1 /* $OpenBSD: tree.h,v 1.6 2002/06/11 22:09:52 provos Exp $ */
3 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 * This file defines data structures for different types of trees:
32 * splay trees and red-black trees.
34 * A splay tree is a self-organizing data structure. Every operation
35 * on the tree causes a splay to happen. The splay moves the requested
36 * node to the root of the tree and partly rebalances it.
38 * This has the benefit that request locality causes faster lookups as
39 * the requested nodes move to the top of the tree. On the other hand,
40 * every lookup causes memory writes.
42 * The Balance Theorem bounds the total access time for m operations
43 * and n inserts on an initially empty tree as O((m + n)lg n). The
44 * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
46 * A red-black tree is a binary search tree with the node color as an
47 * extra attribute. It fulfills a set of conditions:
48 * - every search path from the root to a leaf consists of the
49 * same number of black nodes,
50 * - each red node (except for the root) has a black parent,
51 * - each leaf node is black.
53 * Every operation on a red-black tree is bounded as O(lg n).
54 * The maximum height of a red-black tree is 2lg (n+1).
57 #define SPLAY_HEAD(name, type) \
59 struct type *sph_root; /* root of the tree */ \
62 #define SPLAY_INITIALIZER(root) \
65 #define SPLAY_INIT(root) do { \
66 (root)->sph_root = NULL; \
69 #define SPLAY_ENTRY(type) \
71 struct type *spe_left; /* left element */ \
72 struct type *spe_right; /* right element */ \
75 #define SPLAY_LEFT(elm, field) (elm)->field.spe_left
76 #define SPLAY_RIGHT(elm, field) (elm)->field.spe_right
77 #define SPLAY_ROOT(head) (head)->sph_root
78 #define SPLAY_EMPTY(head) (SPLAY_ROOT(head) == NULL)
80 /* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
81 #define SPLAY_ROTATE_RIGHT(head, tmp, field) do { \
82 SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field); \
83 SPLAY_RIGHT(tmp, field) = (head)->sph_root; \
84 (head)->sph_root = tmp; \
87 #define SPLAY_ROTATE_LEFT(head, tmp, field) do { \
88 SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field); \
89 SPLAY_LEFT(tmp, field) = (head)->sph_root; \
90 (head)->sph_root = tmp; \
93 #define SPLAY_LINKLEFT(head, tmp, field) do { \
94 SPLAY_LEFT(tmp, field) = (head)->sph_root; \
95 tmp = (head)->sph_root; \
96 (head)->sph_root = SPLAY_LEFT((head)->sph_root, field); \
99 #define SPLAY_LINKRIGHT(head, tmp, field) do { \
100 SPLAY_RIGHT(tmp, field) = (head)->sph_root; \
101 tmp = (head)->sph_root; \
102 (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field); \
105 #define SPLAY_ASSEMBLE(head, node, left, right, field) do { \
106 SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field); \
107 SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
108 SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field); \
109 SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field); \
112 /* Generates prototypes and inline functions */
114 #define SPLAY_PROTOTYPE(name, type, field, cmp) \
115 void name##_SPLAY(struct name *, struct type *); \
116 void name##_SPLAY_MINMAX(struct name *, int); \
117 struct type *name##_SPLAY_INSERT(struct name *, struct type *); \
118 struct type *name##_SPLAY_REMOVE(struct name *, struct type *); \
120 /* Finds the node with the same key as elm */ \
121 static __inline struct type * \
122 name##_SPLAY_FIND(struct name *head, struct type *elm) \
124 if (SPLAY_EMPTY(head)) \
126 name##_SPLAY(head, elm); \
127 if ((cmp)(elm, (head)->sph_root) == 0) \
128 return (head->sph_root); \
132 static __inline struct type * \
133 name##_SPLAY_NEXT(struct name *head, struct type *elm) \
135 name##_SPLAY(head, elm); \
136 if (SPLAY_RIGHT(elm, field) != NULL) { \
137 elm = SPLAY_RIGHT(elm, field); \
138 while (SPLAY_LEFT(elm, field) != NULL) { \
139 elm = SPLAY_LEFT(elm, field); \
146 static __inline struct type * \
147 name##_SPLAY_MIN_MAX(struct name *head, int val) \
149 name##_SPLAY_MINMAX(head, val); \
150 return (SPLAY_ROOT(head)); \
153 /* Main splay operation.
