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queue.h
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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 * $FreeBSD$
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 be traversed in either 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_FROM + + + +
92 * _FOREACH_SAFE + + + +
93 * _FOREACH_FROM_SAFE + + + +
94 * _FOREACH_REVERSE - - - +
95 * _FOREACH_REVERSE_FROM - - - +
96 * _FOREACH_REVERSE_SAFE - - - +
97 * _FOREACH_REVERSE_FROM_SAFE - - - +
98 * _INSERT_HEAD + + + +
99 * _INSERT_BEFORE - + - +
100 * _INSERT_AFTER + + + +
101 * _INSERT_TAIL - - + +
102 * _CONCAT - - + +
103 * _REMOVE_AFTER + - + -
104 * _REMOVE_HEAD + - + -
105 * _REMOVE + + + +
106 * _SWAP + + + +
107 *
108 */
109#ifdef QUEUE_MACRO_DEBUG
110/* Store the last 2 places the queue element or head was altered */
111struct qm_trace {
112 unsigned long lastline;
113 unsigned long prevline;
114 const char *lastfile;
115 const char *prevfile;
116};
117
118#define TRACEBUF struct qm_trace trace;
119#define TRACEBUF_INITIALIZER { __FILE__, __LINE__, NULL, 0 } ,
120#define TRASHIT(x) do {(x) = (void *)-1;} while (0)
121#define QMD_SAVELINK(name, link) void **name = (void *)&(link)
122
123#define QMD_TRACE_HEAD(head) do { \
124 (head)->trace.prevline = (head)->trace.lastline; \
125 (head)->trace.prevfile = (head)->trace.lastfile; \
126 (head)->trace.lastline = __LINE__; \
127 (head)->trace.lastfile = __FILE__; \
128} while (0)
129
130#define QMD_TRACE_ELEM(elem) do { \
131 (elem)->trace.prevline = (elem)->trace.lastline; \
132 (elem)->trace.prevfile = (elem)->trace.lastfile; \
133 (elem)->trace.lastline = __LINE__; \
134 (elem)->trace.lastfile = __FILE__; \
135} while (0)
136
137#else
138#define QMD_TRACE_ELEM(elem)
139#define QMD_TRACE_HEAD(head)
140#define QMD_SAVELINK(name, link)
141#define TRACEBUF
142#define TRACEBUF_INITIALIZER
143#define TRASHIT(x)
144#endif /* QUEUE_MACRO_DEBUG */
145
146/*
147 * Singly-linked List declarations.
148 */
149#define SLIST_HEAD(name, type) \
150struct name { \
151 struct type *slh_first; /* first element */ \
152}
153
154#define SLIST_HEAD_INITIALIZER(head) \
155 { NULL }
156
157#define SLIST_ENTRY(type) \
158struct { \
159 struct type *sle_next; /* next element */ \
160}
161
162/*
163 * Singly-linked List functions.
164 */
165#define SLIST_EMPTY(head) ((head)->slh_first == NULL)
166
167#define SLIST_FIRST(head) ((head)->slh_first)
168
169#define SLIST_FOREACH(var, head, field) \
170 for ((var) = SLIST_FIRST((head)); \
171 (var); \
172 (var) = SLIST_NEXT((var), field))
173
174#define SLIST_FOREACH_FROM(var, head, field) \
175 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
176 (var); \
177 (var) = SLIST_NEXT((var), field))
178
179#define SLIST_FOREACH_SAFE(var, head, field, tvar) \
180 for ((var) = SLIST_FIRST((head)); \
181 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
182 (var) = (tvar))
183
184#define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \
185 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
186 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
187 (var) = (tvar))
188
189#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
190 for ((varp) = &SLIST_FIRST((head)); \
191 ((var) = *(varp)) != NULL; \
192 (varp) = &SLIST_NEXT((var), field))
193
194#define SLIST_INIT(head) do { \
195 SLIST_FIRST((head)) = NULL; \
196} while (0)
197
198#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
199 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
200 SLIST_NEXT((slistelm), field) = (elm); \
201} while (0)
202
203#define SLIST_INSERT_HEAD(head, elm, field) do { \
204 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
205 SLIST_FIRST((head)) = (elm); \
206} while (0)
207
208#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
209
210#define SLIST_REMOVE(head, elm, type, field) do { \
211 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \
212 if (SLIST_FIRST((head)) == (elm)) { \
213 SLIST_REMOVE_HEAD((head), field); \
214 } \
215 else { \
216 struct type *curelm = SLIST_FIRST((head)); \
217 while (SLIST_NEXT(curelm, field) != (elm)) \
218 curelm = SLIST_NEXT(curelm, field); \
219 SLIST_REMOVE_AFTER(curelm, field); \
220 } \
221 TRASHIT(*oldnext); \
222} while (0)
223
224#define SLIST_REMOVE_AFTER(elm, field) do { \
225 SLIST_NEXT(elm, field) = \
226 SLIST_NEXT(SLIST_NEXT(elm, field), field); \
227} while (0)
228
229#define SLIST_REMOVE_HEAD(head, field) do { \
230 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
231} while (0)
232
233#define SLIST_SWAP(head1, head2, type) do { \
234 struct type *swap_first = SLIST_FIRST(head1); \
235 SLIST_FIRST(head1) = SLIST_FIRST(head2); \
236 SLIST_FIRST(head2) = swap_first; \
237} while (0)
238
239/*
240 * Singly-linked Tail queue declarations.
