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Damien Millera95c0c22007-10-26 16:46:31 +10001/* $OpenBSD: queue.h,v 1.32 2007/04/30 18:42:34 pedro Exp $ */
Kevin Steves2c65ada2000-12-06 22:25:40 +00002/* $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.
Damien Miller329638e2003-06-03 12:12:50 +100016 * 3. Neither the name of the University nor the names of its contributors
Kevin Steves2c65ada2000-12-06 22:25:40 +000017 * 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
Darren Tucker7f24a0e2005-11-10 16:18:56 +110035/* OPENBSD ORIGINAL: sys/sys/queue.h */
36
Ben Lindstromefec7c22004-05-23 06:22:27 +000037#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
Kevin Steves2c65ada2000-12-06 22:25:40 +0000122
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
Damien Millera95c0c22007-10-26 16:46:31 +1000170#if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC))
Damien Miller03c618a2007-10-26 16:45:32 +1000171#define _Q_INVALIDATE(a) (a) = ((void *)-1)
172#else
173#define _Q_INVALIDATE(a)
174#endif
175
Kevin Steves2c65ada2000-12-06 22:25:40 +0000176/*
177 * Singly-linked List definitions.
178 */
179#define SLIST_HEAD(name, type) \
180struct name { \
181 struct type *slh_first; /* first element */ \
182}
183
184#define SLIST_HEAD_INITIALIZER(head) \
185 { NULL }
186
187#define SLIST_ENTRY(type) \
188struct { \
189 struct type *sle_next; /* next element */ \
190}
191
192/*
193 * Singly-linked List access methods.
194 */
195#define SLIST_FIRST(head) ((head)->slh_first)
196#define SLIST_END(head) NULL
197#define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head))
198#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
199
200#define SLIST_FOREACH(var, head, field) \
201 for((var) = SLIST_FIRST(head); \
202 (var) != SLIST_END(head); \
203 (var) = SLIST_NEXT(var, field))
204
Damien Miller1824c072004-04-20 20:10:46 +1000205#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
206 for ((varp) = &SLIST_FIRST((head)); \
207 ((var) = *(varp)) != SLIST_END(head); \
208 (varp) = &SLIST_NEXT((var), field))
209
Kevin Steves2c65ada2000-12-06 22:25:40 +0000210/*
211 * Singly-linked List functions.
212 */
213#define SLIST_INIT(head) { \
214 SLIST_FIRST(head) = SLIST_END(head); \
215}
216
217#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
218 (elm)->field.sle_next = (slistelm)->field.sle_next; \
219 (slistelm)->field.sle_next = (elm); \
220} while (0)
221
222#define SLIST_INSERT_HEAD(head, elm, field) do { \
223 (elm)->field.sle_next = (head)->slh_first; \
224 (head)->slh_first = (elm); \
225} while (0)
226
Damien Miller1824c072004-04-20 20:10:46 +1000227#define SLIST_REMOVE_NEXT(head, elm, field) do { \
228 (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \
229} while (0)
230
Kevin Steves2c65ada2000-12-06 22:25:40 +0000231#define SLIST_REMOVE_HEAD(head, field) do { \
232 (head)->slh_first = (head)->slh_first->field.sle_next; \
233} while (0)
234
Damien Miller8e3bdca2002-02-13 16:00:15 +1100235#define SLIST_REMOVE(head, elm, type, field) do { \
236 if ((head)->slh_first == (elm)) { \
237 SLIST_REMOVE_HEAD((head), field); \
Damien Millerd129ecb2007-10-26 16:41:14 +1000238 } else { \
Damien Miller8e3bdca2002-02-13 16:00:15 +1100239 struct type *curelm = (head)->slh_first; \
Damien Millerd129ecb2007-10-26 16:41:14 +1000240 \
241 while (curelm->field.sle_next != (elm)) \
Damien Miller8e3bdca2002-02-13 16:00:15 +1100242 curelm = curelm->field.sle_next; \
243 curelm->field.sle_next = \
244 curelm->field.sle_next->field.sle_next; \
Damien Miller03c618a2007-10-26 16:45:32 +1000245 _Q_INVALIDATE((elm)->field.sle_next); \
Damien Miller8e3bdca2002-02-13 16:00:15 +1100246 } \
247} while (0)
248
Kevin Steves2c65ada2000-12-06 22:25:40 +0000249/*
250 * List definitions.
