Thanks
tomhukins, this looks to be what is needed. And your explanation of
copy on write memory sheds light on why I was experiencing the unsharing of memory.
I do have another related question: are there any methods for sharing a process (or a Perl object) among processes? For example, I want one shared object to update the data structure, to ensure integrity and to write the changes back to the persistent storage. Or is there a better method for handling this than one shared object attempting to service many requests?