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 $
48 /* See also: ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change */
50 #ifndef _LDAP_QUEUE_H_
51 #define _LDAP_QUEUE_H_
54 * This file defines five types of data structures: singly-linked lists,
55 * singly-linked tail queues, lists, tail queues, and circular queues.
57 * A singly-linked list is headed by a single forward pointer. The elements
58 * are singly linked for minimum space and pointer manipulation overhead at
59 * the expense of O(n) removal for arbitrary elements. New elements can be
60 * added to the list after an existing element or at the head of the list.
61 * Elements being removed from the head of the list should use the explicit
62 * macro for this purpose for optimum efficiency. A singly-linked list may
63 * only be traversed in the forward direction. Singly-linked lists are ideal
64 * for applications with large datasets and few or no removals or for
65 * implementing a LIFO queue.
67 * A singly-linked tail queue is headed by a pair of pointers, one to the
68 * head of the list and the other to the tail of the list. The elements are
69 * singly linked for minimum space and pointer manipulation overhead at the
70 * expense of O(n) removal for arbitrary elements. New elements can be added
71 * to the list after an existing element, at the head of the list, or at the
72 * end of the list. Elements being removed from the head of the tail queue
73 * should use the explicit macro for this purpose for optimum efficiency.
74 * A singly-linked tail queue may only be traversed in the forward direction.
75 * Singly-linked tail queues are ideal for applications with large datasets
76 * and few or no removals or for implementing a FIFO queue.
78 * A list is headed by a single forward pointer (or an array of forward
79 * pointers for a hash table header). The elements are doubly linked
80 * so that an arbitrary element can be removed without a need to
81 * traverse the list. New elements can be added to the list before
82 * or after an existing element or at the head of the list. A list
83 * may only be traversed in the forward direction.
85 * A tail queue is headed by a pair of pointers, one to the head of the
86 * list and the other to the tail of the list. The elements are doubly
87 * linked so that an arbitrary element can be removed without a need to
88 * traverse the list. New elements can be added to the list before or
89 * after an existing element, at the head of the list, or at the end of
90 * the list. A tail queue may be traversed in either direction.
92 * A circle queue is headed by a pair of pointers, one to the head of the
93 * list and the other to the tail of the list. The elements are doubly
94 * linked so that an arbitrary element can be removed without a need to
95 * traverse the list. New elements can be added to the list before or after
96 * an existing element, at the head of the list, or at the end of the list.
97 * A circle queue may be traversed in either direction, but has a more
98 * complex end of list detection.
100 * For details on the use of these macros, see the queue(3) manual page.
101 * All macros are prefixed with LDAP_.
103 * SLIST_ LIST_ STAILQ_ TAILQ_ CIRCLEQ_
113 * _FOREACH_REVERSE - - - + +
114 * _INSERT_HEAD + + + + +
115 * _INSERT_BEFORE - + - + +
116 * _INSERT_AFTER + + + + +
117 * _INSERT_TAIL - - + + +
118 * _REMOVE_HEAD + - + - -
124 * Singly-linked List definitions.
126 #define LDAP_SLIST_HEAD(name, type) \
128 struct type *slh_first; /* first element */ \
131 #define LDAP_SLIST_HEAD_INITIALIZER(head) \
134 #define LDAP_SLIST_ENTRY(type) \
136 struct type *sle_next; /* next element */ \
139 #define LDAP_SLIST_ENTRY_INITIALIZER(entry) \
143 * Singly-linked List functions.
145 #define LDAP_SLIST_EMPTY(head) ((head)->slh_first == NULL)
147 #define LDAP_SLIST_FIRST(head) ((head)->slh_first)
149 #define LDAP_SLIST_FOREACH(var, head, field) \
150 for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)
152 #define LDAP_SLIST_INIT(head) { \
153 (head)->slh_first = NULL; \
156 #define LDAP_SLIST_INSERT_AFTER(slistelm, elm, field) do { \
157 (elm)->field.sle_next = (slistelm)->field.sle_next; \
158 (slistelm)->field.sle_next = (elm); \
161 #define LDAP_SLIST_INSERT_HEAD(head, elm, field) do { \
162 (elm)->field.sle_next = (head)->slh_first; \
163 (head)->slh_first = (elm); \
166 #define LDAP_SLIST_NEXT(elm, field) ((elm)->field.sle_next)
168 #define LDAP_SLIST_REMOVE_HEAD(head, field) do { \
169 (head)->slh_first = (head)->slh_first->field.sle_next; \
172 #define LDAP_SLIST_REMOVE(head, elm, type, field) do { \
173 if ((head)->slh_first == (elm)) { \
174 LDAP_SLIST_REMOVE_HEAD((head), field); \
177 struct type *curelm = (head)->slh_first; \
178 while( curelm->field.sle_next != (elm) ) \
179 curelm = curelm->field.sle_next; \
180 curelm->field.sle_next = \
181 curelm->field.sle_next->field.sle_next; \
186 * Singly-linked Tail queue definitions.
