d712253aed9456eac67099e7ce7477b326900569
[sip-router] / list.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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
30  * $FreeBSD: /repoman/r/ncvs/src/sys/sys/queue.h,v 1.68 2006/10/24 11:20:29 ru Exp $
31  */
32
33 #ifndef _SER_LIST_H
34 #define _SER_LIST_H
35
36 /* #include <sys/cdefs.h> - not needed and not present on all the systems */
37
38 /*
39  * This file defines four types of data structures: singly-linked lists,
40  * singly-linked tail queues, lists and tail queues.
41  *
42  * A singly-linked list is headed by a single forward pointer. The elements
43  * are singly linked for minimum space and pointer manipulation overhead at
44  * the expense of O(n) removal for arbitrary elements. New elements can be
45  * added to the list after an existing element or at the head of the list.
46  * Elements being removed from the head of the list should use the explicit
47  * macro for this purpose for optimum efficiency. A singly-linked list may
48  * only be traversed in the forward direction.  Singly-linked lists are ideal
49  * for applications with large datasets and few or no removals or for
50  * implementing a LIFO queue.
51  *
52  * A singly-linked tail queue is headed by a pair of pointers, one to the
53  * head of the list and the other to the tail of the list. The elements are
54  * singly linked for minimum space and pointer manipulation overhead at the
55  * expense of O(n) removal for arbitrary elements. New elements can be added
56  * to the list after an existing element, at the head of the list, or at the
57  * end of the list. Elements being removed from the head of the tail queue
58  * should use the explicit macro for this purpose for optimum efficiency.
59  * A singly-linked tail queue may only be traversed in the forward direction.
60  * Singly-linked tail queues are ideal for applications with large datasets
61  * and few or no removals or for implementing a FIFO queue.
62  *
63  * A list is headed by a single forward pointer (or an array of forward
64  * pointers for a hash table header). The elements are doubly linked
65  * so that an arbitrary element can be removed without a need to
66  * traverse the list. New elements can be added to the list before
67  * or after an existing element or at the head of the list. A list
68  * may only be traversed in the forward direction.
69  *
70  * A tail queue is headed by a pair of pointers, one to the head of the
71  * list and the other to the tail of the list. The elements are doubly
72  * linked so that an arbitrary element can be removed without a need to
73  * traverse the list. New elements can be added to the list before or
74  * after an existing element, at the head of the list, or at the end of
75  * the list. A tail queue may be traversed in either direction.
76  *
77  * For details on the use of these macros, see the queue(3) manual page.
78  *
79  *
80  *                              SLIST   LIST    STAILQ  TAILQ
81  * _HEAD                        +       +       +       +
82  * _HEAD_INITIALIZER            +       +       +       +
83  * _ENTRY                       +       +       +       +
84  * _INIT                        +       +       +       +
85  * _EMPTY                       +       +       +       +
86  * _FIRST                       +       +       +       +
87  * _NEXT                        +       +       +       +
88  * _PREV                        -       -       -       +
89  * _LAST                        -       -       +       +
90  * _FOREACH                     +       +       +       +
91  * _FOREACH_SAFE                +       +       +       +
92  * _FOREACH_REVERSE             -       -       -       +
93  * _FOREACH_REVERSE_SAFE        -       -       -       +
94  * _INSERT_HEAD                 +       +       +       +
95  * _INSERT_BEFORE               -       +       -       +
96  * _INSERT_AFTER                +       +       +       +
97  * _INSERT_TAIL                 -       -       +       +
98  * _CONCAT                      -       -       +       +
99  * _REMOVE_HEAD                 +       -       +       -
100  * _REMOVE                      +       +       +       +
101  *
102  */
103 #ifdef QUEUE_MACRO_DEBUG
104 /* Store the last 2 places the queue element or head was altered */
105 struct qm_trace {
106         char * lastfile;
107         int lastline;
108         char * prevfile;
109         int prevline;
110 };
111
112 #define TRACEBUF        struct qm_trace trace;
113 #define TRASHIT(x)      do {(x) = (void *)-1;} while (0)
114
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__;                              \
120 } while (0)
121
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__;                              \
127 } while (0)
128
129 #else
130 #define QMD_TRACE_ELEM(elem)
131 #define QMD_TRACE_HEAD(head)
132 #define TRACEBUF
133 #define TRASHIT(x)
134 #endif  /* QUEUE_MACRO_DEBUG */
135
136 /*
137  * Singly-linked List declarations.
138  */
139 #define SLIST_HEAD(name, type)                                          \
140 struct name {                                                           \
141         struct type *slh_first; /* first element */                     \
142 }
143
144 #define SLIST_HEAD_INITIALIZER(head)                                    \
145         { NULL }
146
147 #define SLIST_ENTRY(type)                                               \
148 struct {                                                                \
149         struct type *sle_next;  /* next element */                      \
150 }
151
152 /*
153  * Singly-linked List functions.
