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 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)queue.h 8.5 (Berkeley) 8/20/94
30 * $FreeBSD: src/sys/sys/queue.h,v 1.68.2.4 2011/05/24 16:06:26 mdf Exp $
31 */
32
33 #ifndef _SYS_QUEUE_H_
34 #define _SYS_QUEUE_H_
35
36 #include <sys/cdefs.h>
37
38 /*
39 * This file defines four types of data structures: singly-linked lists,
40 * singly-linked tail queues, lists and tail queues.
41 *
42 * A singly-linked list is headed by a single forward pointer. The elements
43 * are singly linked for minimum space and pointer manipulation overhead at
44 * the expense of O(n) removal for arbitrary elements. New elements can be
45 * added to the list after an existing element or at the head of the list.
46 * Elements being removed from the head of the list should use the explicit
47 * macro for this purpose for optimum efficiency. A singly-linked list may
48 * only be traversed in the forward direction. Singly-linked lists are ideal
49 * for applications with large datasets and few or no removals or for
50 * implementing a LIFO queue.
51 *
52 * A singly-linked tail queue is headed by a pair of pointers, one to the
53 * head of the list and the other to the tail of the list. The elements are
54 * singly linked for minimum space and pointer manipulation overhead at the
55 * expense of O(n) removal for arbitrary elements. New elements can be added
56 * to the list after an existing element, at the head of the list, or at the
57 * end of the list. Elements being removed from the head of the tail queue
58 * should use the explicit macro for this purpose for optimum efficiency.
59 * A singly-linked tail queue may only be traversed in the forward direction.
60 * Singly-linked tail queues are ideal for applications with large datasets
61 * and few or no removals or for implementing a FIFO queue.
62 *
63 * A list is headed by a single forward pointer (or an array of forward
64 * pointers for a hash table header). The elements are doubly linked
65 * so that an arbitrary element can be removed without a need to
66 * traverse the list. New elements can be added to the list before
67 * or after an existing element or at the head of the list. A list
68 * may only be traversed in the forward direction.
69 *
70 * A tail queue is headed by a pair of pointers, one to the head of the
71 * list and the other to the tail of the list. The elements are doubly
72 * linked 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 or
74 * after an existing element, at the head of the list, or at the end of
75 * the list. A tail queue may be traversed in either direction.
76 *
77 * For details on the use of these macros, see the queue(3) manual page.
78 *
79 *
80 * SLIST LIST STAILQ TAILQ
81 * _HEAD + + + +
82 * _HEAD_INITIALIZER + + + +
83 * _ENTRY + + + +
84 * _INIT + + + +
85 * _EMPTY + + + +
86 * _FIRST + + + +
87 * _NEXT + + + +
88 * _PREV - - - +
89 * _LAST - - + +
90 * _FOREACH + + + +
91 * _FOREACH_SAFE + + + +
92 * _FOREACH_REVERSE - - - +
93 * _FOREACH_REVERSE_SAFE - - - +
94 * _INSERT_HEAD + + + +
95 * _INSERT_BEFORE - + - +
96 * _INSERT_AFTER + + + +
97 * _INSERT_TAIL - - + +
98 * _CONCAT - - + +
99 * _REMOVE_AFTER + - + -
100 * _REMOVE_HEAD + - + -
101 * _REMOVE + + + +
102 * _SWAP + + + +
103 *
104 */
105 #ifdef QUEUE_MACRO_DEBUG
106 /* Store the last 2 places the queue element or head was altered */
107 struct qm_trace {
108 char * lastfile;
109 int lastline;
110 char * prevfile;
111 int prevline;
112 };
113
114 #define TRACEBUF struct qm_trace trace;
115 #define TRASHIT(x) do {(x) = (void *)-1;} while (0)
116 #define QMD_SAVELINK(name, link) void **name = (void *)&(link)
117
118 #define QMD_TRACE_HEAD(head) do { \
119 (head)->trace.prevline = (head)->trace.lastline; \
120 (head)->trace.prevfile = (head)->trace.lastfile; \
121 (head)->trace.lastline = __LINE__; \
122 (head)->trace.lastfile = __FILE__; \
123 } while (0)
124
125 #define QMD_TRACE_ELEM(elem) do { \
126 (elem)->trace.prevline = (elem)->trace.lastline; \
127 (elem)->trace.prevfile = (elem)->trace.lastfile; \
128 (elem)->trace.lastline = __LINE__; \
129 (elem)->trace.lastfile = __FILE__; \
130 } while (0)
131
132 #else
133 #define QMD_TRACE_ELEM(elem)
134 #define QMD_TRACE_HEAD(head)
135 #define QMD_SAVELINK(name, link)
136 #define TRACEBUF
137 #define TRASHIT(x)
138 #endif /* QUEUE_MACRO_DEBUG */
139
140 /*
141 * Singly-linked List declarations.
