From: Csaba Henk <csaba@...>
Date: 2006-07-21T07:05:05+09:00
Subject: Re: Beyond threads? Better concurrency methods?

On 2006-07-20, tsuraan@tsuraan.net <tsuraan@tsuraan.net> wrote:
> Erlang's sort of a strange one.  Obviously, it can't be called 
> academic, and the programming model is entirely based on concurrency, 
> but at the same time, it doesn't support native threading.  I've always 
> thought that is a strange choice.  They have really fast user-space 
> threading, but it will never use multiple processors unless you're 
> running multiple Erlang VMs, and then you have to explicitly start your 
> thread on the VM of your choice, from what I understand.

I read somewhere about Erlang that the next release of the VM will
support using OS threads for pooling Erlang processes transparently.

I can't recall though when the referred statement was written -- it's
possible that it was written long before and that "next release" has
came to reality since then. 

> Still, I love 
> the language.  I wish ruby allowed overloading of the ! operator, just 
> so I could implement a ruby thread wrapper that could accept messages 
> with Erlang syntax :)

Well, in Erlang it's a principle that processes may communicate _only_
via the messaging interface. It's achieved by the (almost) pure
functional semantics. Data is never modified in-place, always copied. A
function (in particular one ran in a process) can see only the values
which were passed to it as arguments (by value). 

[Disclaimer: AFAICS, IANAEH]

I wonder how would you enforce this strong separation in ruby... maybe
_why-s shiny Sandbox could be made use of?

Regards,
Csaba