[Zope] SESSION Errors

[Dennis Allison]

Might work, but I doubt it.  I think it's always best to attack this sort
of stuff on first principles.  The quantity of code is tiny (10s of lines)
but it's hard to grok.

On Thu, 19 Feb 2004, Paul Howell wrote:

> C and D:
> As to conflict errors, does this mean READ conflicts, as in trying to read 
> the session info?
> 
> If that is the case, then might it not work to try reading twice before 
> flipping to the error?
> 
> Here's the code snippet from Dennis:
> 
> >request=container.REQUEST
> >try:
> >     session=request['SESSION']
> >     return session[varname]
> >except KeyError:
> >     container.oopsSession( varname )
> >     raise
> 
> Why not make this more like (completely untested, and this is not my forte, 
> but just thinking out loud):
> 
> request=container.REQUEST
> try:
>      session=request['SESSION']
>      return session[varname]
> except try:
>      session=request['SESSION']
>      return session[varname]
> except KeyError:
>      container.oopsSession( varname )
>      raise
> 
> 100:1 against this "try:try:except" structure being valid, but given that 
> there is some analogous structure that would have this effect, I would 
> think that if there is a 1 in 10,000 chance of failure reading the SESSION 
> once, then there's a similar 1 in 10,000 chance of failure reading it a 
> second time, and that makes it a 1 in 100,000,000 chance of failure by 
> nesting... and the nested try: would only be activated maybe once 1 in 
> 10,000 times, making it a non-issue as far as performance.
> 
> Just my ha'penny, unencumbered by real knowledge of these deep innards of 
> zope...
> =Paul
> 
> 
> At 05:36 PM 2/19/2004, Chris McDonough wrote:
> >On Thu, 2004-02-19 at 16:30, Dennis Allison wrote:
> > > Chris--
> > > I need to squash this bug.  Any thoughts as to were to begin.  Have you
> > > tried to locate the error?
> > >       -d
> >
> >Yes.  And I haven't been successful.  I suspect that it's something
> >related to conflict errors.
> >
> >- C
> 
> 
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