[Zope-dev] RE: [Python 2.3.4c1] nasty LinuxThread problem not solved

[Dieter Maurer]

Tim Peters wrote at 2004-5-21 10:16 -0400:
>[Dieter Maurer]
>> I just checked that Python 2.3.4c1 does not yet fix our
>> LinuxThread-Crash problem -- the problem that
>> lets a multi-threaded application enter a curious state
>> when one on the threads crashes.
>> ...
>> And this despite the patch for this problem in Python's collector...
>
>There's a patch that squashes the specific symptom you have in mind, but at
>the cost of other breakage -- the original patch was added for a reason too.

I verified that

<http://sourceforge.net/tracker/index.php?func=detail&aid=949332&group_id=5470&atid=305470>

indeed fixes the problem.

It might introduce other subtle problems but at least none that
are revealed by Python's regression test suite...

Moreover, I doubt that such problems will be significant in practise:

  The patch prevents blocking of signals that should (as specified by the
  PThreads standard)
  not be blocked -- as the operating system uses these signals
  to report serious problems. No application should use
  these threads for application specific communication.

  Therefore, a violation of Python's principle to only
  deliver signals to the main thread seems appropriate
  for these signals.

As an automatic restart after a crash is vital for our
productive Zope2 installations, we will probably bite
the bullet and maintain our own Python version.

-- 
Dieter