text: /**
   * 
   * I grub it from linux kernel source code and fix it for user space
   * program. Of course, this is a GPL licensed header file.
   *
   * Here is a recipe to cook list.h for user space program
   *
   * 1. copy list.h from linux/include/list.h
   * 2. remove 
   *     - #ifdef __KERNE__ and its #endif
   *     - all #include line
   *     - prefetch() and rcu related functions
   * 3. add macro offsetof() and container_of
   *
   * - kazutomo@mcs.anl.gov
   */
  #ifndef _LINUX_LIST_H
  #define _LINUX_LIST_H
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /**
   * @name from other kernel headers
   */
  /*@{*/
  
  /**
   * Get offset of a member
   */
  #ifndef offsetof
  #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
  #endif
  
  /**
   * Casts a member of a structure out to the containing structure
   * @param ptr        the pointer to the member.
   * @param type       the type of the container struct this is embedded in.
   * @param member     the name of the member within the struct.
   *
   */
  #define container_of(ptr, type, member) ({                      \
          const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
          (type *)( (char *)__mptr - offsetof(type,member) );})
  /*@}*/
  
  
  /*
   * These are non-NULL pointers that will result in page faults
   * under normal circumstances, used to verify that nobody uses
   * non-initialized list entries.
   */
  #define LIST_POISON1  ((void *) 0x00100100)
  #define LIST_POISON2  ((void *) 0x00200200)
  
  /**
   * 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)
  
  #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_element,
  			      struct list_head *prev,
  			      struct list_head *next)
  {
  	next->prev = new_element;
  	new_element->next = next;
  	new_element->prev = prev;
  	prev->next = new_element;
  }
  
  /**
   * 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_element, struct list_head *head)
  {
  	__list_add(new_element, 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_element, struct list_head *head)
  {
  	__list_add(new_element, 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 = (struct list_head *)LIST_POISON1;
  	entry->prev = (struct list_head *)LIST_POISON2;
  }
  
  
  
  /**
   * 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(const 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) \
  	container_of(ptr, type, member)
  
  /**
   * list_first_entry - get the first element from a list
   * @ptr:	the list head to take the element from.
   * @type:	the type of the struct this is embedded in.
   * @member:	the name of the list_head within the struct.
   *
   * Note, that list is expected to be not empty.
   */
  #define list_first_entry(ptr, type, member) \
  	list_entry((ptr)->next, type, member)
  
  /**
   * list_last_entry - get the last element from a list
   * @ptr:	the list head to take the element from.
   * @type:	the type of the struct this is embedded in.
   * @member:	the name of the list_head within the struct.
   *
   * Note, that list is expected to be not empty.
   */
  #define list_last_entry(ptr, type, member) \
  	list_entry((ptr)->prev, type, 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	-	iterate over a list
   * @pos:	the &struct list_head to use as a loop counter.
   * @head:	the head for your list.
   *
   * This variant differs from list_for_each() in that it's the
   * simplest possible list iteration code, no prefetching is done.
   * Use this for code that knows the list to be very short (empty
   * or 1 entry) most of the time.
   */
  #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; prefetch(pos->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_reverse - iterate backwards 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_reverse(pos, head, member)			\
  	for (pos = list_entry((head)->prev, typeof(*pos), member);	\
  	     &pos->member != (head); 	\
  	     pos = list_entry(pos->member.prev, typeof(*pos), member))
  
  /**
   * list_prepare_entry - prepare a pos entry for use as a start point in
   *			list_for_each_entry_continue
   * @pos:	the type * to use as a start point
   * @head:	the head of the list
   * @member:	the name of the list_struct within the struct.
   */
  #define list_prepare_entry(pos, head, member) \
  	((pos) ? : list_entry(head, typeof(*pos), member))
  
  /**
   * list_for_each_entry_continue -	iterate over list of given type
   *			continuing after existing point
   * @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_continue(pos, head, member) 		\
  	for (pos = list_entry(pos->member.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))
  
  /**
   * list_for_each_entry_safe_continue -	iterate over list of given type
   *			continuing after existing point 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_continue(pos, n, head, member) 		\
  	for (pos = list_entry(pos->member.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))
  
  /**
   * list_for_each_entry_safe_reverse - iterate backwards 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_reverse(pos, n, head, member)		\
  	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
  		n = list_entry(pos->member.prev, typeof(*pos), member);	\
  	     &pos->member != (head); 					\
  	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))
  