188 #define LDAP_STAILQ_HEAD(name, type) \
190 struct type *stqh_first;/* first element */ \
191 struct type **stqh_last;/* addr of last next element */ \
194 #define LDAP_STAILQ_HEAD_INITIALIZER(head) \
195 { NULL, &(head).stqh_first }
197 #define LDAP_STAILQ_ENTRY(type) \
199 struct type *stqe_next; /* next element */ \
202 #define LDAP_STAILQ_ENTRY_INITIALIZER(entry) \
206 * Singly-linked Tail queue functions.
208 #define LDAP_STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
210 #define LDAP_STAILQ_INIT(head) do { \
211 (head)->stqh_first = NULL; \
212 (head)->stqh_last = &(head)->stqh_first; \
215 #define LDAP_STAILQ_FIRST(head) ((head)->stqh_first)
217 #define LDAP_STAILQ_LAST(head, type, field) \
218 (LDAP_STAILQ_EMPTY(head) ? \
221 ((char *)((head)->stqh_last) - offsetof(struct type, field))))
223 #define LDAP_STAILQ_FOREACH(var, head, field) \
224 for((var) = (head)->stqh_first; (var); (var) = (var)->field.stqe_next)
226 #define LDAP_STAILQ_INSERT_HEAD(head, elm, field) do { \
227 if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \
228 (head)->stqh_last = &(elm)->field.stqe_next; \
229 (head)->stqh_first = (elm); \
232 #define LDAP_STAILQ_INSERT_TAIL(head, elm, field) do { \
233 (elm)->field.stqe_next = NULL; \
234 *(head)->stqh_last = (elm); \
235 (head)->stqh_last = &(elm)->field.stqe_next; \
238 #define LDAP_STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
239 if (((elm)->field.stqe_next = (tqelm)->field.stqe_next) == NULL)\
240 (head)->stqh_last = &(elm)->field.stqe_next; \
241 (tqelm)->field.stqe_next = (elm); \
244 #define LDAP_STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
246 #define LDAP_STAILQ_REMOVE_HEAD(head, field) do { \
247 if (((head)->stqh_first = \
248 (head)->stqh_first->field.stqe_next) == NULL) \
249 (head)->stqh_last = &(head)->stqh_first; \
252 #define LDAP_STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \
253 if (((head)->stqh_first = (elm)->field.stqe_next) == NULL) \
254 (head)->stqh_last = &(head)->stqh_first; \
257 #define LDAP_STAILQ_REMOVE(head, elm, type, field) do { \
258 if ((head)->stqh_first == (elm)) { \
259 LDAP_STAILQ_REMOVE_HEAD(head, field); \
262 struct type *curelm = (head)->stqh_first; \
263 while( curelm->field.stqe_next != (elm) ) \
264 curelm = curelm->field.stqe_next; \
265 if((curelm->field.stqe_next = \
266 curelm->field.stqe_next->field.stqe_next) == NULL) \
267 (head)->stqh_last = &(curelm)->field.stqe_next; \
274 #define LDAP_LIST_HEAD(name, type) \
276 struct type *lh_first; /* first element */ \
279 #define LDAP_LIST_HEAD_INITIALIZER(head) \
282 #define LDAP_LIST_ENTRY(type) \
284 struct type *le_next; /* next element */ \
285 struct type **le_prev; /* address of previous next element */ \
288 #define LDAP_LIST_ENTRY_INITIALIZER(entry) \
295 #define LDAP_LIST_EMPTY(head) ((head)->lh_first == NULL)
297 #define LDAP_LIST_FIRST(head) ((head)->lh_first)
299 #define LDAP_LIST_FOREACH(var, head, field) \
300 for((var) = (head)->lh_first; (var); (var) = (var)->field.le_next)
302 #define LDAP_LIST_INIT(head) do { \
303 (head)->lh_first = NULL; \
306 #define LDAP_LIST_INSERT_AFTER(listelm, elm, field) do { \
307 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
308 (listelm)->field.le_next->field.le_prev = \
309 &(elm)->field.le_next; \
310 (listelm)->field.le_next = (elm); \
311 (elm)->field.le_prev = &(listelm)->field.le_next; \
314 #define LDAP_LIST_INSERT_BEFORE(listelm, elm, field) do { \
315 (elm)->field.le_prev = (listelm)->field.le_prev; \
316 (elm)->field.le_next = (listelm); \
