[Python-Dev] Backport threading.py fix to 2.5.2?

[Guido van Rossum]

OK, I'll backport it.

On Jan 4, 2008 4:49 AM, Thomas Wouters <twouters at google.com> wrote:
>
>
>
> On Jan 4, 2008 2:46 AM, Guido van Rossum <guido at python.org> wrote:
> > See http://bugs.python.org/issue1731. Should we consider it safe to
> > backport r57216 to 2.5.2? This is Thomas Wouters's code to disable
> > spurious tracebacks when daemon threads die. We're running some 2.4
> > apps with (a variant of) this at Google that get many 1000s of
> > invocations a day, so I'm pretty confident that it works.
> >
>
> I'm also pretty confident it works, although it isn't really guaranteed to
> catch *all* such situations. No reason not to backport it, just a remark
> about how it checks to see if Python is shutting down. It is, however,
> incredibly unlikely '_sys' won't be gone when we check for it if the
> exception is indeed a spurious one. What could happen is that a legitimate
> exception happens right before interpreter shutdown, then a thread switch
> occurs before Python tries to report the exception, the interpreter exits,
> and then the daemonic thread starts to report its exception. The only way to
> catch that is to do the 'are we exiting' check in the C code that does the
> actual thread-exception reporting. I'm not sure if it's worth it, as the
> timing has to be pretty exact for that to happen, and you wouldn't want to
> introduce a bug there; could be years before someone figures it out :P
>
> --
> Thomas Wouters <twouters at google.com>
>
> Hi! I'm a .signature virus! copy me into your .signature file to help me
> spread!



-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)