| /* |
| * Copyright (C) 2002 Free Software Foundation, Inc. |
| * (originally part of the GNU C Library and Userspace RCU) |
| * Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. |
| * |
| * Copyright (C) 2009 Pierre-Marc Fournier |
| * Conversion to RCU list. |
| * Copyright (C) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, see |
| * <http://www.gnu.org/licenses/>. |
| */ |
| |
| #ifndef LIST_H |
| #define LIST_H 1 |
| |
| /* |
| * The definitions of this file are adopted from those which can be |
| * found in the Linux kernel headers to enable people familiar with the |
| * latter find their way in these sources as well. |
| */ |
| |
| /* Basic type for the double-link list. */ |
| struct list_head { |
| struct list_head *next, *prev; |
| }; |
| |
| /* avoid conflicts with BSD-only sys/queue.h */ |
| #undef LIST_HEAD |
| /* Define a variable with the head and tail of the list. */ |
| #define LIST_HEAD(name) \ |
| struct list_head name = { &(name), &(name) } |
| |
| /* Initialize a new list head. */ |
| #define INIT_LIST_HEAD(ptr) \ |
| (ptr)->next = (ptr)->prev = (ptr) |
| |
| #define LIST_HEAD_INIT(name) { &(name), &(name) } |
| |
| /* Add new element at the head of the list. */ |
| static inline void list_add(struct list_head *newp, struct list_head *head) |
| { |
| head->next->prev = newp; |
| newp->next = head->next; |
| newp->prev = head; |
| head->next = newp; |
| } |
| |
| /* Add new element at the tail of the list. */ |
| static inline void list_add_tail(struct list_head *newp, struct list_head *head) |
| { |
| head->prev->next = newp; |
| newp->next = head; |
| newp->prev = head->prev; |
| head->prev = newp; |
| } |
| |
| /* Remove element from list. */ |
| static inline void __list_del(struct list_head *prev, struct list_head *next) |
| { |
| next->prev = prev; |
| prev->next = next; |
| } |
| |
| /* Remove element from list. */ |
| static inline void list_del(struct list_head *elem) |
| { |
| __list_del(elem->prev, elem->next); |
| } |
| |
| /* Remove element from list, initializing the element's list pointers. */ |
| static inline void list_del_init(struct list_head *elem) |
| { |
| list_del(elem); |
| INIT_LIST_HEAD(elem); |
| } |
| |
| /* Delete from list, add to another list as head. */ |
| static inline void list_move(struct list_head *elem, struct list_head *head) |
| { |
| __list_del(elem->prev, elem->next); |
| list_add(elem, head); |
| } |
| |
| /* Replace an old entry. */ |
| static inline void list_replace(struct list_head *old, struct list_head *newp) |
| { |
| newp->next = old->next; |
| newp->prev = old->prev; |
| newp->prev->next = newp; |
| newp->next->prev = newp; |
| } |
| |
| /* Join two lists. */ |
| static inline void list_splice(struct list_head *add, struct list_head *head) |
| { |
| /* Do nothing if the list which gets added is empty. */ |
| if (add != add->next) { |
| add->next->prev = head; |
| add->prev->next = head->next; |
| head->next->prev = add->prev; |
| head->next = add->next; |
| } |
| } |
| |
| /* Get typed element from list at a given position. */ |
| #define list_entry(ptr, type, member) \ |
| ((type *) ((char *) (ptr) - offsetof(type, member))) |
| |
| /* Get first entry from a list. */ |
| #define list_first_entry(ptr, type, member) \ |
| list_entry((ptr)->next, type, member) |
| |
| /* Iterate forward over the elements of the list. */ |
| #define list_for_each(pos, head) \ |
| for (pos = (head)->next; pos != (head); pos = pos->next) |
| |
| /* |
| * Iterate forward over the elements list. The list elements can be |
| * removed from the list while doing this. |
| */ |
| #define list_for_each_safe(pos, p, head) \ |
| for (pos = (head)->next, p = pos->next; \ |
| pos != (head); \ |
| pos = p, p = pos->next) |
| |
| /* Iterate backward over the elements of the list. */ |
| #define list_for_each_prev(pos, head) \ |
| for (pos = (head)->prev; pos != (head); pos = pos->prev) |
| |
| /* |
| * Iterate backwards over the elements list. The list elements can be |
| * removed from the list while doing this. |
| */ |
| #define list_for_each_prev_safe(pos, p, head) \ |
| for (pos = (head)->prev, p = pos->prev; \ |
| pos != (head); \ |
| pos = p, p = pos->prev) |
| |
| static inline int list_empty(struct list_head *head) |
| { |
| return head == head->next; |
| } |
| |
| static inline void list_replace_init(struct list_head *old, |
| struct list_head *newp) |
| { |
| struct list_head *head = old->next; |
| |
| list_del(old); |
| list_add_tail(newp, head); |
| INIT_LIST_HEAD(old); |
| } |
| |
| #endif /* LIST_H */ |