Phobos: Posix hands down open files to sub processes.

[Marco Leise]

Am Mon, 11 Mar 2013 06:32:42 +0100
schrieb "Vladimir Panteleev" <vladimir at thecybershadow.net>:

> On Monday, 11 March 2013 at 05:24:49 UTC, Marco Leise wrote:
> >
> > Python:
> >
> >> def _mkstemp_inner(dir, pre, suf, flags):
> >>     """Code common to mkstemp, TemporaryFile, and 
> >> NamedTemporaryFile."""
> 
> So it only sets the flag on temporary files?

It's the only place where I could quickly identify it with a
grep. Even for Python 3.4 this is still an open issue it seems,
like this bug report shows: http://bugs.python.org/issue12107
It also discusses pros and cons a bit.

> > I think they just rely on the C library at the moment for their 
> > System.IO,
> > which in turn doesn't set FD_CLOEXEC.
> 
> > Rust:
> >
> > Uses C stdlib.
> 
> Is there any discussion on why libc doesn't do it, and what do 
> APIs that wrap the C API do?

I haven't researched any of that so far. All I know is that
glibc added a new flag with 2.7 for that:

> e (since glibc 2.7)
>     Open the file with the O_CLOEXEC flag.  See open(2) for more
>     information.  This flag is ignored for fdopen().

> > Despite the increased maintenance cost I think we should adapt 
> > that behavoir in D as well.
> 
> I don't think there would be a maintenance cost to speak of. 
> Wouldn't it be a one-line addition to a few places?

More or less. You have to query the flags, add FD_CLOEXEC and
set them again. Error handling wouldn't be bad either. Its
enough to write a helper function for that.

-- 
Marco