From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.atheros.com ([12.36.123.2]:45853 "EHLO mail.atheros.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751376AbYHDWsE (ORCPT ); Mon, 4 Aug 2008 18:48:04 -0400 From: "Luis R. Rodriguez" To: , , , , CC: "Luis R. Rodriguez" , , Subject: [PATCH 1/4] list.h: Add list_splice_tail() and list_splice_tail_init() Date: Mon, 4 Aug 2008 15:48:00 -0700 Message-ID: <1217890080-12073-1-git-send-email-lrodriguez@atheros.com> (sfid-20080805_004809_490471_AFB0D0D6) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: 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: Luis R. Rodriguez --- include/linux/list.h | 45 ++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 44 insertions(+), 1 deletions(-) diff --git a/include/linux/list.h b/include/linux/list.h index 453916b..594f67c 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -229,7 +229,7 @@ static inline void __list_splice(const struct list_head *list, } /** - * 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. */ @@ -256,6 +256,49 @@ static inline void list_splice_init(struct list_head *list, } } +static inline void __list_splice_tail(const struct list_head *list, + struct list_head *head) +{ + struct list_head *first = list->next; + struct list_head *last = list->prev; + struct list_head *current_tail = head->prev; + + current_tail->next = first; + last->next = head; + head->prev = last; + first->prev = current_tail; +} + +/** + * 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(const struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) + __list_splice_tail(list, head); +} + +/** + * 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_tail(list, head); + INIT_LIST_HEAD(list); + } +} + + /** * list_entry - get the struct for this entry * @ptr: the &struct list_head pointer. -- 1.5.6.rc2.15.g457bb.dirty