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