2 * Copyright 2001-2003 The OpenLDAP Foundation, Redwood City, California, USA
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted only as authorized by the OpenLDAP
7 * Public License. A copy of this license is available at
8 * http://www.OpenLDAP.org/license.html or in file LICENSE in the
9 * top-level directory of the distribution.
11 /* stolen from FreeBSD for use in OpenLDAP */
14 * Copyright (c) 1991, 1993
15 * The Regents of the University of California. All rights reserved.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 * 3. All advertising materials mentioning features or use of this software
26 * must display the following acknowledgement:
27 * This product includes software developed by the University of
28 * California, Berkeley and its contributors.
29 * 4. Neither the name of the University nor the names of its contributors
30 * may be used to endorse or promote products derived from this software
31 * without specific prior written permission.
33 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
34 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
35 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
37 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
41 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
42 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
45 * @(#)queue.h 8.5 (Berkeley) 8/20/94
46 * $FreeBSD: src/sys/sys/queue.h,v 1.32.2.5 2001/09/30 21:12:54 luigi Exp $
49 #ifndef _LDAP_QUEUE_H_
50 #define _LDAP_QUEUE_H_
53 * This file defines five types of data structures: singly-linked lists,
54 * singly-linked tail queues, lists, tail queues, and circular queues.
56 * A singly-linked list is headed by a single forward pointer. The elements
57 * are singly linked for minimum space and pointer manipulation overhead at
58 * the expense of O(n) removal for arbitrary elements. New elements can be
59 * added to the list after an existing element or at the head of the list.
60 * Elements being removed from the head of the list should use the explicit
61 * macro for this purpose for optimum efficiency. A singly-linked list may
62 * only be traversed in the forward direction. Singly-linked lists are ideal
63 * for applications with large datasets and few or no removals or for
64 * implementing a LIFO queue.
66 * A singly-linked tail queue is headed by a pair of pointers, one to the
67 * head of the list and the other to the tail of the list. The elements are
68 * singly linked for minimum space and pointer manipulation overhead at the
69 * expense of O(n) removal for arbitrary elements. New elements can be added
70 * to the list after an existing element, at the head of the list, or at the
71 * end of the list. Elements being removed from the head of the tail queue
72 * should use the explicit macro for this purpose for optimum efficiency.
73 * A singly-linked tail queue may only be traversed in the forward direction.
74 * Singly-linked tail queues are ideal for applications with large datasets
75 * and few or no removals or for implementing a FIFO queue.
77 * A list is headed by a single forward pointer (or an array of forward
78 * pointers for a hash table header). The elements are doubly linked
79 * so that an arbitrary element can be removed without a need to
80 * traverse the list. New elements can be added to the list before
81 * or after an existing element or at the head of the list. A list
82 * may only be traversed in the forward direction.
84 * A tail queue is headed by a pair of pointers, one to the head of the
85 * list and the other to the tail of the list. The elements are doubly
86 * linked so that an arbitrary element can be removed without a need to
87 * traverse the list. New elements can be added to the list before or
88 * after an existing element, at the head of the list, or at the end of
89 * the list. A tail queue may be traversed in either direction.
91 * A circle queue is headed by a pair of pointers, one to the head of the
92 * list and the other to the tail of the list. The elements are doubly
93 * linked so that an arbitrary element can be removed without a need to
94 * traverse the list. New elements can be added to the list before or after
95 * an existing element, at the head of the list, or at the end of the list.
96 * A circle queue may be traversed in either direction, but has a more
97 * complex end of list detection.
99 * For details on the use of these macros, see the queue(3) manual page.
100 * All macros are prefixed with LDAP_.
102 * SLIST_ LIST_ STAILQ_ TAILQ_ CIRCLEQ_
112 * _FOREACH_REVERSE - - - + +
113 * _INSERT_HEAD + + + + +
114 * _INSERT_BEFORE - + - + +
115 * _INSERT_AFTER + + + + +
116 * _INSERT_TAIL - - + + +
117 * _REMOVE_HEAD + - + - -
123 * Singly-linked List definitions.
125 #define LDAP_SLIST_HEAD(name, type) \
127 struct type *slh_first; /* first element */ \
130 #define LDAP_SLIST_HEAD_INITIALIZER(head) \
133 #define LDAP_SLIST_ENTRY(type) \
135 struct type *sle_next; /* next element */ \
138 #define LDAP_SLIST_ENTRY_INITIALIZER(entry) \
142 * Singly-linked List functions.
