master
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)queue.h 8.5 (Berkeley) 8/20/94
32 */
33
34#ifndef _SYS_QUEUE_H_
35#define _SYS_QUEUE_H_
36
37#include <sys/cdefs.h>
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 be traversed in either 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 * Below is a summary of implemented functions where:
81 * + means the macro is available
82 * - means the macro is not available
83 * s means the macro is available but is slow (runs in O(n) time)
84 *
85 * SLIST LIST STAILQ TAILQ
86 * _HEAD + + + +
87 * _CLASS_HEAD + + + +
88 * _HEAD_INITIALIZER + + + +
89 * _ENTRY + + + +
90 * _CLASS_ENTRY + + + +
91 * _INIT + + + +
92 * _EMPTY + + + +
93 * _END + + + +
94 * _FIRST + + + +
95 * _NEXT + + + +
96 * _PREV - + - +
97 * _LAST - - + +
98 * _LAST_FAST - - - +
99 * _FOREACH + + + +
100 * _FOREACH_FROM + + + +
101 * _FOREACH_SAFE + + + +
102 * _FOREACH_FROM_SAFE + + + +
103 * _FOREACH_REVERSE - - - +
104 * _FOREACH_REVERSE_FROM - - - +
105 * _FOREACH_REVERSE_SAFE - - - +
106 * _FOREACH_REVERSE_FROM_SAFE - - - +
107 * _INSERT_HEAD + + + +
108 * _INSERT_BEFORE - + - +
109 * _INSERT_AFTER + + + +
110 * _INSERT_TAIL - - + +
111 * _CONCAT s s + +
112 * _REMOVE_AFTER + - + -
113 * _REMOVE_HEAD + + + +
114 * _REMOVE s + s +
115 * _REPLACE - + - +
116 * _SWAP + + + +
117 *
118 */
119#ifdef QUEUE_MACRO_DEBUG
120#warn Use QUEUE_MACRO_DEBUG_TRACE and/or QUEUE_MACRO_DEBUG_TRASH
121#define QUEUE_MACRO_DEBUG_TRACE
122#define QUEUE_MACRO_DEBUG_TRASH
123#endif
124
125#ifdef QUEUE_MACRO_DEBUG_TRACE
126/* Store the last 2 places the queue element or head was altered */
127struct qm_trace {
128 unsigned long lastline;
129 unsigned long prevline;
130 const char *lastfile;
131 const char *prevfile;
132};
133
134#define TRACEBUF struct qm_trace trace;
135#define TRACEBUF_INITIALIZER { __LINE__, 0, __FILE__, NULL } ,
136
137#define QMD_TRACE_HEAD(head) do { \
138 (head)->trace.prevline = (head)->trace.lastline; \
139 (head)->trace.prevfile = (head)->trace.lastfile; \
140 (head)->trace.lastline = __LINE__; \
141 (head)->trace.lastfile = __FILE__; \
142} while (0)
143
144#define QMD_TRACE_ELEM(elem) do { \
145 (elem)->trace.prevline = (elem)->trace.lastline; \
146 (elem)->trace.prevfile = (elem)->trace.lastfile; \
147 (elem)->trace.lastline = __LINE__; \
148 (elem)->trace.lastfile = __FILE__; \
149} while (0)
150
151#else /* !QUEUE_MACRO_DEBUG_TRACE */
152#define QMD_TRACE_ELEM(elem)
153#define QMD_TRACE_HEAD(head)
154#define TRACEBUF
155#define TRACEBUF_INITIALIZER
156#endif /* QUEUE_MACRO_DEBUG_TRACE */
157
158#ifdef QUEUE_MACRO_DEBUG_TRASH
159#define QMD_SAVELINK(name, link) void **name = (void *)&(link)
160#define TRASHIT(x) do {(x) = (void *)-1;} while (0)
161#define QMD_IS_TRASHED(x) ((x) == (void *)(intptr_t)-1)
162#else /* !QUEUE_MACRO_DEBUG_TRASH */
163#define QMD_SAVELINK(name, link)
164#define TRASHIT(x)
165#define QMD_IS_TRASHED(x) 0
166#endif /* QUEUE_MACRO_DEBUG_TRASH */
167
168#ifdef __cplusplus
169/*
170 * In C++ there can be structure lists and class lists:
171 */
172#define QUEUE_TYPEOF(type) type
173#else
174#define QUEUE_TYPEOF(type) struct type
175#endif
176
177/*
178 * Singly-linked List declarations.
