1 /*
2 * Copyright © 2008, 2010 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24 /**
25 * \file list.h
26 * \brief Doubly-linked list abstract container type.
27 *
28 * Each doubly-linked list has a sentinel head and tail node. These nodes
29 * contain no data. The head sentinel can be identified by its \c prev
30 * pointer being \c NULL. The tail sentinel can be identified by its
31 * \c next pointer being \c NULL.
32 *
33 * A list is empty if either the head sentinel's \c next pointer points to the
34 * tail sentinel or the tail sentinel's \c prev poiner points to the head
35 * sentinel. The head sentinel and tail sentinel nodes are allocated within the
36 * list structure.
37 *
38 * Do note that this means that the list nodes will contain pointers into the
39 * list structure itself and as a result you may not \c realloc() an \c
40 * exec_list or any structure in which an \c exec_list is embedded.
41 */
42
43 #ifndef LIST_CONTAINER_H
44 #define LIST_CONTAINER_H
45
46 #ifndef __cplusplus
47 #include <stddef.h>
48 #endif
49 #include <assert.h>
50
51 #include "util/ralloc.h"
52
53 struct exec_node {
54 struct exec_node *next;
55 struct exec_node *prev;
56
57 #ifdef __cplusplus
58 DECLARE_RZALLOC_CXX_OPERATORS(exec_node)
59
exec_nodeexec_node60 exec_node() : next(NULL), prev(NULL)
61 {
62 /* empty */
63 }
64
65 const exec_node *get_next() const;
66 exec_node *get_next();
67
68 const exec_node *get_prev() const;
69 exec_node *get_prev();
70
71 void remove();
72
73 /**
74 * Link a node with itself
75 *
76 * This creates a sort of degenerate list that is occasionally useful.
77 */
78 void self_link();
79
80 /**
81 * Insert a node in the list after the current node
82 */
83 void insert_after(exec_node *after);
84 /**
85 * Insert a node in the list before the current node
86 */
87 void insert_before(exec_node *before);
88
89 /**
90 * Insert another list in the list before the current node
91 */
92 void insert_before(struct exec_list *before);
93
94 /**
95 * Replace the current node with the given node.
96 */
97 void replace_with(exec_node *replacement);
98
99 /**
100 * Is this the sentinel at the tail of the list?
101 */
102 bool is_tail_sentinel() const;
103
104 /**
105 * Is this the sentinel at the head of the list?
106 */
107 bool is_head_sentinel() const;
108 #endif
109 };
110
111 static inline void
exec_node_init(struct exec_node * n)112 exec_node_init(struct exec_node *n)
113 {
114 n->next = NULL;
115 n->prev = NULL;
116 }
117
118 static inline const struct exec_node *
exec_node_get_next_const(const struct exec_node * n)119 exec_node_get_next_const(const struct exec_node *n)
120 {
121 return n->next;
122 }
123
124 static inline struct exec_node *
exec_node_get_next(struct exec_node * n)125 exec_node_get_next(struct exec_node *n)
126 {
127 return n->next;
128 }
129
130 static inline const struct exec_node *
exec_node_get_prev_const(const struct exec_node * n)131 exec_node_get_prev_const(const struct exec_node *n)
132 {
133 return n->prev;
134 }
135
136 static inline struct exec_node *
exec_node_get_prev(struct exec_node * n)137 exec_node_get_prev(struct exec_node *n)
138 {
139 return n->prev;
140 }
141
142 static inline void
exec_node_remove(struct exec_node * n)143 exec_node_remove(struct exec_node *n)
144 {
145 n->next->prev = n->prev;
146 n->prev->next = n->next;
147 n->next = NULL;
148 n->prev = NULL;
149 }
150
