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00001 /* $OpenBSD: queue.h,v 1.1 2007/10/26 03:14:08 niallo Exp $ */ 00002 /* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ 00003 00004 /* 00005 * Copyright (c) 1991, 1993 00006 * The Regents of the University of California. All rights reserved. 00007 * 00008 * Redistribution and use in source and binary forms, with or without 00009 * modification, are permitted provided that the following conditions 00010 * are met: 00011 * 1. Redistributions of source code must retain the above copyright 00012 * notice, this list of conditions and the following disclaimer. 00013 * 2. Redistributions in binary form must reproduce the above copyright 00014 * notice, this list of conditions and the following disclaimer in the 00015 * documentation and/or other materials provided with the distribution. 00016 * 3. Neither the name of the University nor the names of its contributors 00017 * may be used to endorse or promote products derived from this software 00018 * without specific prior written permission. 00019 * 00020 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 00021 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00022 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00023 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 00024 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00025 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 00026 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 00027 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00028 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 00029 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00030 * SUCH DAMAGE. 00031 * 00032 * @(#)queue.h 8.5 (Berkeley) 8/20/94 00033 */ 00034 00035 #ifndef _SYS_QUEUE_H_ 00036 #define _SYS_QUEUE_H_ 00037 00038 /* 00039 * This file defines five types of data structures: singly-linked lists, 00040 * lists, simple queues, tail queues, and circular queues. 00041 * 00042 * 00043 * A singly-linked list is headed by a single forward pointer. The elements 00044 * are singly linked for minimum space and pointer manipulation overhead at 00045 * the expense of O(n) removal for arbitrary elements. New elements can be 00046 * added to the list after an existing element or at the head of the list. 00047 * Elements being removed from the head of the list should use the explicit 00048 * macro for this purpose for optimum efficiency. A singly-linked list may 00049 * only be traversed in the forward direction. Singly-linked lists are ideal 00050 * for applications with large datasets and few or no removals or for 00051 * implementing a LIFO queue. 00052 * 00053 * A list is headed by a single forward pointer (or an array of forward 00054 * pointers for a hash table header). The elements are doubly linked 00055 * so that an arbitrary element can be removed without a need to 00056 * traverse the list. New elements can be added to the list before 00057 * or after an existing element or at the head of the list. A list 00058 * may only be traversed in the forward direction. 00059 * 00060 * A simple queue is headed by a pair of pointers, one the head of the 00061 * list and the other to the tail of the list. The elements are singly 00062 * linked to save space, so elements can only be removed from the 00063 * head of the list. New elements can be added to the list before or after 00064 * an existing element, at the head of the list, or at the end of the 00065 * list. A simple queue may only be traversed in the forward direction. 00066 * 00067 * A tail queue is headed by a pair of pointers, one to the head of the 00068 * list and the other to the tail of the list. The elements are doubly 00069 * linked so that an arbitrary element can be removed without a need to 00070 * traverse the list. New elements can be added to the list before or 00071 * after an existing element, at the head of the list, or at the end of 00072 * the list. A tail queue may be traversed in either direction. 