RFR: 8005582 - java/lang/Runtime/exec/WinCommand.java intermittent test failures

[Stuart Marks]

On 1/9/13 5:26 PM, Martin Buchholz wrote:
> Well, if this is the behavior you can expect from Windows, carry on!
>
> But how can anyone get reliable behavior if a file delete can fail capriciously
> in two dimensions - it might be "in use" , or it might be an already deleted ghost?

In other words, how can anyone ever get any work done on Windows? That is an 
excellent question, one for which I do not have the answer. :-)

I think the practical answer is that everybody puts up with it and tries to 
come up with hacky workarounds. For example, the Mercurial developers have run 
into this; see [1] and the links at the bottom of that page. They ended up with 
a policy of first renaming the file to a random name, retrying 10 times if 
necessary. Then they try to unlink. If at that point the unlink fails, they try 
to remove the READONLY attribute and retry. If the unlink still fails, they 
give up. See win32.unlink at line 344 in [2].

There is the inevitable stackoverflow page [3]. They basically ended up with 
something similar, renaming before deleting, although it's amusing that using 
GetTempFileName() creates a uniquely named temp file, which must be deleted 
before something can be renamed onto it, oh wait....

And then there is the rant at [4] which points the accusing finger at the 
Windows Application Experience server (same as DeHaven in his analysis of the 
Arrrghs fix), which also mentions the terrible consequences if you decide to 
disable this service in a vain attempt to speed up your system.

I envision a task for someone in the near future of writing a 
rename-to-random-filename-then-delete utility function in Java (similar to 
Mercurial's win32.unlink) and converting the tests to use it. Maybe we should 
consider changing File.delete() and Files.delete() to do this by default on 
Windows... urgghhhh....

s'marks


[1] http://mercurial.selenic.com/wiki/UnlinkingFilesOnWindows

[2] http://selenic.com/hg/file/a4765077b65e/mercurial/win32.py

[3] 
http://stackoverflow.com/questions/3764072/c-win32-how-to-wait-for-a-pending-delete-to-complete

[4] 
http://www.retrocopy.com/blog/28/cant-delete-exe-files-in-vista--windows-7-solved.aspx