No you did not declare @state. You declared $state which is an entirely different variable. Most probably make_shared_array() returns an array reference to you. Check the documentation.

And BTW, dont call it as &make_shared_array(): that is very "old" style and it has side-effects you probably do not know about.

Deleting use strict is not a good idea. It pointed an error out to you. Removing use strict does not make the error go away, only the error message, the error being that @state is not the shared variable you think it is, a very fundamental error.

Update: A rather handy trick you can try is using Data::Dumper to inspect your arrays and hashes. Then you do not have to write all these for loops with nothing but a print inside.