sys-queue.h revision 126274
1/* OPENBSD ORIGINAL: sys/sys/queue.h */ 2 3/* $OpenBSD: queue.h,v 1.23 2003/06/02 23:28:21 millert Exp $ */ 4/* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ 5 6/* 7 * Copyright (c) 1991, 1993 8 * The Regents of the University of California. All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)queue.h 8.5 (Berkeley) 8/20/94 35 */ 36 37#ifndef _FAKE_QUEUE_H_ 38#define _FAKE_QUEUE_H_ 39 40/* 41 * Ignore all <sys/queue.h> since older platforms have broken/incomplete 42 * <sys/queue.h> that are too hard to work around. 43 */ 44#undef SLIST_HEAD 45#undef SLIST_HEAD_INITIALIZER 46#undef SLIST_ENTRY 47#undef SLIST_FIRST 48#undef SLIST_END 49#undef SLIST_EMPTY 50#undef SLIST_NEXT 51#undef SLIST_FOREACH 52#undef SLIST_INIT 53#undef SLIST_INSERT_AFTER 54#undef SLIST_INSERT_HEAD 55#undef SLIST_REMOVE_HEAD 56#undef SLIST_REMOVE 57#undef LIST_HEAD 58#undef LIST_HEAD_INITIALIZER 59#undef LIST_ENTRY 60#undef LIST_FIRST 61#undef LIST_END 62#undef LIST_EMPTY 63#undef LIST_NEXT 64#undef LIST_FOREACH 65#undef LIST_INIT 66#undef LIST_INSERT_AFTER 67#undef LIST_INSERT_BEFORE 68#undef LIST_INSERT_HEAD 69#undef LIST_REMOVE 70#undef LIST_REPLACE 71#undef SIMPLEQ_HEAD 72#undef SIMPLEQ_HEAD_INITIALIZER 73#undef SIMPLEQ_ENTRY 74#undef SIMPLEQ_FIRST 75#undef SIMPLEQ_END 76#undef SIMPLEQ_EMPTY 77#undef SIMPLEQ_NEXT 78#undef SIMPLEQ_FOREACH 79#undef SIMPLEQ_INIT 80#undef SIMPLEQ_INSERT_HEAD 81#undef SIMPLEQ_INSERT_TAIL 82#undef SIMPLEQ_INSERT_AFTER 83#undef SIMPLEQ_REMOVE_HEAD 84#undef TAILQ_HEAD 85#undef TAILQ_HEAD_INITIALIZER 86#undef TAILQ_ENTRY 87#undef TAILQ_FIRST 88#undef TAILQ_END 89#undef TAILQ_NEXT 90#undef TAILQ_LAST 91#undef TAILQ_PREV 92#undef TAILQ_EMPTY 93#undef TAILQ_FOREACH 94#undef TAILQ_FOREACH_REVERSE 95#undef TAILQ_INIT 96#undef TAILQ_INSERT_HEAD 97#undef TAILQ_INSERT_TAIL 98#undef TAILQ_INSERT_AFTER 99#undef TAILQ_INSERT_BEFORE 100#undef TAILQ_REMOVE 101#undef TAILQ_REPLACE 102#undef CIRCLEQ_HEAD 103#undef CIRCLEQ_HEAD_INITIALIZER 104#undef CIRCLEQ_ENTRY 105#undef CIRCLEQ_FIRST 106#undef CIRCLEQ_LAST 107#undef CIRCLEQ_END 108#undef CIRCLEQ_NEXT 109#undef CIRCLEQ_PREV 110#undef CIRCLEQ_EMPTY 111#undef CIRCLEQ_FOREACH 112#undef CIRCLEQ_FOREACH_REVERSE 113#undef CIRCLEQ_INIT 114#undef CIRCLEQ_INSERT_AFTER 115#undef CIRCLEQ_INSERT_BEFORE 116#undef CIRCLEQ_INSERT_HEAD 117#undef CIRCLEQ_INSERT_TAIL 118#undef CIRCLEQ_REMOVE 119#undef CIRCLEQ_REPLACE 120 121/* 122 * This file defines five types of data structures: singly-linked lists, 123 * lists, simple queues, tail queues, and circular queues. 124 * 125 * 126 * A singly-linked list is headed by a single forward pointer. The elements 127 * are singly linked for minimum space and pointer manipulation overhead at 128 * the expense of O(n) removal for arbitrary elements. New elements can be 129 * added to the list after an existing element or at the head of the list. 130 * Elements being removed from the head of the list should use the explicit 131 * macro for this purpose for optimum efficiency. A singly-linked list may 132 * only be traversed in the forward direction. Singly-linked lists are ideal 133 * for applications with large datasets and few or no removals or for 134 * implementing a LIFO queue. 135 * 136 * A list is headed by a single forward pointer (or an array of forward 137 * pointers for a hash table header). The elements are doubly linked 138 * so that an arbitrary element can be removed without a need to 139 * traverse the list. New elements can be added to the list before 140 * or after an existing element or at the head of the list. A list 141 * may only be traversed in the forward direction. 