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installer: Re-add the TEST_DEV command which was removed accidentally.
[dragonfly.git] / sys / sys / queue.h
blobc9761ceb2da4e9c438c5f9193d0f67caa667bc12
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_ */
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