So I escape your wise warning re: freezing objects because the control thread destroys its copies of them as soon as they're frozen and passed off to the worker.

In effect, you are not sharing an object between threads, you are actually just passing an object template that you want to be construct by the receiving thread. The only benefit you are gaining from doing it this way is the encapsulation of the objects class into the queued (Storable) string. Though I guess it does allow you to build the object instance by calling multiple methods prior to freezing it, which means that the object is validated before you pass it.

I think that passing a hash or an array containing the parameters to be used in the constructor in the destination thread--along with some convention of passing the class of the object as a named parameter in the hash or as the first element of the array would be just as clean, and probably somewhat more efficient. For one thing it would allow you to avoid loading the code for every class of object into the main thread as well as every receiving thread.

Then again, I guess it does simplify the re-construction at the receiving end. Storable does all the work for you. And I haven't benchmarked it, and so as long as your not trying to use the objects concurrently from multiple threads, it should be fine.

On the filehandle stuff, using a filemode of 'r+' and/or '+< &=$fileno', appears to let you read and write to the file from either thread, but it's not quite right. I'm convinced that the semantics of using the "&=$fileno" open is screwed up somehow--at least when combined with threads--but I'm not sure that I understand what the semantics should be in non-threaded code, so it's difficult to tell. It could just be another "not quite POSIX behaviour" win32 thing? Sorry, but I can't be much help there.

It might be worth taking up the problem with as a Storable/IO::* limitation with the p5p guys. Their greater understanding may see the reason/cause for it, and they may be able to suggest something?