File:  [ELWIX - Embedded LightWeight unIX -] / libelwix / inc / elwix / atree.h
Revision 1.3: download - view: text, annotated - select for diffs - revision graph
Thu Jun 25 17:53:49 2015 UTC (8 years, 10 months ago) by misho
Branches: MAIN
CVS tags: elwix5_7, elwix5_6, elwix5_5, elwix5_4, elwix5_3, elwix5_2, elwix5_1, elwix5_0, elwix4_9, elwix4_8, elwix4_7, elwix4_6, elwix4_5, elwix4_4, elwix4_3, elwix4_26, elwix4_25, elwix4_24, elwix4_23, elwix4_22, elwix4_21, elwix4_20, elwix4_2, elwix4_19, elwix4_18, elwix4_17, elwix4_16, elwix4_15, elwix4_14, elwix4_13, elwix4_12, elwix4_11, elwix4_10, elwix4_1, elwix3_9, elwix3_8, HEAD, ELWIX5_6, ELWIX5_5, ELWIX5_4, ELWIX5_3, ELWIX5_2, ELWIX5_1, ELWIX5_0, ELWIX4_9, ELWIX4_8, ELWIX4_7, ELWIX4_6, ELWIX4_5, ELWIX4_4, ELWIX4_3, ELWIX4_26, ELWIX4_25, ELWIX4_24, ELWIX4_23, ELWIX4_22, ELWIX4_21, ELWIX4_20, ELWIX4_2, ELWIX4_19, ELWIX4_18, ELWIX4_17, ELWIX4_16, ELWIX4_15, ELWIX4_14, ELWIX4_13, ELWIX4_12, ELWIX4_11, ELWIX4_10, ELWIX4_1, ELWIX4_0, ELWIX3_8, ELWIX3_7
version 3.7

/*************************************************************************
* (C) 2011 AITNET ltd - Sofia/Bulgaria - <misho@aitnet.org>
*  by Michael Pounov <misho@elwix.org>
*
* $Author: misho $
* $Id: atree.h,v 1.3 2015/06/25 17:53:49 misho Exp $
*
**************************************************************************
The ELWIX and AITNET software is distributed under the following
terms:

All of the documentation and software included in the ELWIX and AITNET
Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>

Copyright 2004 - 2015
	by Michael Pounov <misho@elwix.org>.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
   must display the following acknowledgement:
This product includes software developed by Michael Pounov <misho@elwix.org>
ELWIX - Embedded LightWeight unIX and its contributors.
4. Neither the name of AITNET nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
*/
/*
 *
 * AVL tree implementation, changes in other trees and file are
 * Copyrighted 2011 Michael Pounov <misho@elwix.org>
 * All rights reserved.
 *
 */
/*	$OpenBSD: tree.h,v 1.12 2009/03/02 09:42:55 mikeb Exp $	*/
/*
 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef	_SYS_TREE_H_
#define	_SYS_TREE_H_

/*
 * This file defines data structures for different types of trees:
 * splay trees and red-black trees.
 *
 * A splay tree is a self-organizing data structure.  Every operation
 * on the tree causes a splay to happen.  The splay moves the requested
 * node to the root of the tree and partly rebalances it.
 *
 * This has the benefit that request locality causes faster lookups as
 * the requested nodes move to the top of the tree.  On the other hand,
 * every lookup causes memory writes.
 *
 * The Balance Theorem bounds the total access time for m operations
 * and n inserts on an initially empty tree as O((m + n)lg n).  The
 * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
 *
 * A red-black tree is a binary search tree with the node color as an
 * extra attribute.  It fulfills a set of conditions:
 *	- every search path from the root to a leaf consists of the
 *	  same number of black nodes,
 *	- each red node (except for the root) has a black parent,
 *	- each leaf node is black.
 *
 * Every operation on a red-black tree is bounded as O(lg n).
 * The maximum height of a red-black tree is 2lg (n+1).
 */

#define SPLAY_HEAD(name, type)						\
struct name {								\
	struct type *sph_root; /* root of the tree */			\
}

#define SPLAY_INITIALIZER(root)						\
	{ NULL }

#define SPLAY_INIT(root) do {						\
	(root)->sph_root = NULL;					\
} while (0)

#define SPLAY_ENTRY(type)						\
struct {								\
	struct type *spe_left; /* left element */			\
	struct type *spe_right; /* right element */			\
}

#define SPLAY_LEFT(elm, field)		(elm)->field.spe_left
#define SPLAY_RIGHT(elm, field)		(elm)->field.spe_right
#define SPLAY_ROOT(head)		(head)->sph_root
#define SPLAY_EMPTY(head)		(SPLAY_ROOT(head) == NULL)

/* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
#define SPLAY_ROTATE_RIGHT(head, tmp, field) do {			\
	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field);	\
	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
	(head)->sph_root = tmp;						\
} while (0)

#define SPLAY_ROTATE_LEFT(head, tmp, field) do {			\
	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field);	\
	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
	(head)->sph_root = tmp;						\
} while (0)

#define SPLAY_LINKLEFT(head, tmp, field) do {				\
	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
	tmp = (head)->sph_root;						\
	(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);		\
} while (0)

#define SPLAY_LINKRIGHT(head, tmp, field) do {				\
	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
	tmp = (head)->sph_root;						\
	(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);	\
} while (0)