144 #define LDAP_SLIST_EMPTY(head) ((head)->slh_first == NULL)
146 #define LDAP_SLIST_FIRST(head) ((head)->slh_first)
148 #define LDAP_SLIST_FOREACH(var, head, field) \
149 for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)
151 #define LDAP_SLIST_INIT(head) { \
152 (head)->slh_first = NULL; \
155 #define LDAP_SLIST_INSERT_AFTER(slistelm, elm, field) do { \
156 (elm)->field.sle_next = (slistelm)->field.sle_next; \
157 (slistelm)->field.sle_next = (elm); \
160 #define LDAP_SLIST_INSERT_HEAD(head, elm, field) do { \
161 (elm)->field.sle_next = (head)->slh_first; \
162 (head)->slh_first = (elm); \
165 #define LDAP_SLIST_NEXT(elm, field) ((elm)->field.sle_next)
167 #define LDAP_SLIST_REMOVE_HEAD(head, field) do { \
168 (head)->slh_first = (head)->slh_first->field.sle_next; \
171 #define LDAP_SLIST_REMOVE(head, elm, type, field) do { \
172 if ((head)->slh_first == (elm)) { \
173 LDAP_SLIST_REMOVE_HEAD((head), field); \
176 struct type *curelm = (head)->slh_first; \
177 while( curelm->field.sle_next != (elm) ) \
178 curelm = curelm->field.sle_next; \
179 curelm->field.sle_next = \
180 curelm->field.sle_next->field.sle_next; \
185 * Singly-linked Tail queue definitions.
187 #define LDAP_STAILQ_HEAD(name, type) \
189 struct type *stqh_first;/* first element */ \
190 struct type **stqh_last;/* addr of last next element */ \
193 #define LDAP_STAILQ_HEAD_INITIALIZER(head) \
194 { NULL, &(head).stqh_first }
196 #define LDAP_STAILQ_ENTRY(type) \
198 struct type *stqe_next; /* next element */ \
201 #define LDAP_STAILQ_ENTRY_INITIALIZER(entry) \
205 * Singly-linked Tail queue functions.
207 #define LDAP_STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
209 #define LDAP_STAILQ_INIT(head) do { \
210 (head)->stqh_first = NULL; \
211 (head)->stqh_last = &(head)->stqh_first; \
214 #define LDAP_STAILQ_FIRST(head) ((head)->stqh_first)
216 #define LDAP_STAILQ_LAST(head, type, field) \
217 (LDAP_STAILQ_EMPTY(head) ? \
220 ((char *)((head)->stqh_last) - offsetof(struct type, field))))
222 #define LDAP_STAILQ_FOREACH(var, head, field) \
223 for((var) = (head)->stqh_first; (var); (var) = (var)->field.stqe_next)
225 #define LDAP_STAILQ_INSERT_HEAD(head, elm, field) do { \
226 if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \
227 (head)->stqh_last = &(elm)->field.stqe_next; \
228 (head)->stqh_first = (elm); \
231 #define LDAP_STAILQ_INSERT_TAIL(head, elm, field) do { \
232 (elm)->field.stqe_next = NULL; \
233 *(head)->stqh_last = (elm); \
234 (head)->stqh_last = &(elm)->field.stqe_next; \
237 #define LDAP_STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
238 if (((elm)->field.stqe_next = (tqelm)->field.stqe_next) == NULL)\
239 (head)->stqh_last = &(elm)->field.stqe_next; \
240 (tqelm)->field.stqe_next = (elm); \
243 #define LDAP_STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
245 #define LDAP_STAILQ_REMOVE_HEAD(head, field) do { \
246 if (((head)->stqh_first = \
247 (head)->stqh_first->field.stqe_next) == NULL) \
248 (head)->stqh_last = &(head)->stqh_first; \
251 #define LDAP_STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \
252 if (((head)->stqh_first = (elm)->field.stqe_next) == NULL) \
253 (head)->stqh_last = &(head)->stqh_first; \
256 #define LDAP_STAILQ_REMOVE(head, elm, type, field) do { \
257 if ((head)->stqh_first == (elm)) { \
258 LDAP_STAILQ_REMOVE_HEAD(head, field); \
261 struct type *curelm = (head)->stqh_first; \
262 while( curelm->field.stqe_next != (elm) ) \
263 curelm = curelm->field.stqe_next; \
264 if((curelm->field.stqe_next = \
265 curelm->field.stqe_next->field.stqe_next) == NULL) \
266 (head)->stqh_last = &(curelm)->field.stqe_next; \
273 #define LDAP_LIST_HEAD(name, type) \
275 struct type *lh_first; /* first element */ \
278 #define LDAP_LIST_HEAD_INITIALIZER(head) \
281 #define LDAP_LIST_ENTRY(type) \
283 struct type *le_next; /* next element */ \
284 struct type **le_prev; /* address of previous next element */ \
287 #define LDAP_LIST_ENTRY_INITIALIZER(entry) \
294 #define LDAP_LIST_EMPTY(head) ((head)->lh_first == NULL)
296 #define LDAP_LIST_FIRST(head) ((head)->lh_first)
298 #define LDAP_LIST_FOREACH(var, head, field) \