251 */
252#define LIST_HEAD(name, type) \
253struct name { \
254 struct type *lh_first; /* first element */ \
255}
256
257#define LIST_HEAD_INITIALIZER(head) \
258 { NULL }
259
260#define LIST_ENTRY(type) \
261struct { \
262 struct type *le_next; /* next element */ \
263 struct type **le_prev; /* address of previous next element */ \
264}
265
266/*
267 * List access methods
268 */
269#define LIST_FIRST(head) ((head)->lh_first)
270#define LIST_END(head) NULL
271#define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head))
272#define LIST_NEXT(elm, field) ((elm)->field.le_next)
273
274#define LIST_FOREACH(var, head, field) \
275 for((var) = LIST_FIRST(head); \
276 (var)!= LIST_END(head); \
277 (var) = LIST_NEXT(var, field))
278
279/*
280 * List functions.
281 */
282#define LIST_INIT(head) do { \
283 LIST_FIRST(head) = LIST_END(head); \
284} while (0)
285
286#define LIST_INSERT_AFTER(listelm, elm, field) do { \
287 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
288 (listelm)->field.le_next->field.le_prev = \
289 &(elm)->field.le_next; \
290 (listelm)->field.le_next = (elm); \
291 (elm)->field.le_prev = &(listelm)->field.le_next; \
292} while (0)
293
294#define LIST_INSERT_BEFORE(listelm, elm, field) do { \
295 (elm)->field.le_prev = (listelm)->field.le_prev; \
296 (elm)->field.le_next = (listelm); \
297 *(listelm)->field.le_prev = (elm); \
298 (listelm)->field.le_prev = &(elm)->field.le_next; \
299} while (0)
300
301#define LIST_INSERT_HEAD(head, elm, field) do { \
302 if (((elm)->field.le_next = (head)->lh_first) != NULL) \
303 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
304 (head)->lh_first = (elm); \
305 (elm)->field.le_prev = &(head)->lh_first; \
306} while (0)
307
308#define LIST_REMOVE(elm, field) do { \
309 if ((elm)->field.le_next != NULL) \
310 (elm)->field.le_next->field.le_prev = \
311 (elm)->field.le_prev; \
312 *(elm)->field.le_prev = (elm)->field.le_next; \
Damien Miller03c618a2007-10-26 16:45:32 +1000313 _Q_INVALIDATE((elm)->field.le_prev); \
314 _Q_INVALIDATE((elm)->field.le_next); \
Kevin Steves2c65ada2000-12-06 22:25:40 +0000315} while (0)
316
317#define LIST_REPLACE(elm, elm2, field) do { \
318 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \
319 (elm2)->field.le_next->field.le_prev = \
320 &(elm2)->field.le_next; \
321 (elm2)->field.le_prev = (elm)->field.le_prev; \
322 *(elm2)->field.le_prev = (elm2); \
Damien Miller03c618a2007-10-26 16:45:32 +1000323 _Q_INVALIDATE((elm)->field.le_prev); \
324 _Q_INVALIDATE((elm)->field.le_next); \
Kevin Steves2c65ada2000-12-06 22:25:40 +0000325} while (0)
326
327/*
328 * Simple queue definitions.
329 */
330#define SIMPLEQ_HEAD(name, type) \
331struct name { \
332 struct type *sqh_first; /* first element */ \
333 struct type **sqh_last; /* addr of last next element */ \
334}
335
336#define SIMPLEQ_HEAD_INITIALIZER(head) \
337 { NULL, &(head).sqh_first }
338
339#define SIMPLEQ_ENTRY(type) \
340struct { \
341 struct type *sqe_next; /* next element */ \
342}
343
344/*
345 * Simple queue access methods.
346 */
347#define SIMPLEQ_FIRST(head) ((head)->sqh_first)
348#define SIMPLEQ_END(head) NULL
349#define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head))
350#define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next)
351
352#define SIMPLEQ_FOREACH(var, head, field) \
353 for((var) = SIMPLEQ_FIRST(head); \
354 (var) != SIMPLEQ_END(head); \
355 (var) = SIMPLEQ_NEXT(var, field))
356
357/*
358 * Simple queue functions.
359 */
360#define SIMPLEQ_INIT(head) do { \
361 (head)->sqh_first = NULL; \
362 (head)->sqh_last = &(head)->sqh_first; \
363} while (0)
364
365#define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \
366 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \
367 (head)->sqh_last = &(elm)->field.sqe_next; \
368 (head)->sqh_first = (elm); \
369} while (0)
370
371#define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \
372 (elm)->field.sqe_next = NULL; \
373 *(head)->sqh_last = (elm); \
374 (head)->sqh_last = &(elm)->field.sqe_next; \
375} while (0)
376
377#define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
378 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
379 (head)->sqh_last = &(elm)->field.sqe_next; \
380 (listelm)->field.sqe_next = (elm); \
381} while (0)
382
Damien Millerb99f5f72007-10-26 16:40:20 +1000383#define SIMPLEQ_REMOVE_HEAD(head, field) do { \
384 if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \
Kevin Steves2c65ada2000-12-06 22:25:40 +0000385 (head)->sqh_last = &(head)->sqh_first; \
386} while (0)
387
388/*
389 * Tail queue definitions.
