/* * 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 */