1 /* BEGIN CSTYLED */
2 /*-
3 * Copyright (c) 1991, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 4. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * @(#)queue.h 8.5 (Berkeley) 8/20/94
31 * $FreeBSD: /repoman/r/ncvs/src/sys/sys/queue.h,v 1.66 2006/05/26 18:17:53 emaste Exp $
32 */
33
34 #ifndef _SYS_QUEUE_H_
35 #define _SYS_QUEUE_H_
36
37 #pragma ident "%Z%%M% %I% %E% SMI"
38
39 /*
40 * This file defines four types of data structures: singly-linked lists,
41 * singly-linked tail queues, lists and tail queues.
42 *
43 * A singly-linked list is headed by a single forward pointer. The elements
44 * are singly linked for minimum space and pointer manipulation overhead at
45 * the expense of O(n) removal for arbitrary elements. New elements can be
46 * added to the list after an existing element or at the head of the list.
47 * Elements being removed from the head of the list should use the explicit
48 * macro for this purpose for optimum efficiency. A singly-linked list may
49 * only be traversed in the forward direction. Singly-linked lists are ideal
50 * for applications with large datasets and few or no removals or for
51 * implementing a LIFO queue.
52 *
53 * A singly-linked tail queue is headed by a pair of pointers, one to the
54 * head of the list and the other to the tail of the list. The elements are
55 * singly linked for minimum space and pointer manipulation overhead at the
56 * expense of O(n) removal for arbitrary elements. New elements can be added
57 * to the list after an existing element, at the head of the list, or at the
58 * end of the list. Elements being removed from the head of the tail queue
59 * should use the explicit macro for this purpose for optimum efficiency.
60 * A singly-linked tail queue may only be traversed in the forward direction.
61 * Singly-linked tail queues are ideal for applications with large datasets
62 * and few or no removals or for implementing a FIFO queue.
63 *
64 * A list is headed by a single forward pointer (or an array of forward
65 * pointers for a hash table header). The elements are doubly linked
66 * so that an arbitrary element can be removed without a need to
67 * traverse the list. New elements can be added to the list before
68 * or after an existing element or at the head of the list. A list
69 * may only be traversed in the forward direction.
70 *
71 * A tail queue is headed by a pair of pointers, one to the head of the
72 * list and the other to the tail of the list. The elements are doubly
73 * linked so that an arbitrary element can be removed without a need to
74 * traverse the list. New elements can be added to the list before or
75 * after an existing element, at the head of the list, or at the end of
76 * the list. A tail queue may be traversed in either direction.
77 *
78 * For details on the use of these macros, see the queue(3) manual page.
79 *
80 *
81 * SLIST LIST STAILQ TAILQ
82 * _HEAD + + + +
83 * _HEAD_INITIALIZER + + + +
84 * _ENTRY + + + +
85 * _INIT + + + +
86 * _EMPTY + + + +
87 * _FIRST + + + +
88 * _NEXT + + + +
89 * _PREV - - - +
90 * _LAST - - + +
91 * _FOREACH + + + +
92 * _FOREACH_SAFE + + + +
93 * _FOREACH_REVERSE - - - +
94 * _FOREACH_REVERSE_SAFE - - - +
95 * _INSERT_HEAD + + + +
96 * _INSERT_BEFORE - + - +
97 * _INSERT_AFTER + + + +
98 * _INSERT_TAIL - - + +
99 * _CONCAT - - + +
100 * _REMOVE_HEAD + - + -
101 * _REMOVE + + + +
102 *
103 */
104 #ifdef QUEUE_MACRO_DEBUG
105 /* Store the last 2 places the queue element or head was altered */
106 struct qm_trace {
107 char * lastfile;
108 int lastline;
109 char * prevfile;
110 int prevline;
111 };
112
113 #define TRACEBUF struct qm_trace trace;
114 #define TRASHIT(x) do {(x) = (void *)-1;} while (*"\0")
115
116 #define QMD_TRACE_HEAD(head) do { \
117 (head)->trace.prevline = (head)->trace.lastline; \
118 (head)->trace.prevfile = (head)->trace.lastfile; \
119 (head)->trace.lastline = __LINE__; \
120 (head)->trace.lastfile = __FILE__; \
121 } while (*"\0")
122
123 #define QMD_TRACE_ELEM(elem) do { \
124 (elem)->trace.prevline = (elem)->trace.lastline; \
125 (elem)->trace.prevfile = (elem)->trace.lastfile; \
126 (elem)->trace.lastline = __LINE__; \
127 (elem)->trace.lastfile = __FILE__; \
128 } while (*"\0")
129
130 #else
131 #define QMD_TRACE_ELEM(elem)
132 #define QMD_TRACE_HEAD(head)
133 #define TRACEBUF
134 #define TRASHIT(x)
135 #endif /* QUEUE_MACRO_DEBUG */
136
137 /*
138 * Singly-linked List declarations.
