urcu/rcuhlist.h

   1 /*
   2  * Copyright (C) 2002 Free Software Foundation, Inc.
   3  * (originally part of the GNU C Library)
   4  * Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   5  *
   6  * Copyright (C) 2009 Pierre-Marc Fournier
   7  * Conversion to RCU list.
   8  * Copyright (C) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 #ifndef _URCU_RCUHLIST_H
  26 #define _URCU_RCUHLIST_H
  27
  28 #include <urcu/hlist.h>
  29 #include <urcu/arch.h>
  30 #include <urcu-pointer.h>
  31
  32 /* Add new element at the head of the list.
  33  */
  34 static inline void cds_hlist_add_head_rcu(struct cds_hlist_node *newp,
  35                                       struct cds_hlist_head *head)
  36 {
  37         newp->next = head->next;
  38         newp->prev = (struct cds_hlist_node *)head;
  39         cmm_smp_wmb();
  40         if (head->next)
  41                 head->next->prev = newp;
  42         head->next = newp;
  43 }
  44
  45 /* Remove element from list. */
  46 static inline void cds_hlist_del_rcu(struct cds_hlist_node *elem)
  47 {
  48         if (elem->next)
  49                 elem->next->prev = elem->prev;
  50         elem->prev->next = elem->next;
  51 }
  52
  53 /*
  54  * Get first element from a RCU hlist. Assumes the hlist is not empty.
  55  * This must be done while rcu_read_lock() is held.
  56  */
  57 #define cds_hlist_first_rcu(ptr, type)                                  \
  58         rcu_dereference((ptr)->next)
  59
  60 /*
  61  * Get first entry from a RCU hlist. Assumes the hlist is not empty.
  62  * This must be done while rcu_read_lock() is held.
  63  */
  64 #define cds_hlist_first_entry_rcu(ptr, type, member)                    \
  65         cds_hlist_entry(rcu_dereference((ptr)->next), type, member)
  66
  67 /*
  68  * Iterate through nodes of the list.
  69  * This must be done while rcu_read_lock() is held.
  70  */
  71
  72 #define cds_hlist_for_each_rcu(pos, head)                               \
  73         for (pos = rcu_dereference((head)->next);                       \
  74              pos != NULL;                                               \
  75              pos = rcu_dereference((pos)->next))
  76
  77 /*
  78  * Iterate through elements of the list.
  79  * This must be done while rcu_read_lock() is held.
  80  */
  81
  82 #define cds_hlist_for_each_entry_rcu(entry, pos, head, member)          \
  83         for (pos = rcu_dereference((head)->next),                       \
  84                      entry = cds_hlist_entry(pos, __typeof__(*entry), member);  \
  85              pos != NULL;                                               \
  86              pos = rcu_dereference(pos->next),                          \
  87                      entry = cds_hlist_entry(pos, __typeof__(*entry), member))
  88
  89 #endif  /* _URCU_RCUHLIST_H */