241 */
242#define STAILQ_HEAD(name, type) \
243struct name { \
244 struct type *stqh_first;/* first element */ \
245 struct type **stqh_last;/* addr of last next element */ \
246}
247
248#define STAILQ_HEAD_INITIALIZER(head) \
249 { NULL, &(head).stqh_first }
250
251#define STAILQ_ENTRY(type) \
252struct { \
253 struct type *stqe_next; /* next element */ \
254}
255
256/*
257 * Singly-linked Tail queue functions.
258 */
259#define STAILQ_CONCAT(head1, head2) do { \
260 if (!STAILQ_EMPTY((head2))) { \
261 *(head1)->stqh_last = (head2)->stqh_first; \
262 (head1)->stqh_last = (head2)->stqh_last; \
263 STAILQ_INIT((head2)); \
264 } \
265} while (0)
266
267#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
268
269#define STAILQ_FIRST(head) ((head)->stqh_first)
270
271#define STAILQ_FOREACH(var, head, field) \
272 for((var) = STAILQ_FIRST((head)); \
273 (var); \
274 (var) = STAILQ_NEXT((var), field))
275
276#define STAILQ_FOREACH_FROM(var, head, field) \
277 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
278 (var); \
279 (var) = STAILQ_NEXT((var), field))
280
281#define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
282 for ((var) = STAILQ_FIRST((head)); \
283 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
284 (var) = (tvar))
285
286#define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \
287 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
288 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
289 (var) = (tvar))
290
291#define STAILQ_INIT(head) do { \
292 STAILQ_FIRST((head)) = NULL; \
293 (head)->stqh_last = &STAILQ_FIRST((head)); \
294} while (0)
295
296#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
297 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
298 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
299 STAILQ_NEXT((tqelm), field) = (elm); \
300} while (0)
301
302#define STAILQ_INSERT_HEAD(head, elm, field) do { \
303 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
304 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
305 STAILQ_FIRST((head)) = (elm); \
306} while (0)
307
308#define STAILQ_INSERT_TAIL(head, elm, field) do { \
309 STAILQ_NEXT((elm), field) = NULL; \
310 *(head)->stqh_last = (elm); \
311 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
312} while (0)
313
314#define STAILQ_LAST(head, type, field) \
315 (STAILQ_EMPTY((head)) ? NULL : \
316 __containerof((head)->stqh_last, struct type, field.stqe_next))
317
318#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
319
320#define STAILQ_REMOVE(head, elm, type, field) do { \
321 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \
322 if (STAILQ_FIRST((head)) == (elm)) { \
323 STAILQ_REMOVE_HEAD((head), field); \
324 } \
325 else { \
326 struct type *curelm = STAILQ_FIRST((head)); \
327 while (STAILQ_NEXT(curelm, field) != (elm)) \
328 curelm = STAILQ_NEXT(curelm, field); \
329 STAILQ_REMOVE_AFTER(head, curelm, field); \
330 } \
331 TRASHIT(*oldnext); \
332} while (0)
333
334#define STAILQ_REMOVE_AFTER(head, elm, field) do { \
335 if ((STAILQ_NEXT(elm, field) = \
336 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \
337 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
338} while (0)
339
340#define STAILQ_REMOVE_HEAD(head, field) do { \
341 if ((STAILQ_FIRST((head)) = \
342 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
343 (head)->stqh_last = &STAILQ_FIRST((head)); \
344} while (0)
345
346#define STAILQ_SWAP(head1, head2, type) do { \
347 struct type *swap_first = STAILQ_FIRST(head1); \
348 struct type **swap_last = (head1)->stqh_last; \
349 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \
350 (head1)->stqh_last = (head2)->stqh_last; \
351 STAILQ_FIRST(head2) = swap_first; \
352 (head2)->stqh_last = swap_last; \
353 if (STAILQ_EMPTY(head1)) \
354 (head1)->stqh_last = &STAILQ_FIRST(head1); \
355 if (STAILQ_EMPTY(head2)) \
356 (head2)->stqh_last = &STAILQ_FIRST(head2); \
357} while (0)
358
359
360/*
361 * List declarations.
