[IronPython] Multiple engine instances in IP 2.0 and beyond (was IronPython 2.0 Alpha 1 Released)

[Michael Foord]

Dino Viehland wrote:
> I'm not actually the one working on the engine APIs so that's the reason I've tended to be vague.  I'll talk to the people doing it and let you know what I hear.
>
> But the more info you can give us the better decision we'll be able to make.  For example what do you actually need to be isolated?  Do you need multiple system states so they get their own modules, console, etc...  do you need everything in sys isolated?  Do you need to guarantee the isolation even if .NET code is called (e.g. they could smuggled data via a static field).  If they do need some rather high level of isolation are app domains good enough?  Do you need to marshal a lot of data in/out?  Or is the effort to spin up and use app domains correctly?
>   
At Resolver we are currently using multiple IronPython engines. Moving 
to AppDomains is a long term goal for us, but is actually quite a lot of 
work (we would have *lots* of cross-domain calls and so to avoid that we 
have to find an efficient way of pumping lots of data in and then out of 
the app domain).

Switching to app domains is not a high priority task for us, and in the 
meantime we *can't* upgrade to IronPython 2 if it doesn't support 
multiple engines.

Isolation of engines is only a minor benefit (it is a positive side 
effect - but not the reason we started using them) for us at the moment, 
and an isolated system state (although nice) is not vital.

All the best,

Michael Foord
http://www.voidspace.org.uk/ironpython/index.shtml