#define SPLAY_ASSEMBLE(head, node, left, right, field) do {		\
	SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field);	\
	SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field);	\
	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field);	\
} while (0)

/* Generates prototypes and inline functions */

#define SPLAY_PROTOTYPE(name, type, field, cmp)				\
void name##_SPLAY(struct name *, struct type *);			\
void name##_SPLAY_MINMAX(struct name *, int);				\
struct type *name##_SPLAY_INSERT(struct name *, struct type *);		\
struct type *name##_SPLAY_REMOVE(struct name *, struct type *);		\
									\
/* Finds the node with the same key as elm */				\
static __inline struct type *						\
name##_SPLAY_FIND(struct name *head, struct type *elm)			\
{									\
	if (SPLAY_EMPTY(head))						\
		return(NULL);						\
	name##_SPLAY(head, elm);					\
	if ((cmp)(elm, (head)->sph_root) == 0)				\
		return (head->sph_root);				\
	return (NULL);							\
}									\
									\
static __inline struct type *						\
name##_SPLAY_NEXT(struct name *head, struct type *elm)			\
{									\
	name##_SPLAY(head, elm);					\
	if (SPLAY_RIGHT(elm, field) != NULL) {				\
		elm = SPLAY_RIGHT(elm, field);				\
		while (SPLAY_LEFT(elm, field) != NULL) {		\
			elm = SPLAY_LEFT(elm, field);			\
		}							\
	} else								\
		elm = NULL;						\
	return (elm);							\
}									\
									\
static __inline struct type *						\
name##_SPLAY_MIN_MAX(struct name *head, int val)			\
{									\
	name##_SPLAY_MINMAX(head, val);					\
        return (SPLAY_ROOT(head));					\
}

/* Main splay operation.
 * Moves node close to the key of elm to top
 */
#define SPLAY_GENERATE(name, type, field, cmp)				\
struct type *								\
name##_SPLAY_INSERT(struct name *head, struct type *elm)		\
{									\
    if (SPLAY_EMPTY(head)) {						\
	    SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;	\
    } else {								\
	    int __comp;							\
	    name##_SPLAY(head, elm);					\
	    __comp = (cmp)(elm, (head)->sph_root);			\
	    if(__comp < 0) {						\
		    SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
		    SPLAY_RIGHT(elm, field) = (head)->sph_root;		\
		    SPLAY_LEFT((head)->sph_root, field) = NULL;		\
	    } else if (__comp > 0) {					\
		    SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
		    SPLAY_LEFT(elm, field) = (head)->sph_root;		\
		    SPLAY_RIGHT((head)->sph_root, field) = NULL;	\
	    } else							\
		    return ((head)->sph_root);				\
    }									\
    (head)->sph_root = (elm);						\
    return (NULL);							\
}									\
									\
struct type *								\
name##_SPLAY_REMOVE(struct name *head, struct type *elm)		\
{									\
	struct type *__tmp;						\
	if (SPLAY_EMPTY(head))						\
		return (NULL);						\
	name##_SPLAY(head, elm);					\
	if ((cmp)(elm, (head)->sph_root) == 0) {			\
		if (SPLAY_LEFT((head)->sph_root, field) == NULL) {	\
			(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
		} else {						\
			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
			(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
			name##_SPLAY(head, elm);			\
			SPLAY_RIGHT((head)->sph_root, field) = __tmp;	\
		}							\
		return (elm);						\
	}								\
	return (NULL);							\
}									\
									\
void									\
name##_SPLAY(struct name *head, struct type *elm)			\
{									\
	struct type __node, *__left, *__right, *__tmp;			\
	int __comp;							\
\
	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
	__left = __right = &__node;					\
\
	while ((__comp = (cmp)(elm, (head)->sph_root))) {		\
		if (__comp < 0) {					\
			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
			if (__tmp == NULL)				\
				break;					\
			if ((cmp)(elm, __tmp) < 0){			\
				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
					break;				\
			}						\
			SPLAY_LINKLEFT(head, __right, field);		\
		} else if (__comp > 0) {				\
			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
			if (__tmp == NULL)				\
				break;					\
			if ((cmp)(elm, __tmp) > 0){			\
				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
					break;				\
			}						\
			SPLAY_LINKRIGHT(head, __left, field);		\
		}							\
	}								\
	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
}									\
									\
/* Splay with either the minimum or the maximum element			\
 * Used to find minimum or maximum element in tree.			\
 */									\
void name##_SPLAY_MINMAX(struct name *head, int __comp) \
{									\
	struct type __node, *__left, *__right, *__tmp;			\
\
	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
	__left = __right = &__node;					\
\
	while (1) {							\
		if (__comp < 0) {					\
			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
			if (__tmp == NULL)				\
				break;					\
			if (__comp < 0){				\
				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
					break;				\
			}						\
			SPLAY_LINKLEFT(head, __right, field);		\
		} else if (__comp > 0) {				\
			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
			if (__tmp == NULL)				\
				break;					\
			if (__comp > 0) {				\
				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
					break;				\
			}						\
			SPLAY_LINKRIGHT(head, __left, field);		\
		}							\
	}								\
	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
}

