RCU list: add rcuhlist.h, add list_replace_rcu

[urcu.git] / urcu / rcuhlist.h

diff --git a/urcu/rcuhlist.h b/urcu/rcuhlist.h
new file mode 100644 (file)
index 0000000..be74145
--- /dev/null
+++ b/urcu/rcuhlist.h
@@ -0,0 +1,64 @@
+/* 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
+
+   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_RCUHLIST_H
+#define _URCU_RCUHLIST_H
+
+#include <urcu/hlist.h>
+#include <urcu/arch.h>
+#include <urcu-pointer.h>
+
+/* Add new element at the head of the list.
+ */
+static inline void hlist_add_head(struct hlist_node *newp,
+                                 struct hlist_head *head)
+{
+       newp->next = head->next;
+       newp->prev = (struct hlist_node *)head;
+       smp_wmb();
+       if (head->next)
+               head->next->prev = newp;
+       head->next = newp;
+}
+
+/* Remove element from list. */
+static inline void hlist_del_rcu(struct hlist_node *elem)
+{
+       if (elem->next)
+               elem->next->prev = elem->prev;
+       elem->prev->next = elem->next;
+}
+
+
+/* Iterate through elements of the list.
+ * This must be done while rcu_read_lock() is held.
+ */
+
+#define hlist_for_each_entry_rcu(entry, pos, head, member)             \
+       for (pos = rcu_dereference((head)->next),                       \
+                    entry = hlist_entry(pos, typeof(*entry), member);  \
+            pos != NULL;                                               \
+            pos = rcu_dereference(pos->next),                          \
+                    entry = hlist_entry(pos, typeof(*entry), member))
+
+#endif /* _URCU_RCUHLIST_H */