On Fri, Jul 5, 2013 at 9:41 PM, Jörn Engel <jo...@logfs.org> wrote:
> I have seen a lot of boilerplate code that either follows the pattern of
> while (!list_empty(head)) {
> pos = list_entry(head->next, struct foo, list);
> list_del(pos->list);
> ...
> }
> or some variant thereof.
>
> With this patch in, people can use
> list_del_each_entry(pos, head, list) {
> ...
> }
>
> The patch also adds a list_del_each variant, even though I have
> only found a single user for that one so far.
>
> Signed-off-by: Joern Engel <jo...@logfs.org>
> ---
> include/linux/list.h | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/include/linux/list.h b/include/linux/list.h
> index 6a1f8df..ab39c7d 100644
> --- a/include/linux/list.h
> +++ b/include/linux/list.h
> @@ -557,6 +557,24 @@ static inline void list_splice_tail_init(struct
> list_head *list,
> #define list_safe_reset_next(pos, n, member) \
> n = list_entry(pos->member.next, typeof(*pos), member)
>
> +/**
> + * list_del_each - removes an entry from the list until it is empty
> + * @pos: the &struct list_head to use as a loop cursor.
> + * @head: the head of your list.
> + */
> +#define list_del_each(pos, head) \
> + while (list_empty(head) ? 0 : (pos = (head)->next, list_del(pos), 1))
> +
> +/**
> + * list_del_each_entry - removes an entry from the list until it is empty
> + * @pos: the type * to use as loop cursor.
> + * @head: the head of your list.
> + * @member: the name of the list_struct within the struct
> + */
> +#define list_del_each_entry(pos, head, member) \
> + while (list_empty(head) && (pos = list_first_entry((head), \
> + typeof(*pos), member), list_del((head)->next), 1))
> +
Shouldn't it be while (!list_empty(head) ... ?
(not operator addition)
thanks
> /*
> * Double linked lists with a single pointer list head.
> * Mostly useful for hash tables where the two pointer list head is
> --
> 1.7.10.4
>
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"Reasonable men adapt themselves to the world.
Unreasonable men adapt the world to themselves.
That's why all progress depends on unreasonable men."
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