154 * Moves node close to the key of elm to top
156 #define SPLAY_GENERATE(name, type, field, cmp) \
158 name##_SPLAY_INSERT(struct name *head, struct type *elm) \
160 if (SPLAY_EMPTY(head)) { \
161 SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL; \
164 name##_SPLAY(head, elm); \
165 __comp = (cmp)(elm, (head)->sph_root); \
167 SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
168 SPLAY_RIGHT(elm, field) = (head)->sph_root; \
169 SPLAY_LEFT((head)->sph_root, field) = NULL; \
170 } else if (__comp > 0) { \
171 SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
172 SPLAY_LEFT(elm, field) = (head)->sph_root; \
173 SPLAY_RIGHT((head)->sph_root, field) = NULL; \
175 return ((head)->sph_root); \
177 (head)->sph_root = (elm); \
182 name##_SPLAY_REMOVE(struct name *head, struct type *elm) \
184 struct type *__tmp; \
185 if (SPLAY_EMPTY(head)) \
187 name##_SPLAY(head, elm); \
188 if ((cmp)(elm, (head)->sph_root) == 0) { \
189 if (SPLAY_LEFT((head)->sph_root, field) == NULL) { \
190 (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
192 __tmp = SPLAY_RIGHT((head)->sph_root, field); \
193 (head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
194 name##_SPLAY(head, elm); \
195 SPLAY_RIGHT((head)->sph_root, field) = __tmp; \
203 name##_SPLAY(struct name *head, struct type *elm) \
205 struct type __node, *__left, *__right, *__tmp; \
208 SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
209 __left = __right = &__node; \
211 while ((__comp = (cmp)(elm, (head)->sph_root))) { \
213 __tmp = SPLAY_LEFT((head)->sph_root, field); \
216 if ((cmp)(elm, __tmp) < 0){ \
217 SPLAY_ROTATE_RIGHT(head, __tmp, field); \
218 if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
221 SPLAY_LINKLEFT(head, __right, field); \
222 } else if (__comp > 0) { \
223 __tmp = SPLAY_RIGHT((head)->sph_root, field); \
226 if ((cmp)(elm, __tmp) > 0){ \
227 SPLAY_ROTATE_LEFT(head, __tmp, field); \
228 if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
231 SPLAY_LINKRIGHT(head, __left, field); \
234 SPLAY_ASSEMBLE(head, &__node, __left, __right, field); \
237 /* Splay with either the minimum or the maximum element \
238 * Used to find minimum or maximum element in tree. \
240 void name##_SPLAY_MINMAX(struct name *head, int __comp) \
242 struct type __node, *__left, *__right, *__tmp; \
244 SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
245 __left = __right = &__node; \
249 __tmp = SPLAY_LEFT((head)->sph_root, field); \
253 SPLAY_ROTATE_RIGHT(head, __tmp, field); \
254 if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
257 SPLAY_LINKLEFT(head, __right, field); \
258 } else if (__comp > 0) { \
259 __tmp = SPLAY_RIGHT((head)->sph_root, field); \
263 SPLAY_ROTATE_LEFT(head, __tmp, field); \
264 if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
267 SPLAY_LINKRIGHT(head, __left, field); \
270 SPLAY_ASSEMBLE(head, &__node, __left, __right, field); \
273 #define SPLAY_NEGINF -1
276 #define SPLAY_INSERT(name, x, y) name##_SPLAY_INSERT(x, y)
277 #define SPLAY_REMOVE(name, x, y) name##_SPLAY_REMOVE(x, y)
278 #define SPLAY_FIND(name, x, y) name##_SPLAY_FIND(x, y)
279 #define SPLAY_NEXT(name, x, y) name##_SPLAY_NEXT(x, y)
