Re: Flushing global variables

[Tony Finch <dot@...>]

Murray S. Kucherawy <msk@cloudmark.com> wrote:

> I'm working on an application that's multi-threaded, and to avoid a
> newstate-load-pcall-close series for every time I want to invoke a
> script, I'm thinking of allocating a pool of states and just pulling one
> out when it's time to run, which leaves me with just load-pcall every
> time.

Why not cache the parsed scripts, so it's just a pcall each time?

> One thing I'm not certain about with that design: Will the garbage
> collector purge any global variables that exist in the state on
> completion of the pcall, or will they linger around for the next
> load-pcall on the same state object?  If the latter, can I use some
> getfenv/setfenv magic to reset things for the next iteration?  Or do I
> have to bite the bullet and do it the more expensive way?

Yes, it sounds like you want some kind of setfenv sandbox. You can use a
__index metatable entry on the temporary environment to pull in the
persistent global functions efficiently.

Tony.
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