Re: [Caml-list] Concurrent/parallel programming

[Yotam Barnoy <yotambarnoy@gmail.com>]

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Thanks for the links and info, everyone.

Gerd, would it be possible to put netmulticore up on opam? I realize this
is a sensitive topic for you, but from what I can tell, this is the most
comprehensive and efficient solution to parallel programming that exists
for ocaml, so why not make it as easily available as possible?

Also, regarding the ocaml_modify() and ocaml_initialize() regression in
4.01 -- yikes! Is there any way to get support back for writing outside of
the ocaml heap? This seems like a pretty big deal! (Sorry if I'm arriving
late for whatever discussion took place about this before).

-Yotam


On Tue, Jan 7, 2014 at 3:35 PM, Gerd Stolpmann <info@gerd-stolpmann.de>wrote:

> There is Netmulticore, a part of Ocamlnet:
>
>
> http://projects.camlcity.org/projects/dl/ocamlnet-3.7.3/doc/html-main/Intro.html#ch_comp
>
> It utilizes shared memory, and accesses it from several processes. There
> is no C code involved, but it is fairly unsafe nevertheless, because you
> need to stick to certain programming rules, or the program crashes.
> However, if you manage to encapsulate all the unsafe things, it is a
> good option. I'm using Netmulticore in the Plasma Map/Reduce
> implementation.
>
> Gerd
>
> Am Dienstag, den 07.01.2014, 14:54 -0500 schrieb Yotam Barnoy:
> > Hi List
> >
> >
> > So far, I've been programming in ocaml using only sequential programs.
> > In my last project, which was an implementation of a large machine
> > learning algorithm, I tried to speed up computation using a little bit
> > of parallelism with ParMap, and it was a complete failure. It's
> > possible that more time would have yielded better results, but I just
> > didn't have the time to invest in it given how bad the initial results
> > were.
> >
> >
> > My question is, what are the options right now as far as parallelism
> > is concerned? I'm not talking about cooperative multitasking, but
> > about really taking advantage of multiple cores. I'm well aware of the
> > runtime lock and I'm ok with message passing between processes or a
> > shared area in memory, but I'd rather have something more high level
> > than starting up several processes, creating a named pipe or a socket,
> > and trying to pass messages through that. Also, I assume that using a
> > shared area in memory involves some C code? Am I wrong about that?
> >
> >
> > I was expecting Core's Async to fill this role, but realworldocaml is
> > fuzzy on this topic, apparently preferring to dwell on cooperative
> > multitasking (which is fine but not what I'm looking for), and I
> > couldn't find any other documentation that was clearer.
> >
> >
> > Thanks
> >
> > Yotam
> >
>
> --
> ------------------------------------------------------------
> Gerd Stolpmann, Darmstadt, Germany    gerd@gerd-stolpmann.de
> My OCaml site:          http://www.camlcity.org
> Contact details:        http://www.camlcity.org/contact.html
> Company homepage:       http://www.gerd-stolpmann.de
> ------------------------------------------------------------
>

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