151 static inline void
exec_node_self_link(struct exec_node * n)152 exec_node_self_link(struct exec_node *n)
153 {
154 n->next = n;
155 n->prev = n;
156 }
157
158 static inline void
exec_node_insert_after(struct exec_node * n,struct exec_node * after)159 exec_node_insert_after(struct exec_node *n, struct exec_node *after)
160 {
161 after->next = n->next;
162 after->prev = n;
163
164 n->next->prev = after;
165 n->next = after;
166 }
167
168 static inline void
exec_node_insert_node_before(struct exec_node * n,struct exec_node * before)169 exec_node_insert_node_before(struct exec_node *n, struct exec_node *before)
170 {
171 before->next = n;
172 before->prev = n->prev;
173
174 n->prev->next = before;
175 n->prev = before;
176 }
177
178 static inline void
exec_node_replace_with(struct exec_node * n,struct exec_node * replacement)179 exec_node_replace_with(struct exec_node *n, struct exec_node *replacement)
180 {
181 replacement->prev = n->prev;
182 replacement->next = n->next;
183
184 n->prev->next = replacement;
185 n->next->prev = replacement;
186 }
187
188 static inline bool
exec_node_is_tail_sentinel(const struct exec_node * n)189 exec_node_is_tail_sentinel(const struct exec_node *n)
190 {
191 return n->next == NULL;
192 }
193
194 static inline bool
exec_node_is_head_sentinel(const struct exec_node * n)195 exec_node_is_head_sentinel(const struct exec_node *n)
196 {
197 return n->prev == NULL;
198 }
199
200 #ifdef __cplusplus
get_next()201 inline const exec_node *exec_node::get_next() const
202 {
203 return exec_node_get_next_const(this);
204 }
205
get_next()206 inline exec_node *exec_node::get_next()
207 {
208 return exec_node_get_next(this);
209 }
210
get_prev()211 inline const exec_node *exec_node::get_prev() const
212 {
213 return exec_node_get_prev_const(this);
214 }
215
get_prev()216 inline exec_node *exec_node::get_prev()
217 {
218 return exec_node_get_prev(this);
219 }
220
remove()221 inline void exec_node::remove()
222 {
223 exec_node_remove(this);
224 }
225
self_link()226 inline void exec_node::self_link()
227 {
228 exec_node_self_link(this);
229 }
230
insert_after(exec_node * after)231 inline void exec_node::insert_after(exec_node *after)
232 {
233 exec_node_insert_after(this, after);
234 }
235
insert_before(exec_node * before)236 inline void exec_node::insert_before(exec_node *before)
237 {
238 exec_node_insert_node_before(this, before);
239 }
240
replace_with(exec_node * replacement)241 inline void exec_node::replace_with(exec_node *replacement)
242 {
243 exec_node_replace_with(this, replacement);
244 }
245
is_tail_sentinel()246 inline bool exec_node::is_tail_sentinel() const
247 {
248 return exec_node_is_tail_sentinel(this);
249 }
250
is_head_sentinel()251 inline bool exec_node::is_head_sentinel() const
252 {
253 return exec_node_is_head_sentinel(this);
254 }
255 #endif
256
257 #ifdef __cplusplus
258 /* This macro will not work correctly if `t' uses virtual inheritance. If you
259 * are using virtual inheritance, you deserve a slow and painful death. Enjoy!
260 */
261 #define exec_list_offsetof(t, f, p) \
262 (((char *) &((t *) p)->f) - ((char *) p))
263 #else
264 #define exec_list_offsetof(t, f, p) offsetof(t, f)
265 #endif
266
267 /**
268 * Get a pointer to the structure containing an exec_node
269 *
270 * Given a pointer to an \c exec_node embedded in a structure, get a pointer to
271 * the containing structure.