179 */
180#define SLIST_HEAD(name, type) \
181struct name { \
182 struct type *slh_first; /* first element */ \
183}
184
185#define SLIST_CLASS_HEAD(name, type) \
186struct name { \
187 class type *slh_first; /* first element */ \
188}
189
190#define SLIST_HEAD_INITIALIZER(head) \
191 { NULL }
192
193#define SLIST_ENTRY(type) \
194struct { \
195 struct type *sle_next; /* next element */ \
196}
197
198#define SLIST_CLASS_ENTRY(type) \
199struct { \
200 class type *sle_next; /* next element */ \
201}
202
203/*
204 * Singly-linked List functions.
205 */
206#if (defined(_KERNEL) && defined(INVARIANTS))
207#define QMD_SLIST_CHECK_PREVPTR(prevp, elm) do { \
208 if (*(prevp) != (elm)) \
209 panic("Bad prevptr *(%p) == %p != %p", \
210 (prevp), *(prevp), (elm)); \
211} while (0)
212#else
213#define QMD_SLIST_CHECK_PREVPTR(prevp, elm)
214#endif
215
216#define SLIST_CONCAT(head1, head2, type, field) do { \
217 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head1); \
218 if (curelm == NULL) { \
219 if ((SLIST_FIRST(head1) = SLIST_FIRST(head2)) != NULL) \
220 SLIST_INIT(head2); \
221 } else if (SLIST_FIRST(head2) != NULL) { \
222 while (SLIST_NEXT(curelm, field) != NULL) \
223 curelm = SLIST_NEXT(curelm, field); \
224 SLIST_NEXT(curelm, field) = SLIST_FIRST(head2); \
225 SLIST_INIT(head2); \
226 } \
227} while (0)
228
229#define SLIST_EMPTY(head) ((head)->slh_first == NULL)
230
231#define SLIST_FIRST(head) ((head)->slh_first)
232
233#define SLIST_FOREACH(var, head, field) \
234 for ((var) = SLIST_FIRST((head)); \
235 (var); \
236 (var) = SLIST_NEXT((var), field))
237
238#define SLIST_FOREACH_FROM(var, head, field) \
239 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
240 (var); \
241 (var) = SLIST_NEXT((var), field))
242
243#define SLIST_FOREACH_SAFE(var, head, field, tvar) \
244 for ((var) = SLIST_FIRST((head)); \
245 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
246 (var) = (tvar))
247
248#define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \
249 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
250 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
251 (var) = (tvar))
252
253#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
254 for ((varp) = &SLIST_FIRST((head)); \
255 ((var) = *(varp)) != NULL; \
256 (varp) = &SLIST_NEXT((var), field))
257
258#define SLIST_INIT(head) do { \
259 SLIST_FIRST((head)) = NULL; \
260} while (0)
261
262#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
263 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
264 SLIST_NEXT((slistelm), field) = (elm); \
265} while (0)
266
267#define SLIST_INSERT_HEAD(head, elm, field) do { \
268 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
269 SLIST_FIRST((head)) = (elm); \
270} while (0)
271
272#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
273
274#define SLIST_REMOVE(head, elm, type, field) do { \
275 if (SLIST_FIRST((head)) == (elm)) { \
276 SLIST_REMOVE_HEAD((head), field); \
277 } \
278 else { \
279 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head); \
280 while (SLIST_NEXT(curelm, field) != (elm)) \
281 curelm = SLIST_NEXT(curelm, field); \
282 SLIST_REMOVE_AFTER(curelm, field); \
283 } \
284} while (0)
285
286#define SLIST_REMOVE_AFTER(elm, field) do { \
287 QMD_SAVELINK(oldnext, SLIST_NEXT(elm, field)->field.sle_next); \
288 SLIST_NEXT(elm, field) = \
289 SLIST_NEXT(SLIST_NEXT(elm, field), field); \
290 TRASHIT(*oldnext); \
291} while (0)
292
293#define SLIST_REMOVE_HEAD(head, field) do { \
294 QMD_SAVELINK(oldnext, SLIST_FIRST(head)->field.sle_next); \
295 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
296 TRASHIT(*oldnext); \
297} while (0)
298
299#define SLIST_REMOVE_PREVPTR(prevp, elm, field) do { \
300 QMD_SLIST_CHECK_PREVPTR(prevp, elm); \
301 *(prevp) = SLIST_NEXT(elm, field); \
302 TRASHIT((elm)->field.sle_next); \
303} while (0)
304
305#define SLIST_SWAP(head1, head2, type) do { \
306 QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1); \
307 SLIST_FIRST(head1) = SLIST_FIRST(head2); \
308 SLIST_FIRST(head2) = swap_first; \
309} while (0)
310
311#define SLIST_END(head) NULL
312
313/*
314 * Singly-linked Tail queue declarations.
