Jorge Herskovic added the comment:
Ok, I *think* I tracked it down to Connections getting cleaned up in a
non-orderly fashion, sometimes while _run_finalizers is executing. The
following patch to lib/python3.4/multiprocessing/connection.py cures the
problem on my machine.
@@ -124,10 +124,10
Jorge Herskovic added the comment:
20,000+ iterations of the test suite with my homebuilt 3.4.3 throw no
exceptions.
Weirder and weirder.
Any suggestions? Without any actual knowledge (unencumbered by the thought
process), a concurrency issue in the interpreter itself is my guess
Jorge Herskovic added the comment:
Finally able to repro on my old Mac Pro at work (Universal 64/32bit 3.4.3 from
python.org, OS X 10.10.3). For some reason I can't quite fathom, there were two
exceptions this time.
Error in atexit._run_exitfuncs:
Traceback (most recent call last):
File
Jorge Herskovic added the comment:
Ok, sorry, one more important thing I omitted in the previous comment.
^^^ The second exception above seems to be related to a new test I added, one
that includes a daemonic process which itself relies on daemonic threads.
The cleanup of that seems
Jorge Herskovic added the comment:
More data:
I've been unable to replicate this behavior on Ubuntu 15.04 on Python 3.4.3
over ~20 thousand test runs. (Same machine, running in a VM)
An overnight repeated run on the original machine on OS X, 3.4.3, official
distribution gave an actual
Jorge Herskovic added the comment:
The failing Python:
3.4.3 (v3.4.3:9b73f1c3e601, Feb 23 2015, 02:52:03)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)]
The non-failing Python:
3.4.3 (default, Jun 23 2015, 06:33:02)
[GCC 4.2.1 Compatible Apple LLVM 6.1.0 (clang-602.0.53)]
The non-failing python
Jorge Herskovic added the comment:
This happens reliably between 1-5% of the time on my home Mac (a 4.0 GHz i7).
My work Mac Pro, a lot slower, doesn't exhibit this behavior on the same 3.4.3
interpreter.
Could it be related to a concurrency issue in the interpreter?
We're attempting
New submission from Jorge Herskovic:
I'm writing a library on top of multiprocessing. As part of the test suite, I
create and destroy dozens of processes repeatedly. About once in 50 runs, the
tests complete successfully but the program crashes with:
Error in atexit._run_exitfuncs:
Traceback
New submission from Jorge Herskovic jorge.r.hersko...@uth.tmc.edu:
The shelve module documentation states that by default, mutations to
persistent-dictionary mutable entries are not automatically written
back. If the optional writeback parameter is set to True, all entries
accessed are cached
