urcu/rculist.h

   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    Copyright (C) 2009 Pierre-Marc Fournier
   6    Conversion to RCU list.
   7    Copyright (C) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8
   9    The GNU C Library is free software; you can redistribute it and/or
  10    modify it under the terms of the GNU Lesser General Public
  11    License as published by the Free Software Foundation; either
  12    version 2.1 of the License, or (at your option) any later version.
  13
  14    The GNU C Library is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17    Lesser General Public License for more details.
  18
  19    You should have received a copy of the GNU Lesser General Public
  20    License along with the GNU C Library; if not, write to the Free
  21    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  22    02111-1307 USA.  */
  23
  24 #ifndef _URCU_RCULIST_H
  25 #define _URCU_RCULIST_H
  26
  27 #include <urcu/list.h>
  28 #include <urcu/arch.h>
  29 #include <urcu-pointer.h>
  30
  31 /* Add new element at the head of the list.
  32  */
  33 static inline void cds_list_add_rcu(list_t *newp, list_t *head)
  34 {
  35         newp->next = head->next;
  36         newp->prev = head;
  37         cmm_smp_wmb();
  38         head->next->prev = newp;
  39         head->next = newp;
  40 }
  41
  42 /* replace an old entry atomically.
  43  */
  44 static inline void cds_list_replace_rcu(list_t *old, list_t *_new)
  45 {
  46         _new->next = old->next;
  47         _new->prev = old->prev;
  48         rcu_assign_pointer(_new->prev->next, _new);
  49         _new->next->prev = _new;
  50 }
  51
  52 /* Remove element from list. */
  53 static inline void cds_list_del_rcu(list_t *elem)
  54 {
  55         elem->next->prev = elem->prev;
  56         elem->prev->next = elem->next;
  57 }
  58
  59 /*
  60  * Iteration through all elements of the list must be done while rcu_read_lock()
  61  * is held.
  62  */
  63
  64 /* Iterate forward over the elements of the list.  */
  65 #define cds_list_for_each_rcu(pos, head) \
  66   for (pos = rcu_dereference((head)->next); pos != (head); \
  67        pos = rcu_dereference(pos->next))
  68
  69
  70 /* Iterate through elements of the list.
  71  */
  72 #define cds_list_for_each_entry_rcu(pos, head, member)                          \
  73         for (pos = cds_list_entry(rcu_dereference((head)->next), typeof(*pos), member); \
  74              &pos->member != (head);                                    \
  75              pos = cds_list_entry(rcu_dereference(pos->member.next), typeof(*pos), member))
  76
  77 #endif  /* _URCU_RCULIST_H */