315 */
316#define STAILQ_HEAD(name, type) \
317struct name { \
318 struct type *stqh_first;/* first element */ \
319 struct type **stqh_last;/* addr of last next element */ \
320}
321
322#define STAILQ_CLASS_HEAD(name, type) \
323struct name { \
324 class type *stqh_first; /* first element */ \
325 class type **stqh_last; /* addr of last next element */ \
326}
327
328#define STAILQ_HEAD_INITIALIZER(head) \
329 { NULL, &(head).stqh_first }
330
331#define STAILQ_ENTRY(type) \
332struct { \
333 struct type *stqe_next; /* next element */ \
334}
335
336#define STAILQ_CLASS_ENTRY(type) \
337struct { \
338 class type *stqe_next; /* next element */ \
339}
340
341/*
342 * Singly-linked Tail queue functions.
343 */
344#define STAILQ_CONCAT(head1, head2) do { \
345 if (!STAILQ_EMPTY((head2))) { \
346 *(head1)->stqh_last = (head2)->stqh_first; \
347 (head1)->stqh_last = (head2)->stqh_last; \
348 STAILQ_INIT((head2)); \
349 } \
350} while (0)
351
352#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
353
354#define STAILQ_FIRST(head) ((head)->stqh_first)
355
356#define STAILQ_FOREACH(var, head, field) \
357 for((var) = STAILQ_FIRST((head)); \
358 (var); \
359 (var) = STAILQ_NEXT((var), field))
360
361#define STAILQ_FOREACH_FROM(var, head, field) \
362 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
363 (var); \
364 (var) = STAILQ_NEXT((var), field))
365
366#define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
367 for ((var) = STAILQ_FIRST((head)); \
368 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
369 (var) = (tvar))
370
371#define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \
372 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
373 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
374 (var) = (tvar))
375
376#define STAILQ_INIT(head) do { \
377 STAILQ_FIRST((head)) = NULL; \
378 (head)->stqh_last = &STAILQ_FIRST((head)); \
379} while (0)
380
381#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
382 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
383 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
384 STAILQ_NEXT((tqelm), field) = (elm); \
385} while (0)
386
387#define STAILQ_INSERT_HEAD(head, elm, field) do { \
388 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
389 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
390 STAILQ_FIRST((head)) = (elm); \
391} while (0)
392
393#define STAILQ_INSERT_TAIL(head, elm, field) do { \
394 STAILQ_NEXT((elm), field) = NULL; \
395 *(head)->stqh_last = (elm); \
396 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
397} while (0)
398
399#define STAILQ_LAST(head, type, field) \
400 (STAILQ_EMPTY((head)) ? NULL : \
401 __containerof((head)->stqh_last, \
402 QUEUE_TYPEOF(type), field.stqe_next))
403
404#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
405
406#define STAILQ_REMOVE(head, elm, type, field) do { \
407 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \
408 if (STAILQ_FIRST((head)) == (elm)) { \
409 STAILQ_REMOVE_HEAD((head), field); \
410 } \
411 else { \
