On Thu, Oct 17, 2013 at 4:24 AM, Jonathan Slenders < jonathan.slend...@gmail.com> wrote:
> The global state problem is something that's been bothering me for a long > while, but after seeing a presentation of Alex Gaynor [1] from last year, I > started thinking about this again. > > The main problem is that you'd need to have a DjangoProject object which > contains the root configuration and you'd have to somehow pass that object > around everywhere. > > Maybe I'm not the first to think about this, but what's wrong with > thread-local-storage? > What's wrong with thread local storage? Well, try this though experiment. Everywhere that you see the word "thread local", replace it with "global variable". Now re-read your argument. It doesn't matter how you gussy it up -- a thread local is a global variable, with all the software engineering consequences that follow from that, including increased coupling, decreased cohesion, complications for testing, and so on. > In Django, we have a huge advantage above nodejs in that there's only one > active request per thread and that request should belong to only one > DjangoProject instance. (We don't have unexpected contextswitches in the > same thread, like in Twisted or Tulip. -- We can make that assumption.) > Yet. :-) I don't know that we can rely on this being true for all time. (This is an admittedly weak argument -- I certainly wouldn't base any objection to thread locals on this alone) Actually we are already using threadlocals for the current active language > [2], so I don't see any reason for not using the same approach to keep > track of the currently active DjangoApplication object. > You're correct -- however, I'd call this a wart, not a pattern to be followed. If we were in a position to remove these thread locals, I would. Yours, Russ Magee %-) -- You received this message because you are subscribed to the Google Groups "Django developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To post to this group, send email to django-developers@googlegroups.com. Visit this group at http://groups.google.com/group/django-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/CAJxq848XP6mqctJ3dkMVKbzMkpk%3DChETGy3Ws_oORt9xnArzfA%40mail.gmail.com. For more options, visit https://groups.google.com/groups/opt_out.
