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29 * @(#)queue.h 8.5 (Berkeley) 8/20/94
30 * $FreeBSD: src/sys/sys/queue.h,v 1.58 2004/04/07 04:19:49 imp Exp $
31 * $Id: //depot/sw/branches/fusion_usb/target_firmware/wlan/target/madwifi/include/sys/queue.h#1 $
38 * This file defines four types of data structures: singly-linked lists,
39 * singly-linked tail queues, lists and tail queues.
41 * A singly-linked list is headed by a single forward pointer. The elements
42 * are singly linked for minimum space and pointer manipulation overhead at
43 * the expense of O(n) removal for arbitrary elements. New elements can be
44 * added to the list after an existing element or at the head of the list.
45 * Elements being removed from the head of the list should use the explicit
46 * macro for this purpose for optimum efficiency. A singly-linked list may
47 * only be traversed in the forward direction. Singly-linked lists are ideal
48 * for applications with large datasets and few or no removals or for
49 * implementing a LIFO queue.
51 * A singly-linked tail queue is headed by a pair of pointers, one to the
52 * head of the list and the other to the tail of the list. The elements are
53 * singly linked for minimum space and pointer manipulation overhead at the
54 * expense of O(n) removal for arbitrary elements. New elements can be added
55 * to the list after an existing element, at the head of the list, or at the
56 * end of the list. Elements being removed from the head of the tail queue
57 * should use the explicit macro for this purpose for optimum efficiency.
58 * A singly-linked tail queue may only be traversed in the forward direction.
59 * Singly-linked tail queues are ideal for applications with large datasets
60 * and few or no removals or for implementing a FIFO queue.
62 * A list is headed by a single forward pointer (or an array of forward
63 * pointers for a hash table header). The elements are doubly linked
64 * so that an arbitrary element can be removed without a need to
65 * traverse the list. New elements can be added to the list before
66 * or after an existing element or at the head of the list. A list
67 * may only be traversed in the forward direction.
69 * A tail queue is headed by a pair of pointers, one to the head of the
70 * list and the other to the tail of the list. The elements are doubly
71 * linked so that an arbitrary element can be removed without a need to
72 * traverse the list. New elements can be added to the list before or
73 * after an existing element, at the head of the list, or at the end of
74 * the list. A tail queue may be traversed in either direction.
76 * For details on the use of these macros, see the queue(3) manual page.
79 * SLIST LIST STAILQ TAILQ
81 * _HEAD_INITIALIZER + + + +
90 * _FOREACH_SAFE + + + +
91 * _FOREACH_REVERSE - - - +
92 * _FOREACH_REVERSE_SAFE - - - +
93 * _INSERT_HEAD + + + +
94 * _INSERT_BEFORE - + - +
95 * _INSERT_AFTER + + + +
96 * _INSERT_TAIL - - + +
98 * _REMOVE_HEAD + - + -
102 #define QUEUE_MACRO_DEBUG 0
103 #if QUEUE_MACRO_DEBUG
104 /* Store the last 2 places the queue element or head was altered */
112 #define TRACEBUF struct qm_trace trace;
113 #define TRASHIT(x) do {(x) = (void *)-1;} while (0)
115 #define QMD_TRACE_HEAD(head) do { \
116 (head)->trace.prevline = (head)->trace.lastline; \
117 (head)->trace.prevfile = (head)->trace.lastfile; \
118 (head)->trace.lastline = __LINE__; \
119 (head)->trace.lastfile = __FILE__; \
122 #define QMD_TRACE_ELEM(elem) do { \
123 (elem)->trace.prevline = (elem)->trace.lastline; \
124 (elem)->trace.prevfile = (elem)->trace.lastfile; \
125 (elem)->trace.lastline = __LINE__; \
126 (elem)->trace.lastfile = __FILE__; \
130 #define QMD_TRACE_ELEM(elem)
131 #define QMD_TRACE_HEAD(head)
134 #endif /* QUEUE_MACRO_DEBUG */
137 * Singly-linked List declarations.
