.Return the first element in an iteration.
p_ht is the hash table to iterate in,
p_it is a pointer to the iterator to initialize, and
pp_key is filled in with a pointer to the key for the current item.
This function should be used for iteration and is used together with
ght_next() Note that you cannot assume anything about the order in which the entries are
accessed. If an entry is inserted during an iteration, the entry might or
might not occur in the iteration. Note that removal during an iteration is
only safe for the current entry or an entry which has already been iterated
The use of the
ght_iterator_t allows for several concurrent iterations, where you would use one
ght_iterator_t for each iteration. In threaded environments, you should still lock access to
the hash table for insertion and removal.