154  */
155 #define SLIST_EMPTY(head)       ((head)->slh_first == NULL)
156
157 #define SLIST_FIRST(head)       ((head)->slh_first)
158
159 #define SLIST_FOREACH(var, head, field)                                 \
160         for ((var) = SLIST_FIRST((head));                               \
161             (var);                                                      \
162             (var) = SLIST_NEXT((var), field))
163
164 #define SLIST_FOREACH_SAFE(var, head, field, tvar)                      \
165         for ((var) = SLIST_FIRST((head));                               \
166             (var) && ((tvar) = SLIST_NEXT((var), field), 1);            \
167             (var) = (tvar))
168
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))
173
174 #define SLIST_INIT(head) do {                                           \
175         SLIST_FIRST((head)) = NULL;                                     \
176 } while (0)
177
178 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
179         SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);       \
180         SLIST_NEXT((slistelm), field) = (elm);                          \
181 } while (0)
182
183 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
184         SLIST_NEXT((elm), field) = SLIST_FIRST((head));                 \
185         SLIST_FIRST((head)) = (elm);                                    \
186 } while (0)
187
188 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
189
190 #define SLIST_REMOVE(head, elm, type, field) do {                       \
191         if (SLIST_FIRST((head)) == (elm)) {                             \
192                 SLIST_REMOVE_HEAD((head), field);                       \
193         }                                                               \
194         else {                                                          \
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);       \
200         }                                                               \
201         TRASHIT((elm)->field.sle_next);                                 \
202 } while (0)
203
204 #define SLIST_REMOVE_HEAD(head, field) do {                             \
205         SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);   \
206 } while (0)
207
208 /*
209  * Singly-linked Tail queue declarations.
210  */
211 #define STAILQ_HEAD(name, type)                                         \
212 struct name {                                                           \
213         struct type *stqh_first;/* first element */                     \
214         struct type **stqh_last;/* addr of last next element */         \
215 }
216
217 #define STAILQ_HEAD_INITIALIZER(head)                                   \
218         { NULL, &(head).stqh_first }
219
220 #define STAILQ_ENTRY(type)                                              \
221 struct {                                                                \
222         struct type *stqe_next; /* next element */                      \
223 }
224
225 /*
226  * Singly-linked Tail queue functions.
227  */
228 #define STAILQ_CONCAT(head1, head2) do {                                \
229         if (!STAILQ_EMPTY((head2))) {                                   \
230                 *(head1)->stqh_last = (head2)->stqh_first;              \
231                 (head1)->stqh_last = (head2)->stqh_last;                \
232                 STAILQ_INIT((head2));                                   \
233         }                                                               \
234 } while (0)
235
236 #define STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
237
238 #define STAILQ_FIRST(head)      ((head)->stqh_first)
239
240 #define STAILQ_FOREACH(var, head, field)                                \
241         for((var) = STAILQ_FIRST((head));                               \
242            (var);                                                       \
243            (var) = STAILQ_NEXT((var), field))
244
245
246 #define STAILQ_FOREACH_SAFE(var, head, field, tvar)                     \
247         for ((var) = STAILQ_FIRST((head));                              \
248             (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
249             (var) = (tvar))
250
251 #define STAILQ_INIT(head) do {                                          \
252         STAILQ_FIRST((head)) = NULL;                                    \
253         (head)->stqh_last = &STAILQ_FIRST((head));                      \
254 } while (0)
255
256 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
257         if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
258                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
259         STAILQ_NEXT((tqelm), field) = (elm);                            \
260 } while (0)
261
262 #define STAILQ_INSERT_HEAD(head, elm, field) do {                       \
263         if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
264                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
265         STAILQ_FIRST((head)) = (elm);                                   \
266 } while (0)
267
268 #define STAILQ_INSERT_TAIL(head, elm, field) do {                       \
269         STAILQ_NEXT((elm), field) = NULL;                               \
270         *(head)->stqh_last = (elm);                                     \
271         (head)->stqh_last = &STAILQ_NEXT((elm), field);                 \
272 } while (0)
273
274 #define STAILQ_LAST(head, type, field)                                  \
275         (STAILQ_EMPTY((head)) ?                                         \
276                 NULL :                                                  \
277                 ((struct type *)(void *)                                \
278                 ((char *)((head)->stqh_last) - __offsetof(struct type, field))))
279
280 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
281
282 #define STAILQ_REMOVE(head, elm, type, field) do {                      \
283         if (STAILQ_FIRST((head)) == (elm)) {                            \
284                 STAILQ_REMOVE_HEAD((head), field);                      \
285         }                                                               \
286         else {                                                          \
287                 struct type *curelm = STAILQ_FIRST((head));             \
288                 while (STAILQ_NEXT(curelm, field) != (elm))             \
289                         curelm = STAILQ_NEXT(curelm, field);            \
290                 if ((STAILQ_NEXT(curelm, field) =                       \
291                      STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\
292                         (head)->stqh_last = &STAILQ_NEXT((curelm), field);\
293         }                                                               \
294         TRASHIT((elm)->field.stqe_next);                                \
295 } while (0)
296
297 #define STAILQ_REMOVE_HEAD(head, field) do {                            \
298         if ((STAILQ_FIRST((head)) =                                     \
299              STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)         \
300                 (head)->stqh_last = &STAILQ_FIRST((head));              \
301 } while (0)
302
303 /*
304  * List declarations.
