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[asterisk/asterisk.git] / include / solaris-compat / sys / queue.h
1 /*
2  * Copyright (c) 1991, 1993
3  *      The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *      This product includes software developed by the University of
16  *      California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
34  * $FreeBSD: src/sys/sys/queue.h,v 1.24.2.4 2000/05/05 01:41:41 archie Exp $
35  */
36
37 #ifndef _SYS_QUEUE_H_
38 #define _SYS_QUEUE_H_
39
40 /*
41  * This file defines five types of data structures: singly-linked lists,
42  * singly-linked tail queues, lists, tail queues, and circular queues.
43  *
44  * A singly-linked list is headed by a single forward pointer. The elements
45  * are singly linked for minimum space and pointer manipulation overhead at
46  * the expense of O(n) removal for arbitrary elements. New elements can be
47  * added to the list after an existing element or at the head of the list.
48  * Elements being removed from the head of the list should use the explicit
49  * macro for this purpose for optimum efficiency. A singly-linked list may
50  * only be traversed in the forward direction.  Singly-linked lists are ideal
51  * for applications with large datasets and few or no removals or for
52  * implementing a LIFO queue.
53  *
54  * A singly-linked tail queue is headed by a pair of pointers, one to the
55  * head of the list and the other to the tail of the list. The elements are
56  * singly linked for minimum space and pointer manipulation overhead at the
57  * expense of O(n) removal for arbitrary elements. New elements can be added
58  * to the list after an existing element, at the head of the list, or at the
59  * end of the list. Elements being removed from the head of the tail queue
60  * should use the explicit macro for this purpose for optimum efficiency.
61  * A singly-linked tail queue may only be traversed in the forward direction.
62  * Singly-linked tail queues are ideal for applications with large datasets
63  * and few or no removals or for implementing a FIFO queue.
64  *
65  * A list is headed by a single forward pointer (or an array of forward
66  * pointers for a hash table header). The elements are doubly linked
67  * so that an arbitrary element can be removed without a need to
68  * traverse the list. New elements can be added to the list before
69  * or after an existing element or at the head of the list. A list
70  * may only be traversed in the forward direction.
71  *
72  * A tail queue is headed by a pair of pointers, one to the head of the
73  * list and the other to the tail of the list. The elements are doubly
74  * linked so that an arbitrary element can be removed without a need to
75  * traverse the list. New elements can be added to the list before or
76  * after an existing element, at the head of the list, or at the end of
77  * the list. A tail queue may be traversed in either direction.
78  *
79  * A circle queue is headed by a pair of pointers, one to the head of the
80  * list and the other to the tail of the list. The elements are doubly
81  * linked so that an arbitrary element can be removed without a need to
82  * traverse the list. New elements can be added to the list before or after
83  * an existing element, at the head of the list, or at the end of the list.
84  * A circle queue may be traversed in either direction, but has a more
85  * complex end of list detection.
86  *
87  * For details on the use of these macros, see the queue(3) manual page.
88  *
89  *
90  *                      SLIST   LIST    STAILQ  TAILQ   CIRCLEQ
91  * _HEAD                +       +       +       +       +
92  * _ENTRY               +       +       +       +       +
93  * _INIT                +       +       +       +       +
94  * _EMPTY               +       +       +       +       +
95  * _FIRST               +       +       +       +       +
96  * _NEXT                +       +       +       +       +
97  * _PREV                -       -       -       +       +
98  * _LAST                -       -       +       +       +
99  * _FOREACH             +       +       +       +       +
100  * _FOREACH_REVERSE     -       -       -       +       +
101  * _INSERT_HEAD         +       +       +       +       +
102  * _INSERT_BEFORE       -       +       -       +       +
103  * _INSERT_AFTER        +       +       +       +       +
104  * _INSERT_TAIL         -       -       +       +       +
105  * _REMOVE_HEAD         +       -       +       -       -
106  * _REMOVE              +       +       +       +       +
107  *
108  */
109
110 /*
111  * Singly-linked List definitions.
