From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Fri, 24 Aug 2012 21:29:52 +0000 (-0400)
Subject: hlist: implement cds_hlist_first_entry_rcu
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=df65c98a4b6a3c3ba5e55c448521605fe14b6ec3;p=urcu.git

hlist: implement cds_hlist_first_entry_rcu

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/urcu/rcuhlist.h b/urcu/rcuhlist.h
index 8549550..4635593 100644
--- a/urcu/rcuhlist.h
+++ b/urcu/rcuhlist.h
@@ -50,6 +50,12 @@ static inline void cds_hlist_del_rcu(struct cds_hlist_node *elem)
 	elem->prev->next = elem->next;
 }
 
+/*
+ * Get first entry from a RCU hlist. Assumes the hlist is not empty.
+ * This must be done while rcu_read_lock() is held.
+ */
+#define cds_hlist_first_entry_rcu(ptr, type, member) \
+	cds_hlist_entry(rcu_dereference((ptr)->next), type, member)
 
 /* Iterate through elements of the list.
  * This must be done while rcu_read_lock() is held.