From: "Iñaki Baz Castillo" <ibc@...>
Date: 2008-07-02T05:58:59+09:00
Subject: Re: Threads and Ruby

El Martes, 1 de Julio de 2008, Charles Oliver Nutter escribió:
> Iñaki Baz Castillo wrote:
> > Now I'm doing a server in Ruby using green threads (Ruby MRI).
> > In the future it's possible I try to migrate it to JRuby to use real
> > threads.
> >
> > Just a question:  Will my code and for now green threads work correctly
> > under JRuby and green threads will become OS threads magically? or must I
> > change my code to work with OS threads?
>
> You should not need to do anything and the threads will "just be
> native". We do that by hobbling native threads slightly so they check
> for those "unsafe" events like kill, raise, and critical.
>
> One down side to native threads is that launching a thread in JRuby is a
> lot more costly than in MRI, but we also have a thread pool (somewhat
> experimental, but people are using it) to mitigate that cost:
>
> Normal:
>                             user     system      total        real
> control loop           0.005000   0.000000   0.005000 (  0.006000)
> Thread.new.join loop   2.569000   0.000000   2.569000 (  2.569000)
>
> -J-Djruby.thread.pool.enabled=true:
>                             user     system      total        real
> control loop           0.009000   0.000000   0.009000 (  0.009000)
> Thread.new.join loop   0.655000   0.000000   0.655000 (  0.654000)
>
> This improves more with a longer run.

Great. Thanks a lot.

-- 
Iñaki Baz Castillo