142 */
143 #define SLIST_HEAD(name, type) \
144 struct name { \
145 struct type *slh_first; /* first element */ \
146 }
147
148 #define SLIST_HEAD_INITIALIZER(head) \
149 { NULL }
150
151 #define SLIST_ENTRY(type) \
152 struct { \
153 struct type *sle_next; /* next element */ \
154 }
155
156 /*
157 * Singly-linked List functions.
158 */
159 #define SLIST_EMPTY(head) ((head)->slh_first == NULL)
160
161 #define SLIST_FIRST(head) ((head)->slh_first)
162
163 #define SLIST_FOREACH(var, head, field) \
164 for ((var) = SLIST_FIRST((head)); \
165 (var); \
166 (var) = SLIST_NEXT((var), field))
167
168 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \
169 for ((var) = SLIST_FIRST((head)); \
170 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
171 (var) = (tvar))
172
173 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
174 for ((varp) = &SLIST_FIRST((head)); \
175 ((var) = *(varp)) != NULL; \
176 (varp) = &SLIST_NEXT((var), field))
177
178 #define SLIST_INIT(head) do { \
179 SLIST_FIRST((head)) = NULL; \
180 } while (0)
181
182 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
183 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
184 SLIST_NEXT((slistelm), field) = (elm); \
185 } while (0)
186
187 #define SLIST_INSERT_HEAD(head, elm, field) do { \
188 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
189 SLIST_FIRST((head)) = (elm); \
190 } while (0)
191
192 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
193
194 #define SLIST_REMOVE(head, elm, type, field) do { \
195 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \
196 if (SLIST_FIRST((head)) == (elm)) { \
197 SLIST_REMOVE_HEAD((head), field); \
198 } \
199 else { \
200 struct type *curelm = SLIST_FIRST((head)); \
201 while (SLIST_NEXT(curelm, field) != (elm)) \
202 curelm = SLIST_NEXT(curelm, field); \
203 SLIST_REMOVE_AFTER(curelm, field); \
204 } \
205 TRASHIT(*oldnext); \
206 } while (0)
207
208 #define SLIST_REMOVE_AFTER(elm, field) do { \
209 SLIST_NEXT(elm, field) = \
210 SLIST_NEXT(SLIST_NEXT(elm, field), field); \
211 } while (0)
212
213 #define SLIST_REMOVE_HEAD(head, field) do { \
214 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
215 } while (0)
216
217 /*
218 * Singly-linked Tail queue declarations.
219 */
220 #define STAILQ_HEAD(name, type) \
221 struct name { \
222 struct type *stqh_first;/* first element */ \
223 struct type **stqh_last;/* addr of last next element */ \
224 }
225
226 #define STAILQ_HEAD_INITIALIZER(head) \
227 { NULL, &(head).stqh_first }
228
229 #define STAILQ_ENTRY(type) \
230 struct { \
231 struct type *stqe_next; /* next element */ \
232 }
233
234 /*
235 * Singly-linked Tail queue functions.