272 *
273 * \param type Base type of the structure containing the node
274 * \param node Pointer to the \c exec_node
275 * \param field Name of the field in \c type that is the embedded \c exec_node
276 */
277 #define exec_node_data(type, node, field) \
278 ((type *) (((char *) node) - exec_list_offsetof(type, field, node)))
279
280 #ifdef __cplusplus
281 struct exec_node;
282 #endif
283
284 struct exec_list {
285 struct exec_node head_sentinel;
286 struct exec_node tail_sentinel;
287
288 #ifdef __cplusplus
289 DECLARE_RALLOC_CXX_OPERATORS(exec_list)
290
exec_listexec_list291 exec_list()
292 {
293 make_empty();
294 }
295
296 void make_empty();
297
298 bool is_empty() const;
299
300 const exec_node *get_head() const;
301 exec_node *get_head();
302 const exec_node *get_head_raw() const;
303 exec_node *get_head_raw();
304
305 const exec_node *get_tail() const;
306 exec_node *get_tail();
307 const exec_node *get_tail_raw() const;
308 exec_node *get_tail_raw();
309
310 unsigned length() const;
311
312 void push_head(exec_node *n);
313 void push_tail(exec_node *n);
314 void push_degenerate_list_at_head(exec_node *n);
315
316 /**
317 * Remove the first node from a list and return it
318 *
319 * \return
320 * The first node in the list or \c NULL if the list is empty.
321 *
322 * \sa exec_list::get_head
323 */
324 exec_node *pop_head();
325
326 /**
327 * Move all of the nodes from this list to the target list
328 */
329 void move_nodes_to(exec_list *target);
330
331 /**
332 * Append all nodes from the source list to the end of the target list
333 */
334 void append_list(exec_list *source);
335
336 /**
337 * Prepend all nodes from the source list to the beginning of the target
338 * list
339 */
340 void prepend_list(exec_list *source);
341 #endif
342 };
343
344 static inline void
exec_list_make_empty(struct exec_list * list)345 exec_list_make_empty(struct exec_list *list)
346 {
347 list->head_sentinel.next = &list->tail_sentinel;
348 list->head_sentinel.prev = NULL;
349 list->tail_sentinel.next = NULL;
350 list->tail_sentinel.prev = &list->head_sentinel;
351 }
352
353 static inline bool
exec_list_is_empty(const struct exec_list * list)354 exec_list_is_empty(const struct exec_list *list)
355 {
356 /* There are three ways to test whether a list is empty or not.
357 *
358 * - Check to see if the head sentinel's \c next is the tail sentinel.
359 * - Check to see if the tail sentinel's \c prev is the head sentinel.
360 * - Check to see if the head is the sentinel node by test whether its
361 * \c next pointer is \c NULL.
362 *
363 * The first two methods tend to generate better code on modern systems
364 * because they save a pointer dereference.
365 */
366 return list->head_sentinel.next == &list->tail_sentinel;
367 }
368
369 static inline const struct exec_node *
exec_list_get_head_const(const struct exec_list * list)370 exec_list_get_head_const(const struct exec_list *list)
371 {
372 return !exec_list_is_empty(list) ? list->head_sentinel.next : NULL;
373 }
374
375 static inline struct exec_node *
exec_list_get_head(struct exec_list * list)376 exec_list_get_head(struct exec_list *list)
377 {
378 return !exec_list_is_empty(list) ? list->head_sentinel.next : NULL;
379 }
380
381 static inline const struct exec_node *
exec_list_get_head_raw_const(const struct exec_list * list)382 exec_list_get_head_raw_const(const struct exec_list *list)
383 {
384 return list->head_sentinel.next;
385 }
386
387 static inline struct exec_node *
exec_list_get_head_raw(struct exec_list * list)388 exec_list_get_head_raw(struct exec_list *list)
389 {
390 return list->head_sentinel.next;
391 }
392
393 static inline const struct exec_node *