#define SPLAY_NEGINF	-1
#define SPLAY_INF	1

#define SPLAY_INSERT(name, x, y)	name##_SPLAY_INSERT(x, y)
#define SPLAY_REMOVE(name, x, y)	name##_SPLAY_REMOVE(x, y)
#define SPLAY_FIND(name, x, y)		name##_SPLAY_FIND(x, y)
#define SPLAY_NEXT(name, x, y)		name##_SPLAY_NEXT(x, y)
#define SPLAY_MIN(name, x)		(SPLAY_EMPTY(x) ? NULL	\
					: name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
#define SPLAY_MAX(name, x)		(SPLAY_EMPTY(x) ? NULL	\
					: name##_SPLAY_MIN_MAX(x, SPLAY_INF))

#define SPLAY_FOREACH(x, name, head)					\
	for ((x) = SPLAY_MIN(name, head);				\
	     (x) != NULL;						\
	     (x) = SPLAY_NEXT(name, head, x))

#define SPLAY_FOREACH_SAFE(x, name, head, y)				\
	for ((x) = SPLAY_MIN(name, head);				\
	    ((x) != NULL) && 						\
			((y) = SPLAY_NEXT(name, head, x), (x) != NULL);	\
	     (x) = (y))


/* Macros that define a red-black tree */
#define RB_HEAD(name, type)						\
struct name {								\
	struct type *rbh_root; /* root of the tree */			\
}

#define RB_INITIALIZER(root)						\
	{ NULL }

#define RB_INIT(root) do {						\
	(root)->rbh_root = NULL;					\
} while (0)

#define RB_BLACK	0
#define RB_RED		1
#define RB_ENTRY(type)							\
struct {								\
	struct type *rbe_left;		/* left element */		\
	struct type *rbe_right;		/* right element */		\
	struct type *rbe_parent;	/* parent element */		\
	int rbe_color;			/* node color */		\
}

#define RB_LEFT(elm, field)		(elm)->field.rbe_left
#define RB_RIGHT(elm, field)		(elm)->field.rbe_right
#define RB_PARENT(elm, field)		(elm)->field.rbe_parent
#define RB_COLOR(elm, field)		(elm)->field.rbe_color
#define RB_ROOT(head)			(head)->rbh_root
#define RB_EMPTY(head)			(RB_ROOT(head) == NULL)

#define RB_SET(elm, parent, field) do {					\
	RB_PARENT(elm, field) = parent;					\
	RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;		\
	RB_COLOR(elm, field) = RB_RED;					\
} while (0)

#define RB_SET_BLACKRED(black, red, field) do {				\
	RB_COLOR(black, field) = RB_BLACK;				\
	RB_COLOR(red, field) = RB_RED;					\
} while (0)

#ifndef RB_AUGMENT
#define RB_AUGMENT(x) (void)(x)
#endif

#define RB_ROTATE_LEFT(head, elm, tmp, field) do {			\
	(tmp) = RB_RIGHT(elm, field);					\
	if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) {		\
		RB_PARENT(RB_LEFT(tmp, field), field) = (elm);		\
	}								\
	RB_AUGMENT(elm);						\
	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
		else							\
			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
	} else								\
		(head)->rbh_root = (tmp);				\
	RB_LEFT(tmp, field) = (elm);					\
	RB_PARENT(elm, field) = (tmp);					\
	RB_AUGMENT(tmp);						\
	if ((RB_PARENT(tmp, field)))					\
		RB_AUGMENT(RB_PARENT(tmp, field));			\
} while (0)

#define RB_ROTATE_RIGHT(head, elm, tmp, field) do {			\
	(tmp) = RB_LEFT(elm, field);					\
	if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) {		\
		RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);		\
	}								\
	RB_AUGMENT(elm);						\
	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
		else							\
			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
	} else								\
		(head)->rbh_root = (tmp);				\
	RB_RIGHT(tmp, field) = (elm);					\
	RB_PARENT(elm, field) = (tmp);					\
	RB_AUGMENT(tmp);						\
	if ((RB_PARENT(tmp, field)))					\
		RB_AUGMENT(RB_PARENT(tmp, field));			\
} while (0)

/* Generates prototypes and inline functions */
#define RB_PROTOTYPE(name, type, field, cmp)				\
	RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
#define	RB_PROTOTYPE_STATIC(name, type, field, cmp)			\
	RB_PROTOTYPE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr)		\
attr void name##_RB_INSERT_COLOR(struct name *, struct type *);		\
attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
attr struct type *name##_RB_REMOVE(struct name *, struct type *);	\
attr struct type *name##_RB_INSERT(struct name *, struct type *);	\
attr struct type *name##_RB_FIND(struct name *, struct type *);		\
attr struct type *name##_RB_NFIND(struct name *, struct type *);	\
attr struct type *name##_RB_NEXT(struct type *);			\
attr struct type *name##_RB_PREV(struct type *);			\
attr struct type *name##_RB_MINMAX(struct name *, int);			\
									\

