[IronPython] The tale of a full HybridMapping and a not so tempfile

[Dino Viehland]

Thanks for the great detail here.  As you said the fix is easy and I believe
I have it ready to go.  We're already kicking off our RC2 build so I don't
know that it'll make it until that build (or 2.6.0 for that matter) but it'll
be fixed by 2.6.1 at the latest.

> -----Original Message-----
> From: users-bounces at lists.ironpython.com [mailto:users-
> bounces at lists.ironpython.com] On Behalf Of Martin (gzlist)
> Sent: Thursday, October 22, 2009 2:50 PM
> To: users at lists.ironpython.com
> Subject: [IronPython] The tale of a full HybridMapping and a not so tempfile
> 
> I'm trying to complete some work getting a big project running on
> IronPython, but hit an issue where everything in the test suite would
> start failing after a certain point with errors along the lines of:
> 
> Traceback (most recent call last):
> ...
>   File "C:\Program Files\IronPython 2.6\Lib\tempfile.py", line 444, in
> NamedTemporaryFile
>     (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags)
>   File "C:\Program Files\IronPython 2.6\Lib\tempfile.py", line 228, in
> _mkstemp_inner
>     fd = _os.open(file, flags, 0600)
> OSError: [Errno -2146233079] HybridMapping is full
> 
> After a long boring trek over the hills of ignorance that may have
> been shorter if I'd seen that traceback first rather than other more
> obscure ones, the root cause turned out to be a failure to clean up
> temporary files. After IronPython has created 4096 of them and not
> removed any afterwards everything involving filenos starts to
> throwing. (As an aside, I wonder if using non-integer unique tokens
> like Jython mightn't be a better approach).
> 
> The following issue tracker entry covers the tempfile issue:
> 
> <http://ironpython.codeplex.com/WorkItem/View.aspx?WorkItemId=23936>
> 
> However the bug report gets it a little wrong, the problem is not that
> sys.platform == "win32" is false under IronPython, but rather that
> os.name == "nt" is still true, but IronPython silently ignores the
> os.O_TEMPORARY flag.
> 
> A trivial work around is:
> 
>     if sys.platform == "cli":
>         os.name = "nty"
>         import tempfile
>         os.name = "nt"
> 
> However fixing this properly is also pretty simple, in
> Src/IronPython.Modules/nt.cs the open function just needs to make sure
> that File.Open gets passed DeleteOnClose. There may as well be a
> FileOptionsFromFlags as per the existing FileModeFromFlags and
> FileAccessFromFlags so that the following mappings are correct as
> well:
> 
> os.O_SHORT_LIVED -> ? -> FILE_ATTRIBUTE_TEMPORARY
> os.O_TEMPORARY -> FileOptions.DeleteOnClose -> FILE_FLAG_DELETE_ON_CLOSE
> os.O_RANDOM -> FileOptions.RandomAccess -> FILE_FLAG_RANDOM_ACCESS
> os.O_SEQUENTIAL -> FileOptions.SequentialScan -> FILE_FLAG_SEQUENTIAL_SCAN
> 
> Martin
> _______________________________________________
> Users mailing list
> Users at lists.ironpython.com
> http://lists.ironpython.com/listinfo.cgi/users-ironpython.com