139 */
140 #define SLIST_HEAD(name, type) \
141 struct name { \
142 struct type *slh_first; /* first element */ \
143 }
144
145 #define SLIST_HEAD_INITIALIZER(head) \
146 { NULL }
147
148 #define SLIST_ENTRY(type) \
149 struct { \
150 struct type *sle_next; /* next element */ \
151 }
152
153 /*
154 * Singly-linked List functions.
155 */
156 #define SLIST_EMPTY(head) ((head)->slh_first == NULL)
157
158 #define SLIST_FIRST(head) ((head)->slh_first)
159
160 #define SLIST_FOREACH(var, head, field) \
161 for ((var) = SLIST_FIRST((head)); \
162 (var); \
163 (var) = SLIST_NEXT((var), field))
164
165 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \
166 for ((var) = SLIST_FIRST((head)); \
167 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
168 (var) = (tvar))
169
170 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
171 for ((varp) = &SLIST_FIRST((head)); \
172 ((var) = *(varp)) != NULL; \
173 (varp) = &SLIST_NEXT((var), field))
174
175 #define SLIST_INIT(head) do { \
176 SLIST_FIRST((head)) = NULL; \
177 } while (*"\0")
178
179 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
180 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
181 SLIST_NEXT((slistelm), field) = (elm); \
182 } while (*"\0")
183
184 #define SLIST_INSERT_HEAD(head, elm, field) do { \
185 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
186 SLIST_FIRST((head)) = (elm); \
187 } while (*"\0")
188
189 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
190
191 #define SLIST_REMOVE(head, elm, type, field) do { \
192 if (SLIST_FIRST((head)) == (elm)) { \
193 SLIST_REMOVE_HEAD((head), field); \
194 } \
195 else { \
196 struct type *curelm = SLIST_FIRST((head)); \
197 while (SLIST_NEXT(curelm, field) != (elm)) \
198 curelm = SLIST_NEXT(curelm, field); \
199 SLIST_NEXT(curelm, field) = \
200 SLIST_NEXT(SLIST_NEXT(curelm, field), field); \
201 } \
202 TRASHIT((elm)->field.sle_next); \
203 } while (*"\0")
204
205 #define SLIST_REMOVE_HEAD(head, field) do { \
206 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
207 } while (*"\0")
208
209 /*
210 * Singly-linked Tail queue declarations.
211 */
212 #define STAILQ_HEAD(name, type) \
213 struct name { \
214 struct type *stqh_first;/* first element */ \
215 struct type **stqh_last;/* addr of last next element */ \
216 }
217
218 #define STAILQ_HEAD_INITIALIZER(head) \
219 { NULL, &(head).stqh_first }
220
221 #define STAILQ_ENTRY(type) \
222 struct { \
223 struct type *stqe_next; /* next element */ \
224 }
225
226 /*
227 * Singly-linked Tail queue functions.
