+
+ /**
+ * Mutations requested by the client that we're
+ * unable to execute right now because we're iterating
+ * over the underlying hash map of elements.
+ */
+ struct PendingMutation *pending_mutations_head;
+
+ /**
+ * Mutations requested by the client that we're
+ * unable to execute right now because we're iterating
+ * over the underlying hash map of elements.
+ */
+ struct PendingMutation *pending_mutations_tail;
+
+ /**
+ * Number of concurrently active iterators.
+ */
+ int iterator_count;