系统内核链表linux/list.h
#ifndef __LIST_H
#define __LIST_H
/* This file is from Linux Kernel (include/linux/list.h)
* * and modified by simply removing hardware prefetching of list items.
* * Here by copyright, credits attributed to wherever they belong.
* * Kulesh Shanmugasundaram (kulesh [squiggly] isis.poly.edu)
* */
/*
* * Simple doubly linked list implementation.
* *
* * Some of the internal functions (“__xxx”) are useful when
* * manipulating whole lists rather than single entries, as
* * sometimes we already know the next/prev entries and we can
* * generate better code by using them directly rather than
* * using the generic single-entry routines.
* */
struct list_head {
struct list_head *next, *prev;
};
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
static inline void INIT_LIST_HEAD(struct list_head *list)
{
list->next = list;
list->prev = list;
}
/*
* * Insert a new entry between two known consecutive entries.
* *
* * This is only for internal list manipulation where we know
* * the prev/next entries already!
* */
static inline void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
next->prev = new;
new->next = next;
new->prev = prev;
prev->next = new;
}
/**
* * list_add – add a new entry
* * @new: new entry to be added
* * @head: list head to add it after
* *
* * Insert a new entry after the specified head.
* * This is good for implementing stacks.
* */
static inline void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
/**
* * list_add_tail – add a new entry
* * @new: new entry to be added
* * @head: list head to add it before
* *
* * Insert a new entry before the specified head.
* * This is useful for implementing queues.
* */
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
__list_add(new, head->prev, head);
}
/*
* * Delete a list entry by making the prev/next entries
* * point to each other.
* *
* * This is only for internal list manipulation where we know
* * the prev/next entries already!
* */
static inline void __list_del(struct list_head *prev, struct list_head *next)
{
next->prev = prev;
prev->next = next;
}
/**
* * list_del – deletes entry from list.
* * @entry: the element to delete from the list.
* * Note: list_empty on entry does not return true after this, the entry is in an undefined state.
* */
static inline void list_del(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
entry->next = (void *) 0;
entry->prev = (void *) 0;
}
/**
* * list_del_init – deletes entry from list and reinitialize it.
* * @entry: the element to delete from the list.
* */
static inline void list_del_init(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
INIT_LIST_HEAD(entry);
}
/**
* * list_move – delete from one list and add as another’s head
* * @list: the entry to move
* * @head: the head that will precede our entry
* */
static inline void list_move(struct list_head *list, struct list_head *head)
{
__list_del(list->prev, list->next);
list_add(list, head);
}
/**
* * list_move_tail – delete from one list and add as another’s tail
* * @list: the entry to move
* * @head: the head that will follow our entry
* */
static inline void list_move_tail(struct list_head *list,
struct list_head *head)
{
__list_del(list->prev, list->next);
list_add_tail(list, head);
}
/**
* * list_empty – tests whether a list is empty
* * @head: the list to test.
* */
static inline int list_empty(struct list_head *head)
{
return head->next == head;
}
static inline void __list_splice(struct list_head *list,
struct list_head *head)
{
struct list_head *first = list->next;
struct list_head *last = list->prev;
struct list_head *at = head->next;
first->prev = head;
head->next = first;
last->next = at;
at->prev = last;
}
/**
* * list_splice – join two lists
* * @list: the new list to add.
* * @head: the place to add it in the first list.
* */
static inline void list_splice(struct list_head *list, struct list_head *head)
{
if (!list_empty(list))
__list_splice(list, head);
}
/**
* * list_splice_init – join two lists 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_init(struct list_head *list,
struct list_head *head)
{
if (!list_empty(list)) {
__list_splice(list, head);
INIT_LIST_HEAD(list);
}
}
/**
* * list_entry – get the struct for this entry
* * @ptr: the &struct list_head pointer.
* * @type: the type of the struct this is embedded in.
* * @member: the name of the list_struct within the struct.
* */
#define list_entry(ptr, type, member) \
((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
/**
* * list_for_each - iterate over a list
* * @pos: the &struct list_head to use as a loop counter.
* * @head: the head for your list.
* */
#define list_for_each(pos, head) \
for (pos = (head)->next; pos != (head); \
pos = pos->next)
/**
* * list_for_each_prev - iterate over a list backwards
* * @pos: the &struct list_head to use as a loop counter.
* * @head: the head for your list.
* */
#define list_for_each_prev(pos, head) \
for (pos = (head)->prev; pos != (head); \
pos = pos->prev)
/**
* * list_for_each_safe - iterate over a list safe against removal of list entry
* * @pos: the &struct list_head to use as a loop counter.
* * @n: another &struct list_head to use as temporary storage
* * @head: the head for your list.
* */
#define list_for_each_safe(pos, n, head) \
for (pos = (head)->next, n = pos->next; pos != (head);\
pos = n, n = pos->next)
/**
* * list_for_each_entry - iterate over list of given type
* * @pos: the type * to use as a loop counter.
* * @head: the head for your list.
* * @member: the name of the list_struct within the struct.
* */
#define list_for_each_entry(pos, head, member) \
for (pos = list_entry((head)->next,typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry(pos->member.next, typeof(*pos), member))
/**
* * list_for_each_entry_safe – iterate over list of given type safe against removal of list entry
* * @pos: the type * to use as a loop counter.
* * @n: another type * to use as temporary storage
* * @head: the head for your list.
* * @member: the name of the list_struct within the struct.
* */
#define list_for_each_entry_safe(pos, n, head, member) \
for (pos = list_entry((head)->next, typeof(*pos), member), \
n = list_entry(pos->member.next, typeof(*pos), member); \
&pos->member != (head); \
pos = n, n = list_entry(n->member.next, typeof(*n), member))
#endif
网友评论