228 */
229 #define STAILQ_CONCAT(head1, head2) do { \
230 if (!STAILQ_EMPTY((head2))) { \
231 *(head1)->stqh_last = (head2)->stqh_first; \
232 (head1)->stqh_last = (head2)->stqh_last; \
233 STAILQ_INIT((head2)); \
234 } \
235 } while (*"\0")
236
237 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
238
239 #define STAILQ_FIRST(head) ((head)->stqh_first)
240
241 #define STAILQ_FOREACH(var, head, field) \
242 for((var) = STAILQ_FIRST((head)); \
243 (var); \
244 (var) = STAILQ_NEXT((var), field))
245
246
247 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
248 for ((var) = STAILQ_FIRST((head)); \
249 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
250 (var) = (tvar))
251
252 #define STAILQ_INIT(head) do { \
253 STAILQ_FIRST((head)) = NULL; \
254 (head)->stqh_last = &STAILQ_FIRST((head)); \
255 } while (*"\0")
256
257 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
258 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
259 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
260 STAILQ_NEXT((tqelm), field) = (elm); \
261 } while (*"\0")
262
263 #define STAILQ_INSERT_HEAD(head, elm, field) do { \
264 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
265 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
266 STAILQ_FIRST((head)) = (elm); \
267 } while (*"\0")
268
269 #define STAILQ_INSERT_TAIL(head, elm, field) do { \
270 STAILQ_NEXT((elm), field) = NULL; \
271 *(head)->stqh_last = (elm); \
272 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
273 } while (*"\0")
274
275 #define STAILQ_LAST(head, type, field) \
276 (STAILQ_EMPTY((head)) ? \
277 NULL : \
278 ((struct type *)(void *) \
279 ((char *)((head)->stqh_last) - __offsetof(struct type, field))))
280
281 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
282
283 #define STAILQ_REMOVE(head, elm, type, field) do { \
284 if (STAILQ_FIRST((head)) == (elm)) { \
285 STAILQ_REMOVE_HEAD((head), field); \
286 } \
287 else { \
288 struct type *curelm = STAILQ_FIRST((head)); \
289 while (STAILQ_NEXT(curelm, field) != (elm)) \
290 curelm = STAILQ_NEXT(curelm, field); \
291 if ((STAILQ_NEXT(curelm, field) = \
292 STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\
293 (head)->stqh_last = &STAILQ_NEXT((curelm), field);\
294 } \
295 TRASHIT((elm)->field.stqe_next); \
296 } while (*"\0")
297
298 #define STAILQ_REMOVE_HEAD(head, field) do { \
299 if ((STAILQ_FIRST((head)) = \
300 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
301 (head)->stqh_last = &STAILQ_FIRST((head)); \
302 } while (*"\0")
303
304 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \
305 if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \
306 (head)->stqh_last = &STAILQ_FIRST((head)); \
307 } while (*"\0")
308
309 /*
310 * List declarations.
311 */
312 #define LIST_HEAD(name, type) \
313 struct name { \
314 struct type *lh_first; /* first element */ \
315 }
316
317 #define LIST_HEAD_INITIALIZER(head) \
318 { NULL }
319
320 #define LIST_ENTRY(type) \
321 struct { \
322 struct type *le_next; /* next element */ \
323 struct type **le_prev; /* address of previous next element */ \
324 }
325
326 /*
327 * List functions.
328 */
329
330 #if (defined(_KERNEL) && defined(INVARIANTS))
331 #define QMD_LIST_CHECK_HEAD(head, field) do { \
332 if (LIST_FIRST((head)) != NULL && \
333 LIST_FIRST((head))->field.le_prev != \
334 &LIST_FIRST((head))) \
335 panic("Bad list head %p first->prev != head", (head)); \
336 } while (*"\0")
337
338 #define QMD_LIST_CHECK_NEXT(elm, field) do { \
339 if (LIST_NEXT((elm), field) != NULL && \
340 LIST_NEXT((elm), field)->field.le_prev != \
341 &((elm)->field.le_next)) \
342 panic("Bad link elm %p next->prev != elm", (elm)); \
343 } while (*"\0")
344
345 #define QMD_LIST_CHECK_PREV(elm, field) do { \
346 if (*(elm)->field.le_prev != (elm)) \
347 panic("Bad link elm %p prev->next != elm", (elm)); \
348 } while (*"\0")
349 #else
350 #define QMD_LIST_CHECK_HEAD(head, field)