/* Main rb operation.
 * Moves node close to the key of elm to top
 */
#define	RB_GENERATE(name, type, field, cmp)				\
	RB_GENERATE_INTERNAL(name, type, field, cmp,)
#define	RB_GENERATE_STATIC(name, type, field, cmp)			\
	RB_GENERATE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr)		\
attr void								\
name##_RB_INSERT_COLOR(struct name *head, struct type *elm)		\
{									\
	struct type *parent, *gparent, *tmp;				\
	while ((parent = RB_PARENT(elm, field)) &&			\
	    RB_COLOR(parent, field) == RB_RED) {			\
		gparent = RB_PARENT(parent, field);			\
		if (parent == RB_LEFT(gparent, field)) {		\
			tmp = RB_RIGHT(gparent, field);			\
			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
				RB_COLOR(tmp, field) = RB_BLACK;	\
				RB_SET_BLACKRED(parent, gparent, field);\
				elm = gparent;				\
				continue;				\
			}						\
			if (RB_RIGHT(parent, field) == elm) {		\
				RB_ROTATE_LEFT(head, parent, tmp, field);\
				tmp = parent;				\
				parent = elm;				\
				elm = tmp;				\
			}						\
			RB_SET_BLACKRED(parent, gparent, field);	\
			RB_ROTATE_RIGHT(head, gparent, tmp, field);	\
		} else {						\
			tmp = RB_LEFT(gparent, field);			\
			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
				RB_COLOR(tmp, field) = RB_BLACK;	\
				RB_SET_BLACKRED(parent, gparent, field);\
				elm = gparent;				\
				continue;				\
			}						\
			if (RB_LEFT(parent, field) == elm) {		\
				RB_ROTATE_RIGHT(head, parent, tmp, field);\
				tmp = parent;				\
				parent = elm;				\
				elm = tmp;				\
			}						\
			RB_SET_BLACKRED(parent, gparent, field);	\
			RB_ROTATE_LEFT(head, gparent, tmp, field);	\
		}							\
	}								\
	RB_COLOR(head->rbh_root, field) = RB_BLACK;			\
}									\
									\
attr void								\
name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
{									\
	struct type *tmp;						\
	while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) &&	\
	    elm != RB_ROOT(head)) {					\
		if (RB_LEFT(parent, field) == elm) {			\
			tmp = RB_RIGHT(parent, field);			\
			if (RB_COLOR(tmp, field) == RB_RED) {		\
				RB_SET_BLACKRED(tmp, parent, field);	\
				RB_ROTATE_LEFT(head, parent, tmp, field);\
				tmp = RB_RIGHT(parent, field);		\
			}						\
			if ((RB_LEFT(tmp, field) == NULL ||		\
			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
			    (RB_RIGHT(tmp, field) == NULL ||		\
			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
				RB_COLOR(tmp, field) = RB_RED;		\
				elm = parent;				\
				parent = RB_PARENT(elm, field);		\
			} else {					\
				if (RB_RIGHT(tmp, field) == NULL ||	\
				    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
					struct type *oleft;		\
					if ((oleft = RB_LEFT(tmp, field))) \
						RB_COLOR(oleft, field) = RB_BLACK;\
					RB_COLOR(tmp, field) = RB_RED;	\
					RB_ROTATE_RIGHT(head, tmp, oleft, field);\
					tmp = RB_RIGHT(parent, field);	\
				}					\
				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
				RB_COLOR(parent, field) = RB_BLACK;	\
				if (RB_RIGHT(tmp, field))		\
					RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
				RB_ROTATE_LEFT(head, parent, tmp, field);\
				elm = RB_ROOT(head);			\
				break;					\
			}						\
		} else {						\
			tmp = RB_LEFT(parent, field);			\
			if (RB_COLOR(tmp, field) == RB_RED) {		\
				RB_SET_BLACKRED(tmp, parent, field);	\
				RB_ROTATE_RIGHT(head, parent, tmp, field);\
				tmp = RB_LEFT(parent, field);		\
			}						\
			if ((RB_LEFT(tmp, field) == NULL ||		\
			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
			    (RB_RIGHT(tmp, field) == NULL ||		\
			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
				RB_COLOR(tmp, field) = RB_RED;		\
				elm = parent;				\
				parent = RB_PARENT(elm, field);		\
			} else {					\
				if (RB_LEFT(tmp, field) == NULL ||	\
				    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
					struct type *oright;		\
					if ((oright = RB_RIGHT(tmp, field))) \
						RB_COLOR(oright, field) = RB_BLACK;\
					RB_COLOR(tmp, field) = RB_RED;	\
					RB_ROTATE_LEFT(head, tmp, oright, field);\
					tmp = RB_LEFT(parent, field);	\
				}					\
				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
				RB_COLOR(parent, field) = RB_BLACK;	\
				if (RB_LEFT(tmp, field))		\
					RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
				RB_ROTATE_RIGHT(head, parent, tmp, field);\
				elm = RB_ROOT(head);			\
				break;					\
			}						\
		}							\
	}								\
	if (elm)							\
		RB_COLOR(elm, field) = RB_BLACK;			\
}									\
									\
attr struct type *							\
name##_RB_REMOVE(struct name *head, struct type *elm)			\
{									\
	struct type *child, *parent, *old = elm;			\
	int color;							\
	if (RB_LEFT(elm, field) == NULL)				\
		child = RB_RIGHT(elm, field);				\
	else if (RB_RIGHT(elm, field) == NULL)				\
		child = RB_LEFT(elm, field);				\
	else {								\
		struct type *left;					\
		elm = RB_RIGHT(elm, field);				\
		while ((left = RB_LEFT(elm, field)))			\
			elm = left;					\
		child = RB_RIGHT(elm, field);				\
		parent = RB_PARENT(elm, field);				\
		color = RB_COLOR(elm, field);				\
