[Numpy-discussion] Memmap with multiprocessing

Warren Weckesser warren.weckesser at enthought.com
Tue Apr 26 17:50:48 EDT 2011


On Tue, Apr 26, 2011 at 4:21 PM, Ralf Gommers
<ralf.gommers at googlemail.com>wrote:

> On Mon, Apr 25, 2011 at 1:16 PM, Thiago Franco Moraes
> <totonixsame at gmail.com> wrote:
> > Hi,
> >
> > Has anyone confirmed if this is a bug? Should I post this in the bug
> tracker?
>
> I see the same thing with recent master. Something very strange is
> going on in the memmap.__array_finalize__ method under Windows. Can
> you file a bug?
>
>

Just a confirmation: I get the error with numpy 1.5.1, Python 2.7.1 in
Windows XP, but not in Mac OSX or Linux (Ubuntu).

Warren


 Ralf
>
>
> >
> > Thanks!
> >
> > On Tue, Apr 19, 2011 at 9:01 PM, Thiago Franco de Moraes
> > <totonixsame at gmail.com> wrote:
> >> Hi all,
> >>
> >> I'm having a error using memmap objects shared among processes created
> >> by the multprocessing module. This error only happen in Windows with
> >> numpy 1.5 or above, in numpy 1.4.1 it doesn't happen, In Linux and Mac
> >> OS X it doesn't happen. This error is demonstrated by this little
> >> example script here https://gist.github.com/929168 , and the traceback
> >> is bellow (between <traceback> tags):
> >>
> >> <traceback>
> >> Process Process-1:
> >> Traceback (most recent call last):
> >>  File "C:\Python26\Lib\multiprocessing\process.py", line 232, in
> _bootstrap
> >>    self.run()
> >>  File "C:\Python26\Lib\multiprocessing\process.py", line 88, in run
> >>    self._target(*self._args, **self._kwargs)
> >>  File "C:\Documents and Settings\phamorim\Desktop\test.py", line 7, in
> >> print_ma
> >> trix
> >>    print matrix
> >>  File "C:\Python26\Lib\site-packages\numpy\core\numeric.py", line 1379,
> in
> >> arra
> >> y_str
> >>    return array2string(a, max_line_width, precision, suppress_small, '
> ',
> >> "", s
> >> tr)
> >>  File "C:\Python26\Lib\site-packages\numpy\core\arrayprint.py", line
> 309, in
> >> ar
> >> ray2string
> >>    separator, prefix)
> >>  File "C:\Python26\Lib\site-packages\numpy\core\arrayprint.py", line
> 189, in
> >> _a
> >> rray2string
> >>    data = _leading_trailing(a)
> >>  File "C:\Python26\Lib\site-packages\numpy\core\arrayprint.py", line
> 162, in
> >> _l
> >> eading_trailing
> >>    min(len(a), _summaryEdgeItems))]
> >>  File "C:\Python26\Lib\site-packages\numpy\core\memmap.py", line 257, in
> >> __arra
> >> y_finalize__
> >>    self.filename = obj.filename
> >> AttributeError: 'memmap' object has no attribute 'filename'
> >> Exception AttributeError: AttributeError("'NoneType' object has no
> attribute
> >> 'te
> >> ll'",) in <bound method memmap.__del__ of memmap([0, 0, 0, 0, 0, 0, 0,
> 0, 0,
> >> 0,
> >> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> >>       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> 0,
> >>       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> 0,
> >>       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> 0,
> >>       0, 0, 0, 0, 0, 0, 0, 0], dtype=int16)> ignored
> >> </traceback>
> >>
> >> I don't know if it's a bug, but I thought it's is import to report
> >> because the version 1.4.1 was working and 1.5.0 and above was not.
> >>
> >> Thanks!
> >>
> >>
> > _______________________________________________
> > NumPy-Discussion mailing list
> > NumPy-Discussion at scipy.org
> > http://mail.scipy.org/mailman/listinfo/numpy-discussion
> >
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> http://mail.scipy.org/mailman/listinfo/numpy-discussion
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20110426/f08a62ca/attachment.html>


More information about the NumPy-Discussion mailing list