Messages in this thread Patch in this message | | | Date | Fri, 14 Mar 2008 16:40:36 -0400 | From | Masami Hiramatsu <> | Subject | [PATCH -mm 1/5] list.h: add list_singleton |
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Add list_singleton to check a list has just one entry.
list_singleton is useful to check whether a list_head which have been temporarily allocated for listing objects can be released or not.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> --- include/linux/list.h | 9 +++++++++ 1 file changed, 9 insertions(+)
Index: 2.6.25-rc5-mm1/include/linux/list.h =================================================================== --- 2.6.25-rc5-mm1.orig/include/linux/list.h +++ 2.6.25-rc5-mm1/include/linux/list.h @@ -211,6 +211,15 @@ static inline int list_empty_careful(con return (next == head) && (next == head->prev); }
+/** + * list_singleton - tests whether a list has just one entry. + * @head: the list to test. + */ +static inline int list_singleton(const struct list_head *head) +{ + return !list_empty(head) && (head->next == head->prev); +} + static inline void __list_splice(struct list_head *list, struct list_head *head) { -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division
e-mail: mhiramat@redhat.com
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