Author eryksun
Recipients Carl Osterwisch, Gabi.Davar, John Florian, chary314, dabrahams, davide.rizzo, dlenski, eric.araujo, eric.smith, eryksun, ethan smith, jaraco, jwilk, martin.panter, ncoghlan, njs, paul.moore, piotr.dobrogost, pitrou, r.david.murray, sbt, steve.dower, tim.golden, zach.ware
Date 2020-09-09.18:36:44
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Message-id <1599676605.1.0.690351196903.issue14243@roundup.psfhosted.org>
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> For this case, I think the best thing we can probably do is change the 
> default share mode for _all_ opens to include FILE_SHARE_DELETE. 

The C runtime doesn't provide a way to share delete access, except for the O_TEMPORARY flag, so Python would have to re-implement open(). Also, this doesn't help with re-opening a temporary file in another process since most programs do not share file delete access. 

There could be an option to enable a context-manager delete that's independent of closing the file. For example, if delete=True and delete_on_close=False, then _TemporaryFileCloser.close doesn't delete the file. Instead the file would be deleted via os.unlink in _TemporaryFileWrapper.__exit__. The default would be delete=True and delete_on_close=True, which would use the O_TEMPORARY flag in Windows. Combining delete=False with delete_on_close=True would raise a ValueError.

> bringing the default Windows behaviour slightly more in line with 
> how POSIX likes to do things.

In Windows 10, using FILE_SHARE_DELETE is even closer to POSIX behavior when the filesystem is NTFS, which supports POSIX delete semantics by renaming the file to a hidden system directory ("\$Extend\$Deleted") and setting its delete disposition. WinAPI DeleteFileW has been updated to use POSIX semantics if the filesystem supports it:

    >>> f = tempfile.NamedTemporaryFile()
    >>> h = msvcrt.get_osfhandle(f.fileno())
    >>> os.unlink(f.name)
    >>> info = GetFileInformationByHandleEx(h, FileStandardInfo)
    >>> info['DeletePending']
    True
    >>> GetFinalPathNameByHandle(h, 0)
    '\\\\?\\C:\\$Extend\\$Deleted\\001800000002C4F4301F419F'
History
Date User Action Args
2020-09-09 18:36:45eryksunsetrecipients: + eryksun, paul.moore, jaraco, ncoghlan, pitrou, eric.smith, tim.golden, jwilk, eric.araujo, r.david.murray, njs, dabrahams, davide.rizzo, sbt, Gabi.Davar, martin.panter, piotr.dobrogost, zach.ware, dlenski, steve.dower, Carl Osterwisch, ethan smith, John Florian, chary314
2020-09-09 18:36:45eryksunsetmessageid: <1599676605.1.0.690351196903.issue14243@roundup.psfhosted.org>
2020-09-09 18:36:45eryksunlinkissue14243 messages
2020-09-09 18:36:44eryksuncreate