Thread scheduling

[Peter Hansen]

Jack Orenstein wrote:
>> One thing you might try is experimenting with sys.setcheckinterval(),
>> just to see what effect it might have, if any.
> 
> That does seem to have an impact. At 0, the problem was completely
> reproducible. At 100, I couldn't get it to occur.

If you try other values in between, can you directly affect
the frequency of the failure?  That would appear to suggest
a race condition.

>> It's also possible there were some threading bugs in Py2.2 under
>> Linux.  Maybe you could repeat the test with a more recent
>> version and see if you get different behaviour.  (Not that that
>> proves anything conclusively, but at least it might be a good
>> solution for your immediate problem.)
> 
> 2.3 (on the same machine) does seem better, even with setcheckinterval(0).

The default check interval was changed from 10 in version 2.2
and earlier to 100 in version 2.3.  (See 
http://www.python.org/2.3/highlights.html for details.)

On the other hand, with version 2.3.4 under RH9, I tried values
of 10 and 1 with no failures at any time.  This might still
be an issue with your own particular system, so having others
try it out might be helpful...

-Peter