142 * 143 * A simple queue is headed by a pair of pointers, one the head of the 144 * list and the other to the tail of the list. The elements are singly 145 * linked to save space, so elements can only be removed from the 146 * head of the list. New elements can be added to the list before or after 147 * an existing element, at the head of the list, or at the end of the 148 * list. A simple queue may only be traversed in the forward direction. 149 * 150 * A tail queue is headed by a pair of pointers, one to the head of the 151 * list and the other to the tail of the list. The elements are doubly 152 * linked so that an arbitrary element can be removed without a need to 153 * traverse the list. New elements can be added to the list before or 154 * after an existing element, at the head of the list, or at the end of 155 * the list. A tail queue may be traversed in either direction. 156 * 157 * A circle queue is headed by a pair of pointers, one to the head of the 158 * list and the other to the tail of the list. The elements are doubly 159 * linked so that an arbitrary element can be removed without a need to 160 * traverse the list. New elements can be added to the list before or after 161 * an existing element, at the head of the list, or at the end of the list. 162 * A circle queue may be traversed in either direction, but has a more 163 * complex end of list detection. 164 * 165 * For details on the use of these macros, see the queue(3) manual page. 166 */ 167 168/* 169 * Singly-linked List definitions. 170 */ 171#define SLIST_HEAD(name, type) \ 172struct name { \ 173 struct type *slh_first; /* first element */ \ 174} 175 176#define SLIST_HEAD_INITIALIZER(head) \ 177 { NULL } 178 179#define SLIST_ENTRY(type) \ 180struct { \ 181 struct type *sle_next; /* next element */ \ 182} 183 184/* 185 * Singly-linked List access methods. 186 */ 187#define SLIST_FIRST(head) ((head)->slh_first) 188#define SLIST_END(head) NULL 189#define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) 190#define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 191 192#define SLIST_FOREACH(var, head, field) \ 193 for((var) = SLIST_FIRST(head); \ 194 (var) != SLIST_END(head); \ 195 (var) = SLIST_NEXT(var, field)) 196 197/* 198 * Singly-linked List functions. 199 */ 200#define SLIST_INIT(head) { \ 201 SLIST_FIRST(head) = SLIST_END(head); \ 202} 203 204#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 205 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 206 (slistelm)->field.sle_next = (elm); \ 207} while (0) 208 209#define SLIST_INSERT_HEAD(head, elm, field) do { \ 210 (elm)->field.sle_next = (head)->slh_first; \ 211 (head)->slh_first = (elm); \ 212} while (0) 213 214#define SLIST_REMOVE_HEAD(head, field) do { \ 215 (head)->slh_first = (head)->slh_first->field.sle_next; \ 216} while (0) 217 218#define SLIST_REMOVE(head, elm, type, field) do { \ 219 if ((head)->slh_first == (elm)) { \ 220 SLIST_REMOVE_HEAD((head), field); \ 221 } \ 222 else { \ 223 struct type *curelm = (head)->slh_first; \ 224 while( curelm->field.sle_next != (elm) ) \ 225 curelm = curelm->field.sle_next; \ 226 curelm->field.sle_next = \ 227 curelm->field.sle_next->field.sle_next; \ 228 } \ 229} while (0) 230 231/* 232 * List definitions. 233 */ 234#define LIST_HEAD(name, type) \ 235struct name { \ 236 struct type *lh_first; /* first element */ \ 237} 238 239#define LIST_HEAD_INITIALIZER(head) \ 240 { NULL } 241 242#define LIST_ENTRY(type) \ 243struct { \ 244 struct type *le_next; /* next element */ \ 245 struct type **le_prev; /* address of previous next element */ \ 246} 247 248/* 249 * List access methods 250 */ 251#define LIST_FIRST(head) ((head)->lh_first) 252#define LIST_END(head) NULL 253#define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) 254#define LIST_NEXT(elm, field) ((elm)->field.le_next) 255 256#define LIST_FOREACH(var, head, field) \ 257 for((var) = LIST_FIRST(head); \ 258 (var)!