00073 * 00074 * A circle queue is headed by a pair of pointers, one to the head of the 00075 * list and the other to the tail of the list. The elements are doubly 00076 * linked so that an arbitrary element can be removed without a need to 00077 * traverse the list. New elements can be added to the list before or after 00078 * an existing element, at the head of the list, or at the end of the list. 00079 * A circle queue may be traversed in either direction, but has a more 00080 * complex end of list detection. 00081 * 00082 * For details on the use of these macros, see the queue(3) manual page. 00083 */ 00084 00085 #if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC)) 00086 #define _Q_INVALIDATE(a) (a) = ((void *)-1) 00087 #else 00088 #define _Q_INVALIDATE(a) 00089 #endif 00090 00091 /* 00092 * Singly-linked List definitions. 00093 */ 00094 #define SLIST_HEAD(name, type) \ 00095 struct name { \ 00096 struct type *slh_first; /* first element */ \ 00097 } 00098 00099 #define SLIST_HEAD_INITIALIZER(head) \ 00100 { NULL } 00101 00102 #define SLIST_ENTRY(type) \ 00103 struct { \ 00104 struct type *sle_next; /* next element */ \ 00105 } 00106 00107 /* 00108 * Singly-linked List access methods. 00109 */ 00110 #define SLIST_FIRST(head) ((head)->slh_first) 00111 #define SLIST_END(head) NULL 00112 #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) 00113 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 00114 00115 #define SLIST_FOREACH(var, head, field) \ 00116 for((var) = SLIST_FIRST(head); \ 00117 (var) != SLIST_END(head); \ 00118 (var) = SLIST_NEXT(var, field)) 00119 00120 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 00121 for ((varp) = &SLIST_FIRST((head)); \ 00122 ((var) = *(varp)) != SLIST_END(head); \ 00123 (varp) = &SLIST_NEXT((var), field)) 00124 00125 /* 00126 * Singly-linked List functions. 00127 */ 00128 #define SLIST_INIT(head) { \ 00129 SLIST_FIRST(head) = SLIST_END(head); \ 00130 } 00131 00132 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 00133 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 00134 (slistelm)->field.sle_next = (elm); \ 00135 } while (0) 00136 00137 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 00138 (elm)->field.sle_next = (head)->slh_first; \ 00139 (head)->slh_first = (elm); \ 00140 } while (0) 00141 00142 #define SLIST_REMOVE_NEXT(head, elm, field) do { \ 00143 (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \ 00144 } while (0) 00145 00146 #define SLIST_REMOVE_HEAD(head, field) do { \ 00147 (head)->slh_first = (head)->slh_first->field.sle_next; \ 00148 } while (0) 00149 00150 #define SLIST_REMOVE(head, elm, type, field) do { \ 00151 if ((head)->slh_first == (elm)) { \ 00152 SLIST_REMOVE_HEAD((head), field); \ 00153 } else { \ 00154 struct type *curelm = (head)->slh_first; \ 00155 \ 00156 while (curelm->field.sle_next != (elm)) \ 00157 curelm = curelm->field.sle_next; \ 00158 curelm->field.sle_next = \ 00159 curelm->field.sle_next->field.sle_next; \ 00160 _Q_INVALIDATE((elm)->field.sle_next); \ 00161 } \ 00162 } while (0) 00163 00164 /* 00165 * List definitions. 00166 */ 00167 #define LIST_HEAD(name, type) \ 00168 struct name { \ 00169 struct type *lh_first; /* first element */ \ 00170 } 00171 00172 #define LIST_HEAD_INITIALIZER(head) \ 00173 { NULL } 00174 00175 #define LIST_ENTRY(type) \ 00176 struct { \ 00177 struct type *le_next; /* next element */ \ 00178 struct type **le_prev; /* address of previous next element */ \ 00179 } 00180 00181 /* 00182 * List access methods 00183 */ 00184 #define LIST_FIRST(head) ((head)->lh_first) 00185 #define LIST_END(head) NULL 00186 #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) 00187 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 00188 00189 #define LIST_FOREACH(var, head, field) \ 00190 for((var) = LIST_FIRST(head); \ 00191 (var)!= LIST_END(head); \ 00192 (var) = LIST_NEXT(var, field)) 00193 00194 /* 00195 * List functions. 