412 QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head); \
413 while (STAILQ_NEXT(curelm, field) != (elm)) \
414 curelm = STAILQ_NEXT(curelm, field); \
415 STAILQ_REMOVE_AFTER(head, curelm, field); \
416 } \
417 TRASHIT(*oldnext); \
418} while (0)
419
420#define STAILQ_REMOVE_AFTER(head, elm, field) do { \
421 if ((STAILQ_NEXT(elm, field) = \
422 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \
423 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
424} while (0)
425
426#define STAILQ_REMOVE_HEAD(head, field) do { \
427 if ((STAILQ_FIRST((head)) = \
428 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
429 (head)->stqh_last = &STAILQ_FIRST((head)); \
430} while (0)
431
432#define STAILQ_SWAP(head1, head2, type) do { \
433 QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1); \
434 QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last; \
435 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \
436 (head1)->stqh_last = (head2)->stqh_last; \
437 STAILQ_FIRST(head2) = swap_first; \
438 (head2)->stqh_last = swap_last; \
439 if (STAILQ_EMPTY(head1)) \
440 (head1)->stqh_last = &STAILQ_FIRST(head1); \
441 if (STAILQ_EMPTY(head2)) \
442 (head2)->stqh_last = &STAILQ_FIRST(head2); \
443} while (0)
444
445#define STAILQ_END(head) NULL
446
447
448/*
449 * List declarations.
450 */
451#define LIST_HEAD(name, type) \
452struct name { \
453 struct type *lh_first; /* first element */ \
454}
455
456#define LIST_CLASS_HEAD(name, type) \
457struct name { \
458 class type *lh_first; /* first element */ \
459}
460
461#define LIST_HEAD_INITIALIZER(head) \
462 { NULL }
463
464#define LIST_ENTRY(type) \
465struct { \
466 struct type *le_next; /* next element */ \
467 struct type **le_prev; /* address of previous next element */ \
468}
469
470#define LIST_CLASS_ENTRY(type) \
471struct { \
472 class type *le_next; /* next element */ \
473 class type **le_prev; /* address of previous next element */ \
474}
475
476/*
477 * List functions.
478 */
479
480#if (defined(_KERNEL) && defined(INVARIANTS))
481/*
482 * QMD_LIST_CHECK_HEAD(LIST_HEAD *head, LIST_ENTRY NAME)
483 *
484 * If the list is non-empty, validates that the first element of the list
485 * points back at 'head.'
486 */
487#define QMD_LIST_CHECK_HEAD(head, field) do { \
488 if (LIST_FIRST((head)) != NULL && \
489 LIST_FIRST((head))->field.le_prev != \
490 &LIST_FIRST((head))) \
491 panic("Bad list head %p first->prev != head", (head)); \
492} while (0)
493
494/*
495 * QMD_LIST_CHECK_NEXT(TYPE *elm, LIST_ENTRY NAME)
496 *
497 * If an element follows 'elm' in the list, validates that the next element
498 * points back at 'elm.'
499 */
500#define QMD_LIST_CHECK_NEXT(elm, field) do { \
501 if (LIST_NEXT((elm), field) != NULL && \
502 LIST_NEXT((elm), field)->field.le_prev != \
503 &((elm)->field.le_next)) \
504 panic("Bad link elm %p next->prev != elm", (elm)); \
505} while (0)
506
507/*
508 * QMD_LIST_CHECK_PREV(TYPE *elm, LIST_ENTRY NAME)
509 *
510 * Validates that the previous element (or head of the list) points to 'elm.'