		if (child)						\
			RB_PARENT(child, field) = parent;		\
		if (parent) {						\
			if (RB_LEFT(parent, field) == elm)		\
				RB_LEFT(parent, field) = child;		\
			else						\
				RB_RIGHT(parent, field) = child;	\
			RB_AUGMENT(parent);				\
		} else							\
			RB_ROOT(head) = child;				\
		if (RB_PARENT(elm, field) == old)			\
			parent = elm;					\
		(elm)->field = (old)->field;				\
		if (RB_PARENT(old, field)) {				\
			if (RB_LEFT(RB_PARENT(old, field), field) == old)\
				RB_LEFT(RB_PARENT(old, field), field) = elm;\
			else						\
				RB_RIGHT(RB_PARENT(old, field), field) = elm;\
			RB_AUGMENT(RB_PARENT(old, field));		\
		} else							\
			RB_ROOT(head) = elm;				\
		RB_PARENT(RB_LEFT(old, field), field) = elm;		\
		if (RB_RIGHT(old, field))				\
			RB_PARENT(RB_RIGHT(old, field), field) = elm;	\
		if (parent) {						\
			left = parent;					\
			do {						\
				RB_AUGMENT(left);			\
			} while ((left = RB_PARENT(left, field)));	\
		}							\
		goto color;						\
	}								\
	parent = RB_PARENT(elm, field);					\
	color = RB_COLOR(elm, field);					\
	if (child)							\
		RB_PARENT(child, field) = parent;			\
	if (parent) {							\
		if (RB_LEFT(parent, field) == elm)			\
			RB_LEFT(parent, field) = child;			\
		else							\
			RB_RIGHT(parent, field) = child;		\
		RB_AUGMENT(parent);					\
	} else								\
		RB_ROOT(head) = child;					\
color:									\
	if (color == RB_BLACK)						\
		name##_RB_REMOVE_COLOR(head, parent, child);		\
	return (old);							\
}									\
									\
/* Inserts a node into the RB tree */					\
attr struct type *							\
name##_RB_INSERT(struct name *head, struct type *elm)			\
{									\
	struct type *tmp;						\
	struct type *parent = NULL;					\
	int comp = 0;							\
	tmp = RB_ROOT(head);						\
	while (tmp) {							\
		parent = tmp;						\
		comp = (cmp)(elm, parent);				\
		if (comp < 0)						\
			tmp = RB_LEFT(tmp, field);			\
		else if (comp > 0)					\
			tmp = RB_RIGHT(tmp, field);			\
		else							\
			return (tmp);					\
	}								\
	RB_SET(elm, parent, field);					\
	if (parent != NULL) {						\
		if (comp < 0)						\
			RB_LEFT(parent, field) = elm;			\
		else							\
			RB_RIGHT(parent, field) = elm;			\
		RB_AUGMENT(parent);					\
	} else								\
		RB_ROOT(head) = elm;					\
	name##_RB_INSERT_COLOR(head, elm);				\
	return (NULL);							\
}									\
									\
/* Finds the node with the same key as elm */				\
attr struct type *							\
name##_RB_FIND(struct name *head, struct type *elm)			\
{									\
	struct type *tmp = RB_ROOT(head);				\
	int comp;							\
	while (tmp) {							\
		comp = cmp(elm, tmp);					\
		if (comp < 0)						\
			tmp = RB_LEFT(tmp, field);			\
		else if (comp > 0)					\
			tmp = RB_RIGHT(tmp, field);			\
		else							\
			return (tmp);					\
	}								\
	return (NULL);							\
}									\
									\
/* Finds the first node greater than or equal to the search key */	\
attr struct type *							\
name##_RB_NFIND(struct name *head, struct type *elm)			\
{									\
	struct type *tmp = RB_ROOT(head);				\
	struct type *res = NULL;					\
	int comp;							\
	while (tmp) {							\
		comp = cmp(elm, tmp);					\
		if (comp < 0) {						\
			res = tmp;					\
			tmp = RB_LEFT(tmp, field);			\
		}							\
		else if (comp > 0)					\
			tmp = RB_RIGHT(tmp, field);			\
		else							\
			return (tmp);					\
	}								\
	return (res);							\
}									\
									\
/* ARGSUSED */								\
attr struct type *							\
name##_RB_NEXT(struct type *elm)					\
{									\
	if (RB_RIGHT(elm, field)) {					\
		elm = RB_RIGHT(elm, field);				\
		while (RB_LEFT(elm, field))				\
			elm = RB_LEFT(elm, field);			\
	} else {							\
		if (RB_PARENT(elm, field) &&				\
		    (elm == RB_LEFT(RB_PARENT(elm, field), field)))	\
			elm = RB_PARENT(elm, field);			\
		else {							\
			while (RB_PARENT(elm, field) &&			\
			    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
				elm = RB_PARENT(elm, field);		\
			elm = RB_PARENT(elm, field);			\
		}							\
	}								\
	return (elm);							\
}									\
									\
/* ARGSUSED */								\
attr struct type *							\
name##_RB_PREV(struct type *elm)					\
{									\
	if (RB_LEFT(elm, field)) {					\
		elm = RB_LEFT(elm, field);				\
		while (RB_RIGHT(elm, field))				\
			elm = RB_RIGHT(elm, field);			\
	} else {							\
		if (RB_PARENT(elm, field) &&				\
		    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))	\
			elm = RB_PARENT(elm, field);			\
		else {							\
			while (RB_PARENT(elm, field) &&			\
			    (elm == RB_LEFT(RB_PARENT(elm, field), field)))\
				elm = RB_PARENT(elm, field);		\
			elm = RB_PARENT(elm, field);			\
		}							\
	}								\
	return (elm);							\
}									\
									\
attr struct type *							\
name##_RB_MINMAX(struct name *head, int val)				\
{									\
	struct type *tmp = RB_ROOT(head);				\
	struct type *parent = NULL;					\
	while (tmp) {							\
		parent = tmp;						\
		if (val < 0)						\
			tmp = RB_LEFT(tmp, field);			\
		else							\
			tmp = RB_RIGHT(tmp, field);			\
	}								\
	return (parent);						\
}