362 */
363#define LIST_HEAD(name, type) \
364struct name { \
365 struct type *lh_first; /* first element */ \
366}
367
368#define LIST_HEAD_INITIALIZER(head) \
369 { NULL }
370
371#define LIST_ENTRY(type) \
372struct { \
373 struct type *le_next; /* next element */ \
374 struct type **le_prev; /* address of previous next element */ \
375}
376
377/*
378 * List functions.
379 */
380
381#if (defined(_KERNEL) && defined(INVARIANTS))
382#define QMD_LIST_CHECK_HEAD(head, field) do { \
383 if (LIST_FIRST((head)) != NULL && \
384 LIST_FIRST((head))->field.le_prev != \
385 &LIST_FIRST((head))) \
386 panic("Bad list head %p first->prev != head", (head)); \
387} while (0)
388
389#define QMD_LIST_CHECK_NEXT(elm, field) do { \
390 if (LIST_NEXT((elm), field) != NULL && \
391 LIST_NEXT((elm), field)->field.le_prev != \
392 &((elm)->field.le_next)) \
393 panic("Bad link elm %p next->prev != elm", (elm)); \
394} while (0)
395
396#define QMD_LIST_CHECK_PREV(elm, field) do { \
397 if (*(elm)->field.le_prev != (elm)) \
398 panic("Bad link elm %p prev->next != elm", (elm)); \
399} while (0)
400#else
401#define QMD_LIST_CHECK_HEAD(head, field)
402#define QMD_LIST_CHECK_NEXT(elm, field)
403#define QMD_LIST_CHECK_PREV(elm, field)
404#endif /* (_KERNEL && INVARIANTS) */
405
406#define LIST_EMPTY(head) ((head)->lh_first == NULL)
407
408#define LIST_FIRST(head) ((head)->lh_first)
409
410#define LIST_FOREACH(var, head, field) \
411 for ((var) = LIST_FIRST((head)); \
412 (var); \
413 (var) = LIST_NEXT((var), field))
414
415#define LIST_FOREACH_FROM(var, head, field) \
416 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
417 (var); \
418 (var) = LIST_NEXT((var), field))
419
420#define LIST_FOREACH_SAFE(var, head, field, tvar) \
421 for ((var) = LIST_FIRST((head)); \
422 (var) && ((tvar) = LIST_NEXT((var), field), 1); \
423 (var) = (tvar))
424
425#define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \
426 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
427 (var) && ((tvar) = LIST_NEXT((var), field), 1); \
428 (var) = (tvar))
429
430#define LIST_INIT(head) do { \
431 LIST_FIRST((head)) = NULL; \
432} while (0)
433
434#define LIST_INSERT_AFTER(listelm, elm, field) do { \
435 QMD_LIST_CHECK_NEXT(listelm, field); \
436 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
437 LIST_NEXT((listelm), field)->field.le_prev = \
438 &LIST_NEXT((elm), field); \
439 LIST_NEXT((listelm), field) = (elm); \
440 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \
441} while (0)
442
443#define LIST_INSERT_BEFORE(listelm, elm, field) do { \
444 QMD_LIST_CHECK_PREV(listelm, field); \
445 (elm)->field.le_prev = (listelm)->field.le_prev; \
446 LIST_NEXT((elm), field) = (listelm); \
447 *(listelm)->field.le_prev = (elm); \
448 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \
449} while (0)
450
451#define LIST_INSERT_HEAD(head, elm, field) do { \
452 QMD_LIST_CHECK_HEAD((head), field); \
453 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
454 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
455 LIST_FIRST((head)) = (elm); \
456 (elm)->field.le_prev = &LIST_FIRST((head)); \
457} while (0)
458
459#define LIST_NEXT(elm, field) ((elm)->field.le_next)
460
461#define LIST_PREV(elm, head, type, field) \
462 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \
463 __containerof((elm)->field.le_prev, struct type, field.le_next))
464
465#define LIST_REMOVE(elm, field) do { \
466 QMD_SAVELINK(oldnext, (elm)->field.le_next); \
467 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \
468 QMD_LIST_CHECK_NEXT(elm, field); \
469 QMD_LIST_CHECK_PREV(elm, field); \
470 if (LIST_NEXT((elm), field) != NULL) \
471 LIST_NEXT((elm), field)->field.le_prev = \
472 (elm)->field.le_prev; \
473 *(elm)->field.le_prev = LIST_NEXT((elm), field); \
474 TRASHIT(*oldnext); \
475 TRASHIT(*oldprev); \
476} while (0)
477
478#define LIST_SWAP(head1, head2, type, field) do { \
479 struct type *swap_tmp = LIST_FIRST((head1)); \
480 LIST_FIRST((head1)) = LIST_FIRST((head2)); \
481 LIST_FIRST((head2)) = swap_tmp; \
482 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \
483 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \
484 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \
485 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \
486} while (0)
487
488/*
489 * Tail queue declarations.