351 #define QMD_LIST_CHECK_NEXT(elm, field)
352 #define QMD_LIST_CHECK_PREV(elm, field)
353 #endif /* (_KERNEL && INVARIANTS) */
354
355 #define LIST_EMPTY(head) ((head)->lh_first == NULL)
356
357 #define LIST_FIRST(head) ((head)->lh_first)
358
359 #define LIST_FOREACH(var, head, field) \
360 for ((var) = LIST_FIRST((head)); \
361 (var); \
362 (var) = LIST_NEXT((var), field))
363
364 #define LIST_FOREACH_SAFE(var, head, field, tvar) \
365 for ((var) = LIST_FIRST((head)); \
366 (var) && ((tvar) = LIST_NEXT((var), field), 1); \
367 (var) = (tvar))
368
369 #define LIST_INIT(head) do { \
370 LIST_FIRST((head)) = NULL; \
371 } while (*"\0")
372
373 #define LIST_INSERT_AFTER(listelm, elm, field) do { \
374 QMD_LIST_CHECK_NEXT(listelm, field); \
375 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
376 LIST_NEXT((listelm), field)->field.le_prev = \
377 &LIST_NEXT((elm), field); \
378 LIST_NEXT((listelm), field) = (elm); \
379 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \
380 } while (*"\0")
381
382 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \
383 QMD_LIST_CHECK_PREV(listelm, field); \
384 (elm)->field.le_prev = (listelm)->field.le_prev; \
385 LIST_NEXT((elm), field) = (listelm); \
386 *(listelm)->field.le_prev = (elm); \
387 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \
388 } while (*"\0")
389
390 #define LIST_INSERT_HEAD(head, elm, field) do { \
391 QMD_LIST_CHECK_HEAD((head), field); \
392 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
393 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
394 LIST_FIRST((head)) = (elm); \
395 (elm)->field.le_prev = &LIST_FIRST((head)); \
396 } while (*"\0")
397
398 #define LIST_NEXT(elm, field) ((elm)->field.le_next)
399
400 #define LIST_REMOVE(elm, field) do { \
401 QMD_LIST_CHECK_NEXT(elm, field); \
402 QMD_LIST_CHECK_PREV(elm, field); \
403 if (LIST_NEXT((elm), field) != NULL) \
404 LIST_NEXT((elm), field)->field.le_prev = \
405 (elm)->field.le_prev; \
406 *(elm)->field.le_prev = LIST_NEXT((elm), field); \
407 TRASHIT((elm)->field.le_next); \
408 TRASHIT((elm)->field.le_prev); \
409 } while (*"\0")
410
411 /*
412 * Tail queue declarations.
413 */
414 #define TAILQ_HEAD(name, type) \
415 struct name { \
416 struct type *tqh_first; /* first element */ \
417 struct type **tqh_last; /* addr of last next element */ \
418 TRACEBUF \
419 }
420
421 #define TAILQ_HEAD_INITIALIZER(head) \
422 { NULL, &(head).tqh_first }
423
424 #define TAILQ_ENTRY(type) \
425 struct { \
426 struct type *tqe_next; /* next element */ \
427 struct type **tqe_prev; /* address of previous next element */ \
428 TRACEBUF \
429 }
430
431 /*
432 * Tail queue functions.
433 */
434 #if (defined(_KERNEL) && defined(INVARIANTS))
435 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \
436 if (!TAILQ_EMPTY(head) && \
437 TAILQ_FIRST((head))->field.tqe_prev != \
438 &TAILQ_FIRST((head))) \
439 panic("Bad tailq head %p first->prev != head", (head)); \
440 } while (*"\0")
441
442 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \
443 if (*(head)->tqh_last != NULL) \
444 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
445 } while (*"\0")
446
447 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \
448 if (TAILQ_NEXT((elm), field) != NULL && \
449 TAILQ_NEXT((elm), field)->field.tqe_prev != \
450 &((elm)->field.tqe_next)) \
451 panic("Bad link elm %p next->prev != elm", (elm)); \
452 } while (*"\0")
453
454 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \
455 if (*(elm)->field.tqe_prev != (elm)) \
456 panic("Bad link elm %p prev->next != elm", (elm)); \
457 } while (*"\0")
458 #else
459 #define QMD_TAILQ_CHECK_HEAD(head, field)
460 #define QMD_TAILQ_CHECK_TAIL(head, headname)
461 #define QMD_TAILQ_CHECK_NEXT(elm, field)
462 #define QMD_TAILQ_CHECK_PREV(elm, field)
463 #endif /* (_KERNEL && INVARIANTS) */
464
465 #define TAILQ_CONCAT(head1, head2, field) do { \
466 if (!TAILQ_EMPTY(head2)) { \
467 *(head1)->tqh_last = (head2)->tqh_first; \