139 #define SLIST_HEAD(name, type) \
141 struct type *slh_first; /* first element */ \
144 #define SLIST_HEAD_INITIALIZER(head) \
147 #define SLIST_ENTRY(type) \
149 struct type *sle_next; /* next element */ \
153 * Singly-linked List functions.
155 #define SLIST_EMPTY(head) ((head)->slh_first == NULL)
157 #define SLIST_FIRST(head) ((head)->slh_first)
159 #define SLIST_FOREACH(var, head, field) \
160 for ((var) = SLIST_FIRST((head)); \
162 (var) = SLIST_NEXT((var), field))
164 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \
165 for ((var) = SLIST_FIRST((head)); \
166 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
169 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
170 for ((varp) = &SLIST_FIRST((head)); \
171 ((var) = *(varp)) != NULL; \
172 (varp) = &SLIST_NEXT((var), field))
174 #define SLIST_INIT(head) do { \
175 SLIST_FIRST((head)) = NULL; \
178 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
179 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
180 SLIST_NEXT((slistelm), field) = (elm); \
183 #define SLIST_INSERT_HEAD(head, elm, field) do { \
184 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
185 SLIST_FIRST((head)) = (elm); \
188 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
190 #define SLIST_REMOVE(head, elm, type, field) do { \
191 if (SLIST_FIRST((head)) == (elm)) { \
192 SLIST_REMOVE_HEAD((head), field); \
195 struct type *curelm = SLIST_FIRST((head)); \
196 while (SLIST_NEXT(curelm, field) != (elm)) \
197 curelm = SLIST_NEXT(curelm, field); \
198 SLIST_NEXT(curelm, field) = \
199 SLIST_NEXT(SLIST_NEXT(curelm, field), field); \
203 #define SLIST_REMOVE_HEAD(head, field) do { \
204 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
208 * Singly-linked Tail queue declarations.
210 #define STAILQ_HEAD(name, type) \
212 struct type *stqh_first;/* first element */ \
213 struct type **stqh_last;/* addr of last next element */ \
216 #define STAILQ_HEAD_INITIALIZER(head) \
217 { NULL, &(head).stqh_first }
219 #define STAILQ_ENTRY(type) \
221 struct type *stqe_next; /* next element */ \
225 * Singly-linked Tail queue functions.
227 #define STAILQ_CONCAT(head1, head2) do { \
228 if (!STAILQ_EMPTY((head2))) { \
229 *(head1)->stqh_last = (head2)->stqh_first; \
230 (head1)->stqh_last = (head2)->stqh_last; \
231 STAILQ_INIT((head2)); \
235 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
237 #define STAILQ_FIRST(head) ((head)->stqh_first)
239 #define STAILQ_FOREACH(var, head, field) \
240 for((var) = STAILQ_FIRST((head)); \
242 (var) = STAILQ_NEXT((var), field))
245 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
246 for ((var) = STAILQ_FIRST((head)); \
247 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
250 #define STAILQ_INIT(head) do { \
251 STAILQ_FIRST((head)) = NULL; \
252 (head)->stqh_last = &STAILQ_FIRST((head)); \
255 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
256 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
257 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
258 STAILQ_NEXT((tqelm), field) = (elm); \
261 #define STAILQ_INSERT_HEAD(head, elm, field) do { \
262 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
263 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
264 STAILQ_FIRST((head)) = (elm); \
267 #define STAILQ_INSERT_TAIL(head, elm, field) do { \
268 STAILQ_NEXT((elm), field) = NULL; \
269 *(head)->stqh_last = (elm); \
270 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
273 #define STAILQ_LAST(head, type, field) \
274 (STAILQ_EMPTY((head)) ? \
