I'm having a very hard time explaining why this snippet *sometimes*
raises KeyError:
snippet:
print type(self.pool)
for frag in self.pool.keys():
if frag is fragment_info:
print "the fragment_info *is* in the pool", hash(frag),
hash(fragment_info), hash(frag) == hash(fragment_info), frag == fragment_info, frag in
self.pool, frag in self.pool.keys()
try:
renderer_index = self.pool.pop(fragment_info)
except KeyError:
print "Glorious KeyError!"
for frag in self.pool.keys():
if frag is fragment_info:
print "the fragment_info *is* in the pool", hash(frag),
hash(fragment_info), hash(frag) == hash(fragment_info), frag == fragment_info, frag in
self.pool, frag in self.pool.keys()
raise
output:
<type 'dict'>
the fragment_info *is* in the pool 987212075 987212075 True True False True
Glorious KeyError!
the fragment_info *is* in the pool 987212075 987212075 True True False True
Traceback (most recent call last):
File "/home/yohell/workspace/missy/core/gui.py", line 92, in process_job
renderer_index = self.pool.pop(fragment_info)
KeyError: <core.gui.FragmentInfo object at 0x8fc906c>
This snippet is part of a much larger gtk program, and the problem only
from time to time, predominantly when the cpu is under heavy load and
this method gets called a lot. If I didn't know better I'd say it's a
bug in python's dict implementation, but I do know better, so I know
it's far more likely that I've made a mistake somewhere. I'll be damned
if I can figure out what and where though. I've reproduced this bug (?)
with python-2.5.2 on Ubuntu 8.10 and python-2.5.1 on WinXP.
I would very much like an explanation to this that does not involve
threads, because I haven't made any that I'm aware of. I can't even
understand how this could happen. How do I even debug this?
Please help, I feel like I've taken crazy pills here!
/Joel Hedlund
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