We see that there are huge number of int array instances during deserialization. We understand that this is due to creation of dependency tracking objects (java.io.ObjectInputStream$HandleTable$HandleList) created. As I understand, they are used to propagate ClassNotFoundException to "dependent" objects while reading an object.
Going through the code of ObjectInputStream, I think any ClassNotFoundException could be propagated immediately, rather marking the exception on every dependent object, thus avoiding HandleList and int.
I do realize that HandleTable's "entries" are absolutely required to wire any previously read objects into dependent objects read later from the stream. Just to clarify, question is about significance of java.io.ObjectInputStream$HandleTable$HandleList, which I fail to understand.