112  */
113 #define SLIST_HEAD(name, type)                                          \
114 struct name {                                                           \
115         struct type *slh_first; /* first element */                     \
116 }
117
118 #define SLIST_HEAD_INITIALIZER(head)                                    \
119         { NULL }
120  
121 #define SLIST_ENTRY(type)                                               \
122 struct {                                                                \
123         struct type *sle_next;  /* next element */                      \
124 }
125  
126 /*
127  * Singly-linked List functions.
128  */
129 #define SLIST_EMPTY(head)       ((head)->slh_first == NULL)
130
131 #define SLIST_FIRST(head)       ((head)->slh_first)
132
133 #define SLIST_FOREACH(var, head, field)                                 \
134         for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)
135
136 #define SLIST_INIT(head) {                                              \
137         (head)->slh_first = NULL;                                       \
138 }
139
140 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
141         (elm)->field.sle_next = (slistelm)->field.sle_next;             \
142         (slistelm)->field.sle_next = (elm);                             \
143 } while (0)
144
145 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
146         (elm)->field.sle_next = (head)->slh_first;                      \
147         (head)->slh_first = (elm);                                      \
148 } while (0)
149
150 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
151
152 #define SLIST_REMOVE_HEAD(head, field) do {                             \
153         (head)->slh_first = (head)->slh_first->field.sle_next;          \
154 } while (0)
155
156 #define SLIST_REMOVE(head, elm, type, field) do {                       \
157         if ((head)->slh_first == (elm)) {                               \
158                 SLIST_REMOVE_HEAD((head), field);                       \
159         }                                                               \
160         else {                                                          \
161                 struct type *curelm = (head)->slh_first;                \
162                 while( curelm->field.sle_next != (elm) )                \
163                         curelm = curelm->field.sle_next;                \
164                 curelm->field.sle_next =                                \
165                     curelm->field.sle_next->field.sle_next;             \
166         }                                                               \
167 } while (0)
168
169 /*
170  * Singly-linked Tail queue definitions.
171  */
172 #define STAILQ_HEAD(name, type)                                         \
173 struct name {                                                           \
174         struct type *stqh_first;/* first element */                     \
175         struct type **stqh_last;/* addr of last next element */         \
176 }
177
178 #define STAILQ_HEAD_INITIALIZER(head)                                   \
179         { NULL, &(head).stqh_first }
180
181 #define STAILQ_ENTRY(type)                                              \
182 struct {                                                                \
183         struct type *stqe_next; /* next element */                      \
184 }
185
186 /*
187  * Singly-linked Tail queue functions.
188  */
189 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
190
191 #define STAILQ_INIT(head) do {                                          \
192         (head)->stqh_first = NULL;                                      \
193         (head)->stqh_last = &(head)->stqh_first;                        \
194 } while (0)
195
196 #define STAILQ_FIRST(head)      ((head)->stqh_first)
197 #define STAILQ_LAST(head)       (*(head)->stqh_last)
198
199 #define STAILQ_FOREACH(var, head, field)                                \
200         for((var) = (head)->stqh_first; (var); (var) = (var)->field.stqe_next)
201
202 #define STAILQ_INSERT_HEAD(head, elm, field) do {                       \
203         if (((elm)->field.stqe_next = (head)->stqh_first) == NULL)      \
204                 (head)->stqh_last = &(elm)->field.stqe_next;            \
205         (head)->stqh_first = (elm);                                     \
206 } while (0)
207
208 #define STAILQ_INSERT_TAIL(head, elm, field) do {                       \
209         (elm)->field.stqe_next = NULL;                                  \
210         *(head)->stqh_last = (elm);                                     \
211         (head)->stqh_last = &(elm)->field.stqe_next;                    \
212 } while (0)
213
214 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
215         if (((elm)->field.stqe_next = (tqelm)->field.stqe_next) == NULL)\
216                 (head)->stqh_last = &(elm)->field.stqe_next;            \
217         (tqelm)->field.stqe_next = (elm);                               \
218 } while (0)
219
220 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
221
222 #define STAILQ_REMOVE_HEAD(head, field) do {                            \