00196 */ 00197 #define LIST_INIT(head) do { \ 00198 LIST_FIRST(head) = LIST_END(head); \ 00199 } while (0) 00200 00201 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 00202 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 00203 (listelm)->field.le_next->field.le_prev = \ 00204 &(elm)->field.le_next; \ 00205 (listelm)->field.le_next = (elm); \ 00206 (elm)->field.le_prev = &(listelm)->field.le_next; \ 00207 } while (0) 00208 00209 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 00210 (elm)->field.le_prev = (listelm)->field.le_prev; \ 00211 (elm)->field.le_next = (listelm); \ 00212 *(listelm)->field.le_prev = (elm); \ 00213 (listelm)->field.le_prev = &(elm)->field.le_next; \ 00214 } while (0) 00215 00216 #define LIST_INSERT_HEAD(head, elm, field) do { \ 00217 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 00218 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 00219 (head)->lh_first = (elm); \ 00220 (elm)->field.le_prev = &(head)->lh_first; \ 00221 } while (0) 00222 00223 #define LIST_REMOVE(elm, field) do { \ 00224 if ((elm)->field.le_next != NULL) \ 00225 (elm)->field.le_next->field.le_prev = \ 00226 (elm)->field.le_prev; \ 00227 *(elm)->field.le_prev = (elm)->field.le_next; \ 00228 _Q_INVALIDATE((elm)->field.le_prev); \ 00229 _Q_INVALIDATE((elm)->field.le_next); \ 00230 } while (0) 00231 00232 #define LIST_REPLACE(elm, elm2, field) do { \ 00233 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ 00234 (elm2)->field.le_next->field.le_prev = \ 00235 &(elm2)->field.le_next; \ 00236 (elm2)->field.le_prev = (elm)->field.le_prev; \ 00237 *(elm2)->field.le_prev = (elm2); \ 00238 _Q_INVALIDATE((elm)->field.le_prev); \ 00239 _Q_INVALIDATE((elm)->field.le_next); \ 00240 } while (0) 00241 00242 /* 00243 * Simple queue definitions. 00244 */ 00245 #define SIMPLEQ_HEAD(name, type) \ 00246 struct name { \ 00247 struct type *sqh_first; /* first element */ \ 00248 struct type **sqh_last; /* addr of last next element */ \ 00249 } 00250 00251 #define SIMPLEQ_HEAD_INITIALIZER(head) \ 00252 { NULL, &(head).sqh_first } 00253 00254 #define SIMPLEQ_ENTRY(type) \ 00255 struct { \ 00256 struct type *sqe_next; /* next element */ \ 00257 } 00258 00259 /* 00260 * Simple queue access methods. 00261 */ 00262 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) 00263 #define SIMPLEQ_END(head) NULL 00264 #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) 00265 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 00266 00267 #define SIMPLEQ_FOREACH(var, head, field) \ 00268 for((var) = SIMPLEQ_FIRST(head); \ 00269 (var) != SIMPLEQ_END(head); \ 00270 (var) = SIMPLEQ_NEXT(var, field)) 00271 00272 /* 00273 * Simple queue functions. 00274 */ 00275 #define SIMPLEQ_INIT(head) do { \ 00276 (head)->sqh_first = NULL; \ 00277 (head)->sqh_last = &(head)->sqh_first; \ 00278 } while (0) 00279 00280 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 00281 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 00282 (head)->sqh_last = &(elm)->field.sqe_next; \ 00283 (head)->sqh_first = (elm); \ 00284 } while (0) 00285 00286 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 00287 (elm)->field.sqe_next = NULL; \ 00288 *(head)->sqh_last = (elm); \ 00289 (head)->sqh_last = &(elm)->field.sqe_next; \ 00290 } while (0) 00291 00292 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 00293 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ 00294 (head)->sqh_last = &(elm)->field.sqe_next; \ 00295 (listelm)->field.sqe_next = (elm); \ 00296 } while (0) 00297 00298 #define SIMPLEQ_REMOVE_HEAD(head, field) do { \ 00299 if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \ 00300 (head)->sqh_last = &(head)->sqh_first; \ 00301 } while (0) 00302 00303 /* 00304 * Tail queue definitions. 