urcu/rcuhlist.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
   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_RCUHLIST_H
  25 #define _URCU_RCUHLIST_H
  26
  27 #include <urcu/hlist.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 hlist_add_head(struct hlist_node *newp,
  34                                   struct hlist_head *head)
  35 {
  36         newp->next = head->next;
  37         newp->prev = (struct hlist_node *)head;
  38         smp_wmb();
  39         if (head->next)
  40                 head->next->prev = newp;
  41         head->next = newp;
  42 }
  43
  44 /* Remove element from list. */
  45 static inline void hlist_del_rcu(struct hlist_node *elem)
  46 {
  47         if (elem->next)
  48                 elem->next->prev = elem->prev;
  49         elem->prev->next = elem->next;
  50 }
  51
  52
  53 /* Iterate through elements of the list.
  54  * This must be done while rcu_read_lock() is held.
  55  */
  56
  57 #define hlist_for_each_entry_rcu(entry, pos, head, member)              \
  58         for (pos = rcu_dereference((head)->next),                       \
  59                      entry = hlist_entry(pos, typeof(*entry), member);  \
  60              pos != NULL;                                               \
  61              pos = rcu_dereference(pos->next),                          \
  62                      entry = hlist_entry(pos, typeof(*entry), member))
  63
  64 #endif  /* _URCU_RCUHLIST_H */