1 #ifndef _LINUX_HLIST_H
2 #define _LINUX_HLIST_H
3
4 /*
5 * Double linked lists with a single pointer list head.
6 * Mostly useful for hash tables where the two pointer list head is
7 * too wasteful.
8 * You lose the ability to access the tail in O(1).
9 */
10
11 struct hlist_head {
12 struct hlist_node *first;
13 };
14
15 struct hlist_node {
16 struct hlist_node *next, **pprev;
17 };
18
19 #ifndef offsetof
20 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
21 #endif
22
23 #ifndef container_of
24 /**
25 * container_of - cast a member of a structure out to the containing structure
26 * @ptr: the pointer to the member.
27 * @type: the type of the container struct this is embedded in.
28 * @member: the name of the member within the struct.
29 *
30 */
31 #define container_of(ptr, type, member) ({ 32 const typeof(((type *)0)->member) * __mptr = (ptr); 33 (type *)((char *)__mptr - offsetof(type, member)); })
34 #endif
35
36 #define HLIST_HEAD_INIT { .first = NULL }
37 #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }
38 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
39 static inline void INIT_HLIST_NODE(struct hlist_node *h)
40 {
41 h->next = NULL;
42 h->pprev = NULL;
43 }
44
45 static inline int hlist_unhashed(const struct hlist_node *h)
46 {
47 return !h->pprev;
48 }
49
50 static inline int hlist_empty(const struct hlist_head *h)
51 {
52 return !h->first;
53 }
54
55 static inline void __hlist_del(struct hlist_node *n)
56 {
57 struct hlist_node *next = n->next;
58 struct hlist_node **pprev = n->pprev;
59 *pprev = next;
60 if (next)
61 next->pprev = pprev;
62 }
63
64 static inline void hlist_del(struct hlist_node *n)
65 {
66 __hlist_del(n);
67 INIT_HLIST_NODE(n);
68 }
69
70 static inline void hlist_del_init(struct hlist_node *n)
71 {
72 if (!hlist_unhashed(n)) {
73 __hlist_del(n);
74 INIT_HLIST_NODE(n);
75 }
76 }
77
78 static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
79 {
80 struct hlist_node *first = h->first;
81 n->next = first;
82 if (first)
83 first->pprev = &n->next;
84 h->first = n;
85 n->pprev = &h->first;
86 }
87
88 /* next must be != NULL */
89 static inline void hlist_add_before(struct hlist_node *n,
90 struct hlist_node *next)
91 {
92 n->pprev = next->pprev;
93 n->next = next;
94 next->pprev = &n->next;
95 *(n->pprev) = n;
96 }
97
98 static inline void hlist_add_after(struct hlist_node *n,
99 struct hlist_node *next)
100 {
101 next->next = n->next;
102 n->next = next;
103 next->pprev = &n->next;
104
105 if(next->next)
106 next->next->pprev = &next->next;
107 }
108
109 /* after that we‘ll appear to be on some hlist and hlist_del will work */
110 static inline void hlist_add_fake(struct hlist_node *n)
111 {
112 n->pprev = &n->next;
113 }
114
115 /*
116 * Move a list from one list head to another. Fixup the pprev
117 * reference of the first entry if it exists.
118 */
119 static inline void hlist_move_list(struct hlist_head *old,
120 struct hlist_head *new)
121 {
122 new->first = old->first;
123 if (new->first)
124 new->first->pprev = &new->first;
125 old->first = NULL;
126 }
127
128 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
129
130 #define hlist_for_each(pos, head) 131 for (pos = (head)->first; pos ; pos = pos->next)
132
133 #define hlist_for_each_safe(pos, n, head) 134 for (pos = (head)->first; pos && ({ n = pos->next; 1; }); 135 pos = n)
136
137 /**
138 * hlist_for_each_entry - iterate over list of given type
139 * @tpos: the type * to use as a loop cursor.
140 * @pos: the &struct hlist_node to use as a loop cursor.
141 * @head: the head for your list.
142 * @member: the name of the hlist_node within the struct.
143 */
144 #define hlist_for_each_entry(tpos, pos, head, member) 145 for (pos = (head)->first; 146 pos && 147 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); 148 pos = pos->next)
149
150 /**
151 * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
152 * @tpos: the type * to use as a loop cursor.
153 * @pos: the &struct hlist_node to use as a loop cursor.
154 * @member: the name of the hlist_node within the struct.
155 */
156 #define hlist_for_each_entry_continue(tpos, pos, member) 157 for (pos = (pos)->next; 158 pos && 159 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); 160 pos = pos->next)
161
162 /**
163 * hlist_for_each_entry_from - iterate over a hlist continuing from current point
164 * @tpos: the type * to use as a loop cursor.
165 * @pos: the &struct hlist_node to use as a loop cursor.
166 * @member: the name of the hlist_node within the struct.
167 */
168 #define hlist_for_each_entry_from(tpos, pos, member) 169 for (; pos && 170 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); 171 pos = pos->next)
172
173 /**
174 * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
175 * @tpos: the type * to use as a loop cursor.
176 * @pos: the &struct hlist_node to use as a loop cursor.
177 * @n: another &struct hlist_node to use as temporary storage
178 * @head: the head for your list.
179 * @member: the name of the hlist_node within the struct.
180 */
181 #define hlist_for_each_entry_safe(tpos, pos, n, head, member) 182 for (pos = (head)->first; 183 pos && ({ n = pos->next; 1; }) && 184 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); 185 pos = n)
186
187 #endif
时间： 2024-10-19 05:26:53