280 #define SPLAY_MIN(name, x) (SPLAY_EMPTY(x) ? NULL \
281 : name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
282 #define SPLAY_MAX(name, x) (SPLAY_EMPTY(x) ? NULL \
283 : name##_SPLAY_MIN_MAX(x, SPLAY_INF))
285 #define SPLAY_FOREACH(x, name, head) \
286 for ((x) = SPLAY_MIN(name, head); \
288 (x) = SPLAY_NEXT(name, head, x))
290 /* Macros that define a red-back tree */
291 #define RB_HEAD(name, type) \
293 struct type *rbh_root; /* root of the tree */ \
296 #define RB_INITIALIZER(root) \
299 #define RB_INIT(root) do { \
300 (root)->rbh_root = NULL; \
305 #define RB_ENTRY(type) \
307 struct type *rbe_left; /* left element */ \
308 struct type *rbe_right; /* right element */ \
309 struct type *rbe_parent; /* parent element */ \
310 int rbe_color; /* node color */ \
313 #define RB_LEFT(elm, field) (elm)->field.rbe_left
314 #define RB_RIGHT(elm, field) (elm)->field.rbe_right
315 #define RB_PARENT(elm, field) (elm)->field.rbe_parent
316 #define RB_COLOR(elm, field) (elm)->field.rbe_color
317 #define RB_ROOT(head) (head)->rbh_root
318 #define RB_EMPTY(head) (RB_ROOT(head) == NULL)
320 #define RB_SET(elm, parent, field) do { \
321 RB_PARENT(elm, field) = parent; \
322 RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL; \
323 RB_COLOR(elm, field) = RB_RED; \
326 #define RB_SET_BLACKRED(black, red, field) do { \
327 RB_COLOR(black, field) = RB_BLACK; \
328 RB_COLOR(red, field) = RB_RED; \
332 #define RB_AUGMENT(x)
335 #define RB_ROTATE_LEFT(head, elm, tmp, field) do { \
336 (tmp) = RB_RIGHT(elm, field); \
337 if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) { \
338 RB_PARENT(RB_LEFT(tmp, field), field) = (elm); \
341 if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) { \
342 if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
343 RB_LEFT(RB_PARENT(elm, field), field) = (tmp); \
345 RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
346 RB_AUGMENT(RB_PARENT(elm, field)); \
348 (head)->rbh_root = (tmp); \
349 RB_LEFT(tmp, field) = (elm); \
350 RB_PARENT(elm, field) = (tmp); \
354 #define RB_ROTATE_RIGHT(head, elm, tmp, field) do { \
355 (tmp) = RB_LEFT(elm, field); \
356 if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) { \
357 RB_PARENT(RB_RIGHT(tmp, field), field) = (elm); \
360 if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) { \
361 if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
362 RB_LEFT(RB_PARENT(elm, field), field) = (tmp); \
364 RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
365 RB_AUGMENT(RB_PARENT(elm, field)); \
367 (head)->rbh_root = (tmp); \
368 RB_RIGHT(tmp, field) = (elm); \
369 RB_PARENT(elm, field) = (tmp); \
373 /* Generates prototypes and inline functions */
374 #define RB_PROTOTYPE(name, type, field, cmp) \
375 void name##_RB_INSERT_COLOR(struct name *, struct type *); \
376 void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
377 struct type *name##_RB_REMOVE(struct name *, struct type *); \
378 struct type *name##_RB_INSERT(struct name *, struct type *); \
379 struct type *name##_RB_FIND(struct name *, struct type *); \
380 struct type *name##_RB_NEXT(struct name *, struct type *); \
381 struct type *name##_RB_MINMAX(struct name *, int); \
384 /* Main rb operation.
