urcu-ht: rename "stolen" to "flags"

[urcu.git] / urcu-ht.c

diff --git a/urcu-ht.c b/urcu-ht.c
index 500b8d36fff51dffaa3d2b8548b70f83be60518e..7213c39ce1414d788149dc864f9114bcb814acb0 100644 (file)
--- a/urcu-ht.c
+++ b/urcu-ht.c
@@ -17,13 +17,16 @@
 #include <urcu/jhash.h>
 #include <urcu-ht.h>
 
+/* node flags */
+#define        NODE_STOLEN     (1 << 0)
+
 struct rcu_ht_node;
 
 struct rcu_ht_node {
        struct rcu_ht_node *next;
        void *key;
        void *data;
-       int stolen;
+       unsigned int flags;
 };
 
 struct rcu_ht {
@@ -95,7 +98,7 @@ int ht_add(struct rcu_ht *ht, void *key, void *data)
        new_head = calloc(1, sizeof(struct rcu_ht_node));
        new_head->key = key;
        new_head->data = data;
-       new_head->stolen = 0;
+       new_head->flags = 0;
        /* here comes the fun and tricky part.
         * Add at the beginning with a cmpxchg.
         * Hold a read lock between the moment the first element is read
@@ -174,9 +177,15 @@ retry:
                node = rcu_dereference(*prev);
        }
 
-       /* Another concurrent thread stole it ? If so, let it deal with this. */
-       if (cmpxchg(&node->stolen, 0, 1) != 0)
-               goto error;
+       if (!del_node) {
+               /*
+                * Another concurrent thread stole it ? If so, let it deal with
+                * this. Assume NODE_STOLEN is the only flag. If this changes,
+                * read flags before cmpxchg.
+                */
+               if (cmpxchg(&node->flags, 0, NODE_STOLEN) != 0)
+                       goto error;
+       }
 
        /* Found it ! pointer to object is in "prev" */
        if (rcu_cmpxchg_pointer(prev, node, node->next) == node)