cregit-Linux how code gets into the kernel

Release 4.15 include/linux/rbtree.h

Directory: include/linux
/*
  Red Black Trees
  (C) 1999  Andrea Arcangeli <andrea@suse.de>
  
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  linux/include/linux/rbtree.h

  To use rbtrees you'll have to implement your own insert and search cores.
  This will avoid us to use callbacks and to drop drammatically performances.
  I know it's not the cleaner way,  but in C (not in C++) to get
  performances and genericity...

  See Documentation/rbtree.txt for documentation and samples.
*/

#ifndef	_LINUX_RBTREE_H

#define	_LINUX_RBTREE_H

#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/rcupdate.h>


struct rb_node {
	
unsigned long  __rb_parent_color;
	
struct rb_node *rb_right;
	
struct rb_node *rb_left;
} __attribute__((aligned(sizeof(long))));
    /* The alignment might seem pointless, but allegedly CRIS needs it */


struct rb_root {
	
struct rb_node *rb_node;
};

/*
 * Leftmost-cached rbtrees.
 *
 * We do not cache the rightmost node based on footprint
 * size vs number of potential users that could benefit
 * from O(1) rb_last(). Just not worth it, users that want
 * this feature can always implement the logic explicitly.
 * Furthermore, users that want to cache both pointers may
 * find it a bit asymmetric, but that's ok.
 */

struct rb_root_cached {
	
struct rb_root rb_root;
	
struct rb_node *rb_leftmost;
};


#define rb_parent(r)   ((struct rb_node *)((r)->__rb_parent_color & ~3))


#define RB_ROOT	(struct rb_root) { NULL, }

#define RB_ROOT_CACHED (struct rb_root_cached) { {NULL, }, NULL }

#define	rb_entry(ptr, type, member) container_of(ptr, type, member)


#define RB_EMPTY_ROOT(root)  (READ_ONCE((root)->rb_node) == NULL)

/* 'empty' nodes are nodes that are known not to be inserted in an rbtree */

#define RB_EMPTY_NODE(node)  \
	((node)->__rb_parent_color == (unsigned long)(node))

#define RB_CLEAR_NODE(node)  \
	((node)->__rb_parent_color = (unsigned long)(node))


extern void rb_insert_color(struct rb_node *, struct rb_root *);
extern void rb_erase(struct rb_node *, struct rb_root *);


/* Find logical next and previous nodes in a tree */
extern struct rb_node *rb_next(const struct rb_node *);
extern struct rb_node *rb_prev(const struct rb_node *);
extern struct rb_node *rb_first(const struct rb_root *);
extern struct rb_node *rb_last(const struct rb_root *);

extern void rb_insert_color_cached(struct rb_node *,
				   struct rb_root_cached *, bool);
extern void rb_erase_cached(struct rb_node *node, struct rb_root_cached *);
/* Same as rb_first(), but O(1) */

#define rb_first_cached(root) (root)->rb_leftmost

/* Postorder iteration - always visit the parent after its children */
extern struct rb_node *rb_first_postorder(const struct rb_root *);
extern struct rb_node *rb_next_postorder(const struct rb_node *);

/* Fast replacement of a single node without remove/rebalance/add/rebalance */
extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
			    struct rb_root *root);
extern void rb_replace_node_rcu(struct rb_node *victim, struct rb_node *new,
				struct rb_root *root);
extern void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,
				   struct rb_root_cached *root);


static inline void rb_link_node(struct rb_node *node, struct rb_node *parent, struct rb_node **rb_link) { node->__rb_parent_color = (unsigned long)parent; node->rb_left = node->rb_right = NULL; *rb_link = node; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds3777.08%125.00%
David Woodhouse1020.83%250.00%
Michel Lespinasse12.08%125.00%
Total48100.00%4100.00%


static inline void rb_link_node_rcu(struct rb_node *node, struct rb_node *parent, struct rb_node **rb_link) { node->__rb_parent_color = (unsigned long)parent; node->rb_left = node->rb_right = NULL; rcu_assign_pointer(*rb_link, node); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra51100.00%1100.00%
Total51100.00%1100.00%

#define rb_entry_safe(ptr, type, member) \ ({ typeof(ptr) ____ptr = (ptr); \ ____ptr ? rb_entry(____ptr, type, member) : NULL; \ }) /** * rbtree_postorder_for_each_entry_safe - iterate in post-order over rb_root of * given type allowing the backing memory of @pos to be invalidated * * @pos: the 'type *' to use as a loop cursor. * @n: another 'type *' to use as temporary storage * @root: 'rb_root *' of the rbtree. * @field: the name of the rb_node field within 'type'. * * rbtree_postorder_for_each_entry_safe() provides a similar guarantee as * list_for_each_entry_safe() and allows the iteration to continue independent * of changes to @pos by the body of the loop. * * Note, however, that it cannot handle other modifications that re-order the * rbtree it is iterating over. This includes calling rb_erase() on @pos, as * rb_erase() may rebalance the tree, causing us to miss some nodes. */ #define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \ for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \ pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \ typeof(*pos), field); 1; }); \ pos = n) #endif /* _LINUX_RBTREE_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
David Woodhouse9721.56%520.83%
Linus Torvalds9521.11%14.17%
Davidlohr Bueso A5712.67%28.33%
Peter Zijlstra5512.22%28.33%
Cody P Schafer398.67%312.50%
David Howells204.44%14.17%
Chris Wilson204.44%14.17%
Jens Axboe184.00%14.17%
Jan Kara132.89%14.17%
Andrew Morton112.44%14.17%
Patrick McHardy112.44%14.17%
Michel Lespinasse81.78%28.33%
Artem B. Bityutskiy40.89%14.17%
Paolo 'Blaisorblade' Giarrusso10.22%14.17%
John de la Garza10.22%14.17%
Total450100.00%24100.00%
Directory: include/linux
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