00305 */ 00306 #define TAILQ_HEAD(name, type) \ 00307 struct name { \ 00308 struct type *tqh_first; /* first element */ \ 00309 struct type **tqh_last; /* addr of last next element */ \ 00310 } 00311 00312 #define TAILQ_HEAD_INITIALIZER(head) \ 00313 { NULL, &(head).tqh_first } 00314 00315 #define TAILQ_ENTRY(type) \ 00316 struct { \ 00317 struct type *tqe_next; /* next element */ \ 00318 struct type **tqe_prev; /* address of previous next element */ \ 00319 } 00320 00321 /* 00322 * tail queue access methods 00323 */ 00324 #define TAILQ_FIRST(head) ((head)->tqh_first) 00325 #define TAILQ_END(head) NULL 00326 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 00327 #define TAILQ_LAST(head, headname) \ 00328 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 00329 /* XXX */ 00330 #define TAILQ_PREV(elm, headname, field) \ 00331 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 00332 #define TAILQ_EMPTY(head) \ 00333 (TAILQ_FIRST(head) == TAILQ_END(head)) 00334 00335 #define TAILQ_FOREACH(var, head, field) \ 00336 for((var) = TAILQ_FIRST(head); \ 00337 (var) != TAILQ_END(head); \ 00338 (var) = TAILQ_NEXT(var, field)) 00339 00340 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 00341 for((var) = TAILQ_LAST(head, headname); \ 00342 (var) != TAILQ_END(head); \ 00343 (var) = TAILQ_PREV(var, headname, field)) 00344 00345 /* 00346 * Tail queue functions. 00347 */ 00348 #define TAILQ_INIT(head) do { \ 00349 (head)->tqh_first = NULL; \ 00350 (head)->tqh_last = &(head)->tqh_first; \ 00351 } while (0) 00352 00353 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 00354 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 00355 (head)->tqh_first->field.tqe_prev = \ 00356 &(elm)->field.tqe_next; \ 00357 else \ 00358 (head)->tqh_last = &(elm)->field.tqe_next; \ 00359 (head)->tqh_first = (elm); \ 00360 (elm)->field.tqe_prev = &(head)->tqh_first; \ 00361 } while (0) 00362 00363 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 00364 (elm)->field.tqe_next = NULL; \ 00365 (elm)->field.tqe_prev = (head)->tqh_last; \ 00366 *(head)->tqh_last = (elm); \ 00367 (head)->tqh_last = &(elm)->field.tqe_next; \ 00368 } while (0) 00369 00370 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 00371 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 00372 (elm)->field.tqe_next->field.tqe_prev = \ 00373 &(elm)->field.tqe_next; \ 00374 else \ 00375 (head)->tqh_last = &(elm)->field.tqe_next; \ 00376 (listelm)->field.tqe_next = (elm); \ 00377 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 00378 } while (0) 00379 00380 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 00381 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 00382 (elm)->field.tqe_next = (listelm); \ 00383 *(listelm)->field.tqe_prev = (elm); \ 00384 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 00385 } while (0) 00386 00387 #define TAILQ_REMOVE(head, elm, field) do { \ 00388 if (((elm)->field.tqe_next) != NULL) \ 00389 (elm)->field.tqe_next->field.tqe_prev = \ 00390 (elm)->field.tqe_prev; \ 00391 else \ 00392 (head)->tqh_last = (elm)->field.tqe_prev; \ 00393 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 00394 _Q_INVALIDATE((elm)->field.tqe_prev); \ 00395 _Q_INVALIDATE((elm)->field.tqe_next); \ 00396 } while (0) 00397 00398 #define TAILQ_REPLACE(head, elm, elm2, field) do { \ 00399 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ 00400 (elm2)->field.tqe_next->field.tqe_prev = \ 00401 &(elm2)->field.tqe_next; \ 00402 else \ 00403 (head)->tqh_last = &(elm2)->field.tqe_next; \ 00404 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 00405 *(elm2)->field.tqe_prev = (elm2); \ 00406 _Q_INVALIDATE((elm)->field.tqe_prev); \ 00407 _Q_INVALIDATE((elm)->field.tqe_next); \ 00408 } while (0) 00409 00410 /* Swaps two consecutive elements. 'second' *MUST* follow 'first' */ 00411 #define TAILQ_SWAP(first, second, head, field) do { \ 00412 *((first)->field.tqe_prev) = (second); \ 00413 (second)->field.tqe_prev = (first)->field.tqe_prev; \ 00414 (first)->field.tqe_prev = &((second)->field.tqe_next); \ 00415 (first)->field.tqe_next = (second)->field.tqe_next; \ 00416 if ((second)->field.tqe_next) \ 00417 (second)->field.tqe_next->field.tqe_prev = &((first)->field.tqe_next); \ 00418 (second)->field.tqe_next = first; \ 00419 if ((head)->tqh_last == &((second)->field.tqe_next)) \ 00420 (head)->tqh_last = &((first)->field.tqe_next); \ 00421 } while (0) 00422 00423 /* 00424 * Circular queue definitions. 