[urcu.git] / urcu / list.h

/* Copyright (C) 2002 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C 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.

   The GNU C 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 the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#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.  */
typedef struct list_head
{
  struct list_head *next;
  struct list_head *prev;
} list_t;


/* Define a variable with the head and tail of the list.  */
#define LIST_HEAD(name) \
  list_t name = { &(name), &(name) }

/* Initialize a new list head.  */
#define INIT_LIST_HEAD(ptr) \
  (ptr)->next = (ptr)->prev = (ptr)

#define LIST_HEAD_INIT(name) { .prev = &(name), .next = &(name) }

/* Add new element at the head of the list.  */
static inline void
list_add (list_t *newp, list_t *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 (list_t *newp, list_t *head)
{
  head->prev->next = newp;
  newp->next = head;
  newp->prev = head->prev;
  head->prev = newp;
}


/* Remove element from list.  */
static inline void
__list_del (list_t *prev, list_t *next)
{
  next->prev = prev;
  prev->next = next;
}

/* Remove element from list.  */
static inline void
list_del (list_t *elem)
{
  __list_del (elem->prev, elem->next);
}

/* delete from list, add to another list as head */
static inline void
list_move (list_t *elem, list_t *head)
{
  __list_del (elem->prev, elem->next);
  list_add (elem, head);
}

/* replace an old entry.
 */
static inline void
list_replace(list_t *old, list_t *_new)
{
	_new->next = old->next;
	_new->prev = old->prev;
	_new->prev->next = _new;
	_new->next->prev = _new;
}

/* Join two lists.  */
static inline void
list_splice (list_t *add, list_t *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) - (unsigned long) (&((type *) 0)->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 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)

#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))

#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))

#define list_for_each_entry_safe(pos, p, head, member)			\
	for (pos = list_entry((head)->next, typeof(*pos), member),	\
		     p = list_entry(pos->member.next,typeof(*pos), member); \
	     &pos->member != (head);					\
	     pos = p, p = list_entry(pos->member.next, typeof(*pos), member))

static inline int list_empty(list_t *head)
{
	return head == head->next;
}

static inline void list_replace_init(list_t *old,
				     list_t *new)
{
	list_t *head = old->next;
	list_del(old);
	list_add_tail(new, head);
	INIT_LIST_HEAD(old);
}

#endif	/* list.h */
Commit	Line	Data
7a50dcf7 MD	1	/* Copyright (C) 2002 Free Software Foundation, Inc.
	2	This file is part of the GNU C Library.
	3	Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, write to the Free
	17	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	18	02111-1307 USA. */
	19
	20	#ifndef _LIST_H
	21	#define _LIST_H 1
	22
	23	/* The definitions of this file are adopted from those which can be
	24	found in the Linux kernel headers to enable people familiar with
	25	the latter find their way in these sources as well. */
	26
	27
	28	/* Basic type for the double-link list. */
	29	typedef struct list_head
	30	{
	31	struct list_head *next;
	32	struct list_head *prev;
	33	} list_t;
	34
	35
	36	/* Define a variable with the head and tail of the list. */
	37	#define LIST_HEAD(name) \
	38	list_t name = { &(name), &(name) }
	39
	40	/* Initialize a new list head. */
	41	#define INIT_LIST_HEAD(ptr) \
	42	(ptr)->next = (ptr)->prev = (ptr)
	43
	44	#define LIST_HEAD_INIT(name) { .prev = &(name), .next = &(name) }
	45
	46	/* Add new element at the head of the list. */
	47	static inline void
	48	list_add (list_t newp, list_t head)
	49	{
	50	head->next->prev = newp;
	51	newp->next = head->next;
	52	newp->prev = head;
	53	head->next = newp;
	54	}
	55
	56
	57	/* Add new element at the tail of the list. */
	58	static inline void
	59	list_add_tail (list_t newp, list_t head)
	60	{
	61	head->prev->next = newp;
	62	newp->next = head;
	63	newp->prev = head->prev;
	64	head->prev = newp;
65	}
66
67
63ff4873 MD	68	/* Remove element from list. */
	69	static inline void
	70	__list_del (list_t prev, list_t next)
	71	{
	72	next->prev = prev;
	73	prev->next = next;
	74	}
	75
7a50dcf7 MD	76	/* Remove element from list. */
	77	static inline void
	78	list_del (list_t *elem)
	79	{
63ff4873	80	__list_del (elem->prev, elem->next);
7a50dcf7 MD	81	}
7a50dcf7 MD	82
ac956d00 MD	83	/* delete from list, add to another list as head */
	84	static inline void
	85	list_move (list_t elem, list_t head)
	86	{
	87	__list_del (elem->prev, elem->next);
	88	list_add (elem, head);
	89	}
7a50dcf7	90
5db941e8 MD	91	/* replace an old entry.
	92	*/
	93	static inline void
	94	list_replace(list_t old, list_t _new)
	95	{
	96	_new->next = old->next;
	97	_new->prev = old->prev;
	98	_new->prev->next = _new;
	99	_new->next->prev = _new;
	100	}
	101
7a50dcf7 MD	102	/* Join two lists. */
	103	static inline void
	104	list_splice (list_t add, list_t head)
	105	{
	106	/* Do nothing if the list which gets added is empty. */
	107	if (add != add->next)
	108	{
	109	add->next->prev = head;
	110	add->prev->next = head->next;
	111	head->next->prev = add->prev;
	112	head->next = add->next;
	113	}
	114	}
	115
	116
	117	/* Get typed element from list at a given position. */
	118	#define list_entry(ptr, type, member) \
	119	((type ) ((char ) (ptr) - (unsigned long) (&((type *) 0)->member)))
	120
	121
	122
	123	/* Iterate forward over the elements of the list. */
	124	#define list_for_each(pos, head) \
	125	for (pos = (head)->next; pos != (head); pos = pos->next)
	126
	127
	128	/* Iterate forward over the elements of the list. */
	129	#define list_for_each_prev(pos, head) \
	130	for (pos = (head)->prev; pos != (head); pos = pos->prev)
	131
	132
	133	/* Iterate backwards over the elements list. The list elements can be
	134	removed from the list while doing this. */
	135	#define list_for_each_prev_safe(pos, p, head) \
	136	for (pos = (head)->prev, p = pos->prev; \
	137	pos != (head); \
	138	pos = p, p = pos->prev)
	139
	140	#define list_for_each_entry(pos, head, member) \
	141	for (pos = list_entry((head)->next, typeof(*pos), member); \
	142	&pos->member != (head); \
	143	pos = list_entry(pos->member.next, typeof(*pos), member))
	144
	145	#define list_for_each_entry_reverse(pos, head, member) \
	146	for (pos = list_entry((head)->prev, typeof(*pos), member); \
	147	&pos->member != (head); \
	148	pos = list_entry(pos->member.prev, typeof(*pos), member))
	149
	150	#define list_for_each_entry_safe(pos, p, head, member) \
	151	for (pos = list_entry((head)->next, typeof(*pos), member), \
	152	p = list_entry(pos->member.next,typeof(*pos), member); \
	153	&pos->member != (head); \
	154	pos = p, p = list_entry(pos->member.next, typeof(*pos), member))
	155
	156	static inline int list_empty(list_t *head)
	157	{
	158	return head == head->next;
	159	}
	160
	161	static inline void list_replace_init(list_t *old,
	162	list_t *new)
	163	{
	164	list_t *head = old->next;
	165	list_del(old);
166	list_add_tail(new, head);
167	INIT_LIST_HEAD(old);
168	}
169
170	#endif /* list.h */