Re: wip-ports-refactor

[ludo@gnu.org (Ludovic Courtès)]

Hi!

Andy Wingo <wingo@pobox.com> skribis:

> I have been working on a refactor to ports.  The goal is to have a
> better concurrency story.  Let me tell that story then get down to the
> details.

In addition to concurrency and thread-safety, I’m very much interested
in the impact of this change on the API (I’ve always found the port API
in C to be really bad), on the flexibility it would provide, and on
performance—‘read-char’ and ‘get-u8’ are currently prohibitively slow!

> Going forward we need to define a Scheme data type for ports, and to
> allow the read/write procedures to be called from Scheme, and to allow
> Scheme implementaitons of those procedures.  We also need to figure out
> how to do non-blocking I/O, both on files and non-files; should we set
> all our FD's to O_NONBLOCK?  How does it affect our internal
> interfaces?  I do not know yet.

I think this part can come later, after the refactoring is done.

> There's still space for different schedulers.  I wouldn't want to
> include a scheduler and a thread concept in Guile 2.2.0 I don't think --
> but if we can build it in such a way that it seems natural, on top of
> ports, then it sounds like a good idea.

I agree.  If the new implementation gives users more flexibility, then
people will be able to easily experiment with things like 8sync or your
ethreads branch.  From there on, we’ll have a better idea of whether a
scheduler framework or something should be added to Guile proper.

I’ll take a look at the code.

Thanks a lot for fearlessly diving into this!  :-)

Ludo’.