Calling numexpr.evaluate from two different threads at the same time causes a
segfault, unless numexpr.set_num_threads(1) was called prior.
Looking at the code in vm_engine_iter_parallel, it looks to me like it uses a
global variable to store thread information, and so chokes when two different
threads call that function at the same time.
See attached file for a small code sample that reproduces this problem. And
here's what I see when I actually run that script from the shell:
{{{
> python -c 'import numexpr; numexpr.test()'
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Numexpr version: 2.0.1
NumPy version: 1.6.1
Python version: 2.7.2 (default, Dec 13 2011, 14:11:54)
[GCC 4.1.2 20080704 (Red Hat 4.1.2-50)]
Platform: linux2-x86_64
AMD/Intel CPU? True
VML available? False
Detected cores: 24
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[... snip ...]
----------------------------------------------------------------------
Ran 5103 tests in 3.805s
OK
> python numexprCore.py
Starting threads
Waiting
Segmentation fault (core dumped)
}}}
Original issue reported on code.google.com by vovan...@gmail.com on 30 Apr 2012 at 9:46
Original issue reported on code.google.com by
vovan...@gmail.comon 30 Apr 2012 at 9:46Attachments: