From: Tony Arcieri <tony.arcieri@...>
Date: 2011-10-29T03:40:43+09:00
Subject: Re: Ruby and threading

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On Thu, Oct 27, 2011 at 9:28 PM, Alexey Petrushin <axyd80@gmail.com> wrote:

> I don't understand this. Ruby has no support for parallel execution
> (except jRuby and similar platforms), so no matter what technics do You
> apply - the program always will be on the single processor core.
>

So use JRuby or Rubinius if you want real multicore concurrency. Problem
solved.

Threads are still useful even if you have a GIL. Rails can use threads to
service more than one request at a time per Ruby interpreter. Without
threads each connection to a web site requires a dedicated Ruby VM to
service it. Seems bad, but people have made it work.


> Clojure otherwise - allows You to use all available cores and makes it
> simple by applying modern approaches of dealing with concurrency.


Clojure has a lot of neat tools, like immutable persistent data structures,
agents, and STM. However, none of these are a panacea for concurrency bugs.
Clojure provides a very thin interop wrapper around the JVM and existing
Java libraries, which you'll find yourself using all the time when you write
Clojure programs. Since the Java libraries use mutable state and allow you
to get below the abstractions Clojure otherwise provides, you can still wind
up with thread safety bugs in your Clojure programs which are identical to
the kind you'd find in Ruby programs.

-- 
Tony Arcieri

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