[zeromq-dev] Access to underlying Linux socket?

[Mark Gillott]

On Wed, 2016-02-10 at 23:33 +0000, Luca Boccassi wrote:
> On Feb 10, 2016 20:39, "Mark Gillott" <mgillott at brocade.com> wrote:
> >
> > On Wed, 2016-02-10 at 20:45 +0100, Pieter Hintjens wrote:
> > > You can't do this really, since one ZeroMQ socket can map to 0..n
> > > system sockets.
> > >
> >
> > Had a feeling that was going to be the case.
> >
> > > There is a new option on libzmq master that lets you pre-configure
> a
> > > FD and give it to ZeroMQ to use for its first pipe. (ZMQ_USE_FD).
> > >
> >
> > Care to expand a bit more? Is there something (test code? source
> module)
> > you can point me at?
> 
> I can point you to the guy who developed that option. He sits a few
> meters from you in the same office and he has an awesome beard. :-)
> 

Is that the Italian guy who likes to add chicken to his pizza? :-).

> > > A custom hook to configure new sockets is a nice idea.
> > >
> >
> > So you register a hook with a newly created socket and you would get
> a
> > callback just prior to any bind/connect. Is that the idea? In czmq
> > terms, something like:
> >
> > s = zsock_new(ZMQ_REP)
> > zsock_configure(s, myfunc, myarg)
> > zsock_bind(s)
> >
> > The callback would be provided with the base socket?
> 
> Nice. That could work because all actual system sockets are created
> after bind/connect. And in CZMQ we could add a global zys switch that
> applies it automatically to all sockets to make it more convenient.
> 
> But the problem is that such callback should be executed for all
> sockets, be they TCP or IPC or inproc. So, there needs to be a way to
> discriminate somehow, as what you can do with the FD varies wildly.
> 
> It could be left to the application developer to be careful, but I
> think that's confusing and likely to cause troubles.
> 

Rather than a global callback, couldn't you attach the callback to
individual sockets?

Catch you later (if you're still talking to me!),

Mark

> Kind regards,
> Luca Boccassi
>