[Python-Dev] windows file closing race condition?

Tim Golden mail at timgolden.me.uk
Fri Sep 6 12:23:39 CEST 2013


On 06/09/2013 11:14, Antoine Pitrou wrote:
> Le Fri, 06 Sep 2013 08:58:06 +0100,
> Tim Golden <mail at timgolden.me.uk> a écrit :
>>
>> What should Python do?
> 
> Maybe using FILE_SHARE_DELETE could help?
> http://bugs.python.org/issue15244

I don't think so. It's the use of FILE_SHARE_DELETE (by other programs,
eg Virus Checkers) that typically causes the problem. IOW, the sequence is:

* [Some Other Prog] takes FILE_SHARE_DELETE handle, allowing other
programs to delete the file even while this handle is still open

* Python calls DeleteFile -- succeeds if the only open handles are
FILE_SHARE_DELETE; carries on

* File has apparently disappeared but still has open handles

* Any attempt to create a file of the same name or to delete a
containing directory fail because the file is still open, even though
it's successfully been deleted.

* (Some time later) [Some Other Prog] closes its handle and the file is
now completely gone


Unless I'm missing something, there's nothing Python can do to help here
apart from the sort of delay-retry dance which test.support uses and
which I'm advocating against as a core feature.


TJG


More information about the Python-Dev mailing list