[pypy-dev] multiple isolated VMs in a single process

[Tobias Oberstein]

Are there any design plans regarding threading architecture yet?
I particular, are you planning to support having multiple
interpreters in one process _without_ sharing objects (no free
threading but VM-wise locking). Supporting this would require
early design decisions like

 - no global data for the interpreter/VM
 - no global data in object implementations
 - but what about extension modules? many have global data ..

isn't it? Also, in an  C embedding API, will the VM-state be
take from thread-local storage or passed into every function
by the embedding application via an opaque pointer?

I'm thinking of embedding a dynamic language into an
multithreaded OODBMS. The different VMs within the server process
would share data via objects instantiated from a special
extension class that wraps up the OODBMS. Synchronisation on
these objects is taken care of by the OODBMS. No need to share
objects local to each VM.

Sadly, as I was told, fixing above issues for CPython would
be hard like shit. It's so sad that global data has not been
avoided from the very beginning in the CPython.

Tobias