385 * Moves node close to the key of elm to top
387 #define RB_GENERATE(name, type, field, cmp) \
389 name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \
391 struct type *parent, *gparent, *tmp; \
392 while ((parent = RB_PARENT(elm, field)) && \
393 RB_COLOR(parent, field) == RB_RED) { \
394 gparent = RB_PARENT(parent, field); \
395 if (parent == RB_LEFT(gparent, field)) { \
396 tmp = RB_RIGHT(gparent, field); \
397 if (tmp && RB_COLOR(tmp, field) == RB_RED) { \
398 RB_COLOR(tmp, field) = RB_BLACK; \
399 RB_SET_BLACKRED(parent, gparent, field);\
403 if (RB_RIGHT(parent, field) == elm) { \
404 RB_ROTATE_LEFT(head, parent, tmp, field);\
409 RB_SET_BLACKRED(parent, gparent, field); \
410 RB_ROTATE_RIGHT(head, gparent, tmp, field); \
412 tmp = RB_LEFT(gparent, field); \
413 if (tmp && RB_COLOR(tmp, field) == RB_RED) { \
414 RB_COLOR(tmp, field) = RB_BLACK; \
415 RB_SET_BLACKRED(parent, gparent, field);\
419 if (RB_LEFT(parent, field) == elm) { \
420 RB_ROTATE_RIGHT(head, parent, tmp, field);\
425 RB_SET_BLACKRED(parent, gparent, field); \
426 RB_ROTATE_LEFT(head, gparent, tmp, field); \
429 RB_COLOR(head->rbh_root, field) = RB_BLACK; \
433 name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
436 while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) && \
437 elm != RB_ROOT(head)) { \
438 if (RB_LEFT(parent, field) == elm) { \
439 tmp = RB_RIGHT(parent, field); \
440 if (RB_COLOR(tmp, field) == RB_RED) { \
441 RB_SET_BLACKRED(tmp, parent, field); \
442 RB_ROTATE_LEFT(head, parent, tmp, field);\
443 tmp = RB_RIGHT(parent, field); \
445 if ((RB_LEFT(tmp, field) == NULL || \
446 RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
447 (RB_RIGHT(tmp, field) == NULL || \
448 RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
449 RB_COLOR(tmp, field) = RB_RED; \
451 parent = RB_PARENT(elm, field); \
453 if (RB_RIGHT(tmp, field) == NULL || \
454 RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
455 struct type *oleft; \
456 if ((oleft = RB_LEFT(tmp, field)))\
457 RB_COLOR(oleft, field) = RB_BLACK;\
458 RB_COLOR(tmp, field) = RB_RED; \
459 RB_ROTATE_RIGHT(head, tmp, oleft, field);\
460 tmp = RB_RIGHT(parent, field); \
462 RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
463 RB_COLOR(parent, field) = RB_BLACK; \
464 if (RB_RIGHT(tmp, field)) \
465 RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
466 RB_ROTATE_LEFT(head, parent, tmp, field);\
467 elm = RB_ROOT(head); \
471 tmp = RB_LEFT(parent, field); \
472 if (RB_COLOR(tmp, field) == RB_RED) { \
473 RB_SET_BLACKRED(tmp, parent, field); \
474 RB_ROTATE_RIGHT(head, parent, tmp, field);\
475 tmp = RB_LEFT(parent, field); \
477 if ((RB_LEFT(tmp, field) == NULL || \
478 RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
479 (RB_RIGHT(tmp, field) == NULL || \
480 RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
481 RB_COLOR(tmp, field) = RB_RED; \
483 parent = RB_PARENT(elm, field); \
485 if (RB_LEFT(tmp, field) == NULL || \
486 RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
487 struct type *oright; \
488 if ((oright = RB_RIGHT(tmp, field)))\
489 RB_COLOR(oright, field) = RB_BLACK;\
490 RB_COLOR(tmp, field) = RB_RED; \
491 RB_ROTATE_LEFT(head, tmp, oright, field);\
492 tmp = RB_LEFT(parent, field); \
494 RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
495 RB_COLOR(parent, field) = RB_BLACK; \
496 if (RB_LEFT(tmp, field)) \
497 RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
498 RB_ROTATE_RIGHT(head, parent, tmp, field);\