277 ((char *)((head)->stqh_last) - asf_offsetof(struct type, field))))
279 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
281 #define STAILQ_REMOVE(head, elm, type, field) do { \
282 if (STAILQ_FIRST((head)) == (elm)) { \
283 STAILQ_REMOVE_HEAD((head), field); \
286 struct type *curelm = STAILQ_FIRST((head)); \
287 while (STAILQ_NEXT(curelm, field) != (elm)) \
288 curelm = STAILQ_NEXT(curelm, field); \
289 if ((STAILQ_NEXT(curelm, field) = \
290 STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\
291 (head)->stqh_last = &STAILQ_NEXT((curelm), field);\
296 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \
297 if (STAILQ_NEXT(elm, field)) { \
298 if ((STAILQ_NEXT(elm, field) = \
299 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL)\
300 (head)->stqh_last = &STAILQ_NEXT((elm), field); \
305 #define STAILQ_REMOVE_HEAD(head, field) do { \
306 if ((STAILQ_FIRST((head)) = \
307 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
308 (head)->stqh_last = &STAILQ_FIRST((head)); \
311 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \
312 if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \
313 (head)->stqh_last = &STAILQ_FIRST((head)); \
319 #define LIST_HEAD(name, type) \
321 struct type *lh_first; /* first element */ \
324 #define ATH_LIST_HEAD(name, type) \
326 struct type *lh_first; /* first element */ \
329 #define LIST_HEAD_INITIALIZER(head) \
332 #define LIST_ENTRY(type) \
334 struct type *le_next; /* next element */ \
335 struct type **le_prev; /* address of previous next element */ \
342 #define LIST_EMPTY(head) ((head)->lh_first == NULL)
344 #define LIST_FIRST(head) ((head)->lh_first)
346 #define LIST_FOREACH(var, head, field) \
347 for ((var) = LIST_FIRST((head)); \
349 (var) = LIST_NEXT((var), field))
351 #define LIST_FOREACH_SAFE(var, head, field, tvar) \
352 for ((var) = LIST_FIRST((head)); \
353 (var) && ((tvar) = LIST_NEXT((var), field), 1); \
356 #define LIST_INIT(head) do { \
357 LIST_FIRST((head)) = NULL; \
360 #define LIST_INSERT_AFTER(listelm, elm, field) do { \
361 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
362 LIST_NEXT((listelm), field)->field.le_prev = \
363 &LIST_NEXT((elm), field); \
364 LIST_NEXT((listelm), field) = (elm); \
365 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \
368 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \
369 (elm)->field.le_prev = (listelm)->field.le_prev; \
370 LIST_NEXT((elm), field) = (listelm); \
371 *(listelm)->field.le_prev = (elm); \
372 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \
375 #define LIST_INSERT_HEAD(head, elm, field) do { \
376 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
377 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
378 LIST_FIRST((head)) = (elm); \
379 (elm)->field.le_prev = &LIST_FIRST((head)); \
382 #define LIST_NEXT(elm, field) ((elm)->field.le_next)
384 #define LIST_REMOVE(elm, field) do { \
385 if (LIST_NEXT((elm), field) != NULL) \
386 LIST_NEXT((elm), field)->field.le_prev = \
387 (elm)->field.le_prev; \
388 *(elm)->field.le_prev = LIST_NEXT((elm), field); \
392 * Tail queue declarations.
394 #define TAILQ_HEAD(name, type) \
396 struct type *tqh_first; /* first element */ \
397 struct type **tqh_last; /* addr of last next element */ \
401 #define TAILQ_HEAD_INITIALIZER(head) \
402 { NULL, &(head).tqh_first }
404 #define TAILQ_ENTRY(type) \
406 struct type *tqe_next; /* next element */ \
407 struct type **tqe_prev; /* address of previous next element */ \
412 * Tail queue functions.