236 */
237 #define STAILQ_CONCAT(head1, head2) do { \
238 if (!STAILQ_EMPTY((head2))) { \
239 *(head1)->stqh_last = (head2)->stqh_first; \
240 (head1)->stqh_last = (head2)->stqh_last; \
241 STAILQ_INIT((head2)); \
242 } \
243 } while (0)
244
245 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
246
247 #define STAILQ_FIRST(head) ((head)->stqh_first)
248
249 #define STAILQ_FOREACH(var, head, field) \
250 for((var) = STAILQ_FIRST((head)); \
251 (var); \
252 (var) = STAILQ_NEXT((var), field))
253
254
255 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
256 for ((var) = STAILQ_FIRST((head)); \
257 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
258 (var) = (tvar))
259
260 #define STAILQ_INIT(head) do { \
261 STAILQ_FIRST((head)) = NULL; \
262 (head)->stqh_last = &STAILQ_FIRST((head)); \
263 } while (0)
264
265 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
266 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
267 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
268 STAILQ_NEXT((tqelm), field) = (elm); \
269 } while (0)
270
271 #define STAILQ_INSERT_HEAD(head, elm, field) do { \
272 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
273 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
274 STAILQ_FIRST((head)) = (elm); \
275 } while (0)
276
277 #define STAILQ_INSERT_TAIL(head, elm, field) do { \
278 STAILQ_NEXT((elm), field) = NULL; \
279 *(head)->stqh_last = (elm); \
280 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
281 } while (0)
282
283 #define STAILQ_LAST(head, type, field) \
284 (STAILQ_EMPTY((head)) ? \
285 NULL : \
286 ((struct type *)(void *) \
287 ((char *)((head)->stqh_last) - __offsetof(struct type, field))))
288
289 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
290
291 #define STAILQ_REMOVE(head, elm, type, field) do { \
292 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \
293 if (STAILQ_FIRST((head)) == (elm)) { \
294 STAILQ_REMOVE_HEAD((head), field); \
295 } \
296 else { \
297 struct type *curelm = STAILQ_FIRST((head)); \
298 while (STAILQ_NEXT(curelm, field) != (elm)) \
299 curelm = STAILQ_NEXT(curelm, field); \
300 STAILQ_REMOVE_AFTER(head, curelm, field); \
301 } \
302 TRASHIT(*oldnext); \
303 } while (0)
304
305 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \
306 if ((STAILQ_NEXT(elm, field) = \
307 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \
308 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
309 } while (0)
310
311 #define STAILQ_REMOVE_HEAD(head, field) do { \
312 if ((STAILQ_FIRST((head)) = \
313 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
314 (head)->stqh_last = &STAILQ_FIRST((head)); \
315 } while (0)
316
317 #define STAILQ_SWAP(head1, head2, type) do { \
318 struct type *swap_first = STAILQ_FIRST(head1); \
319 struct type **swap_last = (head1)->stqh_last; \
320 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \
321 (head1)->stqh_last = (head2)->stqh_last; \
322 STAILQ_FIRST(head2) = swap_first; \
323 (head2)->stqh_last = swap_last; \
324 if (STAILQ_EMPTY(head1)) \
325 (head1)->stqh_last = &STAILQ_FIRST(head1); \
326 if (STAILQ_EMPTY(head2)) \
327 (head2)->stqh_last = &STAILQ_FIRST(head2); \
328 } while (0)
329
330
331 /*
332 * List declarations.
333 */
334 #define LIST_HEAD(name, type) \
335 struct name { \
336 struct type *lh_first; /* first element */ \
337 }
338
339 #define LIST_HEAD_INITIALIZER(head) \
340 { NULL }
341
342 #define LIST_ENTRY(type) \
343 struct { \
344 struct type *le_next; /* next element */ \
345 struct type **le_prev; /* address of previous next element */ \
346 }
347
348 /*
349 * List functions.
