[Web-SIG] Alternative to threading.local, based on the stack

[Martijn Faassen]

Hi there,

2008/7/4 Iwan Vosloo <iwan at reahl.org>:
[snip]
> A lot of the frameworks use a thread local context to solve this
> problem. I'm assuming these are based on threading.local.
>
> (See, for example:
> http://www.sqlalchemy.org/docs/05/session.html#unitofwork_contextual )

scoped_session is actually, I think, a bad example, as SQLAlchemy uses
the thread id to scope things per session, not threading.local. As
long as there's a way to uniquely identify "context", scoped_session
could also be scoped differently, as long as it has a way identify the
context that doesn't need any non-global parameters.

Zope 3 may be a better example, as it does use thread locals to scope
things per thread (I believe this requirement by Zope was actually one
of the reasons this feature was moved into Python). There may also be
other parts of SQLAlchemy that indeed use thread local variables.

Regards,

Martijn