Fix: handle sys_futex() FUTEX_WAIT interrupted by signal

[urcu.git] / urcu / rculist.h

diff --git a/urcu/rculist.h b/urcu/rculist.h
index 621831ce0aec6d3bd8117faa1aeed3b76bb64e16..1fd2df388f57cefc0ea19fa02a0c8c0b627847e8 100644 (file)
--- a/urcu/rculist.h
+++ b/urcu/rculist.h
@@ -1,25 +1,26 @@
-/* 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 <mathieu.desnoyers@efficios.com>
-
-   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.  */
+/*
+ * Copyright (C) 2002 Free Software Foundation, Inc.
+ * (originally 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 <mathieu.desnoyers@efficios.com>
+ *
+ * This 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.
+ *
+ * This 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
 
 #ifndef _URCU_RCULIST_H
 #define _URCU_RCULIST_H
@@ -28,20 +29,34 @@
 #include <urcu/arch.h>
 #include <urcu-pointer.h>
 
-/* Add new element at the head of the list.
- */
-static inline void cds_list_add_rcu(struct cds_list_head *newp, struct cds_list_head *head)
+/* Add new element at the head of the list. */
+static inline
+void cds_list_add_rcu(struct cds_list_head *newp, struct cds_list_head *head)
 {
        newp->next = head->next;
        newp->prev = head;
-       cmm_smp_wmb();
        head->next->prev = newp;
-       head->next = newp;
+       rcu_assign_pointer(head->next, newp);
+}
+
+/* Add new element at the tail of the list. */
+static inline
+void cds_list_add_tail_rcu(struct cds_list_head *newp,
+               struct cds_list_head *head)
+{
+       newp->next = head;
+       newp->prev = head->prev;
+       rcu_assign_pointer(head->prev->next, newp);
+       head->prev = newp;
 }
 
-/* replace an old entry atomically.
+/*
+ * Replace an old entry atomically with respect to concurrent RCU
+ * traversal. Mutual exclusion against concurrent updates is required
+ * though.
  */
-static inline void cds_list_replace_rcu(struct cds_list_head *old, struct cds_list_head *_new)
+static inline
+void cds_list_replace_rcu(struct cds_list_head *old, struct cds_list_head *_new)
 {
        _new->next = old->next;
        _new->prev = old->prev;
@@ -50,10 +65,11 @@ static inline void cds_list_replace_rcu(struct cds_list_head *old, struct cds_li
 }
 
 /* Remove element from list. */
-static inline void cds_list_del_rcu(struct cds_list_head *elem)
+static inline
+void cds_list_del_rcu(struct cds_list_head *elem)
 {
        elem->next->prev = elem->prev;
-       elem->prev->next = elem->next;
+       CMM_STORE_SHARED(elem->prev->next, elem->next);
 }
 
 /*
@@ -63,15 +79,14 @@ static inline void cds_list_del_rcu(struct cds_list_head *elem)
 
 /* Iterate forward over the elements of the list.  */
 #define cds_list_for_each_rcu(pos, head) \
-  for (pos = rcu_dereference((head)->next); pos != (head); \
-       pos = rcu_dereference(pos->next))
+       for (pos = rcu_dereference((head)->next); pos != (head); \
+               pos = rcu_dereference(pos->next))
 
 
-/* Iterate through elements of the list.
- */
-#define cds_list_for_each_entry_rcu(pos, head, member)                         \
-       for (pos = cds_list_entry(rcu_dereference((head)->next), typeof(*pos), member); \
-            &pos->member != (head);                                    \
-            pos = cds_list_entry(rcu_dereference(pos->member.next), typeof(*pos), member))
+/* Iterate through elements of the list. */
+#define cds_list_for_each_entry_rcu(pos, head, member) \
+       for (pos = cds_list_entry(rcu_dereference((head)->next), __typeof__(*pos), member); \
+               &pos->member != (head); \
+               pos = cds_list_entry(rcu_dereference(pos->member.next), __typeof__(*pos), member))
 
 #endif /* _URCU_RCULIST_H */