223         if (((head)->stqh_first =                                       \
224              (head)->stqh_first->field.stqe_next) == NULL)              \
225                 (head)->stqh_last = &(head)->stqh_first;                \
226 } while (0)
227
228 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do {                 \
229         if (((head)->stqh_first = (elm)->field.stqe_next) == NULL)      \
230                 (head)->stqh_last = &(head)->stqh_first;                \
231 } while (0)
232
233 #define STAILQ_REMOVE(head, elm, type, field) do {                      \
234         if ((head)->stqh_first == (elm)) {                              \
235                 STAILQ_REMOVE_HEAD(head, field);                        \
236         }                                                               \
237         else {                                                          \
238                 struct type *curelm = (head)->stqh_first;               \
239                 while( curelm->field.stqe_next != (elm) )               \
240                         curelm = curelm->field.stqe_next;               \
241                 if((curelm->field.stqe_next =                           \
242                     curelm->field.stqe_next->field.stqe_next) == NULL)  \
243                         (head)->stqh_last = &(curelm)->field.stqe_next; \
244         }                                                               \
245 } while (0)
246
247 /*
248  * List definitions.
249  */
250 #define LIST_HEAD(name, type)                                           \
251 struct name {                                                           \
252         struct type *lh_first;  /* first element */                     \
253 }
254
255 #define LIST_HEAD_INITIALIZER(head)                                     \
256         { NULL }
257
258 #define LIST_ENTRY(type)                                                \
259 struct {                                                                \
260         struct type *le_next;   /* next element */                      \
261         struct type **le_prev;  /* address of previous next element */  \
262 }
263
264 /*
265  * List functions.
266  */
267
268 #define LIST_EMPTY(head) ((head)->lh_first == NULL)
269
270 #define LIST_FIRST(head)        ((head)->lh_first)
271
272 #define LIST_FOREACH(var, head, field)                                  \
273         for((var) = (head)->lh_first; (var); (var) = (var)->field.le_next)
274
275 #define LIST_INIT(head) do {                                            \
276         (head)->lh_first = NULL;                                        \
277 } while (0)
278
279 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
280         if (((elm)->field.le_next = (listelm)->field.le_next) != NULL)  \
281                 (listelm)->field.le_next->field.le_prev =               \
282                     &(elm)->field.le_next;                              \
283         (listelm)->field.le_next = (elm);                               \
284         (elm)->field.le_prev = &(listelm)->field.le_next;               \
285 } while (0)
286
287 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
288         (elm)->field.le_prev = (listelm)->field.le_prev;                \
289         (elm)->field.le_next = (listelm);                               \
290         *(listelm)->field.le_prev = (elm);                              \
291         (listelm)->field.le_prev = &(elm)->field.le_next;               \
292 } while (0)
293
294 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
295         if (((elm)->field.le_next = (head)->lh_first) != NULL)          \
296                 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
297         (head)->lh_first = (elm);                                       \
298         (elm)->field.le_prev = &(head)->lh_first;                       \
299 } while (0)
300
301 #define LIST_NEXT(elm, field)   ((elm)->field.le_next)
302
303 #define LIST_REMOVE(elm, field) do {                                    \
304         if ((elm)->field.le_next != NULL)                               \
305                 (elm)->field.le_next->field.le_prev =                   \
306                     (elm)->field.le_prev;                               \
307         *(elm)->field.le_prev = (elm)->field.le_next;                   \
308 } while (0)
309
310 /*
311  * Tail queue definitions.
312  */
313 #define TAILQ_HEAD(name, type)                                          \
314 struct name {                                                           \
315         struct type *tqh_first; /* first element */                     \
316         struct type **tqh_last; /* addr of last next element */         \
317 }
318
319 #define TAILQ_HEAD_INITIALIZER(head)                                    \
320         { NULL, &(head).tqh_first }
321
322 #define TAILQ_ENTRY(type)                                               \
323 struct {                                                                \
324         struct type *tqe_next;  /* next element */                      \
325         struct type **tqe_prev; /* address of previous next element */  \
326 }
327
328 /*
329  * Tail queue functions.
