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         struct prio_tree_root   *root;
  22         pgoff_t                 r_index;
  23         pgoff_t                 h_index;
  24 };
  25
  26 static inline void prio_tree_iter_init(struct prio_tree_iter *iter,
  27                 struct prio_tree_root *root, pgoff_t r_index, pgoff_t h_index)
  28 {
  29         iter->root = root;
  30         iter->r_index = r_index;
  31         iter->h_index = h_index;
  32 }
  33
  34 #define INIT_PRIO_TREE_ROOT(ptr)        \
  35 do {                                    \
  36         (ptr)->prio_tree_node = NULL;   \
  37         (ptr)->index_bits = 1;          \
  38 } while (0)
  39
  40 #define INIT_PRIO_TREE_NODE(ptr)                                \
  41 do {                                                            \
  42         (ptr)->left = (ptr)->right = (ptr)->parent = (ptr);     \
  43 } while (0)
  44
  45 #define INIT_PRIO_TREE_ITER(ptr)        \
  46 do {                                    \
  47         (ptr)->cur = NULL;              \
  48         (ptr)->mask = 0UL;              \
  49         (ptr)->value = 0UL;             \
  50         (ptr)->size_level = 0;          \
  51 } while (0)
  52
  53 #define prio_tree_entry(ptr, type, member) \
  54        ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
  55
  56 static inline int prio_tree_empty(const struct prio_tree_root *root)
  57 {
  58         return root->prio_tree_node == NULL;
  59 }
  60
  61 static inline int prio_tree_root(const struct prio_tree_node *node)
  62 {
  63         return node->parent == node;
  64 }
  65
  66 static inline int prio_tree_left_empty(const struct prio_tree_node *node)
  67 {
  68         return node->left == node;
  69 }
  70
  71 static inline int prio_tree_right_empty(const struct prio_tree_node *node)
  72 {
  73         return node->right == node;
  74 }
  75
  76 #endif /* _LINUX_PRIO_TREE_H */