SystemConfiguration.fproj/reachability/rb.h

   1 /* $NetBSD: rb.h,v 1.13 2009/08/16 10:57:01 yamt Exp $ */
   2
   3 /*-
   4  * Copyright (c) 2001 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
   8  *
   9  * This code is derived from software contributed to The NetBSD Foundation
  10  * by Matt Thomas <matt@3am-software.com>.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  */
  33 #ifndef _SYS_RB_H_
  34 #define _SYS_RB_H_
  35
  36 #if defined(_KERNEL) || defined(_STANDALONE)
  37 #include <sys/types.h>
  38 #else
  39 #include <stdbool.h>
  40 #include <inttypes.h>
  41 #endif
  42 #include <sys/queue.h>
  43 #ifndef __APPLE__
  44 #include <sys/endian.h>
  45 #endif
  46
  47 struct rb_node {
  48         struct rb_node *rb_nodes[2];
  49 #define RB_DIR_LEFT             0
  50 #define RB_DIR_RIGHT            1
  51 #define RB_DIR_OTHER            1
  52 #define rb_left                 rb_nodes[RB_DIR_LEFT]
  53 #define rb_right                rb_nodes[RB_DIR_RIGHT]
  54
  55         /*
  56          * rb_info contains the two flags and the parent back pointer.
  57          * We put the two flags in the low two bits since we know that
  58          * rb_node will have an alignment of 4 or 8 bytes.
  59          */
  60         uintptr_t rb_info;
  61 #define RB_FLAG_POSITION        0x2
  62 #define RB_FLAG_RED             0x1
  63 #define RB_FLAG_MASK            (RB_FLAG_POSITION|RB_FLAG_RED)
  64 #define RB_FATHER(rb) \
  65     ((struct rb_node *)((rb)->rb_info & ~RB_FLAG_MASK))
  66 #define RB_SET_FATHER(rb, father) \
  67     ((void)((rb)->rb_info = (uintptr_t)(father)|((rb)->rb_info & RB_FLAG_MASK)))
  68
  69 #define RB_SENTINEL_P(rb)       ((rb) == NULL)
  70 #define RB_LEFT_SENTINEL_P(rb)  RB_SENTINEL_P((rb)->rb_left)
  71 #define RB_RIGHT_SENTINEL_P(rb) RB_SENTINEL_P((rb)->rb_right)
  72 #define RB_FATHER_SENTINEL_P(rb) RB_SENTINEL_P(RB_FATHER((rb)))
  73 #define RB_CHILDLESS_P(rb) \
  74     (RB_SENTINEL_P(rb) || (RB_LEFT_SENTINEL_P(rb) && RB_RIGHT_SENTINEL_P(rb)))
  75 #define RB_TWOCHILDREN_P(rb) \
  76     (!RB_SENTINEL_P(rb) && !RB_LEFT_SENTINEL_P(rb) && !RB_RIGHT_SENTINEL_P(rb))
  77
  78 #define RB_POSITION(rb) \
  79     (((rb)->rb_info & RB_FLAG_POSITION) ? RB_DIR_RIGHT : RB_DIR_LEFT)
  80 #define RB_RIGHT_P(rb)          (RB_POSITION(rb) == RB_DIR_RIGHT)
  81 #define RB_LEFT_P(rb)           (RB_POSITION(rb) == RB_DIR_LEFT)
  82 #define RB_RED_P(rb)            (!RB_SENTINEL_P(rb) && ((rb)->rb_info & RB_FLAG_RED) != 0)
  83 #define RB_BLACK_P(rb)          (RB_SENTINEL_P(rb) || ((rb)->rb_info & RB_FLAG_RED) == 0)
  84 #define RB_MARK_RED(rb)         ((void)((rb)->rb_info |= RB_FLAG_RED))
  85 #define RB_MARK_BLACK(rb)       ((void)((rb)->rb_info &= ~RB_FLAG_RED))
  86 #define RB_INVERT_COLOR(rb)     ((void)((rb)->rb_info ^= RB_FLAG_RED))
  87 #define RB_ROOT_P(rbt, rb)      ((rbt)->rbt_root == (rb))
  88 #define RB_SET_POSITION(rb, position) \
  89     ((void)((position) ? ((rb)->rb_info |= RB_FLAG_POSITION) : \
  90     ((rb)->rb_info &= ~RB_FLAG_POSITION)))
  91 #define RB_ZERO_PROPERTIES(rb)  ((void)((rb)->rb_info &= ~RB_FLAG_MASK))
  92 #define RB_COPY_PROPERTIES(dst, src) \
  93     ((void)((dst)->rb_info ^= ((dst)->rb_info ^ (src)->rb_info) & RB_FLAG_MASK))
  94 #define RB_SWAP_PROPERTIES(a, b) do { \
  95     uintptr_t xorinfo = ((a)->rb_info ^ (b)->rb_info) & RB_FLAG_MASK; \
  96     (a)->rb_info ^= xorinfo; \
  97     (b)->rb_info ^= xorinfo; \
  98   } while (/*CONSTCOND*/ 0)
  99 #ifdef RBDEBUG
 100         TAILQ_ENTRY(rb_node) rb_link;
 101 #endif
 102 };
 103
 104 #define RB_TREE_MIN(T) rb_tree_iterate((T), NULL, RB_DIR_LEFT)
 105 #define RB_TREE_MAX(T) rb_tree_iterate((T), NULL, RB_DIR_RIGHT)