= LIST_END(head); \ 259 (var) = LIST_NEXT(var, field)) 260 261/* 262 * List functions. 263 */ 264#define LIST_INIT(head) do { \ 265 LIST_FIRST(head) = LIST_END(head); \ 266} while (0) 267 268#define LIST_INSERT_AFTER(listelm, elm, field) do { \ 269 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 270 (listelm)->field.le_next->field.le_prev = \ 271 &(elm)->field.le_next; \ 272 (listelm)->field.le_next = (elm); \ 273 (elm)->field.le_prev = &(listelm)->field.le_next; \ 274} while (0) 275 276#define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 277 (elm)->field.le_prev = (listelm)->field.le_prev; \ 278 (elm)->field.le_next = (listelm); \ 279 *(listelm)->field.le_prev = (elm); \ 280 (listelm)->field.le_prev = &(elm)->field.le_next; \ 281} while (0) 282 283#define LIST_INSERT_HEAD(head, elm, field) do { \ 284 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 285 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 286 (head)->lh_first = (elm); \ 287 (elm)->field.le_prev = &(head)->lh_first; \ 288} while (0) 289 290#define LIST_REMOVE(elm, field) do { \ 291 if ((elm)->field.le_next != NULL) \ 292 (elm)->field.le_next->field.le_prev = \ 293 (elm)->field.le_prev; \ 294 *(elm)->field.le_prev = (elm)->field.le_next; \ 295} while (0) 296 297#define LIST_REPLACE(elm, elm2, field) do { \ 298 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ 299 (elm2)->field.le_next->field.le_prev = \ 300 &(elm2)->field.le_next; \ 301 (elm2)->field.le_prev = (elm)->field.le_prev; \ 302 *(elm2)->field.le_prev = (elm2); \ 303} while (0) 304 305/* 306 * Simple queue definitions. 307 */ 308#define SIMPLEQ_HEAD(name, type) \ 309struct name { \ 310 struct type *sqh_first; /* first element */ \ 311 struct type **sqh_last; /* addr of last next element */ \ 312} 313 314#define SIMPLEQ_HEAD_INITIALIZER(head) \ 315 { NULL, &(head).sqh_first } 316 317#define SIMPLEQ_ENTRY(type) \ 318struct { \ 319 struct type *sqe_next; /* next element */ \ 320} 321 322/* 323 * Simple queue access methods. 324 */ 325#define SIMPLEQ_FIRST(head) ((head)->sqh_first) 326#define SIMPLEQ_END(head) NULL 327#define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) 328#define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 329 330#define SIMPLEQ_FOREACH(var, head, field) \ 331 for((var) = SIMPLEQ_FIRST(head); \ 332 (var) != SIMPLEQ_END(head); \ 333 (var) = SIMPLEQ_NEXT(var, field)) 334 335/* 336 * Simple queue functions. 337 */ 338#define SIMPLEQ_INIT(head) do { \ 339 (head)->sqh_first = NULL; \ 340 (head)->sqh_last = &(head)->sqh_first; \ 341} while (0) 342 343#define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 344 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 345 (head)->sqh_last = &(elm)->field.sqe_next; \ 346 (head)->sqh_first = (elm); \ 347} while (0) 348 349#define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 350 (elm)->field.sqe_next = NULL; \ 351 *(head)->sqh_last = (elm); \ 352 (head)->sqh_last = &(elm)->field.sqe_next; \ 353} while (0) 354 355#define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 356 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ 357 (head)->sqh_last = &(elm)->field.sqe_next; \ 358 (listelm)->field.sqe_next = (elm); \ 359} while (0) 360 361#define SIMPLEQ_REMOVE_HEAD(head, elm, field) do { \ 362 if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) \ 363 (head)->sqh_last = &(head)->sqh_first; \ 364} while (0) 365 366/* 367 * Tail queue definitions. 