DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 053233851C1F
Subject: Re: FILE_ATTRIBUTE_TEMPORARY ?
To: cygwin@cygwin.com
References: <7990f8e3-ebd7-c865-58da-ddb97bd59d5f@gmail.com>
From: Mark Geisert <mark@maxrnd.com>
Message-ID: <295cd16c-9f43-a6b7-9a48-a3aa52310a4f@maxrnd.com>
Date: Wed, 6 Jan 2021 01:44:04 -0800
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Hi Noel,

Noel Grandin via Cygwin wrote:
> Hi
> 
> Does the cygwin
>      tempfile()
> API use the Win32
>      FILE_ATTRIBUTE_TEMPORARY
> flag on the files it creates?
> 
> Asking because that makes a fairly significant performance difference when 
> creating very short lived temp files.

Good question!  If one specifies O_TMPFILE as one of the flags on an open() call, 
Cygwin does set that Win32 attribute as desired.  Unfortunately, Cygwin's 
tmpfile() is supplied by newlib and it does not specify O_TMPFILE on its 
underlying open() call.

That looks like a bug to me, unless I'm missing something subtle there; I'll 
submit a patch and find out.
Thanks!

..mark
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