[PATCH] Cygwin: introduce close_range

[Christian Franke]

Jon Turney wrote:
> On 14/01/2024 16:07, Christian Franke wrote:
>> Recently I learned about the existence and usefulness of close_range():
>> https://github.com/smartmontools/smartmontools/issues/235
>>
>> https://man.freebsd.org/cgi/man.cgi?query=close_range&sektion=2
>> https://man7.org/linux/man-pages/man2/close_range.2.html
>>
>> Note that the above Linux man page is not fully correct. The include 
>> file "linux/close_range.h" exists, but provides only the defines. It 
>> is sufficient to include "unistd.h" as on FreeBSD.
>>
>> The attached patch adds this to Cygwin. It does not implement the 
>> Linux-specific CLOSE_RANGE_UNSHARE as I have no idea how to do this :-)
>
> This API should also be mentioned in the
> "System interfaces compatible with GNU or Linux extensions" section of 
> doc/posix.xml
>
>

Thanks for the info. I used the recent "Cygwin: introduce fallocate(2)" 
patch as a blueprint for which other files should be changed (fallocate 
is also missing in the posix.xml file).

I will provide a new patch soon which also fixes an unlikely but 
possible corner case: Pass a value larger than MAX_INT as lower limit.