350 */
351
352 #if (defined(_KERNEL) && defined(INVARIANTS))
353 #define QMD_LIST_CHECK_HEAD(head, field) do { \
354 if (LIST_FIRST((head)) != NULL && \
355 LIST_FIRST((head))->field.le_prev != \
356 &LIST_FIRST((head))) \
357 panic("Bad list head %p first->prev != head", (head)); \
358 } while (0)
359
360 #define QMD_LIST_CHECK_NEXT(elm, field) do { \
361 if (LIST_NEXT((elm), field) != NULL && \
362 LIST_NEXT((elm), field)->field.le_prev != \
363 &((elm)->field.le_next)) \
364 panic("Bad link elm %p next->prev != elm", (elm)); \
365 } while (0)
366
367 #define QMD_LIST_CHECK_PREV(elm, field) do { \
368 if (*(elm)->field.le_prev != (elm)) \
369 panic("Bad link elm %p prev->next != elm", (elm)); \
370 } while (0)
371 #else
372 #define QMD_LIST_CHECK_HEAD(head, field)
373 #define QMD_LIST_CHECK_NEXT(elm, field)
374 #define QMD_LIST_CHECK_PREV(elm, field)
375 #endif /* (_KERNEL && INVARIANTS) */
376
377 #define LIST_EMPTY(head) ((head)->lh_first == NULL)
378
379 #define LIST_FIRST(head) ((head)->lh_first)
380
381 #define LIST_FOREACH(var, head, field) \
382 for ((var) = LIST_FIRST((head)); \
383 (var); \
384 (var) = LIST_NEXT((var), field))
385
386 #define LIST_FOREACH_SAFE(var, head, field, tvar) \
387 for ((var) = LIST_FIRST((head)); \
388 (var) && ((tvar) = LIST_NEXT((var), field), 1); \
389 (var) = (tvar))
390
391 #define LIST_INIT(head) do { \
392 LIST_FIRST((head)) = NULL; \
393 } while (0)
394
395 #define LIST_INSERT_AFTER(listelm, elm, field) do { \
396 QMD_LIST_CHECK_NEXT(listelm, field); \
397 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
398 LIST_NEXT((listelm), field)->field.le_prev = \
399 &LIST_NEXT((elm), field); \
400 LIST_NEXT((listelm), field) = (elm); \
401 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \
402 } while (0)
403
404 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \
405 QMD_LIST_CHECK_PREV(listelm, field); \
406 (elm)->field.le_prev = (listelm)->field.le_prev; \
407 LIST_NEXT((elm), field) = (listelm); \
408 *(listelm)->field.le_prev = (elm); \
409 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \
410 } while (0)
411
412 #define LIST_INSERT_HEAD(head, elm, field) do { \
413 QMD_LIST_CHECK_HEAD((head), field); \
414 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
415 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
416 LIST_FIRST((head)) = (elm); \
417 (elm)->field.le_prev = &LIST_FIRST((head)); \
418 } while (0)
419
420 #define LIST_NEXT(elm, field) ((elm)->field.le_next)
421
422 #define LIST_REMOVE(elm, field) do { \
423 QMD_SAVELINK(oldnext, (elm)->field.le_next); \
424 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \
425 QMD_LIST_CHECK_NEXT(elm, field); \
426 QMD_LIST_CHECK_PREV(elm, field); \
427 if (LIST_NEXT((elm), field) != NULL) \
428 LIST_NEXT((elm), field)->field.le_prev = \
429 (elm)->field.le_prev; \
430 *(elm)->field.le_prev = LIST_NEXT((elm), field); \
431 TRASHIT(*oldnext); \
432 TRASHIT(*oldprev); \
433 } while (0)
434
435 #define LIST_SWAP(head1, head2, type, field) do { \
436 struct type *swap_tmp = LIST_FIRST((head1)); \
437 LIST_FIRST((head1)) = LIST_FIRST((head2)); \
438 LIST_FIRST((head2)) = swap_tmp; \
439 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \
440 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \
441 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \
442 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \
443 } while (0)
444
445 /*
446 * Tail queue declarations.
447 */
448 #define TAILQ_HEAD(name, type) \
449 struct name { \
450 struct type *tqh_first; /* first element */ \
451 struct type **tqh_last; /* addr of last next element */ \
452 TRACEBUF \
453 }
454
455 #define TAILQ_HEAD_INITIALIZER(head) \
456 { NULL, &(head).tqh_first }
457
458 #define TAILQ_ENTRY(type) \
459 struct { \
460 struct type *tqe_next; /* next element */ \
461 struct type **tqe_prev; /* address of previous next element */ \
462 TRACEBUF \
463 }
464
465 /*
466 * Tail queue functions.