  
  
  
  /*
   * Double linked lists with a single pointer list head.
   * Mostly useful for hash tables where the two pointer list head is
   * too wasteful.
   * You lose the ability to access the tail in O(1).
   */
  
  struct hlist_head {
  	struct hlist_node *first;
  };
  
  struct hlist_node {
  	struct hlist_node *next, **pprev;
  };
  
  #define HLIST_HEAD_INIT { .first = NULL }
  #define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
  #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
  #define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)
  
  static inline int hlist_unhashed(const struct hlist_node *h)
  {
  	return !h->pprev;
  }
  
  static inline int hlist_empty(const struct hlist_head *h)
  {
  	return !h->first;
  }
  
  static inline void __hlist_del(struct hlist_node *n)
  {
  	struct hlist_node *next = n->next;
  	struct hlist_node **pprev = n->pprev;
  	*pprev = next;
  	if (next)
  		next->pprev = pprev;
  }
  
  static inline void hlist_del(struct hlist_node *n)
  {
  	__hlist_del(n);
  	n->next = (struct hlist_node *)LIST_POISON1;
  	n->pprev = (struct hlist_node **)LIST_POISON2;
  }
  
  
  static inline void hlist_del_init(struct hlist_node *n)
  {
  	if (n->pprev)  {
  		__hlist_del(n);
  		INIT_HLIST_NODE(n);
  	}
  }
  
  static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
  {
  	struct hlist_node *first = h->first;
  	n->next = first;
  	if (first)
  		first->pprev = &n->next;
  	h->first = n;
  	n->pprev = &h->first;
  }
  
  
  
  /* next must be != NULL */
  static inline void hlist_add_before(struct hlist_node *n,
  					struct hlist_node *next)
  {
  	n->pprev = next->pprev;
  	n->next = next;
  	next->pprev = &n->next;
  	*(n->pprev) = n;
  }
  
  static inline void hlist_add_after(struct hlist_node *n,
  					struct hlist_node *next)
  {
  	next->next = n->next;
  	n->next = next;
  	next->pprev = &n->next;
  
  	if(next->next)
  		next->next->pprev  = &next->next;
  }
  
  
  
  #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
  
  #define hlist_for_each(pos, head) \
  	for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
  	     pos = pos->next)
  
  #define hlist_for_each_safe(pos, n, head) \
  	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
  	     pos = n)
  
  /**
   * hlist_for_each_entry	- iterate over list of given type
   * @tpos:	the type * to use as a loop counter.
   * @pos:	the &struct hlist_node to use as a loop counter.
   * @head:	the head for your list.
   * @member:	the name of the hlist_node within the struct.
   */
  #define hlist_for_each_entry(tpos, pos, head, member)			 \
  	for (pos = (head)->first;					 \
  	     pos && ({ prefetch(pos->next); 1;}) &&			 \
  		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
  	     pos = pos->next)
  
  /**
   * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
   * @tpos:	the type * to use as a loop counter.
   * @pos:	the &struct hlist_node to use as a loop counter.
   * @member:	the name of the hlist_node within the struct.
   */
  #define hlist_for_each_entry_continue(tpos, pos, member)		 \
  	for (pos = (pos)->next;						 \
  	     pos && ({ prefetch(pos->next); 1;}) &&			 \
  		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
  	     pos = pos->next)
  
  /**
   * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
   * @tpos:	the type * to use as a loop counter.
   * @pos:	the &struct hlist_node to use as a loop counter.
   * @member:	the name of the hlist_node within the struct.
   */
  #define hlist_for_each_entry_from(tpos, pos, member)			 \
  	for (; pos && ({ prefetch(pos->next); 1;}) &&			 \
  		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
  	     pos = pos->next)
  
  /**
   * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
   * @tpos:	the type * to use as a loop counter.
   * @pos:	the &struct hlist_node to use as a loop counter.
   * @n:		another &struct hlist_node to use as temporary storage
   * @head:	the head for your list.
   * @member:	the name of the hlist_node within the struct.
   */
  #define hlist_for_each_entry_safe(tpos, pos, n, head, member) 		 \
  	for (pos = (head)->first;					 \
  	     pos && ({ n = pos->next; 1; }) && 				 \
  		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
  	     pos = n)
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  