511 */
512#define QMD_LIST_CHECK_PREV(elm, field) do { \
513 if (*(elm)->field.le_prev != (elm)) \
514 panic("Bad link elm %p prev->next != elm", (elm)); \
515} while (0)
516#else
517#define QMD_LIST_CHECK_HEAD(head, field)
518#define QMD_LIST_CHECK_NEXT(elm, field)
519#define QMD_LIST_CHECK_PREV(elm, field)
520#endif /* (_KERNEL && INVARIANTS) */
521
522#define LIST_CONCAT(head1, head2, type, field) do { \
523 QUEUE_TYPEOF(type) *curelm = LIST_FIRST(head1); \
524 if (curelm == NULL) { \
525 if ((LIST_FIRST(head1) = LIST_FIRST(head2)) != NULL) { \
526 LIST_FIRST(head2)->field.le_prev = \
527 &LIST_FIRST((head1)); \
528 LIST_INIT(head2); \
529 } \
530 } else if (LIST_FIRST(head2) != NULL) { \
531 while (LIST_NEXT(curelm, field) != NULL) \
532 curelm = LIST_NEXT(curelm, field); \
533 LIST_NEXT(curelm, field) = LIST_FIRST(head2); \
534 LIST_FIRST(head2)->field.le_prev = &LIST_NEXT(curelm, field);\
535 LIST_INIT(head2); \
536 } \
537} while (0)
538
539#define LIST_EMPTY(head) ((head)->lh_first == NULL)
540
541#define LIST_FIRST(head) ((head)->lh_first)
542
543#define LIST_FOREACH(var, head, field) \
544 for ((var) = LIST_FIRST((head)); \
545 (var); \
546 (var) = LIST_NEXT((var), field))
547
548#define LIST_FOREACH_FROM(var, head, field) \
549 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
550 (var); \
551 (var) = LIST_NEXT((var), field))
552
553#define LIST_FOREACH_SAFE(var, head, field, tvar) \
554 for ((var) = LIST_FIRST((head)); \
555 (var) && ((tvar) = LIST_NEXT((var), field), 1); \
556 (var) = (tvar))
557
558#define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \
559 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
560 (var) && ((tvar) = LIST_NEXT((var), field), 1); \
561 (var) = (tvar))
562
563#define LIST_INIT(head) do { \
564 LIST_FIRST((head)) = NULL; \
565} while (0)
566
567#define LIST_INSERT_AFTER(listelm, elm, field) do { \
568 QMD_LIST_CHECK_NEXT(listelm, field); \
569 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
570 LIST_NEXT((listelm), field)->field.le_prev = \
571 &LIST_NEXT((elm), field); \
572 LIST_NEXT((listelm), field) = (elm); \
573 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \
574} while (0)
575
576#define LIST_INSERT_BEFORE(listelm, elm, field) do { \
577 QMD_LIST_CHECK_PREV(listelm, field); \
578 (elm)->field.le_prev = (listelm)->field.le_prev; \
579 LIST_NEXT((elm), field) = (listelm); \
580 *(listelm)->field.le_prev = (elm); \
581 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \
582} while (0)
583
584#define LIST_INSERT_HEAD(head, elm, field) do { \
585 QMD_LIST_CHECK_HEAD((head), field); \
586 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
587 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
588 LIST_FIRST((head)) = (elm); \
589 (elm)->field.le_prev = &LIST_FIRST((head)); \
590} while (0)
591
592#define LIST_NEXT(elm, field) ((elm)->field.le_next)
593
594#define LIST_PREV(elm, head, type, field) \
595 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \
596 __containerof((elm)->field.le_prev, \
597 QUEUE_TYPEOF(type), field.le_next))
598
599#define LIST_REMOVE_HEAD(head, field) \
600 LIST_REMOVE(LIST_FIRST(head), field)
601
602#define LIST_REMOVE(elm, field) do { \
603 QMD_SAVELINK(oldnext, (elm)->field.le_next); \
604 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \
605 QMD_LIST_CHECK_NEXT(elm, field); \
606 QMD_LIST_CHECK_PREV(elm, field); \
607 if (LIST_NEXT((elm), field) != NULL) \
608 LIST_NEXT((elm), field)->field.le_prev = \
609 (elm)->field.le_prev; \
