Re: Per-descriptor state

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

>> Close-on-fork is apparently either coming or already here, [...]
> We don't have it, but it will be in Posix-8.  [...] not sure if
> anyone has thought of a way to add it to socket() -

It's looking to me as though more and more syscalls are having to grow
flags arguments to do things right.  Auto-close-on-fork for socket(),
accept(), and socketpair(); per-operation non-blocking for at least
some half-dozen calls....

I don't see how to avoid it for socket().  For accept(), it could be
shoehorned into a SOL_SOCKET sockopt (SO_AUTO_CLOFORK_ON_ACCEPT, say,
better name welcomed).

> that doesn't look to be trivial, though it might be possible to abuse
> one of the params [socket()] has - probably domain - and add flags in
> upper bits ...

Possible?  Probably.  Good?  No, IMO.

> while having it able to be set/reset via fcntl is useful, to work, it
> needs to be able to be set atomically with the operation that creates
> the fd,

Well, to work for one particularly important use case.  It can work
just fine for various other use cases without that.

> and having it default "on", which would work, would break almost all
> existing non-trivial code).

What about having it default to a per-proces (or per-thread) settable
state?

					Mouse