exec_list_get_tail_const(const struct exec_list * list)394 exec_list_get_tail_const(const struct exec_list *list)
395 {
396 return !exec_list_is_empty(list) ? list->tail_sentinel.prev : NULL;
397 }
398
399 static inline struct exec_node *
exec_list_get_tail(struct exec_list * list)400 exec_list_get_tail(struct exec_list *list)
401 {
402 return !exec_list_is_empty(list) ? list->tail_sentinel.prev : NULL;
403 }
404
405 static inline const struct exec_node *
exec_list_get_tail_raw_const(const struct exec_list * list)406 exec_list_get_tail_raw_const(const struct exec_list *list)
407 {
408 return list->tail_sentinel.prev;
409 }
410
411 static inline struct exec_node *
exec_list_get_tail_raw(struct exec_list * list)412 exec_list_get_tail_raw(struct exec_list *list)
413 {
414 return list->tail_sentinel.prev;
415 }
416
417 static inline unsigned
exec_list_length(const struct exec_list * list)418 exec_list_length(const struct exec_list *list)
419 {
420 unsigned size = 0;
421 struct exec_node *node;
422
423 for (node = list->head_sentinel.next; node->next != NULL; node = node->next) {
424 size++;
425 }
426
427 return size;
428 }
429
430 static inline void
exec_list_push_head(struct exec_list * list,struct exec_node * n)431 exec_list_push_head(struct exec_list *list, struct exec_node *n)
432 {
433 n->next = list->head_sentinel.next;
434 n->prev = &list->head_sentinel;
435
436 n->next->prev = n;
437 list->head_sentinel.next = n;
438 }
439
440 static inline void
exec_list_push_tail(struct exec_list * list,struct exec_node * n)441 exec_list_push_tail(struct exec_list *list, struct exec_node *n)
442 {
443 n->next = &list->tail_sentinel;
444 n->prev = list->tail_sentinel.prev;
445
446 n->prev->next = n;
447 list->tail_sentinel.prev = n;
448 }
449
450 static inline void
exec_list_push_degenerate_list_at_head(struct exec_list * list,struct exec_node * n)451 exec_list_push_degenerate_list_at_head(struct exec_list *list, struct exec_node *n)
452 {
453 assert(n->prev->next == n);
454
455 n->prev->next = list->head_sentinel.next;
456 list->head_sentinel.next->prev = n->prev;
457 n->prev = &list->head_sentinel;
458 list->head_sentinel.next = n;
459 }
460
461 static inline struct exec_node *
exec_list_pop_head(struct exec_list * list)462 exec_list_pop_head(struct exec_list *list)
463 {
464 struct exec_node *const n = exec_list_get_head(list);
465 if (n != NULL)
466 exec_node_remove(n);
467
468 return n;
469 }
470
471 static inline void
exec_list_move_nodes_to(struct exec_list * list,struct exec_list * target)472 exec_list_move_nodes_to(struct exec_list *list, struct exec_list *target)
473 {
474 if (exec_list_is_empty(list)) {
475 exec_list_make_empty(target);
476 } else {
477 target->head_sentinel.next = list->head_sentinel.next;
478 target->head_sentinel.prev = NULL;
479 target->tail_sentinel.next = NULL;
480 target->tail_sentinel.prev = list->tail_sentinel.prev;
481
482 target->head_sentinel.next->prev = &target->head_sentinel;
483 target->tail_sentinel.prev->next = &target->tail_sentinel;
484
485 exec_list_make_empty(list);
486 }
487 }
488
489 static inline void
exec_list_append(struct exec_list * list,struct exec_list * source)490 exec_list_append(struct exec_list *list, struct exec_list *source)
491 {
492 if (exec_list_is_empty(source))
493 return;
494
495 /* Link the first node of the source with the last node of the target list.
496 */
497 list->tail_sentinel.prev->next = source->head_sentinel.next;
498 source->head_sentinel.next->prev = list->tail_sentinel.prev;
499
500 /* Make the tail of the source list be the tail of the target list.
501 */
502 list->tail_sentinel.prev = source->tail_sentinel.prev;
503 list->tail_sentinel.prev->next = &list->tail_sentinel;
504
505 /* Make the source list empty for good measure.