00425 */ 00426 #define CIRCLEQ_HEAD(name, type) \ 00427 struct name { \ 00428 struct type *cqh_first; /* first element */ \ 00429 struct type *cqh_last; /* last element */ \ 00430 } 00431 00432 #define CIRCLEQ_HEAD_INITIALIZER(head) \ 00433 { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } 00434 00435 #define CIRCLEQ_ENTRY(type) \ 00436 struct { \ 00437 struct type *cqe_next; /* next element */ \ 00438 struct type *cqe_prev; /* previous element */ \ 00439 } 00440 00441 /* 00442 * Circular queue access methods 00443 */ 00444 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 00445 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 00446 #define CIRCLEQ_END(head) ((void *)(head)) 00447 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 00448 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 00449 #define CIRCLEQ_EMPTY(head) \ 00450 (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head)) 00451 00452 #define CIRCLEQ_FOREACH(var, head, field) \ 00453 for((var) = CIRCLEQ_FIRST(head); \ 00454 (var) != CIRCLEQ_END(head); \ 00455 (var) = CIRCLEQ_NEXT(var, field)) 00456 00457 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 00458 for((var) = CIRCLEQ_LAST(head); \ 00459 (var) != CIRCLEQ_END(head); \ 00460 (var) = CIRCLEQ_PREV(var, field)) 00461 00462 /* 00463 * Circular queue functions. 00464 */ 00465 #define CIRCLEQ_INIT(head) do { \ 00466 (head)->cqh_first = CIRCLEQ_END(head); \ 00467 (head)->cqh_last = CIRCLEQ_END(head); \ 00468 } while (0) 00469 00470 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 00471 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 00472 (elm)->field.cqe_prev = (listelm); \ 00473 if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \ 00474 (head)->cqh_last = (elm); \ 00475 else \ 00476 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 00477 (listelm)->field.cqe_next = (elm); \ 00478 } while (0) 00479 00480 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 00481 (elm)->field.cqe_next = (listelm); \ 00482 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 00483 if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \ 00484 (head)->cqh_first = (elm); \ 00485 else \ 00486 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 00487 (listelm)->field.cqe_prev = (elm); \ 00488 } while (0) 00489 00490 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 00491 (elm)->field.cqe_next = (head)->cqh_first; \ 00492 (elm)->field.cqe_prev = CIRCLEQ_END(head); \ 00493 if ((head)->cqh_last == CIRCLEQ_END(head)) \ 00494 (head)->cqh_last = (elm); \ 00495 else \ 00496 (head)->cqh_first->field.cqe_prev = (elm); \ 00497 (head)->cqh_first = (elm); \ 00498 } while (0) 00499 00500 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 00501 (elm)->field.cqe_next = CIRCLEQ_END(head); \ 00502 (elm)->field.cqe_prev = (head)->cqh_last; \ 00503 if ((head)->cqh_first == CIRCLEQ_END(head)) \ 00504 (head)->cqh_first = (elm); \ 00505 else \ 00506 (head)->cqh_last->field.cqe_next = (elm); \ 00507 (head)->cqh_last = (elm); \ 00508 } while (0) 00509 00510 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 00511 if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \ 00512 (head)->cqh_last = (elm)->field.cqe_prev; \ 00513 else \ 00514 (elm)->field.cqe_next->field.cqe_prev = \ 00515 (elm)->field.cqe_prev; \ 00516 if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \ 00517 (head)->cqh_first = (elm)->field.cqe_next; \ 00518 else \ 00519 (elm)->field.cqe_prev->field.cqe_next = \ 00520 (elm)->field.cqe_next; \ 00521 _Q_INVALIDATE((elm)->field.cqe_prev); \ 00522 _Q_INVALIDATE((elm)->field.cqe_next); \ 00523 } while (0) 00524 00525 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \ 00526 if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \ 00527 CIRCLEQ_END(head)) \ 00528 (head)->cqh_last = (elm2); \ 00529 else \ 00530 (elm2)->field.cqe_next->field.cqe_prev = (elm2); \ 00531 if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \ 00532 CIRCLEQ_END(head)) \ 00533 (head)->cqh_first = (elm2); \ 00534 else \ 00535 (elm2)->field.cqe_prev->field.cqe_next = (elm2); \ 00536 _Q_INVALIDATE((elm)->field.cqe_prev); \ 00537 _Q_INVALIDATE((elm)->field.cqe_next); \ 00538 } while (0) 00539 00540 #endif /* !_SYS_QUEUE_H_ */