include/linux/prio_tree.h

   1 #ifndef _LINUX_PRIO_TREE_H
   2 #define _LINUX_PRIO_TREE_H
   3
   4 struct prio_tree_node {
   5         struct prio_tree_node   *left;
   6         struct prio_tree_node   *right;
   7         struct prio_tree_node   *parent;
   8 };
   9
  10 struct prio_tree_root {
  11         struct prio_tree_node   *prio_tree_node;
  12         unsigned int            index_bits;
  13 };
  14
  15 struct prio_tree_iter {
  16         struct prio_tree_node   *cur;
  17         unsigned long           mask;
  18         unsigned long           value;
  19         int                     size_level;
  20 };
  21
  22 #define INIT_PRIO_TREE_ROOT(ptr)        \
  23 do {                                    \
  24         (ptr)->prio_tree_node = NULL;   \
  25         (ptr)->index_bits = 1;          \
  26 } while (0)
  27
  28 #define INIT_PRIO_TREE_NODE(ptr)                                \
  29 do {                                                            \
  30         (ptr)->left = (ptr)->right = (ptr)->parent = (ptr);     \
  31 } while (0)
  32
  33 #define INIT_PRIO_TREE_ITER(ptr)        \
  34 do {                                    \
  35         (ptr)->cur = NULL;              \
  36         (ptr)->mask = 0UL;              \
  37         (ptr)->value = 0UL;             \
  38         (ptr)->size_level = 0;          \
  39 } while (0)
  40
  41 #define prio_tree_entry(ptr, type, member) \
  42        ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
  43
  44 static inline int prio_tree_empty(const struct prio_tree_root *root)
  45 {
  46         return root->prio_tree_node == NULL;
  47 }
  48
  49 static inline int prio_tree_root(const struct prio_tree_node *node)
  50 {
  51         return node->parent == node;
  52 }
  53
  54 static inline int prio_tree_left_empty(const struct prio_tree_node *node)
  55 {
  56         return node->left == node;
  57 }
  58
  59 static inline int prio_tree_right_empty(const struct prio_tree_node *node)
  60 {
  61         return node->right == node;
  62 }
  63
  64 #endif /* _LINUX_PRIO_TREE_H */