330  */
331 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
332
333 #define TAILQ_FOREACH(var, head, field)                                 \
334         for (var = TAILQ_FIRST(head); var; var = TAILQ_NEXT(var, field))
335
336 #define TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
337         for ((var) = TAILQ_LAST((head), headname);                      \
338              (var);                                                     \
339              (var) = TAILQ_PREV((var), headname, field))
340
341 #define TAILQ_FIRST(head) ((head)->tqh_first)
342
343 #define TAILQ_LAST(head, headname) \
344         (*(((struct headname *)((head)->tqh_last))->tqh_last))
345
346 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
347
348 #define TAILQ_PREV(elm, headname, field) \
349         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
350
351 #define TAILQ_INIT(head) do {                                           \
352         (head)->tqh_first = NULL;                                       \
353         (head)->tqh_last = &(head)->tqh_first;                          \
354 } while (0)
355
356 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
357         if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)        \
358                 (head)->tqh_first->field.tqe_prev =                     \
359                     &(elm)->field.tqe_next;                             \
360         else                                                            \
361                 (head)->tqh_last = &(elm)->field.tqe_next;              \
362         (head)->tqh_first = (elm);                                      \
363         (elm)->field.tqe_prev = &(head)->tqh_first;                     \
364 } while (0)
365
366 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
367         (elm)->field.tqe_next = NULL;                                   \
368         (elm)->field.tqe_prev = (head)->tqh_last;                       \
369         *(head)->tqh_last = (elm);                                      \
370         (head)->tqh_last = &(elm)->field.tqe_next;                      \
371 } while (0)
372
373 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
374         if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
375                 (elm)->field.tqe_next->field.tqe_prev =                 \
376                     &(elm)->field.tqe_next;                             \
377         else                                                            \
378                 (head)->tqh_last = &(elm)->field.tqe_next;              \
379         (listelm)->field.tqe_next = (elm);                              \
380         (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
381 } while (0)
382
383 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
384         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
385         (elm)->field.tqe_next = (listelm);                              \
386         *(listelm)->field.tqe_prev = (elm);                             \
387         (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
388 } while (0)
389
390 #define TAILQ_REMOVE(head, elm, field) do {                             \
391         if (((elm)->field.tqe_next) != NULL)                            \
392                 (elm)->field.tqe_next->field.tqe_prev =                 \
393                     (elm)->field.tqe_prev;                              \
394         else                                                            \
395                 (head)->tqh_last = (elm)->field.tqe_prev;               \
396         *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
397 } while (0)
398
399 /*
400  * Circular queue definitions.
401  */
402 #define CIRCLEQ_HEAD(name, type)                                        \
403 struct name {                                                           \
404         struct type *cqh_first;         /* first element */             \
405         struct type *cqh_last;          /* last element */              \
406 }
407
408 #define CIRCLEQ_ENTRY(type)                                             \
409 struct {                                                                \
410         struct type *cqe_next;          /* next element */              \
411         struct type *cqe_prev;          /* previous element */          \
412 }
413
414 /*
415  * Circular queue functions.
