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Release 4.12 include/linux/rbtree_augmented.h

Directory: include/linux
/*
  Red Black Trees
  (C) 1999  Andrea Arcangeli <andrea@suse.de>
  (C) 2002  David Woodhouse <dwmw2@infradead.org>
  (C) 2012  Michel Lespinasse <walken@google.com>

  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_augmented.h
*/

#ifndef _LINUX_RBTREE_AUGMENTED_H

#define _LINUX_RBTREE_AUGMENTED_H

#include <linux/compiler.h>
#include <linux/rbtree.h>

/*
 * Please note - only struct rb_augment_callbacks and the prototypes for
 * rb_insert_augmented() and rb_erase_augmented() are intended to be public.
 * The rest are implementation details you are not expected to depend on.
 *
 * See Documentation/rbtree.txt for documentation and samples.
 */


struct rb_augment_callbacks {
	
void (*propagate)(struct rb_node *node, struct rb_node *stop);
	
void (*copy)(struct rb_node *old, struct rb_node *new);
	
void (*rotate)(struct rb_node *old, struct rb_node *new);
};

extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
	void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
/*
 * Fixup the rbtree and update the augmented information when rebalancing.
 *
 * On insertion, the user must update the augmented information on the path
 * leading to the inserted node, then call rb_link_node() as usual and
 * rb_augment_inserted() instead of the usual rb_insert_color() call.
 * If rb_augment_inserted() rebalances the rbtree, it will callback into
 * a user provided function to update the augmented information on the
 * affected subtrees.
 */

static inline void rb_insert_augmented(struct rb_node *node, struct rb_root *root, const struct rb_augment_callbacks *augment) { __rb_insert_augmented(node, root, augment->rotate); }

Contributors

PersonTokensPropCommitsCommitProp
Michel Lespinasse34100.00%1100.00%
Total34100.00%1100.00%

#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \ rbtype, rbaugmented, rbcompute) \ static inline void \ rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \ { \ while (rb != stop) { \ rbstruct *node = rb_entry(rb, rbstruct, rbfield); \ rbtype augmented = rbcompute(node); \ if (node->rbaugmented == augmented) \ break; \ node->rbaugmented = augmented; \ rb = rb_parent(&node->rbfield); \ } \ } \ static inline void \ rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \ { \ rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \ rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \ new->rbaugmented = old->rbaugmented; \ } \ static void \ rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \ { \ rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \ rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \ new->rbaugmented = old->rbaugmented; \ old->rbaugmented = rbcompute(old); \ } \ rbstatic const struct rb_augment_callbacks rbname = { \ .propagate = rbname ## _propagate, \ .copy = rbname ## _copy, \ .rotate = rbname ## _rotate \ }; #define RB_RED 0 #define RB_BLACK 1 #define __rb_parent(pc) ((struct rb_node *)(pc & ~3)) #define __rb_color(pc) ((pc) & 1) #define __rb_is_black(pc) __rb_color(pc) #define __rb_is_red(pc) (!__rb_color(pc)) #define rb_color(rb) __rb_color((rb)->__rb_parent_color) #define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color) #define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color)
static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p) { rb->__rb_parent_color = rb_color(rb) | (unsigned long)p; }

Contributors

PersonTokensPropCommitsCommitProp
Michel Lespinasse32100.00%1100.00%
Total32100.00%1100.00%


static inline void rb_set_parent_color(struct rb_node *rb, struct rb_node *p, int color) { rb->__rb_parent_color = (unsigned long)p | color; }

Contributors

PersonTokensPropCommitsCommitProp
Michel Lespinasse32100.00%1100.00%
Total32100.00%1100.00%


static inline void __rb_change_child(struct rb_node *old, struct rb_node *new, struct rb_node *parent, struct rb_root *root) { if (parent) { if (parent->rb_left == old) WRITE_ONCE(parent->rb_left, new); else WRITE_ONCE(parent->rb_right, new); } else WRITE_ONCE(root->rb_node, new); }