467 */
468 #if (defined(_KERNEL) && defined(INVARIANTS))
469 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \
470 if (!TAILQ_EMPTY(head) && \
471 TAILQ_FIRST((head))->field.tqe_prev != \
472 &TAILQ_FIRST((head))) \
473 panic("Bad tailq head %p first->prev != head", (head)); \
474 } while (0)
475
476 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \
477 if (*(head)->tqh_last != NULL) \
478 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
479 } while (0)
480
481 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \
482 if (TAILQ_NEXT((elm), field) != NULL && \
483 TAILQ_NEXT((elm), field)->field.tqe_prev != \
484 &((elm)->field.tqe_next)) \
485 panic("Bad link elm %p next->prev != elm", (elm)); \
486 } while (0)
487
488 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \
489 if (*(elm)->field.tqe_prev != (elm)) \
490 panic("Bad link elm %p prev->next != elm", (elm)); \
491 } while (0)
492 #else
493 #define QMD_TAILQ_CHECK_HEAD(head, field)
494 #define QMD_TAILQ_CHECK_TAIL(head, headname)
495 #define QMD_TAILQ_CHECK_NEXT(elm, field)
496 #define QMD_TAILQ_CHECK_PREV(elm, field)
497 #endif /* (_KERNEL && INVARIANTS) */
498
499 #define TAILQ_CONCAT(head1, head2, field) do { \
500 if (!TAILQ_EMPTY(head2)) { \
501 *(head1)->tqh_last = (head2)->tqh_first; \
502 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
503 (head1)->tqh_last = (head2)->tqh_last; \
504 TAILQ_INIT((head2)); \
505 QMD_TRACE_HEAD(head1); \
506 QMD_TRACE_HEAD(head2); \
507 } \
508 } while (0)
509
510 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
511
512 #define TAILQ_FIRST(head) ((head)->tqh_first)
513
514 #define TAILQ_FOREACH(var, head, field) \
515 for ((var) = TAILQ_FIRST((head)); \
516 (var); \
517 (var) = TAILQ_NEXT((var), field))
518
519 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
520 for ((var) = TAILQ_FIRST((head)); \
521 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
522 (var) = (tvar))
523
524 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
525 for ((var) = TAILQ_LAST((head), headname); \
526 (var); \
527 (var) = TAILQ_PREV((var), headname, field))
528
529 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
530 for ((var) = TAILQ_LAST((head), headname); \
531 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
532 (var) = (tvar))
533
534 #define TAILQ_INIT(head) do { \
535 TAILQ_FIRST((head)) = NULL; \
536 (head)->tqh_last = &TAILQ_FIRST((head)); \
537 QMD_TRACE_HEAD(head); \
538 } while (0)
539
540 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
541 QMD_TAILQ_CHECK_NEXT(listelm, field); \
542 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
543 TAILQ_NEXT((elm), field)->field.tqe_prev = \
544 &TAILQ_NEXT((elm), field); \
545 else { \
546 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
547 QMD_TRACE_HEAD(head); \
548 } \
549 TAILQ_NEXT((listelm), field) = (elm); \
550 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \
551 QMD_TRACE_ELEM(&(elm)->field); \
552 QMD_TRACE_ELEM(&listelm->field); \
553 } while (0)
554
555 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
556 QMD_TAILQ_CHECK_PREV(listelm, field); \
557 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
558 TAILQ_NEXT((elm), field) = (listelm); \
559 *(listelm)->field.tqe_prev = (elm); \
560 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
561 QMD_TRACE_ELEM(&(elm)->field); \
562 QMD_TRACE_ELEM(&listelm->field); \
563 } while (0)
564
565 #define TAILQ_INSERT_HEAD(head, elm, field) do { \