305  */
306 #define LIST_HEAD(name, type)                                           \
307 struct name {                                                           \
308         struct type *lh_first;  /* first element */                     \
309 }
310
311 #define LIST_HEAD_INITIALIZER(head)                                     \
312         { NULL }
313
314 #define LIST_ENTRY(type)                                                \
315 struct {                                                                \
316         struct type *le_next;   /* next element */                      \
317         struct type **le_prev;  /* address of previous next element */  \
318 }
319
320 /*
321  * List functions.
322  */
323
324 #define LIST_EMPTY(head)        ((head)->lh_first == NULL)
325
326 #define LIST_FIRST(head)        ((head)->lh_first)
327
328 #define LIST_FOREACH(var, head, field)                                  \
329         for ((var) = LIST_FIRST((head));                                \
330             (var);                                                      \
331             (var) = LIST_NEXT((var), field))
332
333 #define LIST_FOREACH_SAFE(var, head, field, tvar)                       \
334         for ((var) = LIST_FIRST((head));                                \
335             (var) && ((tvar) = LIST_NEXT((var), field), 1);             \
336             (var) = (tvar))
337
338 #define LIST_INIT(head) do {                                            \
339         LIST_FIRST((head)) = NULL;                                      \
340 } while (0)
341
342 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
343         QMD_LIST_CHECK_NEXT(listelm, field);                            \
344         if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
345                 LIST_NEXT((listelm), field)->field.le_prev =            \
346                     &LIST_NEXT((elm), field);                           \
347         LIST_NEXT((listelm), field) = (elm);                            \
348         (elm)->field.le_prev = &LIST_NEXT((listelm), field);            \
349 } while (0)
350
351 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
352         QMD_LIST_CHECK_PREV(listelm, field);                            \
353         (elm)->field.le_prev = (listelm)->field.le_prev;                \
354         LIST_NEXT((elm), field) = (listelm);                            \
355         *(listelm)->field.le_prev = (elm);                              \
356         (listelm)->field.le_prev = &LIST_NEXT((elm), field);            \
357 } while (0)
358
359 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
360         QMD_LIST_CHECK_HEAD((head), field);                             \
361         if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)     \
362                 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
363         LIST_FIRST((head)) = (elm);                                     \
364         (elm)->field.le_prev = &LIST_FIRST((head));                     \
365 } while (0)
366
367 #define LIST_NEXT(elm, field)   ((elm)->field.le_next)
368
369 #define LIST_REMOVE(elm, field) do {                                    \
370         QMD_LIST_CHECK_NEXT(elm, field);                                \
371         QMD_LIST_CHECK_PREV(elm, field);                                \
372         if (LIST_NEXT((elm), field) != NULL)                            \
373                 LIST_NEXT((elm), field)->field.le_prev =                \
374                     (elm)->field.le_prev;                               \
375         *(elm)->field.le_prev = LIST_NEXT((elm), field);                \
376         TRASHIT((elm)->field.le_next);                                  \
377         TRASHIT((elm)->field.le_prev);                                  \
378 } while (0)
379
380 /*
381  * Tail queue declarations.
382  */
383 #define TAILQ_HEAD(name, type)                                          \
384 struct name {                                                           \
385         struct type *tqh_first; /* first element */                     \
386         struct type **tqh_last; /* addr of last next element */         \
387         TRACEBUF                                                        \
388 }
389
390 #define TAILQ_HEAD_INITIALIZER(head)                                    \
391         { NULL, &(head).tqh_first }
392
393 #define TAILQ_ENTRY(type)                                               \
394 struct {                                                                \
395         struct type *tqe_next;  /* next element */                      \
396         struct type **tqe_prev; /* address of previous next element */  \
397         TRACEBUF                                                        \
398 }
399
400 /*
401  * Tail queue functions.