416  */
417 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head))
418
419 #define CIRCLEQ_FIRST(head) ((head)->cqh_first)
420
421 #define CIRCLEQ_FOREACH(var, head, field)                               \
422         for((var) = (head)->cqh_first;                                  \
423             (var) != (void *)(head);                                    \
424             (var) = (var)->field.cqe_next)
425
426 #define CIRCLEQ_FOREACH_REVERSE(var, head, field)                       \
427         for((var) = (head)->cqh_last;                                   \
428             (var) != (void *)(head);                                    \
429             (var) = (var)->field.cqe_prev)
430
431 #define CIRCLEQ_INIT(head) do {                                         \
432         (head)->cqh_first = (void *)(head);                             \
433         (head)->cqh_last = (void *)(head);                              \
434 } while (0)
435
436 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
437         (elm)->field.cqe_next = (listelm)->field.cqe_next;              \
438         (elm)->field.cqe_prev = (listelm);                              \
439         if ((listelm)->field.cqe_next == (void *)(head))                \
440                 (head)->cqh_last = (elm);                               \
441         else                                                            \
442                 (listelm)->field.cqe_next->field.cqe_prev = (elm);      \
443         (listelm)->field.cqe_next = (elm);                              \
444 } while (0)
445
446 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do {           \
447         (elm)->field.cqe_next = (listelm);                              \
448         (elm)->field.cqe_prev = (listelm)->field.cqe_prev;              \
449         if ((listelm)->field.cqe_prev == (void *)(head))                \
450                 (head)->cqh_first = (elm);                              \
451         else                                                            \
452                 (listelm)->field.cqe_prev->field.cqe_next = (elm);      \
453         (listelm)->field.cqe_prev = (elm);                              \
454 } while (0)
455
456 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do {                      \
457         (elm)->field.cqe_next = (head)->cqh_first;                      \
458         (elm)->field.cqe_prev = (void *)(head);                         \
459         if ((head)->cqh_last == (void *)(head))                         \
460                 (head)->cqh_last = (elm);                               \
461         else                                                            \
462                 (head)->cqh_first->field.cqe_prev = (elm);              \
463         (head)->cqh_first = (elm);                                      \
464 } while (0)
465
466 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do {                      \
467         (elm)->field.cqe_next = (void *)(head);                         \
468         (elm)->field.cqe_prev = (head)->cqh_last;                       \
469         if ((head)->cqh_first == (void *)(head))                        \
470                 (head)->cqh_first = (elm);                              \
471         else                                                            \
472                 (head)->cqh_last->field.cqe_next = (elm);               \
473         (head)->cqh_last = (elm);                                       \
474 } while (0)
475
476 #define CIRCLEQ_LAST(head) ((head)->cqh_last)
477
478 #define CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next)
479
480 #define CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev)
481
482 #define CIRCLEQ_REMOVE(head, elm, field) do {                           \
483         if ((elm)->field.cqe_next == (void *)(head))                    \
484                 (head)->cqh_last = (elm)->field.cqe_prev;               \
485         else                                                            \
486                 (elm)->field.cqe_next->field.cqe_prev =                 \
487                     (elm)->field.cqe_prev;                              \
488         if ((elm)->field.cqe_prev == (void *)(head))                    \
489                 (head)->cqh_first = (elm)->field.cqe_next;              \
490         else                                                            \
491                 (elm)->field.cqe_prev->field.cqe_next =                 \
492                     (elm)->field.cqe_next;                              \
493 } while (0)
494
495 #ifdef KERNEL
496
497 /*
498  * XXX insque() and remque() are an old way of handling certain queues.
499  * They bogusly assumes that all queue heads look alike.
500  */
501
502 struct quehead {
503         struct quehead *qh_link;
504         struct quehead *qh_rlink;
505 };
506
507 #ifdef  __GNUC__
508
509 static __inline void
510 insque(void *a, void *b)
511 {
512         struct quehead *element = a, *head = b;
513
514         element->qh_link = head->qh_link;
515         element->qh_rlink = head;
516         head->qh_link = element;
517         element->qh_link->qh_rlink = element;
518 }
519
520 static __inline void
521 remque(void *a)
522 {
523         struct quehead *element = a;
524
525         element->qh_link->qh_rlink = element->qh_rlink;
526         element->qh_rlink->qh_link = element->qh_link;
527         element->qh_rlink = 0;
528 }
529
530 #else /* !__GNUC__ */
531
532 void    insque __P((void *a, void *b));
533 void    remque __P((void *a));
534
535 #endif /* __GNUC__ */
536
537 #endif /* KERNEL */
538
539 #endif /* !_SYS_QUEUE_H_ */
540