390 */
391#define TAILQ_HEAD(name, type) \
392struct name { \
393 struct type *tqh_first; /* first element */ \
394 struct type **tqh_last; /* addr of last next element */ \
395}
396
397#define TAILQ_HEAD_INITIALIZER(head) \
398 { NULL, &(head).tqh_first }
399
400#define TAILQ_ENTRY(type) \
401struct { \
402 struct type *tqe_next; /* next element */ \
403 struct type **tqe_prev; /* address of previous next element */ \
404}
405
406/*
407 * tail queue access methods
408 */
409#define TAILQ_FIRST(head) ((head)->tqh_first)
410#define TAILQ_END(head) NULL
411#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
412#define TAILQ_LAST(head, headname) \
413 (*(((struct headname *)((head)->tqh_last))->tqh_last))
414/* XXX */
415#define TAILQ_PREV(elm, headname, field) \
416 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
417#define TAILQ_EMPTY(head) \
418 (TAILQ_FIRST(head) == TAILQ_END(head))
419
420#define TAILQ_FOREACH(var, head, field) \
421 for((var) = TAILQ_FIRST(head); \
422 (var) != TAILQ_END(head); \
423 (var) = TAILQ_NEXT(var, field))
424
Damien Miller1824c072004-04-20 20:10:46 +1000425#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
Kevin Steves2c65ada2000-12-06 22:25:40 +0000426 for((var) = TAILQ_LAST(head, headname); \
427 (var) != TAILQ_END(head); \
428 (var) = TAILQ_PREV(var, headname, field))
429
430/*
431 * Tail queue functions.
432 */
433#define TAILQ_INIT(head) do { \
434 (head)->tqh_first = NULL; \
435 (head)->tqh_last = &(head)->tqh_first; \
436} while (0)
437
438#define TAILQ_INSERT_HEAD(head, elm, field) do { \
439 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
440 (head)->tqh_first->field.tqe_prev = \
441 &(elm)->field.tqe_next; \
442 else \
443 (head)->tqh_last = &(elm)->field.tqe_next; \
444 (head)->tqh_first = (elm); \
445 (elm)->field.tqe_prev = &(head)->tqh_first; \
446} while (0)
447
448#define TAILQ_INSERT_TAIL(head, elm, field) do { \
449 (elm)->field.tqe_next = NULL; \
450 (elm)->field.tqe_prev = (head)->tqh_last; \
451 *(head)->tqh_last = (elm); \
452 (head)->tqh_last = &(elm)->field.tqe_next; \
453} while (0)
454
455#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
456 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
457 (elm)->field.tqe_next->field.tqe_prev = \
458 &(elm)->field.tqe_next; \
459 else \
460 (head)->tqh_last = &(elm)->field.tqe_next; \
461 (listelm)->field.tqe_next = (elm); \
462 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \
463} while (0)
464
465#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
466 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
467 (elm)->field.tqe_next = (listelm); \
468 *(listelm)->field.tqe_prev = (elm); \
469 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
470} while (0)
471
472#define TAILQ_REMOVE(head, elm, field) do { \
473 if (((elm)->field.tqe_next) != NULL) \
474 (elm)->field.tqe_next->field.tqe_prev = \
475 (elm)->field.tqe_prev; \
476 else \
477 (head)->tqh_last = (elm)->field.tqe_prev; \
478 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \
Damien Miller03c618a2007-10-26 16:45:32 +1000479 _Q_INVALIDATE((elm)->field.tqe_prev); \
480 _Q_INVALIDATE((elm)->field.tqe_next); \
Kevin Steves2c65ada2000-12-06 22:25:40 +0000481} while (0)
482
483#define TAILQ_REPLACE(head, elm, elm2, field) do { \
484 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \
485 (elm2)->field.tqe_next->field.tqe_prev = \
486 &(elm2)->field.tqe_next; \
487 else \
488 (head)->tqh_last = &(elm2)->field.tqe_next; \
489 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \
490 *(elm2)->field.tqe_prev = (elm2); \
Damien Miller03c618a2007-10-26 16:45:32 +1000491 _Q_INVALIDATE((elm)->field.tqe_prev); \
492 _Q_INVALIDATE((elm)->field.tqe_next); \
Kevin Steves2c65ada2000-12-06 22:25:40 +0000493} while (0)
494
495/*
496 * Circular queue definitions.
