| msg113864 - (view) |
Author: (cipater) |
Date: 2010-08-14 03:30 |
| I'm running 2.6.6rc1 64 bit on Windows 7 I get the following error when I try to instantiate a Pool: >>> import multiprocessing >>> p = Pool(processes = 2) Traceback (most recent call last): File "", line 1, in File "c:\Python26\lib\multiprocessing\__init__.py", line 227, in Pool return Pool(processes, initializer, initargs) File "c:\Python26\lib\multiprocessing\pool.py", line 84, in __init__ self._setup_queues() File "c:\Python26\lib\multiprocessing\pool.py", line 130, in _setup_queues from .queues import SimpleQueue File "c:\Python26\lib\multiprocessing\queues.py", line 22, in from multiprocessing.synchronize import Lock, BoundedSemaphore, Semaphore, Condition File "c:\Python26\lib\multiprocessing\synchronize.py", line 22, in from multiprocessing.forking import assert_spawning, Popen File "c:\Python26\lib\multiprocessing\forking.py", line 153, in from ._multiprocessing import win32, Connection, PipeConnection ImportError: No module named _multiprocessing >>> |
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| msg113865 - (view) |
Author: (cipater) |
Date: 2010-08-14 03:39 |
| prior to this I already imported Pool (from multiprocessing import Pool) I also tried the 64 bit 2.6.5 and got the same error. |
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| msg113873 - (view) |
Author: Brian Curtin (brian.curtin) *  |
Date: 2010-08-14 05:48 |
| I just fixed a similar problem for #9513 but the problem was only ever seen when test_multiprocessing was run through regrtest on 3.x on Windows. Removing the relative import dot on _multiprocessing imports let them succeed. I've never actually seen this cause a problem on an installed version, though. I'll check out 2.6.6 rc1 tomorrow when I get back to a Windows box to see if I can reproduce this. Reclassifying from crash to behavior - it's just an ImportError, not actually a crash |
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| msg113875 - (view) |
Author: Brian Curtin (brian.curtin) * |
Date: 2010-08-14 05:55 |
| I should correct myself. As seen on the 2.6 Win7 buildbot[0], test_multiprocessing is skipped there likely due to the "from ._multiprocessing..." ImportError. I kind of remember this now but didn't want to backport the fix to release26-maint since it was frozen, and this didn't appear to be an actual bug in the installed version. As said before, I'll investigate tomorrow. [0] http://www.python.org/dev/buildbot/builders/x86%20Windows7%202.6/builds/547/steps/test/logs/stdio |
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| msg113902 - (view) |
Author: Brian Curtin (brian.curtin) * |
Date: 2010-08-14 14:51 |
| Ok, it turns out this is in fact a regression from 2.6.5. My prior investigation for that 3.x issue must not have been on the 2.6 version I thought it was. Barry: the fix from #9513 (e.g., r83722) will correct this. |
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| msg113908 - (view) |
Author: Barry A. Warsaw (barry) * |
Date: 2010-08-14 15:19 |
| Please upload a patch specifically for 2.6.6 finally so that I can review it (and test it locally). It *seems* safe enough so if you and I both have a high confidence it won't regress anything, and it can go in before Monday, then I might approve it. I still can't build on Windows 7 w/VS2010 though unfortunately, but I will locally test Ubuntu (Lucid, Maverick), Debian, and OS X 10.6. |
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| msg113909 - (view) |
Author: Brian Curtin (brian.curtin) * |
Date: 2010-08-14 15:25 |
| Here's the patch. All four changes are one char each and live within win32-specific blocks. |
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| msg113910 - (view) |
Author: Barry A. Warsaw (barry) * |
Date: 2010-08-14 16:33 |
| Looks okay to me on *nix. You can check this in as long as test -u all passes on Windows. Please include a NEWS file entry and close this issue when it's committed. Thanks! |
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| msg113914 - (view) |
Author: Brian Curtin (brian.curtin) * |
Date: 2010-08-14 17:10 |
| Committed in r84031. Thanks for reporting this, cipater. |
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| msg113925 - (view) |
Author: Martin v. Löwis (loewis) * |
Date: 2010-08-14 19:36 |
| Notice that this is also a duplicate of #9144, which was fixed for 2.7, but nobody bothered to move the fix to the other branches. This goes all back to #7902, which has now introduced an incompatible change into 2.6 (otherwise, changing multiprocessing shouldn't have been necessary, despite that having been wrong all the time). I'll reopen that as release-critical for review. |
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