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1da177e4 LT |
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 | ||
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 | ||
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 */ |