Fix: handle sys_futex() FUTEX_WAIT interrupted by signal

[urcu.git] / urcu / rcuhlist.h

diff --git a/urcu/rcuhlist.h b/urcu/rcuhlist.h
index 83b13632536cb15a3a398505da960f4e3417c086..69c4d3184fd50d7f38a730e17447678f5fec3991 100644 (file)
--- a/urcu/rcuhlist.h
+++ b/urcu/rcuhlist.h
@@ -29,37 +29,53 @@
 #include <urcu/arch.h>
 #include <urcu-pointer.h>
 
-/* Add new element at the head of the list.
- */
-static inline void cds_hlist_add_head_rcu(struct cds_hlist_node *newp,
-                                     struct cds_hlist_head *head)
+/* Add new element at the head of the list. */
+static inline
+void cds_hlist_add_head_rcu(struct cds_hlist_node *newp,
+               struct cds_hlist_head *head)
 {
        newp->next = head->next;
        newp->prev = (struct cds_hlist_node *)head;
-       cmm_smp_wmb();
        if (head->next)
                head->next->prev = newp;
-       head->next = newp;
+       rcu_assign_pointer(head->next, newp);
 }
 
 /* Remove element from list. */
-static inline void cds_hlist_del_rcu(struct cds_hlist_node *elem)
+static inline
+void cds_hlist_del_rcu(struct cds_hlist_node *elem)
 {
        if (elem->next)
                elem->next->prev = elem->prev;
-       elem->prev->next = elem->next;
+       CMM_STORE_SHARED(elem->prev->next, elem->next);
 }
 
-
-/* Iterate through elements of the list.
+/*
+ * Iterate through elements of the list.
  * This must be done while rcu_read_lock() is held.
  */
+#define cds_hlist_for_each_rcu(pos, head) \
+       for (pos = rcu_dereference((head)->next); pos != NULL; \
+               pos = rcu_dereference(pos->next))
+
+/*
+ * cds_hlist_for_each_entry_rcu takes 4 arguments, while the Linux
+ * kernel API only takes 3.
+ * We implement cds_hlist_for_each_entry_rcu_2() to follow the Linux
+ * kernel APIs.
+ */
+#define cds_hlist_for_each_entry_rcu(entry, pos, head, member) \
+       for (pos = rcu_dereference((head)->next), \
+                       entry = cds_hlist_entry(pos, __typeof__(*entry), member); \
+               pos != NULL; \
+               pos = rcu_dereference(pos->next), \
+                       entry = cds_hlist_entry(pos, __typeof__(*entry), member))
 
-#define cds_hlist_for_each_entry_rcu(entry, pos, head, member)         \
-       for (pos = rcu_dereference((head)->next),                       \
-                    entry = cds_hlist_entry(pos, typeof(*entry), member);      \
-            pos != NULL;                                               \
-            pos = rcu_dereference(pos->next),                          \
-                    entry = cds_hlist_entry(pos, typeof(*entry), member))
+#define cds_hlist_for_each_entry_rcu_2(entry, head, member) \
+       for (entry = cds_hlist_entry(rcu_dereference((head)->next), \
+                       __typeof__(*entry), member); \
+               &entry->member != NULL; \
+               entry = cds_hlist_entry(rcu_dereference(entry->member.next), \
+                       __typeof__(*entry), member))
 
 #endif /* _URCU_RCUHLIST_H */