506 */
507 exec_list_make_empty(source);
508 }
509
510 static inline void
exec_list_prepend(struct exec_list * list,struct exec_list * source)511 exec_list_prepend(struct exec_list *list, struct exec_list *source)
512 {
513 exec_list_append(source, list);
514 exec_list_move_nodes_to(source, list);
515 }
516
517 static inline void
exec_node_insert_list_before(struct exec_node * n,struct exec_list * before)518 exec_node_insert_list_before(struct exec_node *n, struct exec_list *before)
519 {
520 if (exec_list_is_empty(before))
521 return;
522
523 before->tail_sentinel.prev->next = n;
524 before->head_sentinel.next->prev = n->prev;
525
526 n->prev->next = before->head_sentinel.next;
527 n->prev = before->tail_sentinel.prev;
528
529 exec_list_make_empty(before);
530 }
531
532 static inline void
exec_list_validate(const struct exec_list * list)533 exec_list_validate(const struct exec_list *list)
534 {
535 const struct exec_node *node;
536
537 assert(list->head_sentinel.next->prev == &list->head_sentinel);
538 assert(list->head_sentinel.prev == NULL);
539 assert(list->tail_sentinel.next == NULL);
540 assert(list->tail_sentinel.prev->next == &list->tail_sentinel);
541
542 /* We could try to use one of the interators below for this but they all
543 * either require C++ or assume the exec_node is embedded in a structure
544 * which is not the case for this function.
545 */
546 for (node = list->head_sentinel.next; node->next != NULL; node = node->next) {
547 assert(node->next->prev == node);
548 assert(node->prev->next == node);
549 }
550 }
551
552 #ifdef __cplusplus
make_empty()553 inline void exec_list::make_empty()
554 {
555 exec_list_make_empty(this);
556 }
557
is_empty()558 inline bool exec_list::is_empty() const
559 {
560 return exec_list_is_empty(this);
561 }
562
get_head()563 inline const exec_node *exec_list::get_head() const
564 {
565 return exec_list_get_head_const(this);
566 }
567
get_head()568 inline exec_node *exec_list::get_head()
569 {
570 return exec_list_get_head(this);
571 }
572
get_head_raw()573 inline const exec_node *exec_list::get_head_raw() const
574 {
575 return exec_list_get_head_raw_const(this);
576 }
577
get_head_raw()578 inline exec_node *exec_list::get_head_raw()
579 {
580 return exec_list_get_head_raw(this);
581 }
582
get_tail()583 inline const exec_node *exec_list::get_tail() const
584 {
585 return exec_list_get_tail_const(this);
586 }
587
get_tail()588 inline exec_node *exec_list::get_tail()
589 {
590 return exec_list_get_tail(this);
591 }
592
get_tail_raw()593 inline const exec_node *exec_list::get_tail_raw() const
594 {
595 return exec_list_get_tail_raw_const(this);
596 }
597
get_tail_raw()598 inline exec_node *exec_list::get_tail_raw()
599 {
600 return exec_list_get_tail_raw(this);
601 }
602
length()603 inline unsigned exec_list::length() const
604 {
605 return exec_list_length(this);
606 }
607
push_head(exec_node * n)608 inline void exec_list::push_head(exec_node *n)
609 {
610 exec_list_push_head(this, n);
611 }
612
push_tail(exec_node * n)613 inline void exec_list::push_tail(exec_node *n)
614 {
615 exec_list_push_tail(this, n);
616 }
617
push_degenerate_list_at_head(exec_node * n)618 inline void exec_list::push_degenerate_list_at_head(exec_node *n)
619 {
620 exec_list_push_degenerate_list_at_head(this, n);
621 }
622
pop_head()623 inline exec_node *exec_list::pop_head()
624 {
625 return exec_list_pop_head(this);
626 }
627
move_nodes_to(exec_list * target)628 inline void exec_list::move_nodes_to(exec_list *target)
629 {
630 exec_list_move_nodes_to(this, target);
631 }
632
append_list(exec_list * source)633 inline void exec_list::append_list(exec_list *source)
634 {
635 exec_list_append(this, source);
636 }
637
prepend_list(exec_list * source)638 inline void exec_list::prepend_list(exec_list *source)
639 {
640 exec_list_prepend(this, source);
641 }
642
insert_before(exec_list * before)643 inline void exec_node::insert_before(exec_list *before)
644 {
645 exec_node_insert_list_before(this, before);
646 }
647 #endif
648
649 #define foreach_in_list(__type, __inst, __list) \
650 for (__type *(__inst) = (__type *)(__list)->head_sentinel.next; \
651 !(__inst)->is_tail_sentinel(); \
652 (__inst) = (__type *)(__inst)->next)
653
654 #define foreach_in_list_reverse(__type, __inst, __list) \
655 for (__type *(__inst) = (__type *)(__list)->tail_sentinel.prev; \
656 !(__inst)->is_head_sentinel(); \
657 (__inst) = (__type *)(__inst)->prev)
658
659 /**
660 * This version is safe even if the current node is removed.