566 QMD_TAILQ_CHECK_HEAD(head, field); \
567 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \
568 TAILQ_FIRST((head))->field.tqe_prev = \
569 &TAILQ_NEXT((elm), field); \
570 else \
571 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
572 TAILQ_FIRST((head)) = (elm); \
573 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \
574 QMD_TRACE_HEAD(head); \
575 QMD_TRACE_ELEM(&(elm)->field); \
576 } while (0)
577
578 #define TAILQ_INSERT_TAIL(head, elm, field) do { \
579 QMD_TAILQ_CHECK_TAIL(head, field); \
580 TAILQ_NEXT((elm), field) = NULL; \
581 (elm)->field.tqe_prev = (head)->tqh_last; \
582 *(head)->tqh_last = (elm); \
583 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
584 QMD_TRACE_HEAD(head); \
585 QMD_TRACE_ELEM(&(elm)->field); \
586 } while (0)
587
588 #define TAILQ_LAST(head, headname) \
589 (*(((struct headname *)((head)->tqh_last))->tqh_last))
590
591 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
592
593 #define TAILQ_PREV(elm, headname, field) \
594 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
595
596 #define TAILQ_REMOVE(head, elm, field) do { \
597 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \
598 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \
599 QMD_TAILQ_CHECK_NEXT(elm, field); \
600 QMD_TAILQ_CHECK_PREV(elm, field); \
601 if ((TAILQ_NEXT((elm), field)) != NULL) \
602 TAILQ_NEXT((elm), field)->field.tqe_prev = \
603 (elm)->field.tqe_prev; \
604 else { \
605 (head)->tqh_last = (elm)->field.tqe_prev; \
606 QMD_TRACE_HEAD(head); \
607 } \
608 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
609 TRASHIT(*oldnext); \
610 TRASHIT(*oldprev); \
611 QMD_TRACE_ELEM(&(elm)->field); \
612 } while (0)
613
614 #define TAILQ_SWAP(head1, head2, type, field) do { \
615 struct type *swap_first = (head1)->tqh_first; \
616 struct type **swap_last = (head1)->tqh_last; \
617 (head1)->tqh_first = (head2)->tqh_first; \
618 (head1)->tqh_last = (head2)->tqh_last; \
619 (head2)->tqh_first = swap_first; \
620 (head2)->tqh_last = swap_last; \
621 if ((swap_first = (head1)->tqh_first) != NULL) \
622 swap_first->field.tqe_prev = &(head1)->tqh_first; \
623 else \
624 (head1)->tqh_last = &(head1)->tqh_first; \
625 if ((swap_first = (head2)->tqh_first) != NULL) \
626 swap_first->field.tqe_prev = &(head2)->tqh_first; \
627 else \
628 (head2)->tqh_last = &(head2)->tqh_first; \
629 } while (0)
630
631 #ifdef _KERNEL
632
633 /*
634 * XXX insque() and remque() are an old way of handling certain queues.
635 * They bogusly assumes that all queue heads look alike.
636 */
637
638 struct quehead {
639 struct quehead *qh_link;
640 struct quehead *qh_rlink;
641 };
642
643 #ifdef __CC_SUPPORTS___INLINE
644
645 static __inline void
insque(void * a,void * b)646 insque(void *a, void *b)
647 {
648 struct quehead *element = (struct quehead *)a,
649 *head = (struct quehead *)b;
650
651 element->qh_link = head->qh_link;
652 element->qh_rlink = head;
653 head->qh_link = element;
654 element->qh_link->qh_rlink = element;
655 }
656
657 static __inline void
remque(void * a)658 remque(void *a)
659 {
660 struct quehead *element = (struct quehead *)a;
661
662 element->qh_link->qh_rlink = element->qh_rlink;
663 element->qh_rlink->qh_link = element->qh_link;
664 element->qh_rlink = 0;
665 }
666
667 #else /* !__CC_SUPPORTS___INLINE */
668
669 void insque(void *a, void *b);
670 void remque(void *a);
671
672 #endif /* __CC_SUPPORTS___INLINE */
673
674 #endif /* _KERNEL */
675
676 #endif /* !_SYS_QUEUE_H_ */
677