468 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
469 (head1)->tqh_last = (head2)->tqh_last; \
470 TAILQ_INIT((head2)); \
471 QMD_TRACE_HEAD(head1); \
472 QMD_TRACE_HEAD(head2); \
473 } \
474 } while (*"\0")
475
476 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
477
478 #define TAILQ_FIRST(head) ((head)->tqh_first)
479
480 #define TAILQ_FOREACH(var, head, field) \
481 for ((var) = TAILQ_FIRST((head)); \
482 (var); \
483 (var) = TAILQ_NEXT((var), field))
484
485 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
486 for ((var) = TAILQ_FIRST((head)); \
487 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
488 (var) = (tvar))
489
490 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
491 for ((var) = TAILQ_LAST((head), headname); \
492 (var); \
493 (var) = TAILQ_PREV((var), headname, field))
494
495 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
496 for ((var) = TAILQ_LAST((head), headname); \
497 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
498 (var) = (tvar))
499
500 #define TAILQ_INIT(head) do { \
501 TAILQ_FIRST((head)) = NULL; \
502 (head)->tqh_last = &TAILQ_FIRST((head)); \
503 QMD_TRACE_HEAD(head); \
504 } while (*"\0")
505
506 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
507 QMD_TAILQ_CHECK_NEXT(listelm, field); \
508 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
509 TAILQ_NEXT((elm), field)->field.tqe_prev = \
510 &TAILQ_NEXT((elm), field); \
511 else { \
512 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
513 QMD_TRACE_HEAD(head); \
514 } \
515 TAILQ_NEXT((listelm), field) = (elm); \
516 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \
517 QMD_TRACE_ELEM(&(elm)->field); \
518 QMD_TRACE_ELEM(&listelm->field); \
519 } while (*"\0")
520
521 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
522 QMD_TAILQ_CHECK_PREV(listelm, field); \
523 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
524 TAILQ_NEXT((elm), field) = (listelm); \
525 *(listelm)->field.tqe_prev = (elm); \
526 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
527 QMD_TRACE_ELEM(&(elm)->field); \
528 QMD_TRACE_ELEM(&listelm->field); \
529 } while (*"\0")
530
531 #define TAILQ_INSERT_HEAD(head, elm, field) do { \
532 QMD_TAILQ_CHECK_HEAD(head, field); \
533 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \
534 TAILQ_FIRST((head))->field.tqe_prev = \
535 &TAILQ_NEXT((elm), field); \
536 else \
537 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
538 TAILQ_FIRST((head)) = (elm); \
539 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \
540 QMD_TRACE_HEAD(head); \
541 QMD_TRACE_ELEM(&(elm)->field); \
542 } while (*"\0")
543
544 #define TAILQ_INSERT_TAIL(head, elm, field) do { \
545 QMD_TAILQ_CHECK_TAIL(head, field); \
546 TAILQ_NEXT((elm), field) = NULL; \
547 (elm)->field.tqe_prev = (head)->tqh_last; \
548 *(head)->tqh_last = (elm); \
549 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
550 QMD_TRACE_HEAD(head); \
551 QMD_TRACE_ELEM(&(elm)->field); \
552 } while (*"\0")
553
554 #define TAILQ_LAST(head, headname) \
555 (*(((struct headname *)((head)->tqh_last))->tqh_last))
556
557 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
558
559 #define TAILQ_PREV(elm, headname, field) \
560 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
561
562 #define TAILQ_REMOVE(head, elm, field) do { \
563 QMD_TAILQ_CHECK_NEXT(elm, field); \
564 QMD_TAILQ_CHECK_PREV(elm, field); \
565 if ((TAILQ_NEXT((elm), field)) != NULL) \
566 TAILQ_NEXT((elm), field)->field.tqe_prev = \
567 (elm)->field.tqe_prev; \
568 else { \
569 (head)->tqh_last = (elm)->field.tqe_prev; \
570 QMD_TRACE_HEAD(head); \
571 } \
572 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
573 TRASHIT((elm)->field.tqe_next); \
574 TRASHIT((elm)->field.tqe_prev); \
575 QMD_TRACE_ELEM(&(elm)->field); \
576 } while (*"\0")
577
578
579 #ifdef _KERNEL
580
581 #endif /* _KERNEL */
582
583 #endif /* !_SYS_QUEUE_H_ */
584
585 /* END CSTYLED */