499 elm = RB_ROOT(head); \
505 RB_COLOR(elm, field) = RB_BLACK; \
509 name##_RB_REMOVE(struct name *head, struct type *elm) \
511 struct type *child, *parent, *old = elm; \
513 if (RB_LEFT(elm, field) == NULL) \
514 child = RB_RIGHT(elm, field); \
515 else if (RB_RIGHT(elm, field) == NULL) \
516 child = RB_LEFT(elm, field); \
519 elm = RB_RIGHT(elm, field); \
520 while ((left = RB_LEFT(elm, field))) \
522 child = RB_RIGHT(elm, field); \
523 parent = RB_PARENT(elm, field); \
524 color = RB_COLOR(elm, field); \
526 RB_PARENT(child, field) = parent; \
528 if (RB_LEFT(parent, field) == elm) \
529 RB_LEFT(parent, field) = child; \
531 RB_RIGHT(parent, field) = child; \
532 RB_AUGMENT(parent); \
534 RB_ROOT(head) = child; \
535 if (RB_PARENT(elm, field) == old) \
537 (elm)->field = (old)->field; \
538 if (RB_PARENT(old, field)) { \
539 if (RB_LEFT(RB_PARENT(old, field), field) == old)\
540 RB_LEFT(RB_PARENT(old, field), field) = elm;\
542 RB_RIGHT(RB_PARENT(old, field), field) = elm;\
543 RB_AUGMENT(RB_PARENT(old, field)); \
545 RB_ROOT(head) = elm; \
546 RB_PARENT(RB_LEFT(old, field), field) = elm; \
547 if (RB_RIGHT(old, field)) \
548 RB_PARENT(RB_RIGHT(old, field), field) = elm; \
553 } while ((left = RB_PARENT(left, field))); \
557 parent = RB_PARENT(elm, field); \
558 color = RB_COLOR(elm, field); \
560 RB_PARENT(child, field) = parent; \
562 if (RB_LEFT(parent, field) == elm) \
563 RB_LEFT(parent, field) = child; \
565 RB_RIGHT(parent, field) = child; \
566 RB_AUGMENT(parent); \
568 RB_ROOT(head) = child; \
570 if (color == RB_BLACK) \
571 name##_RB_REMOVE_COLOR(head, parent, child); \
575 /* Inserts a node into the RB tree */ \
577 name##_RB_INSERT(struct name *head, struct type *elm) \
580 struct type *parent = NULL; \
582 tmp = RB_ROOT(head); \
585 comp = (cmp)(elm, parent); \
587 tmp = RB_LEFT(tmp, field); \
589 tmp = RB_RIGHT(tmp, field); \
593 RB_SET(elm, parent, field); \
594 if (parent != NULL) { \
596 RB_LEFT(parent, field) = elm; \
598 RB_RIGHT(parent, field) = elm; \
599 RB_AUGMENT(parent); \
601 RB_ROOT(head) = elm; \
602 name##_RB_INSERT_COLOR(head, elm); \
606 /* Finds the node with the same key as elm */ \
608 name##_RB_FIND(struct name *head, struct type *elm) \
610 struct type *tmp = RB_ROOT(head); \
613 comp = cmp(elm, tmp); \
615 tmp = RB_LEFT(tmp, field); \
617 tmp = RB_RIGHT(tmp, field); \
625 name##_RB_NEXT(struct name *head, struct type *elm) \
627 if (RB_RIGHT(elm, field)) { \
628 elm = RB_RIGHT(elm, field); \
629 while (RB_LEFT(elm, field)) \
630 elm = RB_LEFT(elm, field); \
632 if (RB_PARENT(elm, field) && \
633 (elm == RB_LEFT(RB_PARENT(elm, field), field))) \
634 elm = RB_PARENT(elm, field); \
636 while (RB_PARENT(elm, field) && \
637 (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
638 elm = RB_PARENT(elm, field); \
639 elm = RB_PARENT(elm, field); \
646 name##_RB_MINMAX(struct name *head, int val) \
648 struct type *tmp = RB_ROOT(head); \
649 struct type *parent = NULL; \
653 tmp = RB_LEFT(tmp, field); \
655 tmp = RB_RIGHT(tmp, field); \
663 #define RB_INSERT(name, x, y) name##_RB_INSERT(x, y)
664 #define RB_REMOVE(name, x, y) name##_RB_REMOVE(x, y)
665 #define RB_FIND(name, x, y) name##_RB_FIND(x, y)
666 #define RB_NEXT(name, x, y) name##_RB_NEXT(x, y)
667 #define RB_MIN(name, x) name##_RB_MINMAX(x, RB_NEGINF)
668 #define RB_MAX(name, x) name##_RB_MINMAX(x, RB_INF)
670 #define RB_FOREACH(x, name, head) \
671 for ((x) = RB_MIN(name, head); \
673 (x) = name##_RB_NEXT(head, x))
675 #endif /* _SYS_TREE_H_ */