610 *(elm)->field.le_prev = LIST_NEXT((elm), field); \
611 TRASHIT(*oldnext); \
612 TRASHIT(*oldprev); \
613} while (0)
614
615#define LIST_REPLACE(elm, elm2, field) do { \
616 QMD_SAVELINK(oldnext, (elm)->field.le_next); \
617 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \
618 QMD_LIST_CHECK_NEXT(elm, field); \
619 QMD_LIST_CHECK_PREV(elm, field); \
620 LIST_NEXT((elm2), field) = LIST_NEXT((elm), field); \
621 if (LIST_NEXT((elm2), field) != NULL) \
622 LIST_NEXT((elm2), field)->field.le_prev = \
623 &(elm2)->field.le_next; \
624 (elm2)->field.le_prev = (elm)->field.le_prev; \
625 *(elm2)->field.le_prev = (elm2); \
626 TRASHIT(*oldnext); \
627 TRASHIT(*oldprev); \
628} while (0)
629
630#define LIST_SWAP(head1, head2, type, field) do { \
631 QUEUE_TYPEOF(type) *swap_tmp = LIST_FIRST(head1); \
632 LIST_FIRST((head1)) = LIST_FIRST((head2)); \
633 LIST_FIRST((head2)) = swap_tmp; \
634 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \
635 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \
636 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \
637 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \
638} while (0)
639
640#define LIST_END(head) NULL
641
642/*
643 * Tail queue declarations.
644 */
645#define TAILQ_HEAD(name, type) \
646struct name { \
647 struct type *tqh_first; /* first element */ \
648 struct type **tqh_last; /* addr of last next element */ \
649 TRACEBUF \
650}
651
652#define TAILQ_CLASS_HEAD(name, type) \
653struct name { \
654 class type *tqh_first; /* first element */ \
655 class type **tqh_last; /* addr of last next element */ \
656 TRACEBUF \
657}
658
659#define TAILQ_HEAD_INITIALIZER(head) \
660 { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER }
661
662#define TAILQ_ENTRY(type) \
663struct { \
664 struct type *tqe_next; /* next element */ \
665 struct type **tqe_prev; /* address of previous next element */ \
666 TRACEBUF \
667}
668
669#define TAILQ_CLASS_ENTRY(type) \
670struct { \
671 class type *tqe_next; /* next element */ \
672 class type **tqe_prev; /* address of previous next element */ \
673 TRACEBUF \
674}
675
676/*
677 * Tail queue functions.
678 */
679#if (defined(_KERNEL) && defined(INVARIANTS))
680/*
681 * QMD_TAILQ_CHECK_HEAD(TAILQ_HEAD *head, TAILQ_ENTRY NAME)
682 *
683 * If the tailq is non-empty, validates that the first element of the tailq
684 * points back at 'head.'
685 */
686#define QMD_TAILQ_CHECK_HEAD(head, field) do { \
687 if (!TAILQ_EMPTY(head) && \
688 TAILQ_FIRST((head))->field.tqe_prev != \
689 &TAILQ_FIRST((head))) \
690 panic("Bad tailq head %p first->prev != head", (head)); \
691} while (0)
692
693/*
694 * QMD_TAILQ_CHECK_TAIL(TAILQ_HEAD *head, TAILQ_ENTRY NAME)
695 *
696 * Validates that the tail of the tailq is a pointer to pointer to NULL.
697 */
698#define QMD_TAILQ_CHECK_TAIL(head, field) do { \
699 if (*(head)->tqh_last != NULL) \
700 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
701} while (0)
702
703/*
704 * QMD_TAILQ_CHECK_NEXT(TYPE *elm, TAILQ_ENTRY NAME)
705 *
706 * If an element follows 'elm' in the tailq, validates that the next element
707 * points back at 'elm.'
708 */
709#define QMD_TAILQ_CHECK_NEXT(elm, field) do { \
710 if (TAILQ_NEXT((elm), field) != NULL && \
711 TAILQ_NEXT((elm), field)->field.tqe_prev != \
712 &((elm)->field.tqe_next)) \
713 panic("Bad link elm %p next->prev != elm", (elm)); \
714} while (0)
715
716/*
717 * QMD_TAILQ_CHECK_PREV(TYPE *elm, TAILQ_ENTRY NAME)
718 *
719 * Validates that the previous element (or head of the tailq) points to 'elm.'
