Line data Source code
1 : #ifndef _LINUX_PRIO_TREE_H
2 : #define _LINUX_PRIO_TREE_H
3 :
4 : /*
5 : * K&R 2nd ed. A8.3 somewhat obliquely hints that initial sequences of struct
6 : * fields with identical types should end up at the same location. We'll use
7 : * this until we can scrap struct raw_prio_tree_node.
8 : *
9 : * Note: all this could be done more elegantly by using unnamed union/struct
10 : * fields. However, gcc 2.95.3 and apparently also gcc 3.0.4 don't support this
11 : * language extension.
12 : */
13 :
14 : struct raw_prio_tree_node {
15 : struct prio_tree_node *left;
16 : struct prio_tree_node *right;
17 : struct prio_tree_node *parent;
18 : };
19 1 :
20 : struct prio_tree_node {
21 : struct prio_tree_node *left;
22 : struct prio_tree_node *right;
23 : struct prio_tree_node *parent;
24 : unsigned long start;
25 : unsigned long last; /* last location _in_ interval */
26 : };
27 1 :
28 : struct prio_tree_root {
29 : struct prio_tree_node *prio_tree_node;
30 : unsigned short index_bits;
31 : unsigned short raw;
32 : /*
33 : * 0: nodes are of type struct prio_tree_node
34 : * 1: nodes are of type raw_prio_tree_node
35 : */
36 : };
37 :
38 : struct prio_tree_iter {
39 : struct prio_tree_node *cur;
40 : unsigned long mask;
41 : unsigned long value;
42 : int size_level;
43 :
44 : struct prio_tree_root *root;
45 : pgoff_t r_index;
46 : pgoff_t h_index;
47 : };
48 :
49 : static inline void prio_tree_iter_init(struct prio_tree_iter *iter,
50 : struct prio_tree_root *root, pgoff_t r_index, pgoff_t h_index)
51 : {
52 : iter->root = root;
53 : iter->r_index = r_index;
54 : iter->h_index = h_index;
55 : iter->cur = NULL;
56 : }
57 :
58 : #define __INIT_PRIO_TREE_ROOT(ptr, _raw) \
59 : do { \
60 : (ptr)->prio_tree_node = NULL; \
61 : (ptr)->index_bits = 1; \
62 : (ptr)->raw = (_raw); \
63 : } while (0)
64 :
65 : #define INIT_PRIO_TREE_ROOT(ptr) __INIT_PRIO_TREE_ROOT(ptr, 0)
66 : #define INIT_RAW_PRIO_TREE_ROOT(ptr) __INIT_PRIO_TREE_ROOT(ptr, 1)
67 :
68 : #define INIT_PRIO_TREE_NODE(ptr) \
69 : do { \
70 : (ptr)->left = (ptr)->right = (ptr)->parent = (ptr); \
71 : } while (0)
72 :
73 : #define INIT_PRIO_TREE_ITER(ptr) \
74 : do { \
75 : (ptr)->cur = NULL; \
76 : (ptr)->mask = 0UL; \
77 : (ptr)->value = 0UL; \
78 : (ptr)->size_level = 0; \
79 : } while (0)
80 :
81 : #define prio_tree_entry(ptr, type, member) \
82 : ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
83 :
84 : static inline int prio_tree_empty(const struct prio_tree_root *root)
85 : {
86 : return root->prio_tree_node == NULL;
87 : }
88 :
89 : static inline int prio_tree_root(const struct prio_tree_node *node)
90 : {
91 : return node->parent == node;
92 : }
93 :
94 : static inline int prio_tree_left_empty(const struct prio_tree_node *node)
95 : {
96 : return node->left == node;
97 : }
98 :
99 : static inline int prio_tree_right_empty(const struct prio_tree_node *node)
100 : {
101 : return node->right == node;
102 : }
103 :
104 :
105 : struct prio_tree_node *prio_tree_replace(struct prio_tree_root *root,
106 : struct prio_tree_node *old, struct prio_tree_node *node);
107 : struct prio_tree_node *prio_tree_insert(struct prio_tree_root *root,
108 : struct prio_tree_node *node);
109 : void prio_tree_remove(struct prio_tree_root *root, struct prio_tree_node *node);
110 : struct prio_tree_node *prio_tree_next(struct prio_tree_iter *iter);
111 :
112 : #define raw_prio_tree_replace(root, old, node) \
113 : prio_tree_replace(root, (struct prio_tree_node *) (old), \
114 : (struct prio_tree_node *) (node))
115 : #define raw_prio_tree_insert(root, node) \
116 : prio_tree_insert(root, (struct prio_tree_node *) (node))
117 : #define raw_prio_tree_remove(root, node) \
118 : prio_tree_remove(root, (struct prio_tree_node *) (node))
119 :
120 : #endif /* _LINUX_PRIO_TREE_H */
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