哈希表中的弱引用。

I've using an NSHashTable to store weak references to objects. When an object in the hash table is deallocated and the reference is zeroed within the hash table, the pointer to nil still resides in the hash table, correct? So over time, if objects that are deallocated aren't directly removed from the hash table, the hash table will continue to grow in size? Right now, there is no easy way to send a notification to the object controlling the hash table that one of the hash tables elements have been removed (it's a game where feedback calls mean communication between objects is very indirect, and preferably stays that way). Should I iterate over the hash table periodically to remove nil references?I've using an NSHashTable to store weak referen