402  */
403
404 #define TAILQ_CONCAT(head1, head2, field) do {                          \
405         if (!TAILQ_EMPTY(head2)) {                                      \
406                 *(head1)->tqh_last = (head2)->tqh_first;                \
407                 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
408                 (head1)->tqh_last = (head2)->tqh_last;                  \
409                 TAILQ_INIT((head2));                                    \
410                 QMD_TRACE_HEAD(head1);                                  \
411                 QMD_TRACE_HEAD(head2);                                  \
412         }                                                               \
413 } while (0)
414
415 #define TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
416
417 #define TAILQ_FIRST(head)       ((head)->tqh_first)
418
419 #define TAILQ_FOREACH(var, head, field)                                 \
420         for ((var) = TAILQ_FIRST((head));                               \
421             (var);                                                      \
422             (var) = TAILQ_NEXT((var), field))
423
424 #define TAILQ_FOREACH_SAFE(var, head, field, tvar)                      \
425         for ((var) = TAILQ_FIRST((head));                               \
426             (var) && ((tvar) = TAILQ_NEXT((var), field), 1);            \
427             (var) = (tvar))
428
429 #define TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
430         for ((var) = TAILQ_LAST((head), headname);                      \
431             (var);                                                      \
432             (var) = TAILQ_PREV((var), headname, field))
433
434 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)    \
435         for ((var) = TAILQ_LAST((head), headname);                      \
436             (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
437             (var) = (tvar))
438
439 #define TAILQ_INIT(head) do {                                           \
440         TAILQ_FIRST((head)) = NULL;                                     \
441         (head)->tqh_last = &TAILQ_FIRST((head));                        \
442         QMD_TRACE_HEAD(head);                                           \
443 } while (0)
444
445 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
446         QMD_TAILQ_CHECK_NEXT(listelm, field);                           \
447         if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
448                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
449                     &TAILQ_NEXT((elm), field);                          \
450         else {                                                          \
451                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
452                 QMD_TRACE_HEAD(head);                                   \
453         }                                                               \
454         TAILQ_NEXT((listelm), field) = (elm);                           \
455         (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);          \
456         QMD_TRACE_ELEM(&(elm)->field);                                  \
457         QMD_TRACE_ELEM(&listelm->field);                                \
458 } while (0)
459
460 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
461         QMD_TAILQ_CHECK_PREV(listelm, field);                           \
462         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
463         TAILQ_NEXT((elm), field) = (listelm);                           \
464         *(listelm)->field.tqe_prev = (elm);                             \
465         (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);          \
466         QMD_TRACE_ELEM(&(elm)->field);                                  \
467         QMD_TRACE_ELEM(&listelm->field);                                \
468 } while (0)
469
470 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
471         QMD_TAILQ_CHECK_HEAD(head, field);                              \
472         if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)   \
473                 TAILQ_FIRST((head))->field.tqe_prev =                   \
474                     &TAILQ_NEXT((elm), field);                          \
475         else                                                            \
476                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
477         TAILQ_FIRST((head)) = (elm);                                    \
478         (elm)->field.tqe_prev = &TAILQ_FIRST((head));                   \
479         QMD_TRACE_HEAD(head);                                           \
480         QMD_TRACE_ELEM(&(elm)->field);                                  \
481 } while (0)
482
483 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
484         QMD_TAILQ_CHECK_TAIL(head, field);                              \
485         TAILQ_NEXT((elm), field) = NULL;                                \
486         (elm)->field.tqe_prev = (head)->tqh_last;                       \
487         *(head)->tqh_last = (elm);                                      \
488         (head)->tqh_last = &TAILQ_NEXT((elm), field);                   \
489         QMD_TRACE_HEAD(head);                                           \
490         QMD_TRACE_ELEM(&(elm)->field);                                  \
491 } while (0)
492
493 #define TAILQ_LAST(head, headname)                                      \
494         (*(((struct headname *)((head)->tqh_last))->tqh_last))
495
496 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
497
498 #define TAILQ_PREV(elm, headname, field)                                \
499         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
500
501 #define TAILQ_REMOVE(head, elm, field) do {                             \
502         QMD_TAILQ_CHECK_NEXT(elm, field);                               \
503         QMD_TAILQ_CHECK_PREV(elm, field);                               \
504         if ((TAILQ_NEXT((elm), field)) != NULL)                         \
505                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
506                     (elm)->field.tqe_prev;                              \
507         else {                                                          \
508                 (head)->tqh_last = (elm)->field.tqe_prev;               \
509                 QMD_TRACE_HEAD(head);                                   \
510         }                                                               \
511         *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);              \
512         TRASHIT((elm)->field.tqe_next);                                 \
513         TRASHIT((elm)->field.tqe_prev);                                 \
514         QMD_TRACE_ELEM(&(elm)->field);                                  \
515 } while (0)
516
517 #endif /* !_LIST_H */