497 */
498#define CIRCLEQ_HEAD(name, type) \
499struct name { \
500 struct type *cqh_first; /* first element */ \
501 struct type *cqh_last; /* last element */ \
502}
503
504#define CIRCLEQ_HEAD_INITIALIZER(head) \
505 { CIRCLEQ_END(&head), CIRCLEQ_END(&head) }
506
507#define CIRCLEQ_ENTRY(type) \
508struct { \
509 struct type *cqe_next; /* next element */ \
510 struct type *cqe_prev; /* previous element */ \
511}
512
513/*
514 * Circular queue access methods
515 */
516#define CIRCLEQ_FIRST(head) ((head)->cqh_first)
517#define CIRCLEQ_LAST(head) ((head)->cqh_last)
518#define CIRCLEQ_END(head) ((void *)(head))
519#define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next)
520#define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev)
521#define CIRCLEQ_EMPTY(head) \
522 (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head))
523
524#define CIRCLEQ_FOREACH(var, head, field) \
525 for((var) = CIRCLEQ_FIRST(head); \
526 (var) != CIRCLEQ_END(head); \
527 (var) = CIRCLEQ_NEXT(var, field))
528
529#define CIRCLEQ_FOREACH_REVERSE(var, head, field) \
530 for((var) = CIRCLEQ_LAST(head); \
531 (var) != CIRCLEQ_END(head); \
532 (var) = CIRCLEQ_PREV(var, field))
533
534/*
535 * Circular queue functions.
536 */
537#define CIRCLEQ_INIT(head) do { \
538 (head)->cqh_first = CIRCLEQ_END(head); \
539 (head)->cqh_last = CIRCLEQ_END(head); \
540} while (0)
541
542#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
543 (elm)->field.cqe_next = (listelm)->field.cqe_next; \
544 (elm)->field.cqe_prev = (listelm); \
545 if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \
546 (head)->cqh_last = (elm); \
547 else \
548 (listelm)->field.cqe_next->field.cqe_prev = (elm); \
549 (listelm)->field.cqe_next = (elm); \
550} while (0)
551
552#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \
553 (elm)->field.cqe_next = (listelm); \
554 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \
555 if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \
556 (head)->cqh_first = (elm); \
557 else \
558 (listelm)->field.cqe_prev->field.cqe_next = (elm); \
559 (listelm)->field.cqe_prev = (elm); \
560} while (0)
561
562#define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \
563 (elm)->field.cqe_next = (head)->cqh_first; \
564 (elm)->field.cqe_prev = CIRCLEQ_END(head); \
565 if ((head)->cqh_last == CIRCLEQ_END(head)) \
566 (head)->cqh_last = (elm); \
567 else \
568 (head)->cqh_first->field.cqe_prev = (elm); \
569 (head)->cqh_first = (elm); \
570} while (0)
571
572#define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \
573 (elm)->field.cqe_next = CIRCLEQ_END(head); \
574 (elm)->field.cqe_prev = (head)->cqh_last; \
575 if ((head)->cqh_first == CIRCLEQ_END(head)) \
576 (head)->cqh_first = (elm); \
577 else \
578 (head)->cqh_last->field.cqe_next = (elm); \
579 (head)->cqh_last = (elm); \
580} while (0)
581
582#define CIRCLEQ_REMOVE(head, elm, field) do { \
583 if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \
584 (head)->cqh_last = (elm)->field.cqe_prev; \
585 else \
586 (elm)->field.cqe_next->field.cqe_prev = \
587 (elm)->field.cqe_prev; \
588 if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \
589 (head)->cqh_first = (elm)->field.cqe_next; \
590 else \
591 (elm)->field.cqe_prev->field.cqe_next = \
592 (elm)->field.cqe_next; \
Damien Miller03c618a2007-10-26 16:45:32 +1000593 _Q_INVALIDATE((elm)->field.cqe_prev); \
594 _Q_INVALIDATE((elm)->field.cqe_next); \
Kevin Steves2c65ada2000-12-06 22:25:40 +0000595} while (0)
596
597#define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \
598 if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \
599 CIRCLEQ_END(head)) \
600 (head).cqh_last = (elm2); \
601 else \
602 (elm2)->field.cqe_next->field.cqe_prev = (elm2); \
603 if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \
604 CIRCLEQ_END(head)) \
605 (head).cqh_first = (elm2); \
606 else \
607 (elm2)->field.cqe_prev->field.cqe_next = (elm2); \
Damien Miller03c618a2007-10-26 16:45:32 +1000608 _Q_INVALIDATE((elm)->field.cqe_prev); \
609 _Q_INVALIDATE((elm)->field.cqe_next); \
Kevin Steves2c65ada2000-12-06 22:25:40 +0000610} while (0)
611
Ben Lindstromefec7c22004-05-23 06:22:27 +0000612#endif /* !_FAKE_QUEUE_H_ */