 106 #define RB_TREE_FOREACH(N, T) \
 107     for ((N) = RB_TREE_MIN(T); (N); \
 108         (N) = rb_tree_iterate((T), (N), RB_DIR_RIGHT))
 109 #define RB_TREE_FOREACH_REVERSE(N, T) \
 110     for ((N) = RB_TREE_MAX(T); (N); \
 111         (N) = rb_tree_iterate((T), (N), RB_DIR_LEFT))
 112
 113 #ifdef RBDEBUG
 114 TAILQ_HEAD(rb_node_qh, rb_node);
 115
 116 #define RB_TAILQ_REMOVE(a, b, c)                TAILQ_REMOVE(a, b, c)
 117 #define RB_TAILQ_INIT(a)                        TAILQ_INIT(a)
 118 #define RB_TAILQ_INSERT_HEAD(a, b, c)           TAILQ_INSERT_HEAD(a, b, c)
 119 #define RB_TAILQ_INSERT_BEFORE(a, b, c)         TAILQ_INSERT_BEFORE(a, b, c)
 120 #define RB_TAILQ_INSERT_AFTER(a, b, c, d)       TAILQ_INSERT_AFTER(a, b, c, d)
 121 #else
 122 #define RB_TAILQ_REMOVE(a, b, c)                do { } while (/*CONSTCOND*/0)
 123 #define RB_TAILQ_INIT(a)                        do { } while (/*CONSTCOND*/0)
 124 #define RB_TAILQ_INSERT_HEAD(a, b, c)           do { } while (/*CONSTCOND*/0)
 125 #define RB_TAILQ_INSERT_BEFORE(a, b, c)         do { } while (/*CONSTCOND*/0)
 126 #define RB_TAILQ_INSERT_AFTER(a, b, c, d)       do { } while (/*CONSTCOND*/0)
 127 #endif /* RBDEBUG */
 128
 129 /*
 130  * rbto_compare_nodes_fn:
 131  *      return a positive value if the first node < the second node.
 132  *      return a negative value if the first node > the second node.
 133  *      return 0 if they are considered same.
 134  *
 135  * rbto_compare_key_fn:
 136  *      return a positive value if the node < the key.
 137  *      return a negative value if the node > the key.
 138  *      return 0 if they are considered same.
 139  */
 140
 141 typedef signed int (*const rbto_compare_nodes_fn)(const struct rb_node *,
 142     const struct rb_node *);
 143 typedef signed int (*const rbto_compare_key_fn)(const struct rb_node *,
 144     const void *);
 145
 146 struct rb_tree_ops {
 147         rbto_compare_nodes_fn rbto_compare_nodes;
 148         rbto_compare_key_fn rbto_compare_key;
 149 };
 150
 151 struct rb_tree {
 152         struct rb_node *rbt_root;
 153         const struct rb_tree_ops *rbt_ops;
 154         struct rb_node *rbt_minmax[2];
 155 #ifdef RBDEBUG
 156         struct rb_node_qh rbt_nodes;
 157 #endif
 158         unsigned int rbt_count;
 159 #ifdef RBSTATS
 160         unsigned int rbt_insertions;
 161         unsigned int rbt_removals;
 162         unsigned int rbt_insertion_rebalance_calls;
 163         unsigned int rbt_insertion_rebalance_passes;
 164         unsigned int rbt_removal_rebalance_calls;
 165         unsigned int rbt_removal_rebalance_passes;
 166 #endif
 167 };
 168
 169 #ifdef RBSTATS
 170 #define RBSTAT_INC(v)   ((void)((v)++))
 171 #define RBSTAT_DEC(v)   ((void)((v)--))
 172 #else
 173 #define RBSTAT_INC(v)   do { } while (/*CONSTCOND*/0)
 174 #define RBSTAT_DEC(v)   do { } while (/*CONSTCOND*/0)
 175 #endif
 176
 177 void    rb_tree_init(struct rb_tree *, const struct rb_tree_ops *);
 178 bool    rb_tree_insert_node(struct rb_tree *, struct rb_node *);
 179 struct rb_node  *
 180         rb_tree_find_node(struct rb_tree *, const void *);
 181 struct rb_node  *
 182         rb_tree_find_node_geq(struct rb_tree *, const void *);
 183 struct rb_node  *
 184         rb_tree_find_node_leq(struct rb_tree *, const void *);
 185 void    rb_tree_remove_node(struct rb_tree *, struct rb_node *);
 186 struct rb_node *
 187         rb_tree_iterate(struct rb_tree *, struct rb_node *, const unsigned int);
 188 #ifdef RBDEBUG
 189 void    rb_tree_check(const struct rb_tree *, bool);
 190 #endif
 191 #ifdef RBSTATS
 192 void    rb_tree_depths(const struct rb_tree *, size_t *);
 193 #endif
 194
 195 #endif  /* _SYS_RB_H_*/