299 for((var) = (head)->lh_first; (var); (var) = (var)->field.le_next)
301 #define LDAP_LIST_INIT(head) do { \
302 (head)->lh_first = NULL; \
305 #define LDAP_LIST_INSERT_AFTER(listelm, elm, field) do { \
306 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
307 (listelm)->field.le_next->field.le_prev = \
308 &(elm)->field.le_next; \
309 (listelm)->field.le_next = (elm); \
310 (elm)->field.le_prev = &(listelm)->field.le_next; \
313 #define LDAP_LIST_INSERT_BEFORE(listelm, elm, field) do { \
314 (elm)->field.le_prev = (listelm)->field.le_prev; \
315 (elm)->field.le_next = (listelm); \
316 *(listelm)->field.le_prev = (elm); \
317 (listelm)->field.le_prev = &(elm)->field.le_next; \
320 #define LDAP_LIST_INSERT_HEAD(head, elm, field) do { \
321 if (((elm)->field.le_next = (head)->lh_first) != NULL) \
322 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
323 (head)->lh_first = (elm); \
324 (elm)->field.le_prev = &(head)->lh_first; \
327 #define LDAP_LIST_NEXT(elm, field) ((elm)->field.le_next)
329 #define LDAP_LIST_REMOVE(elm, field) do { \
330 if ((elm)->field.le_next != NULL) \
331 (elm)->field.le_next->field.le_prev = \
332 (elm)->field.le_prev; \
333 *(elm)->field.le_prev = (elm)->field.le_next; \
337 * Tail queue definitions.
339 #define LDAP_TAILQ_HEAD(name, type) \
341 struct type *tqh_first; /* first element */ \
342 struct type **tqh_last; /* addr of last next element */ \
345 #define LDAP_TAILQ_HEAD_INITIALIZER(head) \
346 { NULL, &(head).tqh_first }
348 #define LDAP_TAILQ_ENTRY(type) \
350 struct type *tqe_next; /* next element */ \
351 struct type **tqe_prev; /* address of previous next element */ \
354 #define LDAP_TAILQ_ENTRY_INITIALIZER(entry) \
358 * Tail queue functions.
360 #define LDAP_TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
362 #define LDAP_TAILQ_FOREACH(var, head, field) \
363 for (var = LDAP_TAILQ_FIRST(head); var; var = TAILQ_NEXT(var, field))
365 #define LDAP_TAILQ_FOREACH_REVERSE(var, head, type, field) \
366 for ((var) = LDAP_TAILQ_LAST((head), type, field); \
368 (var) = LDAP_TAILQ_PREV((var), head, type, field))
370 #define LDAP_TAILQ_FIRST(head) ((head)->tqh_first)
372 #define LDAP_TAILQ_LAST(head, type, field) \
373 (LDAP_TAILQ_EMPTY(head) ? \
376 ((char *)((head)->tqh_last) - offsetof(struct type, field))))
378 #define LDAP_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
380 #define LDAP_TAILQ_PREV(elm, head, type, field) \
381 ((struct type *)((elm)->field.tqe_prev) == LDAP_TAILQ_FIRST(head) ? \
384 ((char *)((elm)->field.tqe_prev) - offsetof(struct type, field))))
386 #define LDAP_TAILQ_INIT(head) do { \
387 (head)->tqh_first = NULL; \
388 (head)->tqh_last = &(head)->tqh_first; \
391 #define LDAP_TAILQ_INSERT_HEAD(head, elm, field) do { \
392 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
393 (head)->tqh_first->field.tqe_prev = \
394 &(elm)->field.tqe_next; \
396 (head)->tqh_last = &(elm)->field.tqe_next; \
397 (head)->tqh_first = (elm); \
398 (elm)->field.tqe_prev = &(head)->tqh_first; \
401 #define LDAP_TAILQ_INSERT_TAIL(head, elm, field) do { \
402 (elm)->field.tqe_next = NULL; \
403 (elm)->field.tqe_prev = (head)->tqh_last; \
404 *(head)->tqh_last = (elm); \
405 (head)->tqh_last = &(elm)->field.tqe_next; \
408 #define LDAP_TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
409 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
410 (elm)->field.tqe_next->field.tqe_prev = \
411 &(elm)->field.tqe_next; \
413 (head)->tqh_last = &(elm)->field.tqe_next; \
414 (listelm)->field.tqe_next = (elm); \
415 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \
418 #define LDAP_TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
419 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
420 (elm)->field.tqe_next = (listelm); \
421 *(listelm)->field.tqe_prev = (elm); \
422 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
425 #define LDAP_TAILQ_REMOVE(head, elm, field) do { \
426 if (((elm)->field.tqe_next) != NULL) \
427 (elm)->field.tqe_next->field.tqe_prev = \
428 (elm)->field.tqe_prev; \
430 (head)->tqh_last = (elm)->field.tqe_prev; \
431 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \
435 * Circular queue definitions.
