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author | etobi <git@e-tobi.net> | 2013-09-03 09:48:38 +0200 |
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committer | etobi <git@e-tobi.net> | 2013-09-03 09:48:38 +0200 |
commit | 6e40287e2f39a80fc72bd8d0fbc1a8334d688c2d (patch) | |
tree | 024bef311226653bdd1da4fa588becf5098bcff7 /util/scan/list.h | |
download | linux-dvb-apps-6e40287e2f39a80fc72bd8d0fbc1a8334d688c2d.tar.gz |
Imported Upstream version 1.1.0upstream/1.1.0
Diffstat (limited to 'util/scan/list.h')
-rw-r--r-- | util/scan/list.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/util/scan/list.h b/util/scan/list.h new file mode 100644 index 0000000..6032c22 --- /dev/null +++ b/util/scan/list.h @@ -0,0 +1,140 @@ +#ifndef _LIST_H +#define _LIST_H + + +/* + * Simple doubly linked list implementation. + * + * Some of the internal functions ("__xxx") are useful when + * manipulating whole lists rather than single entries, as + * sometimes we already know the next/prev entries and we can + * generate better code by using them directly rather than + * using the generic single-entry routines. + */ + +struct list_head { + struct list_head *next, *prev; +}; + +#define LIST_HEAD_INIT(name) { &(name), &(name) } + +#define LIST_HEAD(name) \ + struct list_head name = LIST_HEAD_INIT(name) + +#define INIT_LIST_HEAD(ptr) do { \ + (ptr)->next = (ptr); (ptr)->prev = (ptr); \ +} while (0) + +/* + * Insert a new entry between two known consecutive entries. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static __inline__ void __list_add(struct list_head * new, + struct list_head * prev, + struct list_head * next) +{ + next->prev = new; + new->next = next; + new->prev = prev; + prev->next = new; +} + +/** + * list_add - add a new entry + * @new: new entry to be added + * @head: list head to add it after + * + * Insert a new entry after the specified head. + * This is good for implementing stacks. + */ +static __inline__ void list_add(struct list_head *new, struct list_head *head) +{ + __list_add(new, head, head->next); +} + +/** + * list_add_tail - add a new entry + * @new: new entry to be added + * @head: list head to add it before + * + * Insert a new entry before the specified head. + * This is useful for implementing queues. + */ +static __inline__ void list_add_tail(struct list_head *new, struct list_head *head) +{ + __list_add(new, head->prev, head); +} + +/* + * Delete a list entry by making the prev/next entries + * point to each other. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static __inline__ void __list_del(struct list_head * prev, + struct list_head * next) +{ + next->prev = prev; + prev->next = next; +} + +/** + * list_del - deletes entry from list. + * @entry: the element to delete from the list. + * Note: list_empty on entry does not return true after this, the entry is in an undefined state. + */ +static __inline__ void list_del(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); +} + +/** + * list_del_init - deletes entry from list and reinitialize it. + * @entry: the element to delete from the list. + */ +static __inline__ void list_del_init(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + INIT_LIST_HEAD(entry); +} + +/** + * list_empty - tests whether a list is empty + * @head: the list to test. + */ +static __inline__ int list_empty(struct list_head *head) +{ + return head->next == head; +} + +/** + * list_entry - get the struct for this entry + * @ptr: the &struct list_head pointer. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_struct within the struct. + */ +#define list_entry(ptr, type, member) \ + ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) + +/** + * list_for_each - iterate over a list + * @pos: the &struct list_head to use as a loop counter. + * @head: the head for your list. + */ +#define list_for_each(pos, head) \ + for (pos = (head)->next; pos != (head); pos = pos->next) + +/** + * list_for_each_safe - iterate over a list safe against removal of list entry + * @pos: the &struct list_head to use as a loop counter. + * @n: another &struct list_head to use as temporary storage + * @head: the head for your list. + */ +#define list_for_each_safe(pos, n, head) \ + for (pos = (head)->next, n = pos->next; pos != (head); \ + pos = n, n = pos->next) + +#endif |