[Zope] Zope, setlocale(), requests and traversal

[Doyon, Jean-Francois]

Well, I wanted locale.format() and locale.currency() to use a per
request locale setting, instead of the underlying more "global" one that
isn't thread-safe.

So I patched localeconv() to extract the locale setting from the request
instead of wherever it gets it otherwise normally.  I've read through
the locale module, and this seems to be the "deepest" point where to
effect the change.

This does not make the whole module thread-safe by a long shot, and
wasn't intended to.  I just wanted number/currency formatting to work,
which it does format(), currency(), and _group() are safe).

Of course now I've found the Zope 3 Locale and LocaleProvider
Implementation, with number and currency and datetime support ... I may
try to use that instead.

J.F.

-----Original Message-----
From: zope-bounces at zope.org [mailto:zope-bounces at zope.org] On Behalf Of
Dieter Maurer
Sent: December 17, 2006 3:43 AM
To: Doyon, Jean-Francois
Cc: Chris Withers; zope at zope.org
Subject: RE: [Zope] Zope, setlocale(), requests and traversal

Doyon, Jean-Francois wrote at 2006-12-15 08:38 -0500:
>setlocale() is a python thing.  It wraps a C library, and that function

>setups an application wide environment (A bit like an environment 
>variable would ...) ... Which is why it's not thread safe.

If you do not have a thread aware implementation of "setlocale", then it
is *VERY* dangerous to change "setlocale" inside a thread -- as changing
any global data can lead to non-deterministic behaviour in a
multi-threaded environment unless special precautions (locking) are
taken.


Apparently, you are aware of the danger. But, I have not seen how you
avoid the problem in your sketched solution.

--
Dieter
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