720 */
721#define QMD_TAILQ_CHECK_PREV(elm, field) do { \
722 if (*(elm)->field.tqe_prev != (elm)) \
723 panic("Bad link elm %p prev->next != elm", (elm)); \
724} while (0)
725#else
726#define QMD_TAILQ_CHECK_HEAD(head, field)
727#define QMD_TAILQ_CHECK_TAIL(head, headname)
728#define QMD_TAILQ_CHECK_NEXT(elm, field)
729#define QMD_TAILQ_CHECK_PREV(elm, field)
730#endif /* (_KERNEL && INVARIANTS) */
731
732#define TAILQ_CONCAT(head1, head2, field) do { \
733 if (!TAILQ_EMPTY(head2)) { \
734 *(head1)->tqh_last = (head2)->tqh_first; \
735 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
736 (head1)->tqh_last = (head2)->tqh_last; \
737 TAILQ_INIT((head2)); \
738 QMD_TRACE_HEAD(head1); \
739 QMD_TRACE_HEAD(head2); \
740 } \
741} while (0)
742
743#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
744
745#define TAILQ_FIRST(head) ((head)->tqh_first)
746
747#define TAILQ_FOREACH(var, head, field) \
748 for ((var) = TAILQ_FIRST((head)); \
749 (var); \
750 (var) = TAILQ_NEXT((var), field))
751
752#define TAILQ_FOREACH_FROM(var, head, field) \
753 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
754 (var); \
755 (var) = TAILQ_NEXT((var), field))
756
757#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
758 for ((var) = TAILQ_FIRST((head)); \
759 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
760 (var) = (tvar))
761
762#define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \
763 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
764 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
765 (var) = (tvar))
766
767#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
768 for ((var) = TAILQ_LAST((head), headname); \
769 (var); \
770 (var) = TAILQ_PREV((var), headname, field))
771
772#define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \
773 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
774 (var); \
775 (var) = TAILQ_PREV((var), headname, field))
776
777#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
778 for ((var) = TAILQ_LAST((head), headname); \
779 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
780 (var) = (tvar))
781
782#define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar)\
783 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
784 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
785 (var) = (tvar))
786
787#define TAILQ_INIT(head) do { \
788 TAILQ_FIRST((head)) = NULL; \
789 (head)->tqh_last = &TAILQ_FIRST((head)); \
790 QMD_TRACE_HEAD(head); \
791} while (0)
792
793#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
794 QMD_TAILQ_CHECK_NEXT(listelm, field); \
795 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
796 TAILQ_NEXT((elm), field)->field.tqe_prev = \
797 &TAILQ_NEXT((elm), field); \
798 else { \
799 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
800 QMD_TRACE_HEAD(head); \
801 } \
802 TAILQ_NEXT((listelm), field) = (elm); \
803 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \
804 QMD_TRACE_ELEM(&(elm)->field); \
805 QMD_TRACE_ELEM(&(listelm)->field); \
806} while (0)
807
808#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
809 QMD_TAILQ_CHECK_PREV(listelm, field); \
810 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
811 TAILQ_NEXT((elm), field) = (listelm); \
812 *(listelm)->field.tqe_prev = (elm); \
813 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
814 QMD_TRACE_ELEM(&(elm)->field); \
815 QMD_TRACE_ELEM(&(listelm)->field); \
816} while (0)
817
818#define TAILQ_INSERT_HEAD(head, elm, field) do { \
819 QMD_TAILQ_CHECK_HEAD(head, field); \
820 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \
821 TAILQ_FIRST((head))->field.tqe_prev = \
822 &TAILQ_NEXT((elm), field); \
823 else \
824 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
825 TAILQ_FIRST((head)) = (elm); \
826 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \
827 QMD_TRACE_HEAD(head); \
828 QMD_TRACE_ELEM(&(elm)->field); \
829} while (0)
830
831#define TAILQ_INSERT_TAIL(head, elm, field) do { \
832 QMD_TAILQ_CHECK_TAIL(head, field); \
833 TAILQ_NEXT((elm), field) = NULL; \
834 (elm)->field.tqe_prev = (head)->tqh_last; \
835 *(head)->tqh_last = (elm); \
836 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
837 QMD_TRACE_HEAD(head); \
838 QMD_TRACE_ELEM(&(elm)->field); \
839} while (0)
840
841#define TAILQ_LAST(head, headname) \
842 (*(((struct headname *)((head)->tqh_last))->tqh_last))
843
844/*
845 * The FAST function is fast in that it causes no data access other
846 * then the access to the head. The standard LAST function above
847 * will cause a data access of both the element you want and
848 * the previous element. FAST is very useful for instances when
849 * you may want to prefetch the last data element.