368 */ 369#define TAILQ_HEAD(name, type) \ 370struct name { \ 371 struct type *tqh_first; /* first element */ \ 372 struct type **tqh_last; /* addr of last next element */ \ 373} 374 375#define TAILQ_HEAD_INITIALIZER(head) \ 376 { NULL, &(head).tqh_first } 377 378#define TAILQ_ENTRY(type) \ 379struct { \ 380 struct type *tqe_next; /* next element */ \ 381 struct type **tqe_prev; /* address of previous next element */ \ 382} 383 384/* 385 * tail queue access methods 386 */ 387#define TAILQ_FIRST(head) ((head)->tqh_first) 388#define TAILQ_END(head) NULL 389#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 390#define TAILQ_LAST(head, headname) \ 391 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 392/* XXX */ 393#define TAILQ_PREV(elm, headname, field) \ 394 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 395#define TAILQ_EMPTY(head) \ 396 (TAILQ_FIRST(head) == TAILQ_END(head)) 397 398#define TAILQ_FOREACH(var, head, field) \ 399 for((var) = TAILQ_FIRST(head); \ 400 (var) != TAILQ_END(head); \ 401 (var) = TAILQ_NEXT(var, field)) 402 403#define TAILQ_FOREACH_REVERSE(var, head, field, headname) \ 404 for((var) = TAILQ_LAST(head, headname); \ 405 (var) != TAILQ_END(head); \ 406 (var) = TAILQ_PREV(var, headname, field)) 407 408/* 409 * Tail queue functions. 410 */ 411#define TAILQ_INIT(head) do { \ 412 (head)->tqh_first = NULL; \ 413 (head)->tqh_last = &(head)->tqh_first; \ 414} while (0) 415 416#define TAILQ_INSERT_HEAD(head, elm, field) do { \ 417 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 418 (head)->tqh_first->field.tqe_prev = \ 419 &(elm)->field.tqe_next; \ 420 else \ 421 (head)->tqh_last = &(elm)->field.tqe_next; \ 422 (head)->tqh_first = (elm); \ 423 (elm)->field.tqe_prev = &(head)->tqh_first; \ 424} while (0) 425 426#define TAILQ_INSERT_TAIL(head, elm, field) do { \ 427 (elm)->field.tqe_next = NULL; \ 428 (elm)->field.tqe_prev = (head)->tqh_last; \ 429 *(head)->tqh_last = (elm); \ 430 (head)->tqh_last = &(elm)->field.tqe_next; \ 431} while (0) 432 433#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 434 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 435 (elm)->field.tqe_next->field.tqe_prev = \ 436 &(elm)->field.tqe_next; \ 437 else \ 438 (head)->tqh_last = &(elm)->field.tqe_next; \ 439 (listelm)->field.tqe_next = (elm); \ 440 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 441} while (0) 442 443#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 444 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 445 (elm)->field.tqe_next = (listelm); \ 446 *(listelm)->field.tqe_prev = (elm); \ 447 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 448} while (0) 449 450#define TAILQ_REMOVE(head, elm, field) do { \ 451 if (((elm)->field.tqe_next) != NULL) \ 452 (elm)->field.tqe_next->field.tqe_prev = \ 453 (elm)->field.tqe_prev; \ 454 else \ 455 (head)->tqh_last = (elm)->field.tqe_prev; \ 456 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 457} while (0) 458 459#define TAILQ_REPLACE(head, elm, elm2, field) do { \ 460 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ 461 (elm2)->field.tqe_next->field.tqe_prev = \ 462 &(elm2)->field.tqe_next; \ 463 else \ 464 (head)->tqh_last = &(elm2)->field.tqe_next; \ 465 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 466 *(elm2)->field.tqe_prev = (elm2); \ 467} while (0) 468 469/* 470 * Circular queue definitions. 