317 *(listelm)->field.le_prev = (elm); \
318 (listelm)->field.le_prev = &(elm)->field.le_next; \
321 #define LDAP_LIST_INSERT_HEAD(head, elm, field) do { \
322 if (((elm)->field.le_next = (head)->lh_first) != NULL) \
323 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
324 (head)->lh_first = (elm); \
325 (elm)->field.le_prev = &(head)->lh_first; \
328 #define LDAP_LIST_NEXT(elm, field) ((elm)->field.le_next)
330 #define LDAP_LIST_REMOVE(elm, field) do { \
331 if ((elm)->field.le_next != NULL) \
332 (elm)->field.le_next->field.le_prev = \
333 (elm)->field.le_prev; \
334 *(elm)->field.le_prev = (elm)->field.le_next; \
338 * Tail queue definitions.
340 #define LDAP_TAILQ_HEAD(name, type) \
342 struct type *tqh_first; /* first element */ \
343 struct type **tqh_last; /* addr of last next element */ \
346 #define LDAP_TAILQ_HEAD_INITIALIZER(head) \
347 { NULL, &(head).tqh_first }
349 #define LDAP_TAILQ_ENTRY(type) \
351 struct type *tqe_next; /* next element */ \
352 struct type **tqe_prev; /* address of previous next element */ \
355 #define LDAP_TAILQ_ENTRY_INITIALIZER(entry) \
359 * Tail queue functions.
361 #define LDAP_TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
363 #define LDAP_TAILQ_FOREACH(var, head, field) \
364 for (var = LDAP_TAILQ_FIRST(head); var; var = TAILQ_NEXT(var, field))
366 #define LDAP_TAILQ_FOREACH_REVERSE(var, head, type, field) \
367 for ((var) = LDAP_TAILQ_LAST((head), type, field); \
369 (var) = LDAP_TAILQ_PREV((var), head, type, field))
371 #define LDAP_TAILQ_FIRST(head) ((head)->tqh_first)
373 #define LDAP_TAILQ_LAST(head, type, field) \
374 (LDAP_TAILQ_EMPTY(head) ? \
377 ((char *)((head)->tqh_last) - offsetof(struct type, field))))
379 #define LDAP_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
381 #define LDAP_TAILQ_PREV(elm, head, type, field) \
382 ((struct type *)((elm)->field.tqe_prev) == LDAP_TAILQ_FIRST(head) ? \
385 ((char *)((elm)->field.tqe_prev) - offsetof(struct type, field))))
387 #define LDAP_TAILQ_INIT(head) do { \
388 (head)->tqh_first = NULL; \
389 (head)->tqh_last = &(head)->tqh_first; \
392 #define LDAP_TAILQ_INSERT_HEAD(head, elm, field) do { \
393 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
394 (head)->tqh_first->field.tqe_prev = \
395 &(elm)->field.tqe_next; \
397 (head)->tqh_last = &(elm)->field.tqe_next; \
398 (head)->tqh_first = (elm); \
399 (elm)->field.tqe_prev = &(head)->tqh_first; \
402 #define LDAP_TAILQ_INSERT_TAIL(head, elm, field) do { \
403 (elm)->field.tqe_next = NULL; \
404 (elm)->field.tqe_prev = (head)->tqh_last; \
405 *(head)->tqh_last = (elm); \
406 (head)->tqh_last = &(elm)->field.tqe_next; \
409 #define LDAP_TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
410 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
411 (elm)->field.tqe_next->field.tqe_prev = \
412 &(elm)->field.tqe_next; \
414 (head)->tqh_last = &(elm)->field.tqe_next; \
415 (listelm)->field.tqe_next = (elm); \
416 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \
419 #define LDAP_TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
420 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
421 (elm)->field.tqe_next = (listelm); \
422 *(listelm)->field.tqe_prev = (elm); \
423 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
426 #define LDAP_TAILQ_REMOVE(head, elm, field) do { \
427 if (((elm)->field.tqe_next) != NULL) \
428 (elm)->field.tqe_next->field.tqe_prev = \
429 (elm)->field.tqe_prev; \
431 (head)->tqh_last = (elm)->field.tqe_prev; \
432 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \
436 * Circular queue definitions.