Contributors

PersonTokensPropCommitsCommitProp
Michel Lespinasse5882.86%150.00%
Peter Zijlstra1217.14%150.00%
Total70100.00%2100.00%


static inline void __rb_change_child_rcu(struct rb_node *old, struct rb_node *new, struct rb_node *parent, struct rb_root *root) { if (parent) { if (parent->rb_left == old) rcu_assign_pointer(parent->rb_left, new); else rcu_assign_pointer(parent->rb_right, new); } else rcu_assign_pointer(root->rb_node, new); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells70100.00%1100.00%
Total70100.00%1100.00%

extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root, void (*augment_rotate)(struct rb_node *old, struct rb_node *new)); static __always_inline struct rb_node * __rb_erase_augmented(struct rb_node *node, struct rb_root *root, const struct rb_augment_callbacks *augment) { struct rb_node *child = node->rb_right; struct rb_node *tmp = node->rb_left; struct rb_node *parent, *rebalance; unsigned long pc; if (!tmp) { /* * Case 1: node to erase has no more than 1 child (easy!) * * Note that if there is one child it must be red due to 5) * and node must be black due to 4). We adjust colors locally * so as to bypass __rb_erase_color() later on. */ pc = node->__rb_parent_color; parent = __rb_parent(pc); __rb_change_child(node, child, parent, root); if (child) { child->__rb_parent_color = pc; rebalance = NULL; } else rebalance = __rb_is_black(pc) ? parent : NULL; tmp = parent; } else if (!child) { /* Still case 1, but this time the child is node->rb_left */ tmp->__rb_parent_color = pc = node->__rb_parent_color; parent = __rb_parent(pc); __rb_change_child(node, tmp, parent, root); rebalance = NULL; tmp = parent; } else { struct rb_node *successor = child, *child2; tmp = child->rb_left; if (!tmp) { /* * Case 2: node's successor is its right child * * (n) (s) * / \ / \ * (x) (s) -> (x) (c) * \ * (c) */ parent = successor; child2 = successor->rb_right; augment->copy(node, successor); } else { /* * Case 3: node's successor is leftmost under * node's right child subtree * * (n) (s) * / \ / \ * (x) (y) -> (x) (y) * / / * (p) (p) * / / * (s) (c) * \ * (c) */ do { parent = successor; successor = tmp; tmp = tmp->rb_left; } while (tmp); child2 = successor->rb_right; WRITE_ONCE(parent->rb_left, child2); WRITE_ONCE(successor->rb_right, child); rb_set_parent(child, successor); augment->copy(node, successor); augment->propagate(parent, successor); } tmp = node->rb_left; WRITE_ONCE(successor->rb_left, tmp); rb_set_parent(tmp, successor); pc = node->__rb_parent_color; tmp = __rb_parent(pc); __rb_change_child(node, successor, tmp, root); if (child2) { successor->__rb_parent_color = pc; rb_set_parent_color(child2, parent, RB_BLACK); rebalance = NULL; } else { unsigned long pc2 = successor->__rb_parent_color; successor->__rb_parent_color = pc; rebalance = __rb_is_black(pc2) ? parent : NULL; } tmp = successor; } augment->propagate(tmp, NULL); return rebalance;
} static __always_inline void rb_erase_augmented(struct rb_node *node, struct rb_root *root, const struct rb_augment_callbacks *augment) { struct rb_node *rebalance = __rb_erase_augmented(node, root, augment); if (rebalance) __rb_erase_color(rebalance, root, augment->rotate); }

Contributors

PersonTokensPropCommitsCommitProp
Michel Lespinasse52100.00%2100.00%
Total52100.00%2100.00%

#endif /* _LINUX_RBTREE_AUGMENTED_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Michel Lespinasse77987.53%228.57%
David Howells707.87%114.29%
Peter Zijlstra364.04%114.29%
Will Deacon30.34%114.29%
Kees Cook10.11%114.29%
Lai Jiangshan10.11%114.29%
Total890100.00%7100.00%
Directory: include/linux
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