[Python-Dev] PEP 433: Add cloexec argument to functions creating file descriptors

[Antoine Pitrou]

On Sun, 13 Jan 2013 21:13:42 +1000
Nick Coghlan <ncoghlan at gmail.com> wrote:
> >
> > Also, ISTM that Windows also supports this flag. If it does, then
> > "cloexec" might not be the best name, because it refers to the
> > execve() Unix system call. Maybe something like "noinherit" would be
> > clearer (although coming from a Unix background "cloexec" is
> > crystal-clear to me :-).
> 
> Indeed, this may be an area where following the underlying standards
> too closely may not be a good idea. In particular, a *descriptive*
> flag may be better choice than an imperative one.
> 
> For example, if we make the flag "sensitive", then the programmer is
> telling us "this file descriptor is sensitive" and then we get to
> decide what that means in terms of the underlying OS behaviours like
> "close-on-exec" and "no-inherit" (as well as deciding whether or not
> file descriptors are considered sensitive by default).
> 
> It also means we're free to implement a mechanism that tries to close
> all sensitive file descriptors in _PyOS_AfterFork.

Ouch! This actually shows that "noinherit" is a very bad name. The PEP
is about closing fds after exec(), *not* after fork(). So "cloexec" is
really the right, precise, non-ambiguous name here.

Regards

Antoine.