[slime-devel] Multiple connections to a single Lisp image

[Helmut Eller]

Luke Gorrie <luke at bluetail.com> writes:

> Currently it is possible for a Lisp image to support multiple SLIME
> connections. Are we using this functionality, and if so how?

It's currently the only way to get multiple listeners in the same
image.  It is also used by slime-attach-thread.

It seems that the current design of the REPL and stream redirection
should be generalized to support multiple listeners.  The
mk-defsystem/polling issue is also an indicator that there is
something not quite right.

> I was thinking of deleting the 'connection' record and moving its
> fields into global variables. Thoughts?

The protocol code is currently a bit difficult to read, even if the
functionality itself is relatively simple. The function fields (read,
send etc.) in the structure are probably the most confusing part, but
it is hard to support different communications styles without some
form of indirection.  Hard to say if global variables would increase
readability.

The idea of per-connection variables as we have them on the Emacs side
doesn't sound so terrible to me.  The fields in the connection struct
can be viewed as such variables.  In some way it's also cute that
*emacs-connection* is not globally bound (it is only globally
accessible to support the global debugger hook).

If you can rewrite the protocol code more readably, please do so.  I
don't see a good way.

Helmut.