661 */
662 #define foreach_in_list_safe(__type, __node, __list) \
663 for (__type *__node = (__type *)(__list)->head_sentinel.next, \
664 *__next = (__type *)__node->next; \
665 __next != NULL; \
666 __node = __next, __next = (__type *)__next->next)
667
668 #define foreach_in_list_reverse_safe(__type, __node, __list) \
669 for (__type *__node = (__type *)(__list)->tail_sentinel.prev, \
670 *__prev = (__type *)__node->prev; \
671 __prev != NULL; \
672 __node = __prev, __prev = (__type *)__prev->prev)
673
674 #define foreach_in_list_use_after(__type, __inst, __list) \
675 __type *(__inst); \
676 for ((__inst) = (__type *)(__list)->head_sentinel.next; \
677 !(__inst)->is_tail_sentinel(); \
678 (__inst) = (__type *)(__inst)->next)
679 /**
680 * Iterate through two lists at once. Stops at the end of the shorter list.
681 *
682 * This is safe against either current node being removed or replaced.
683 */
684 #define foreach_two_lists(__node1, __list1, __node2, __list2) \
685 for (struct exec_node * __node1 = (__list1)->head_sentinel.next, \
686 * __node2 = (__list2)->head_sentinel.next, \
687 * __next1 = __node1->next, \
688 * __next2 = __node2->next \
689 ; __next1 != NULL && __next2 != NULL \
690 ; __node1 = __next1, \
691 __node2 = __next2, \
692 __next1 = __next1->next, \
693 __next2 = __next2->next)
694
695 #define foreach_list_typed(__type, __node, __field, __list) \
696 for (__type * __node = \
697 exec_node_data(__type, (__list)->head_sentinel.next, __field); \
698 (__node)->__field.next != NULL; \
699 (__node) = exec_node_data(__type, (__node)->__field.next, __field))
700
701 #define foreach_list_typed_from(__type, __node, __field, __list, __start) \
702 for (__type * __node = exec_node_data(__type, (__start), __field); \
703 (__node)->__field.next != NULL; \
704 (__node) = exec_node_data(__type, (__node)->__field.next, __field))
705
706 #define foreach_list_typed_reverse(__type, __node, __field, __list) \
707 for (__type * __node = \
708 exec_node_data(__type, (__list)->tail_sentinel.prev, __field); \
709 (__node)->__field.prev != NULL; \
710 (__node) = exec_node_data(__type, (__node)->__field.prev, __field))
711
712 #define foreach_list_typed_safe(__type, __node, __field, __list) \
713 for (__type * __node = \
714 exec_node_data(__type, (__list)->head_sentinel.next, __field), \
715 * __next = \
716 exec_node_data(__type, (__node)->__field.next, __field); \
717 (__node)->__field.next != NULL; \
718 __node = __next, __next = \
719 exec_node_data(__type, (__next)->__field.next, __field))
720
721 #define foreach_list_typed_reverse_safe(__type, __node, __field, __list) \
722 for (__type * __node = \
723 exec_node_data(__type, (__list)->tail_sentinel.prev, __field), \
724 * __prev = \
725 exec_node_data(__type, (__node)->__field.prev, __field); \
726 (__node)->__field.prev != NULL; \
727 __node = __prev, __prev = \
728 exec_node_data(__type, (__prev)->__field.prev, __field))
729
730 #endif /* LIST_CONTAINER_H */
731