#define RB_NEGINF	-1
#define RB_INF	1

#define RB_INSERT(name, x, y)	name##_RB_INSERT(x, y)
#define RB_REMOVE(name, x, y)	name##_RB_REMOVE(x, y)
#define RB_FIND(name, x, y)	name##_RB_FIND(x, y)
#define RB_NFIND(name, x, y)	name##_RB_NFIND(x, y)
#define RB_NEXT(name, x, y)	name##_RB_NEXT(y)
#define RB_PREV(name, x, y)	name##_RB_PREV(y)
#define RB_MIN(name, x)		name##_RB_MINMAX(x, RB_NEGINF)
#define RB_MAX(name, x)		name##_RB_MINMAX(x, RB_INF)

#define RB_FOREACH(x, name, head)					\
	for ((x) = RB_MIN(name, head);					\
	     (x) != NULL;						\
	     (x) = name##_RB_NEXT(x))

#define RB_FOREACH_FROM(x, name, y)					\
	for ((x) = (y);							\
	    ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL);	\
	     (x) = (y))

#define RB_FOREACH_SAFE(x, name, head, y)				\
	for ((x) = RB_MIN(name, head);					\
	    ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL);	\
	     (x) = (y))

#define RB_FOREACH_REVERSE(x, name, head)				\
	for ((x) = RB_MAX(name, head);					\
	     (x) != NULL;						\
	     (x) = name##_RB_PREV(x))

#define RB_FOREACH_REVERSE_FROM(x, name, y)				\
	for ((x) = (y);							\
	    ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL);	\
	     (x) = (y))

#define RB_FOREACH_REVERSE_SAFE(x, name, head, y)			\
	for ((x) = RB_MAX(name, head);					\
	    ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL);	\
	     (x) = (y))

/* Macros that define a avl tree */
#ifndef AVL_MAX_HEIGHT
#define AVL_MAX_HEIGHT	32
#endif
#define AVL_HEAD(name, type)						\
struct name {								\
	struct type	*avlh_root;	/* root of the tree */		\
}

#define AVL_INITIALIZER(root)						\
	{ NULL }

#define AVL_INIT(root)	do {						\
	(root)->avlh_root = NULL;					\
} while (0)

#define AVL_ENTRY(type)							\
struct {								\
	struct type	*avle_left;		/* left element */	\
	struct type	*avle_right;		/* right element */	\
	int		avle_height;		/* node height */	\
}

#define AVL_LEFT(elm, field)		(elm)->field.avle_left
#define AVL_RIGHT(elm, field)		(elm)->field.avle_right
#define AVL_HEIGHT(elm, field)		(elm)->field.avle_height
#define AVL_ROOT(head)			(head)->avlh_root
#define AVL_EMPTY(head)			(AVL_ROOT(head) == NULL)

/* Generates prototypes and inline functions */
#define	AVL_PROTOTYPE(name, type, field, cmp)				\
	AVL_PROTOTYPE_INTERNAL(name, type, field, cmp,)
#define	AVL_PROTOTYPE_STATIC(name, type, field, cmp)			\
	AVL_PROTOTYPE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
#define AVL_PROTOTYPE_INTERNAL(name, type, field, cmp, attr)		\
attr struct type *name##_AVL_REMOVE(struct name *, struct type *);	\
attr struct type *name##_AVL_INSERT(struct name *, struct type *);	\
attr struct type *name##_AVL_FIND(struct name *, struct type *);	\
attr struct type *name##_AVL_NFIND(struct name *, struct type *);	\
attr struct type *name##_AVL_NEXT(struct name *, struct type *);	\
attr struct type *name##_AVL_PREV(struct name *, struct type *);	\
attr struct type *name##_AVL_MIN(struct name *);			\
attr struct type *name##_AVL_MAX(struct name *);			

#define AVL_ROTATE_LEFT(parent, elm, type, field) do {					\
	struct type *_rl = AVL_LEFT(elm, field);					\
	struct type *_rr = AVL_RIGHT(elm, field);					\
	int _l = !_rl ? 0 : AVL_HEIGHT(_rl, field);					\
											\
	if (_rr && AVL_HEIGHT(_rr, field) >= _l) {					\
		AVL_RIGHT(*parent, field) = _rl;					\
		AVL_HEIGHT(*parent, field) = _l + 1;					\
		AVL_LEFT(elm, field) = (*parent);					\
		AVL_HEIGHT(elm, field) = _l + 2;					\
		(*parent) = (elm);							\
	} else {									\
		AVL_RIGHT(*parent, field) = AVL_LEFT(_rl, field);			\
		AVL_HEIGHT(*parent, field) = _l;					\
		AVL_LEFT(elm, field) = AVL_RIGHT(_rl, field);				\
		AVL_HEIGHT(elm, field) = _l;						\
		AVL_LEFT(_rl, field) = (*parent);					\
		AVL_RIGHT(_rl, field) = (elm);						\
		AVL_HEIGHT(_rl, field) = _l + 1;					\
		(*parent) = _rl;							\
	}										\
} while (0)