414 #define TAILQ_CONCAT(head1, head2, field) do { \
415 if (!TAILQ_EMPTY(head2)) { \
416 *(head1)->tqh_last = (head2)->tqh_first; \
417 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
418 (head1)->tqh_last = (head2)->tqh_last; \
419 TAILQ_INIT((head2)); \
420 QMD_TRACE_HEAD(head); \
421 QMD_TRACE_HEAD(head2); \
425 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
427 #define TAILQ_FIRST(head) ((head)->tqh_first)
429 #define TAILQ_FOREACH(var, head, field) \
430 for ((var) = TAILQ_FIRST((head)); \
432 (var) = TAILQ_NEXT((var), field))
434 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
435 for ((var) = TAILQ_FIRST((head)); \
436 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
439 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
440 for ((var) = TAILQ_LAST((head), headname); \
442 (var) = TAILQ_PREV((var), headname, field))
444 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
445 for ((var) = TAILQ_LAST((head), headname); \
446 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
449 #define TAILQ_INIT(head) do { \
450 TAILQ_FIRST((head)) = NULL; \
451 (head)->tqh_last = &TAILQ_FIRST((head)); \
452 QMD_TRACE_HEAD(head); \
455 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
456 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
457 TAILQ_NEXT((elm), field)->field.tqe_prev = \
458 &TAILQ_NEXT((elm), field); \
460 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
461 QMD_TRACE_HEAD(head); \
463 TAILQ_NEXT((listelm), field) = (elm); \
464 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \
465 QMD_TRACE_ELEM(&(elm)->field); \
466 QMD_TRACE_ELEM(&listelm->field); \
469 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
470 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
471 TAILQ_NEXT((elm), field) = (listelm); \
472 *(listelm)->field.tqe_prev = (elm); \
473 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
474 QMD_TRACE_ELEM(&(elm)->field); \
475 QMD_TRACE_ELEM(&listelm->field); \
478 #define TAILQ_INSERT_HEAD(head, elm, field) do { \
479 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \
480 TAILQ_FIRST((head))->field.tqe_prev = \
481 &TAILQ_NEXT((elm), field); \
483 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
484 TAILQ_FIRST((head)) = (elm); \
485 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \
486 QMD_TRACE_HEAD(head); \
487 QMD_TRACE_ELEM(&(elm)->field); \
490 #define TAILQ_INSERT_TAIL(head, elm, field) do { \
491 TAILQ_NEXT((elm), field) = NULL; \
492 (elm)->field.tqe_prev = (head)->tqh_last; \
493 *(head)->tqh_last = (elm); \
494 (head)->tqh_last = &TAILQ_NEXT((elm), field); \
495 QMD_TRACE_HEAD(head); \
496 QMD_TRACE_ELEM(&(elm)->field); \
499 #define TAILQ_LAST(head, headname) \
500 (*(((struct headname *)((head)->tqh_last))->tqh_last))
502 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
504 #define TAILQ_PREV(elm, headname, field) \
505 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
507 #define TAILQ_REMOVE(head, elm, field) do { \
508 if ((TAILQ_NEXT((elm), field)) != NULL) \
509 TAILQ_NEXT((elm), field)->field.tqe_prev = \
510 (elm)->field.tqe_prev; \
512 (head)->tqh_last = (elm)->field.tqe_prev; \
513 QMD_TRACE_HEAD(head); \
515 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
516 TRASHIT((elm)->field.tqe_next); \
517 TRASHIT((elm)->field.tqe_prev); \
518 QMD_TRACE_ELEM(&(elm)->field); \
525 * XXX insque() and remque() are an old way of handling certain queues.
526 * They bogusly assumes that all queue heads look alike.
530 struct quehead *qh_link;
531 struct quehead *qh_rlink;
534 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
537 insque(void *a, void *b)
539 struct quehead *element = (struct quehead *)a,
540 *head = (struct quehead *)b;
542 element->qh_link = head->qh_link;
543 element->qh_rlink = head;
544 head->qh_link = element;
545 element->qh_link->qh_rlink = element;
551 struct quehead *element = (struct quehead *)a;
553 element->qh_link->qh_rlink = element->qh_rlink;
554 element->qh_rlink->qh_link = element->qh_link;
555 element->qh_rlink = 0;
558 #else /* !(__GNUC__ || __INTEL_COMPILER) */
560 void insque(void *a, void *b);
561 void remque(void *a);
563 #endif /* __GNUC__ || __INTEL_COMPILER */
567 #endif /* !_SYS_QUEUE_H_ */