LXR linux/include/linux/rbtree

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2#ifndef _LINUX_RBTREE_TYPES_H
   3#define _LINUX_RBTREE_TYPES_H
   4
   5struct rb_node {
   6        unsigned long  __rb_parent_color;
   7        struct rb_node *rb_right;
   8        struct rb_node *rb_left;
   9} __attribute__((aligned(sizeof(long))));
  10/* The alignment might seem pointless, but allegedly CRIS needs it */
  11
  12struct rb_root {
  13        struct rb_node *rb_node;
  14};
  15
  16/*
  17 * Leftmost-cached rbtrees.
  18 *
  19 * We do not cache the rightmost node based on footprint
  20 * size vs number of potential users that could benefit
  21 * from O(1) rb_last(). Just not worth it, users that want
  22 * this feature can always implement the logic explicitly.
  23 * Furthermore, users that want to cache both pointers may
  24 * find it a bit asymmetric, but that's ok.
  25 */
  26struct rb_root_cached {
  27        struct rb_root rb_root;
  28        struct rb_node *rb_leftmost;
  29};
  30
  31#define RB_ROOT (struct rb_root) { NULL, }
  32#define RB_ROOT_CACHED (struct rb_root_cached) { {NULL, }, NULL }
  33
  34#endif
  35