#define AVL_ROTATE_RIGHT(parent, elm, type, field) do {					\
	struct type *_ll = AVL_LEFT(elm, field);					\
	struct type *_lr = AVL_RIGHT(elm, field);					\
	int _r = !_lr ? 0 : AVL_HEIGHT(_lr, field);					\
											\
	if (_ll && AVL_HEIGHT(_ll, field) >= _r) {					\
		AVL_LEFT(*(parent), field) = _lr;					\
		AVL_HEIGHT(*(parent), field) = _r + 1;					\
		AVL_RIGHT(elm, field) = *parent;					\
		AVL_HEIGHT(elm, field) = _r + 2;					\
		*(parent) = (elm);							\
	} else {									\
		AVL_RIGHT(elm, field) = AVL_LEFT(_lr, field);				\
		AVL_HEIGHT(elm, field) = _r;						\
		AVL_LEFT(*parent, field) = AVL_RIGHT(_lr, field);			\
		AVL_HEIGHT(*parent, field) = _r;					\
		AVL_LEFT(_lr, field) = (elm);						\
		AVL_RIGHT(_lr, field) = (*parent);					\
		AVL_HEIGHT(_lr, field) = _r + 1;					\
		(*parent) = _lr;							\
	}										\
} while (0)

#define AVL_REBALANCE(_anc, type, field, count)	while (count-- > 0) {			\
	int _lh, _rh;									\
	struct type *_el = NULL;							\
											\
	_lh = !AVL_LEFT(*_anc[count], field) ? 0 : 					\
		AVL_HEIGHT(AVL_LEFT(*_anc[count], field), field);			\
	_rh = !AVL_RIGHT(*_anc[count], field) ? 0 : 					\
		AVL_HEIGHT(AVL_RIGHT(*_anc[count], field), field);			\
											\
	if (_rh - _lh < -1) {								\
		_el = AVL_LEFT(*_anc[count], field);					\
		AVL_ROTATE_RIGHT(_anc[count], _el, type, field);			\
	} else if (_rh - _lh > 1) { 							\
		_el = AVL_RIGHT(*_anc[count], field);					\
		AVL_ROTATE_LEFT(_anc[count], _el, type, field);				\
	} else if (AVL_HEIGHT(*_anc[count], field) != ((_rh > _lh) ? _rh : _lh) + 1)	\
		AVL_HEIGHT(*_anc[count], field) = ((_rh > _lh) ? _rh : _lh) + 1;	\
	else										\
		break;									\
}

