqh_first } 388 389 #define TAILQ_ENTRY(type) \ 390 struct { \ 391 struct type *tqe_next; /* next element */ \ 392 struct type **tqe_prev; /* address of previous next element */ \ 393 } 394 395 /* 396 * tail queue access methods 397 */ 398 #define TAILQ_FIRST(head) ((head)->tqh_first) 399 #define TAILQ_END(head) NULL 400 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 401 #define TAILQ_LAST(head, headname) \ 402 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 403 /* XXX */ 404 #define TAILQ_PREV(elm, headname, field) \ 405 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 406 #define TAILQ_EMPTY(head) \ 407 (TAILQ_FIRST(head) == TAILQ_END(head)) 408 409 #define TAILQ_FOREACH(var, head, field) \ 410 for((var) = TAILQ_FIRST(head); \ 411 (var) != TAILQ_END(head); \ 412 (var) = TAILQ_NEXT(var, field)) 413 414 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 415 for((var) = TAILQ_LAST(head, headname); \ 416 (var) != TAILQ_END(head); \ 417 (var) = TAILQ_PREV(var, headname, field)) 418 419 /* 420 * Tail queue functions. 421 */ 422 #define TAILQ_INIT(head) do { \ 423 (head)->tqh_first = NULL; \ 424 (head)->tqh_last = &(head)->tqh_first; \ 425 } while (0) 426 427 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 428 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 429 (head)->tqh_first->field.tqe_prev = \ 430 &(elm)->field.tqe_next; \ 431 else \ 432 (head)->tqh_last = &(elm)->field.tqe_next; \ 433 (head)->tqh_first = (elm); \ 434 (elm)->field.tqe_prev = &(head)->tqh_first; \ 435 } while (0) 436 437 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 438 (elm)->field.tqe_next = NULL; \ 439 (elm)->field.tqe_prev = (head)->tqh_last; \ 440 *(head)->tqh_last = (elm); \ 441 (head)->tqh_last = &(elm)->field.tqe_next; \ 442 } while (0) 443 444 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 445 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 446 (elm)->field.tqe_next->field.tqe_prev = \ 447 &(elm)->field.tqe_next; \ 448 else \ 449 (head)->tqh_last = &(elm)->field.tqe_next; \ 450 (listelm)->field.tqe_next = (elm); \ 451 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 452 } while (0) 453 454 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 455 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 456 (elm)->field.tqe_next = (listelm); \ 457 *(listelm)->field.tqe_prev = (elm); \ 458 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 459 } while (0) 460 461 #define TAILQ_REMOVE(head, elm, field) do { \ 462 if (((elm)->field.tqe_next) != NULL) \ 463 (elm)->field.tqe_next->field.tqe_prev = \ 464 (elm)->field.tqe_prev; \ 465 else \ 466 (head)->tqh_last = (elm)->field.tqe_prev; \ 467 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 468 } while (0) 469 470 #define TAILQ_REPLACE(head, elm, elm2, field) do { \ 471 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ 472 (elm2)->field.tqe_next->field.tqe_prev = \ 473 &(elm2)->field.tqe_next; \ 474 else \ 475 (head)->tqh_last = &(elm2)->field.tqe_next; \ 476 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 477 *(elm2)->field.tqe_prev = (elm2); \ 478 } while (0) 479 480 /* 481 * Circular queue definitions. 482 */ 483 #define CIRCLEQ_HEAD(name, type) \ 484 struct name { \ 485 struct type *cqh_first; /* first element */ \ 486 struct type *cqh_last; /* last element */ \ 487 } 488 489 #define CIRCLEQ_HEAD_INITIALIZER(head) \ 490 { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } 491 492 #define CIRCLEQ_ENTRY(type) \ 493 struct { \ 494 struct type *cqe_next; /* next element */ \ 495 struct type *cqe_prev; /* previous element */ \ 496 } 497 498 /* 499 * Circular queue access methods 500 */ 501 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 502 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 503 #define CIRCLEQ_END(head) ((void *)(head)) 504 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 505 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 506 #define CIRCLEQ_EMPTY(head) \ 507 (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head)) 508 509 #define CIRCLEQ_FOREACH(var, head, field) \ 510 for((var) = CIRCLEQ_FIRST(head); \ 511 (var) != CIRCLEQ_END(head); \ 512 (var) = CIRCLEQ_NEXT(var, field)) 513 514 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 515 for((var) = CIRCLEQ_LAST(head); \ 516 (var) != CIRCLEQ_END(head); \ 517 (var) = CIRCLEQ_PREV(var, field)) 518 519 /* 520 * Circular queue functions. 521 */ 522 #define CIRCLEQ_INIT(head) do { \ 523 (head)->cqh_first = CIRCLEQ_END(head); \ 524 (head)->cqh_last = CIRCLEQ_END(head); \ 525 } while (0) 526 527 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 528 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 529 (elm)->field.cqe_prev = (listelm); \ 530 if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \ 531 (head)->cqh_last = (elm); \ 532 else \ 533 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 534 (listelm)->field.cqe_next = (elm); \ 535 } while (0) 536 537 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 538 (elm)->field.cqe_next = (listelm); \ 539 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 540 if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \ 541 (head)->cqh_first = (elm); \ 542 else \ 543 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 544 (listelm)->field.cqe_prev = (elm); \ 545 } while (0) 546 547 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 548 (elm)->field.cqe_next = (head)->cqh_first; \ 549 (elm)->field.cqe_prev = CIRCLEQ_END(head); \ 550 if ((head)->cqh_last == CIRCLEQ_END(head)) \ 551 (head)->cqh_last = (elm); \ 552 else \ 553 (head)->cqh_first->field.cqe_prev = (elm); \ 554 (head)->cqh_first = (elm); \ 555 } while (0) 556 557 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 558 (elm)->field.cqe_next = CIRCLEQ_END(head); \ 559 (elm)->field.cqe_prev = (head)->cqh_last; \ 560 if ((head)->cqh_first == CIRCLEQ_END(head)) \ 561 (head)->cqh_first = (elm); \ 562 else \ 563 (head)->cqh_last->field.cqe_next = (elm); \ 564 (head)->cqh_last = (elm); \ 565 } while (0) 566 567 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 568 if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \ 569 (head)->cqh_last = (elm)->field.cqe_prev; \ 570 else \ 571 (elm)->field.cqe_next->field.cqe_prev = \ 572 (elm)->field.cqe_prev; \ 573 if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \ 574 (head)->cqh_first = (elm)->field.cqe_next; \ 575 else \ 576 (elm)->field.cqe_prev->field.cqe_next = \ 577 (elm)->field.cqe_next; \ 578 } while (0) 579 580 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \ 581 if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \ 582 CIRCLEQ_END(head)) \ 583 (head).cqh_last = (elm2); \ 584 else \ 585 (elm2)->field.cqe_next->field.cqe_prev = (elm2); \ 586 if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \ 587 CIRCLEQ_END(head)) \ 588 (head).cqh_first = (elm2); \ 589 else \ 590 (elm2)->field.cqe_prev->field.cqe_next = (elm2); \ 591 } while (0) 592 593 #endif /* !_FAKE_QUEUE_H_ */ 594