437 #define LDAP_CIRCLEQ_HEAD(name, type) \
439 struct type *cqh_first; /* first element */ \
440 struct type *cqh_last; /* last element */ \
443 #define LDAP_CIRCLEQ_ENTRY(type) \
445 struct type *cqe_next; /* next element */ \
446 struct type *cqe_prev; /* previous element */ \
450 * Circular queue functions.
452 #define LDAP_CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head))
454 #define LDAP_CIRCLEQ_FIRST(head) ((head)->cqh_first)
456 #define LDAP_CIRCLEQ_FOREACH(var, head, field) \
457 for((var) = (head)->cqh_first; \
458 (var) != (void *)(head); \
459 (var) = (var)->field.cqe_next)
461 #define LDAP_CIRCLEQ_FOREACH_REVERSE(var, head, field) \
462 for((var) = (head)->cqh_last; \
463 (var) != (void *)(head); \
464 (var) = (var)->field.cqe_prev)
466 #define LDAP_CIRCLEQ_INIT(head) do { \
467 (head)->cqh_first = (void *)(head); \
468 (head)->cqh_last = (void *)(head); \
471 #define LDAP_CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
472 (elm)->field.cqe_next = (listelm)->field.cqe_next; \
473 (elm)->field.cqe_prev = (listelm); \
474 if ((listelm)->field.cqe_next == (void *)(head)) \
475 (head)->cqh_last = (elm); \
477 (listelm)->field.cqe_next->field.cqe_prev = (elm); \
478 (listelm)->field.cqe_next = (elm); \
481 #define LDAP_CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \
482 (elm)->field.cqe_next = (listelm); \
483 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \
484 if ((listelm)->field.cqe_prev == (void *)(head)) \
485 (head)->cqh_first = (elm); \
487 (listelm)->field.cqe_prev->field.cqe_next = (elm); \
488 (listelm)->field.cqe_prev = (elm); \
491 #define LDAP_CIRCLEQ_INSERT_HEAD(head, elm, field) do { \
492 (elm)->field.cqe_next = (head)->cqh_first; \
493 (elm)->field.cqe_prev = (void *)(head); \
494 if ((head)->cqh_last == (void *)(head)) \
495 (head)->cqh_last = (elm); \
497 (head)->cqh_first->field.cqe_prev = (elm); \
498 (head)->cqh_first = (elm); \
501 #define LDAP_CIRCLEQ_INSERT_TAIL(head, elm, field) do { \
502 (elm)->field.cqe_next = (void *)(head); \
503 (elm)->field.cqe_prev = (head)->cqh_last; \
504 if ((head)->cqh_first == (void *)(head)) \
505 (head)->cqh_first = (elm); \
507 (head)->cqh_last->field.cqe_next = (elm); \
508 (head)->cqh_last = (elm); \
511 #define LDAP_CIRCLEQ_LAST(head) ((head)->cqh_last)
513 #define LDAP_CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next)
515 #define LDAP_CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev)
517 #define LDAP_CIRCLEQ_REMOVE(head, elm, field) do { \
518 if ((elm)->field.cqe_next == (void *)(head)) \
519 (head)->cqh_last = (elm)->field.cqe_prev; \
521 (elm)->field.cqe_next->field.cqe_prev = \
522 (elm)->field.cqe_prev; \
523 if ((elm)->field.cqe_prev == (void *)(head)) \
524 (head)->cqh_first = (elm)->field.cqe_next; \
526 (elm)->field.cqe_prev->field.cqe_next = \
527 (elm)->field.cqe_next; \
530 #endif /* !_LDAP_QUEUE_H_ */