/* Main avl operation.
 * Moves node close to the key of elm to top
 */
#define	AVL_GENERATE(name, type, field, cmp)						\
	AVL_GENERATE_INTERNAL(name, type, field, cmp,)
#define	AVL_GENERATE_STATIC(name, type, field, cmp)					\
	AVL_GENERATE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
#define AVL_GENERATE_INTERNAL(name, type, field, cmp, attr)				\
attr struct type *									\
name##_AVL_MIN(struct name *head)							\
{											\
	struct type *t = AVL_ROOT(head);						\
											\
	while (t && AVL_LEFT(t, field))							\
		t = AVL_LEFT(t, field);							\
	return (t);									\
}											\
											\
attr struct type *									\
name##_AVL_MAX(struct name *head)							\
{											\
	struct type *t = AVL_ROOT(head);						\
											\
	while (t && AVL_RIGHT(t, field))						\
		t = AVL_RIGHT(t, field);						\
	return (t);									\
}											\
											\
/* Finds the node with the same key as elm */						\
attr struct type *									\
name##_AVL_FIND(struct name *head, struct type *elm)					\
{											\
	struct type *t = AVL_ROOT(head);						\
	int comp;									\
	while (t) {									\
		comp = cmp(t, elm);							\
		if (!comp)								\
			return (t);							\
		else if (comp < 0)							\
			t = AVL_LEFT(t, field);						\
		else									\
			t = AVL_RIGHT(t, field);					\
	}										\
	return (NULL);									\
}											\
											\
/* Finds the first node less than or equal to the search key */				\
attr struct type *									\
name##_AVL_NFIND(struct name *head, struct type *elm)					\
{											\
	struct type *t = AVL_ROOT(head);						\
	struct type *res = NULL;							\
	int comp;									\
	while (t) {									\
		comp = cmp(t, elm);							\
		if (!comp)								\
			return (t);							\
		else if (comp < 0) {							\
			res = t;							\
			t = AVL_LEFT(t, field);						\
		} else									\
			t = AVL_RIGHT(t, field);					\
	}										\
	return (res);									\
}											\
											\
/* ARGSUSED */										\
attr struct type *									\
name##_AVL_NEXT(struct name *head, struct type *elm)					\
{											\
	struct type *t = AVL_ROOT(head);						\
	struct type *res = NULL;							\
	int comp;									\
	while (t) {									\
		comp = cmp(t, elm);							\
		if (comp < 0) {								\
			res = t;							\
			t = AVL_LEFT(t, field);						\
		} else									\
			t = AVL_RIGHT(t, field);					\
	}										\
	return (res);									\
}											\
											\
/* ARGSUSED */										\
attr struct type *									\
name##_AVL_PREV(struct name *head, struct type *elm)					\
{											\
	struct type *t = AVL_ROOT(head);						\
	struct type *res = NULL;							\
	int comp;									\
	while (t) {									\
		comp = cmp(t, elm);							\
		if (comp > 0) {								\
			res = t;							\
			t = AVL_RIGHT(t, field);					\
		} else									\
			t = AVL_LEFT(t, field);						\
	}										\
	return (res);									\
}											\
											\
/* Inserts a node into the AVL tree */							\
attr struct type *									\
name##_AVL_INSERT(struct name *head, struct type *elm)					\
{											\
	struct type *temp, **pt;							\
	struct type **ancestors[AVL_MAX_HEIGHT] = { 0 };				\
	register int i;									\
	int comp;									\
											\
	for (i = 0, pt = &AVL_ROOT(head); i < AVL_MAX_HEIGHT && *pt; i++) {		\
		temp = *pt;								\
		ancestors[i] = pt;							\
		comp = (cmp)(temp, elm);						\
		if (!comp) 								\
			return temp;							\
		else if (comp < 0)							\
			pt = &AVL_LEFT(temp, field);					\
		else									\
			pt = &AVL_RIGHT(temp, field);					\
	}										\
	*pt = elm;									\
											\
	AVL_LEFT(elm, field) = AVL_RIGHT(elm, field) = (struct type *) NULL;		\
	AVL_HEIGHT(elm, field) = 1;							\
											\
	AVL_REBALANCE(ancestors, type, field, i);					\
	return (NULL);									\
}											\
											\
attr struct type *									\
name##_AVL_REMOVE(struct name *head, struct type *elm)					\
{											\
	struct type *temp, *old, **dp, **pt;						\
	struct type **ancestors[AVL_MAX_HEIGHT] = { 0 };				\
	register int i;									\
	int comp, delcnt;								\
											\
	for (i = 0, pt = &AVL_ROOT(head); i < AVL_MAX_HEIGHT; i++) {			\
		if (!*pt)								\
			return (NULL);							\
		else									\
			temp = *pt;							\
		ancestors[i] = pt;							\
		comp = (cmp)(temp, elm);						\
		if (!comp) 								\
			break;								\
		else if (comp < 0)							\
			pt = &AVL_LEFT(temp, field);					\
		else									\
			pt = &AVL_RIGHT(temp, field);					\
	}										\
	old = temp;									\
											\
	if (!AVL_LEFT(temp, field)) {							\
		*pt = AVL_RIGHT(temp, field);						\
		i--;									\
	} else {									\
		delcnt = i;								\
		dp = pt;								\
		for (pt = &AVL_LEFT(temp, field); i < AVL_MAX_HEIGHT && 		\
				AVL_RIGHT(temp, field); i++) {				\
			temp = *pt;							\
			ancestors[i] = pt;						\
			pt = &AVL_RIGHT(temp, field);					\
		}									\
		*pt = AVL_LEFT(temp, field);						\
											\
		AVL_LEFT(temp, field) = AVL_LEFT(old, field);				\
		AVL_RIGHT(temp, field) = AVL_RIGHT(old, field);				\
		AVL_HEIGHT(temp, field) = AVL_HEIGHT(old, field);			\
		*dp = temp;								\
											\
		ancestors[delcnt] = &AVL_LEFT(temp, field);				\
	}										\
											\
	AVL_REBALANCE(ancestors, type, field, i);					\
	return (old);									\
}

#define AVL_INSERT(name, x, y)	name##_AVL_INSERT(x, y)
#define AVL_REMOVE(name, x, y)	name##_AVL_REMOVE(x, y)
#define AVL_FIND(name, x, y)	name##_AVL_FIND(x, y)
#define AVL_NFIND(name, x, y)	name##_AVL_NFIND(x, y)
#define AVL_NEXT(name, x, y)	name##_AVL_NEXT(x, y)
#define AVL_PREV(name, x, y)	name##_AVL_PREV(x, y)
#define AVL_MIN(name, x)	name##_AVL_MIN(x)
#define AVL_MAX(name, x)	name##_AVL_MAX(x)

#define AVL_FOREACH(x, name, head)							\
	for ((x) = name##_AVL_MIN(head);						\
	     (x) != NULL;								\
	     (x) = name##_AVL_NEXT(head, x))

#define AVL_FOREACH_REVERSE(x, name, head)						\
	for ((x) = name##_AVL_MAX(head);						\
	     (x) != NULL;								\
	     (x) = name##_AVL_PREV(head, x))

#define AVL_FOREACH_SAFE(x, name, head, y)						\
	for ((x) = name##_AVL_MIN(head);						\
	     (x) && ((y) = name##_AVL_NEXT(head, x), (x));				\
	     (x) = (y))

#define AVL_FOREACH_REVERSE_SAFE(x, name, head, y)					\
	for ((x) = name##_AVL_MAX(head);						\
	     (x) && ((y) = name##_AVL_PREV(head, x), (x));				\
	     (x) = (y))


#endif	/* _SYS_TREE_H_ */

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