1 /** 2 * @file op_list.h 3 * Kernel-style lists 4 * 5 * @remark Copyright 2002 OProfile authors 6 * @remark Read the file COPYING 7 * 8 * @author Linux kernel authors 9 */ 10 11 #ifndef OP_LIST_H 12 #define OP_LIST_H 13 14 /* 15 * Simple doubly linked list implementation. 16 * 17 * Some of the internal functions ("__xxx") are useful when 18 * manipulating whole lists rather than single entries, as 19 * sometimes we already know the next/prev entries and we can 20 * generate better code by using them directly rather than 21 * using the generic single-entry routines. 22 */ 23 24 struct list_head { 25 struct list_head * next, * prev; 26 }; 27 28 /** 29 * list_init - init a new entry 30 * @param ptr the list to init 31 * 32 * Init a list head to create an empty list from it 33 */ 34 static __inline__ void list_init(struct list_head * ptr) 35 { 36 ptr->next = ptr; 37 ptr->prev = ptr; 38 } 39 40 /* 41 * Insert a new entry between two known consecutive entries. 42 * 43 * This is only for internal list manipulation where we know 44 * the prev/next entries already! 45 */ 46 static __inline__ void __list_add(struct list_head * new_entry, 47 struct list_head * prev, 48 struct list_head * next) 49 { 50 next->prev = new_entry; 51 new_entry->next = next; 52 new_entry->prev = prev; 53 prev->next = new_entry; 54 } 55 56 /** 57 * list_add - add a new entry 58 * @param new new entry to be added 59 * @param head list head to add it after 60 * 61 * Insert a new entry after the specified head. 62 * This is good for implementing stacks. 63 */ 64 static __inline__ void list_add(struct list_head * new_entry, struct list_head * head) 65 { 66 __list_add(new_entry, head, head->next); 67 } 68 69 /** 70 * list_add_tail - add a new entry 71 * @param new new entry to be added 72 * @param head list head to add it before 73 * 74 * Insert a new entry before the specified head. 75 * This is useful for implementing queues. 76 */ 77 static __inline__ void list_add_tail(struct list_head * new_entry, struct list_head * head) 78 { 79 __list_add(new_entry, head->prev, head); 80 } 81 82 /* 83 * Delete a list entry by making the prev/next entries 84 * point to each other. 85 * 86 * This is only for internal list manipulation where we know 87 * the prev/next entries already! 88 */ 89 static __inline__ void __list_del(struct list_head * prev, 90 struct list_head * next) 91 { 92 next->prev = prev; 93 prev->next = next; 94 } 95 96 /** 97 * list_del - deletes entry from list. 98 * @param entry the element to delete from the list. 99 * Note: list_empty on entry does not return true after this, the entry is in an undefined state. 100 */ 101 static __inline__ void list_del(struct list_head * entry) 102 { 103 __list_del(entry->prev, entry->next); 104 } 105 106 /** 107 * list_del_init - deletes entry from list and reinitialize it. 108 * @param entry the element to delete from the list. 109 */ 110 static __inline__ void list_del_init(struct list_head * entry) 111 { 112 __list_del(entry->prev, entry->next); 113 list_init(entry); 114 } 115 116 /** 117 * list_empty - tests whether a list is empty 118 * @param head the list to test. 119 */ 120 static __inline__ int list_empty(struct list_head const * head) 121 { 122 return head->next == head; 123 } 124 125 /** 126 * list_splice - join two lists 127 * @param list the new list to add. 128 * @param head the place to add it in the first list. 129 */ 130 static __inline__ void list_splice(struct list_head * list, struct list_head * head) 131 { 132 struct list_head * first = list->next; 133 134 if (first != list) { 135 struct list_head * last = list->prev; 136 struct list_head * at = head->next; 137 138 first->prev = head; 139 head->next = first; 140 141 last->next = at; 142 at->prev = last; 143 } 144 } 145 146 /** 147 * list_entry - get the struct for this entry 148 * @param ptr the &struct list_head pointer. 149 * @param type the type of the struct this is embedded in. 150 * @param member the name of the list_struct within the struct. 151 */ 152 #define list_entry(ptr, type, member) \ 153 ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) 154 155 /** 156 * list_for_each - iterate over a list 157 * @param pos the &struct list_head to use as a loop counter. 158 * @param head the head for your list. 159 */ 160 #define list_for_each(pos, head) \ 161 for (pos = (head)->next; pos != (head); pos = pos->next) 162 163 /** 164 * list_for_each_safe - iterate over a list safe against removal of list entry 165 * @param pos the &struct list_head to use as a loop counter. 166 * @param n another &struct list_head to use as temporary storage 167 * @param head the head for your list. 168 */ 169 #define list_for_each_safe(pos, n, head) \ 170 for (pos = (head)->next, n = pos->next; pos != (head); \ 171 pos = n, n = pos->next) 172 173 #define LIST_HEAD_INIT(name) { &(name), &(name) } 174 175 #define LIST_HEAD(name) struct list_head name = LIST_HEAD_INIT(name) 176 177 #endif /* OP_LIST_H */ 178