471 */ 472#define CIRCLEQ_HEAD(name, type) \ 473struct name { \ 474 struct type *cqh_first; /* first element */ \ 475 struct type *cqh_last; /* last element */ \ 476} 477 478#define CIRCLEQ_HEAD_INITIALIZER(head) \ 479 { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } 480 481#define CIRCLEQ_ENTRY(type) \ 482struct { \ 483 struct type *cqe_next; /* next element */ \ 484 struct type *cqe_prev; /* previous element */ \ 485} 486 487/* 488 * Circular queue access methods 489 */ 490#define CIRCLEQ_FIRST(head) ((head)->cqh_first) 491#define CIRCLEQ_LAST(head) ((head)->cqh_last) 492#define CIRCLEQ_END(head) ((void *)(head)) 493#define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 494#define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 495#define CIRCLEQ_EMPTY(head) \ 496 (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head)) 497 498#define CIRCLEQ_FOREACH(var, head, field) \ 499 for((var) = CIRCLEQ_FIRST(head); \ 500 (var) != CIRCLEQ_END(head); \ 501 (var) = CIRCLEQ_NEXT(var, field)) 502 503#define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 504 for((var) = CIRCLEQ_LAST(head); \ 505 (var) != CIRCLEQ_END(head); \ 506 (var) = CIRCLEQ_PREV(var, field)) 507 508/* 509 * Circular queue functions. 510 */ 511#define CIRCLEQ_INIT(head) do { \ 512 (head)->cqh_first = CIRCLEQ_END(head); \ 513 (head)->cqh_last = CIRCLEQ_END(head); \ 514} while (0) 515 516#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 517 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 518 (elm)->field.cqe_prev = (listelm); \ 519 if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \ 520 (head)->cqh_last = (elm); \ 521 else \ 522 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 523 (listelm)->field.cqe_next = (elm); \ 524} while (0) 525 526#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 527 (elm)->field.cqe_next = (listelm); \ 528 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 529 if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \ 530 (head)->cqh_first = (elm); \ 531 else \ 532 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 533 (listelm)->field.cqe_prev = (elm); \ 534} while (0) 535 536#define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 537 (elm)->field.cqe_next = (head)->cqh_first; \ 538 (elm)->field.cqe_prev = CIRCLEQ_END(head); \ 539 if ((head)->cqh_last == CIRCLEQ_END(head)) \ 540 (head)->cqh_last = (elm); \ 541 else \ 542 (head)->cqh_first->field.cqe_prev = (elm); \ 543 (head)->cqh_first = (elm); \ 544} while (0) 545 546#define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 547 (elm)->field.cqe_next = CIRCLEQ_END(head); \ 548 (elm)->field.cqe_prev = (head)->cqh_last; \ 549 if ((head)->cqh_first == CIRCLEQ_END(head)) \ 550 (head)->cqh_first = (elm); \ 551 else \ 552 (head)->cqh_last->field.cqe_next = (elm); \ 553 (head)->cqh_last = (elm); \ 554} while (0) 555 556#define CIRCLEQ_REMOVE(head, elm, field) do { \ 557 if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \ 558 (head)->cqh_last = (elm)->field.cqe_prev; \ 559 else \ 560 (elm)->field.cqe_next->field.cqe_prev = \ 561 (elm)->field.cqe_prev; \ 562 if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \ 563 (head)->cqh_first = (elm)->field.cqe_next; \ 564 else \ 565 (elm)->field.cqe_prev->field.cqe_next = \ 566 (elm)->field.cqe_next; \ 567} while (0) 568 569#define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \ 570 if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \ 571 CIRCLEQ_END(head)) \ 572 (head).cqh_last = (elm2); \ 573 else \ 574 (elm2)->field.cqe_next->field.cqe_prev = (elm2); \ 575 if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \ 576 CIRCLEQ_END(head)) \ 577 (head).cqh_first = (elm2); \ 578 else \ 579 (elm2)->field.cqe_prev->field.cqe_next = (elm2); \ 580} while (0) 581 582#endif /* !_FAKE_QUEUE_H_ */ 583