Logo Search packages:      
Sourcecode: amtterm version File versions

list.h

#ifndef _LIST_H_
#define _LIST_H_
/*
 * Simple doubly linked list implementation.
 *    -- shameless stolen from the linux kernel sources
 *
 * 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)

#define INIT_LIST_HEAD(ptr) do { \
      (ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)

/*
 * 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);
}

/**
 * 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_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;
}

/**
 * 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)
{
      struct list_head *first = list->next;

      if (first != list) {
            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_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_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_prev   -     iterate over a list in reverse order
 * @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)

#endif /* _LIST_H_ */

Generated by  Doxygen 1.6.0   Back to index