bug#10470: MSYS: race in directory access?

[Stefano Lattarini]

On 01/11/2012 08:27 PM, Peter Rosin wrote:
> Stefano Lattarini skrev 2012-01-11 18:31:
>> Hi Peter, sorry for the delay.
> 
> No rush!
> 
>>>>>> We could enhance your original workaround like this:
>>>>>>
>>>>>>  am__remove_distdir = \
>>>>>>    { test ! -d "$(distdir)" \
>>>>>>      || { find "$(distdir)" -type d ! -perm -200 -exec chmod u+w {} ';' \
>>>>>> -         && rm -fr "$(distdir)"; }; }
>>>>>> +         && if rm -fr "$(distdir)"; then :; else \
>>>>>> +## On MSYS (1.0.17) it is not possible to remove a directory that is
>>>>>> +## in use; so, if the first rm fails, we sleep some seconds and retry,
>>>>>> +## to give pending processes some time to exit and "release" the
>>>>>> +## directory before we removed.  See automake bug#10470.
>>>>>> +              sleep 5 && rm -fr "$(distdir)"; fi; }; }
>>>>>>  am__post_remove_distdir = $(am__remove_distdir)
>>>>>>  endif %?TOPDIR_P%
>>>>
>>>>> This works, best so far!  Committable, if you ask me.
>>>>>
>>>
>> Could you try the attached test case to see if it can reliably expose the
>> problem on MSYS/MinGW?  If yes, I'll prepare a patch shortly.
> 
> If I (try to) mend the race (the "rm -rf foo.d" reliably beats the "cd foo.d"
> in the subshell) by adding a "sleep 1" before the "rm -rf foo.d"
>
Thanks for the info, I've amend the test accordingly.

> So, I guess no, the probelm is not exposed by the test.
>
> Did you mean "$my_sleep &" in the foo.test script?
>
Yes, I did; sorry for the sloppiness.

> If add that &, the test fails in much the same way as we've seen previously
> in this bug report.
>
Good!

Attached is the proposed patch series: the first patch should expose the bug,
the second patch should fix it.  I will apply them once I have confirmation
the bug is correctly exposed and fixed.

Thanks,
  Stefano.

0001-coverage-expose-automake-bug-10470-distcheck-related.patch
Description: Text Data

0002-dist-avoid-distdir-removal-failure-on-MSYS-MinGW.patch
Description: Text Data