rcuja: partial implementation of cds_ja_del

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

diff --git a/rcuja/rcuja.c b/rcuja/rcuja.c
index 92e35ea91d4fcb9ada8f185971514d30495aaf56..ea4c887f95bfade74b78df6463bbaa384ebf3189 100644 (file)
--- a/rcuja/rcuja.c
+++ b/rcuja/rcuja.c
@@ -1186,7 +1186,7 @@ retry:
        parent_node_flag =
                (struct cds_ja_inode_flag *) &ja->root; /* Use root ptr address as key for mutex */
        node_flag_ptr = &ja->root;
-       node_flag = rcu_dereference(*node_flag_ptr);
+       node_flag = rcu_dereference(ja->root);
 
        /* Iterate on all internal levels */
        for (i = 1; i < tree_depth; i++) {
@@ -1233,6 +1233,90 @@ end:
        return ret;
 }
 
+static
+int ja_detach_node(struct cds_ja *ja,
+               struct cds_ja_inode_flag **snapshot,
+               int nr_snapshot,
+               uint64_t key,
+               struct cds_ja_node *node)
+{
+       int ret;
+
+       assert(nr_snapshot == ja->tree_depth - 1);
+
+       return ret;
+}
+
+int cds_ja_del(struct cds_ja *ja, uint64_t key,
+               struct cds_ja_node *node)
+{
+       unsigned int tree_depth, i;
+       struct cds_ja_inode_flag *snapshot[JA_MAX_DEPTH];
+       struct cds_ja_inode_flag *node_flag;
+       int nr_snapshot = 0;
+       int ret;
+
+       if (caa_unlikely(key > ja->key_max))
+               return -EINVAL;
+       tree_depth = ja->tree_depth;
+
+retry:
+       dbg_printf("cds_ja_del attempt: key %" PRIu64 ", node %p\n",
+               key, node);
+
+       /* snapshot for level 0 is only for shadow node lookup */
+       snapshot[nr_snapshot++] = (struct cds_ja_inode_flag *) &ja->root;
+       node_flag = rcu_dereference(ja->root);
+
+       /* Iterate on all internal levels */
+       for (i = 1; i < tree_depth; i++) {
+               uint8_t iter_key;
+
+               dbg_printf("cds_ja_del iter node_flag %p\n",
+                               node_flag);
+               if (!ja_node_ptr(node_flag)) {
+                       return -ENOENT;
+               }
+               snapshot[nr_snapshot++] = node_flag;
+               iter_key = (uint8_t) (key >> (JA_BITS_PER_BYTE * (tree_depth - i - 1)));
+               node_flag = ja_node_get_nth(node_flag,
+                       NULL,
+                       iter_key);
+               dbg_printf("cds_ja_del iter key lookup %u finds node_flag %p\n",
+                               (unsigned int) iter_key, node_flag);
+       }
+
+       /*
+        * We reached bottom of tree, try to find the node we are trying
+        * to remove. Fail if we cannot find it.
+        */
+       if (!ja_node_ptr(node_flag)) {
+               return -ENOENT;
+       } else {
+               struct cds_hlist_head *hlist_head;
+               struct cds_hlist_node *hlist_node;
+               struct cds_ja_node *entry;
+               int found;
+
+               hlist_head = (struct cds_hlist_head *) ja_node_ptr(node_flag);
+               cds_hlist_for_each_entry(entry,
+                               hlist_node,
+                               hlist_head,
+                               list) {
+                       if (entry == node) {
+                               found = 1;
+                               break;
+                       }
+               }
+               if (!found)
+                       return -ENOENT;
+               ret = ja_detach_node(ja, snapshot, nr_snapshot, key, node);
+       }
+       if (ret == -EAGAIN)
+               goto retry;
+       return ret;
+}
+
 struct cds_ja *_cds_ja_new(unsigned int key_bits,
                const struct rcu_flavor_struct *flavor)
 {