850 */
851#define TAILQ_LAST_FAST(head, type, field) \
852 (TAILQ_EMPTY(head) ? NULL : __containerof((head)->tqh_last, QUEUE_TYPEOF(type), field.tqe_next))
853
854#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
855
856#define TAILQ_PREV(elm, headname, field) \
857 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
858
859#define TAILQ_PREV_FAST(elm, head, type, field) \
860 ((elm)->field.tqe_prev == &(head)->tqh_first ? NULL : \
861 __containerof((elm)->field.tqe_prev, QUEUE_TYPEOF(type), field.tqe_next))
862
863#define TAILQ_REMOVE_HEAD(head, field) \
864 TAILQ_REMOVE(head, TAILQ_FIRST(head), field)
865
866#define TAILQ_REMOVE(head, elm, field) do { \
867 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \
868 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \
869 QMD_TAILQ_CHECK_NEXT(elm, field); \
870 QMD_TAILQ_CHECK_PREV(elm, field); \
871 if ((TAILQ_NEXT((elm), field)) != NULL) \
872 TAILQ_NEXT((elm), field)->field.tqe_prev = \
873 (elm)->field.tqe_prev; \
874 else { \
875 (head)->tqh_last = (elm)->field.tqe_prev; \
876 QMD_TRACE_HEAD(head); \
877 } \
878 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
879 TRASHIT(*oldnext); \
880 TRASHIT(*oldprev); \
881 QMD_TRACE_ELEM(&(elm)->field); \
882} while (0)
883
884#define TAILQ_REPLACE(head, elm, elm2, field) do { \
885 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \
886 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \
887 QMD_TAILQ_CHECK_NEXT(elm, field); \
888 QMD_TAILQ_CHECK_PREV(elm, field); \
889 TAILQ_NEXT((elm2), field) = TAILQ_NEXT((elm), field); \
890 if (TAILQ_NEXT((elm2), field) != TAILQ_END(head)) \
891 TAILQ_NEXT((elm2), field)->field.tqe_prev = \
892 &(elm2)->field.tqe_next; \
893 else \
894 (head)->tqh_last = &(elm2)->field.tqe_next; \
895 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \
896 *(elm2)->field.tqe_prev = (elm2); \
897 TRASHIT(*oldnext); \
898 TRASHIT(*oldprev); \
899 QMD_TRACE_ELEM(&(elm)->field); \
900} while (0)
901
902#define TAILQ_SWAP(head1, head2, type, field) do { \
903 QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \
904 QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \
905 (head1)->tqh_first = (head2)->tqh_first; \
906 (head1)->tqh_last = (head2)->tqh_last; \
907 (head2)->tqh_first = swap_first; \
908 (head2)->tqh_last = swap_last; \
909 if ((swap_first = (head1)->tqh_first) != NULL) \
910 swap_first->field.tqe_prev = &(head1)->tqh_first; \
911 else \
912 (head1)->tqh_last = &(head1)->tqh_first; \
913 if ((swap_first = (head2)->tqh_first) != NULL) \
914 swap_first->field.tqe_prev = &(head2)->tqh_first; \
915 else \
916 (head2)->tqh_last = &(head2)->tqh_first; \
917} while (0)
918
919#define TAILQ_END(head) NULL
920
921#endif /* !_SYS_QUEUE_H_ */