490 */
491#define TAILQ_HEAD(name, type) \
492struct name { \
493 struct type *tqh_first; /* first element */ \
494 struct type **tqh_last; /* addr of last next element */ \
495 TRACEBUF \
496}
497
498#define TAILQ_HEAD_INITIALIZER(head) \
499 { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER }
500
501#define TAILQ_ENTRY(type) \
502struct { \
503 struct type *tqe_next; /* next element */ \
504 struct type **tqe_prev; /* address of previous next element */ \
505 TRACEBUF \
506}
507
508/*
509 * Tail queue functions.
510 */
511#if (defined(_KERNEL) && defined(INVARIANTS))
512#define QMD_TAILQ_CHECK_HEAD(head, field) do { \
513 if (!TAILQ_EMPTY(head) && \
514 TAILQ_FIRST((head))->field.tqe_prev != \
515 &TAILQ_FIRST((head))) \
516 panic("Bad tailq head %p first->prev != head", (head)); \
517} while (0)
518
519#define QMD_TAILQ_CHECK_TAIL(head, field) do { \
520 if (*(head)->tqh_last != NULL) \
521 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
522} while (0)
523
524#define QMD_TAILQ_CHECK_NEXT(elm, field) do { \
525 if (TAILQ_NEXT((elm), field) != NULL && \
526 TAILQ_NEXT((elm), field)->field.tqe_prev != \
527 &((elm)->field.tqe_next)) \
528 panic("Bad link elm %p next->prev != elm", (elm)); \
529} while (0)
530
531#define QMD_TAILQ_CHECK_PREV(elm, field) do { \
532 if (*(elm)->field.tqe_prev != (elm)) \
533 panic("Bad link elm %p prev->next != elm", (elm)); \
534} while (0)
535#else
536#define QMD_TAILQ_CHECK_HEAD(head, field)
537#define QMD_TAILQ_CHECK_TAIL(head, headname)
538#define QMD_TAILQ_CHECK_NEXT(elm, field)
539#define QMD_TAILQ_CHECK_PREV(elm, field)
540#endif /* (_KERNEL && INVARIANTS) */
541
542#define TAILQ_CONCAT(head1, head2, field) do { \
543 if (!TAILQ_EMPTY(head2)) { \
544 *(head1)->tqh_last = (head2)->tqh_first; \
545 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
546 (head1)->tqh_last = (head2)->tqh_last; \
547 TAILQ_INIT((head2)); \
548 QMD_TRACE_HEAD(head1); \
549 QMD_TRACE_HEAD(head2); \
550 } \
551} while (0)
552
553#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
554
555#define TAILQ_FIRST(head) ((head)->tqh_first)
556
557#define TAILQ_FOREACH(var, head, field) \
558 for ((var) = TAILQ_FIRST((head)); \
559 (var); \
560 (var) = TAILQ_NEXT((var), field))
561
562#define TAILQ_FOREACH_FROM(var, head, field) \
563 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
564 (var); \
565 (var) = TAILQ_NEXT((var), field))
566
567#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
568 for ((var) = TAILQ_FIRST((head)); \
569 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
570 (var) = (tvar))
571
572#define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \
573 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
574 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
575 (var) = (tvar))
576
577#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
578 for ((var) = TAILQ_LAST((head), headname); \
579 (var); \
580 (var) = TAILQ_PREV((var), headname, field))
581
582#define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \
583 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
584 (var); \
585 (var) = TAILQ_PREV((var), headname, field))
586
587#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
588 for ((var) = TAILQ_LAST((head), headname); \
589 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
590 (var) = (tvar))
591
592#define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \
593 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
594 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
595 (var) = (tvar))
596
