The protections are needed even without sharing objects between threads (where changes to an object in one thread are visible in another).

This is only true if

• You create objects prior to spawning your threads
• You attempt to reference or use those objects from multiple threads concurrently and expect them to remain consistent.

I'm suggesting that neither of these is either desirable nor necessary for threaded applications provided you do not try to use threads as you would forks.

I cannot address your comments regarding fork on win32. With the absence of proper signal emulation; the conflicts with global resources, file handles, sockets, environment, etc.; and the performance penalty that the fork emulation layers upon threading; I (personally) would prefer it if the fork emulation did not exist.

In my attempts to use it, it simply isn't sufficiently compatible with Unix fork to make it usable in for the normal "forking idiom" (Silly forker :).

Of more concern to me is that the requirements imposed by the attempted emulation, have a disastrous effect upon the use of threads as threads. It forces me to jump through hoops to avoid the expensive and unwanted automatic duplication of resources, to be able to get 'virgin' threads without pre-existing baggage.

I realise that the emulation came first and threads (as in ithreads) leverage much of the excellent work that went into the original fork emulation, and I am not detracting from that work, but it would be so much better (for me, and my uses) if I could specify use threads qw[NOCLONE];.

Ie. When I create a thread, give me a virgin interpreter running in that thread and let me create the things I need. Please :)

I've never really understood the fork and exec idiom anyway. Why bother going through the process of duplicating the current process in to an exact clone--even with COW--if the next thing you are going to do is throw it all away and load a completely different executable image into that process? Why not just load the image into a new process and have done with it?

I know fork & exec isn't the only use of fork, but it is the most prevalent.