diff options
author | Luis R. Rodriguez <lrodriguez@atheros.com> | 2008-08-06 15:21:26 -0700 |
---|---|---|
committer | John W. Linville <linville@tuxdriver.com> | 2008-08-07 09:49:42 -0400 |
commit | 7d283aee50351ec19eaf654a8690d77c4e1dff50 (patch) | |
tree | 8b0079f19db09ecd264cc2e8c428033fe725015f /include/linux/list.h | |
parent | e6fce5b916cd7f7f79b2b3e53ba74bbfc1d7cf8b (diff) |
list.h: Add list_splice_tail() and list_splice_tail_init()
If you are using linked lists for queues list_splice() will not do what
you would expect even if you use the elements passed reversed. We need
to handle these differently. We add list_splice_tail() and
list_splice_tail_init().
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'include/linux/list.h')
-rw-r--r-- | include/linux/list.h | 47 |
1 files changed, 38 insertions, 9 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index 453916bc041..a886f27a118 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -215,21 +215,21 @@ static inline int list_is_singular(const struct list_head *head) } static inline void __list_splice(const struct list_head *list, - struct list_head *head) + struct list_head *prev, + struct list_head *next) { struct list_head *first = list->next; struct list_head *last = list->prev; - struct list_head *at = head->next; - first->prev = head; - head->next = first; + first->prev = prev; + prev->next = first; - last->next = at; - at->prev = last; + last->next = next; + next->prev = last; } /** - * list_splice - join two lists + * list_splice - join two lists, this is designed for stacks * @list: the new list to add. * @head: the place to add it in the first list. */ @@ -237,7 +237,19 @@ static inline void list_splice(const struct list_head *list, struct list_head *head) { if (!list_empty(list)) - __list_splice(list, head); + __list_splice(list, head, head->next); +} + +/** + * list_splice_tail - join two lists, each list being a queue + * @list: the new list to add. + * @head: the place to add it in the first list. + */ +static inline void list_splice_tail(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) + __list_splice(list, head->prev, head); } /** @@ -251,7 +263,24 @@ static inline void list_splice_init(struct list_head *list, struct list_head *head) { if (!list_empty(list)) { - __list_splice(list, head); + __list_splice(list, head, head->next); + INIT_LIST_HEAD(list); + } +} + +/** + * list_splice_tail_init - join two lists, each list being a queue, and + * reinitialise the emptied list. + * @list: the new list to add. + * @head: the place to add it in the first list. + * + * The list at @list is reinitialised + */ +static inline void list_splice_tail_init(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) { + __list_splice(list, head->prev, head); INIT_LIST_HEAD(list); } } |