add closefrom() call
John Baldwin
jhb at freebsd.org
Tue Jul 17 14:45:55 UTC 2007
On Monday 16 July 2007 02:25:37 pm Julian Elischer wrote:
> Peter Jeremy wrote:
> > On 2007-Jul-15 16:51:38 -0700, Julian Elischer <julian at elischer.org>
wrote:
> >>> void
> >>> closefrom(int lowfd)
> >>> {
> >>> fcntl(lowfd, F_CLOSEM, NULL);
> >>> }
> >> what on earth would that achieve?
> >> (as opposed to just a simple syscall)
> >
> > The only benefit I can think of is minimising the number of syscalls.
> > Is there any other benefit?
> >
>
> I don't think so.. it's less efficient, and harder to do..
> syscalls are not in short supply.
Actually, adding a new fcntl is about the same as adding a new system call
except that you don't have to generate tables, etc. (so it might actually be
simpler). I'm not sure it's such a bad idea to just have a fcntl to get the
max open fd and do the loop in userland so you get better auditing of the
individual close() operations.
--
John Baldwin
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