rculfhash: wait for call_rcu quiescence before destroy

[urcu.git] / urcu / rculist.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.

   Copyright (C) 2009 Pierre-Marc Fournier
   Conversion to RCU list.
   Copyright (C) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

   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 _URCU_RCULIST_H
#define _URCU_RCULIST_H

#include <urcu/list.h>
#include <urcu/arch.h>
#include <urcu-pointer.h>

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

/* replace an old entry atomically.
 */
static inline void cds_list_replace_rcu(struct cds_list_head *old, struct cds_list_head *_new)
{
	_new->next = old->next;
	_new->prev = old->prev;
	rcu_assign_pointer(_new->prev->next, _new);
	_new->next->prev = _new;
}

/* Remove element from list. */
static inline void cds_list_del_rcu(struct cds_list_head *elem)
{
	elem->next->prev = elem->prev;
	elem->prev->next = elem->next;
}

/*
 * Iteration through all elements of the list must be done while rcu_read_lock()
 * is held.
 */

/* Iterate forward over the elements of the list.  */
#define cds_list_for_each_rcu(pos, head) \
  for (pos = rcu_dereference((head)->next); pos != (head); \
       pos = rcu_dereference(pos->next))


/* Iterate through elements of the list.
 */
#define cds_list_for_each_entry_rcu(pos, head, member)				\
	for (pos = cds_list_entry(rcu_dereference((head)->next), typeof(*pos), member);	\
	     &pos->member != (head);					\
	     pos = cds_list_entry(rcu_dereference(pos->member.next), typeof(*pos), member))

#endif	/* _URCU_RCULIST_H */