438 #define LDAP_CIRCLEQ_HEAD(name, type) \
440 struct type *cqh_first; /* first element */ \
441 struct type *cqh_last; /* last element */ \
444 #define LDAP_CIRCLEQ_ENTRY(type) \
446 struct type *cqe_next; /* next element */ \
447 struct type *cqe_prev; /* previous element */ \
451 * Circular queue functions.
453 #define LDAP_CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head))
455 #define LDAP_CIRCLEQ_FIRST(head) ((head)->cqh_first)
457 #define LDAP_CIRCLEQ_FOREACH(var, head, field) \
458 for((var) = (head)->cqh_first; \
459 (var) != (void *)(head); \
460 (var) = (var)->field.cqe_next)
462 #define LDAP_CIRCLEQ_FOREACH_REVERSE(var, head, field) \
463 for((var) = (head)->cqh_last; \
464 (var) != (void *)(head); \
465 (var) = (var)->field.cqe_prev)
467 #define LDAP_CIRCLEQ_INIT(head) do { \
468 (head)->cqh_first = (void *)(head); \
469 (head)->cqh_last = (void *)(head); \
472 #define LDAP_CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
473 (elm)->field.cqe_next = (listelm)->field.cqe_next; \
474 (elm)->field.cqe_prev = (listelm); \
475 if ((listelm)->field.cqe_next == (void *)(head)) \
476 (head)->cqh_last = (elm); \
478 (listelm)->field.cqe_next->field.cqe_prev = (elm); \
479 (listelm)->field.cqe_next = (elm); \
482 #define LDAP_CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \
483 (elm)->field.cqe_next = (listelm); \
484 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \
485 if ((listelm)->field.cqe_prev == (void *)(head)) \
486 (head)->cqh_first = (elm); \
488 (listelm)->field.cqe_prev->field.cqe_next = (elm); \
489 (listelm)->field.cqe_prev = (elm); \
492 #define LDAP_CIRCLEQ_INSERT_HEAD(head, elm, field) do { \
493 (elm)->field.cqe_next = (head)->cqh_first; \
494 (elm)->field.cqe_prev = (void *)(head); \
495 if ((head)->cqh_last == (void *)(head)) \
496 (head)->cqh_last = (elm); \
498 (head)->cqh_first->field.cqe_prev = (elm); \
499 (head)->cqh_first = (elm); \
502 #define LDAP_CIRCLEQ_INSERT_TAIL(head, elm, field) do { \
503 (elm)->field.cqe_next = (void *)(head); \
504 (elm)->field.cqe_prev = (head)->cqh_last; \
505 if ((head)->cqh_first == (void *)(head)) \
506 (head)->cqh_first = (elm); \
508 (head)->cqh_last->field.cqe_next = (elm); \
509 (head)->cqh_last = (elm); \
512 #define LDAP_CIRCLEQ_LAST(head) ((head)->cqh_last)
514 #define LDAP_CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next)
516 #define LDAP_CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev)
518 #define LDAP_CIRCLEQ_REMOVE(head, elm, field) do { \
519 if ((elm)->field.cqe_next == (void *)(head)) \
520 (head)->cqh_last = (elm)->field.cqe_prev; \
522 (elm)->field.cqe_next->field.cqe_prev = \
523 (elm)->field.cqe_prev; \
524 if ((elm)->field.cqe_prev == (void *)(head)) \
525 (head)->cqh_first = (elm)->field.cqe_next; \
527 (elm)->field.cqe_prev->field.cqe_next = \
528 (elm)->field.cqe_next; \
531 #endif /* !_LDAP_QUEUE_H_ */