597#define TAILQ_INIT(head) do { \
598 TAILQ_FIRST((head)) = NULL; \
599 (head)->tqh_last = &TAILQ_FIRST((head)); \
600 QMD_TRACE_HEAD(head); \
601} while (0)
602
603#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
604 QMD_TAILQ_CHECK_NEXT(listelm, field); \
605 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
606 TAILQ_NEXT((elm), field)->field.tqe_prev = \
607 &TAILQ_NEXT((elm), field); \
608 else { \
609 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
610 QMD_TRACE_HEAD(head); \
611 } \
612 TAILQ_NEXT((listelm), field) = (elm); \
613 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \
614 QMD_TRACE_ELEM(&(elm)->field); \
615 QMD_TRACE_ELEM(&listelm->field); \
616} while (0)
617
618#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
619 QMD_TAILQ_CHECK_PREV(listelm, field); \
620 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
621 TAILQ_NEXT((elm), field) = (listelm); \
622 *(listelm)->field.tqe_prev = (elm); \
623 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
624 QMD_TRACE_ELEM(&(elm)->field); \
625 QMD_TRACE_ELEM(&listelm->field); \
626} while (0)
627
628#define TAILQ_INSERT_HEAD(head, elm, field) do { \
629 QMD_TAILQ_CHECK_HEAD(head, field); \
630 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \
631 TAILQ_FIRST((head))->field.tqe_prev = \
632 &TAILQ_NEXT((elm), field); \
633 else \
634 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
635 TAILQ_FIRST((head)) = (elm); \
636 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \
637 QMD_TRACE_HEAD(head); \
638 QMD_TRACE_ELEM(&(elm)->field); \
639} while (0)
640
641#define TAILQ_INSERT_TAIL(head, elm, field) do { \
642 QMD_TAILQ_CHECK_TAIL(head, field); \
643 TAILQ_NEXT((elm), field) = NULL; \
644 (elm)->field.tqe_prev = (head)->tqh_last; \
645 *(head)->tqh_last = (elm); \
646 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
647 QMD_TRACE_HEAD(head); \
648 QMD_TRACE_ELEM(&(elm)->field); \
649} while (0)
650
651#define TAILQ_LAST(head, headname) \
652 (*(((struct headname *)((head)->tqh_last))->tqh_last))
653
654#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
655
656#define TAILQ_PREV(elm, headname, field) \
657 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
658
659#define TAILQ_REMOVE(head, elm, field) do { \
660 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \
661 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \
662 QMD_TAILQ_CHECK_NEXT(elm, field); \
663 QMD_TAILQ_CHECK_PREV(elm, field); \
664 if ((TAILQ_NEXT((elm), field)) != NULL) \
665 TAILQ_NEXT((elm), field)->field.tqe_prev = \
666 (elm)->field.tqe_prev; \
667 else { \
668 (head)->tqh_last = (elm)->field.tqe_prev; \
669 QMD_TRACE_HEAD(head); \
670 } \
671 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
672 TRASHIT(*oldnext); \
673 TRASHIT(*oldprev); \
674 QMD_TRACE_ELEM(&(elm)->field); \
675} while (0)
676
677#define TAILQ_SWAP(head1, head2, type, field) do { \
678 struct type *swap_first = (head1)->tqh_first; \
679 struct type **swap_last = (head1)->tqh_last; \
680 (head1)->tqh_first = (head2)->tqh_first; \
681 (head1)->tqh_last = (head2)->tqh_last; \
682 (head2)->tqh_first = swap_first; \
683 (head2)->tqh_last = swap_last; \
684 if ((swap_first = (head1)->tqh_first) != NULL) \
685 swap_first->field.tqe_prev = &(head1)->tqh_first; \
686 else \
687 (head1)->tqh_last = &(head1)->tqh_first; \
688 if ((swap_first = (head2)->tqh_first) != NULL) \
689 swap_first->field.tqe_prev = &(head2)->tqh_first; \
690 else \
691 (head2)->tqh_last = &(head2)->tqh_first; \
692} while (0)
693
694#endif /* !_SYS_QUEUE_H_ */