From: Voroztsov Artem <artem.voroztsov@...>
Date: 2007-11-24T23:43:39+09:00
Subject: will there be ability to use both native and green threads in Ruby 1.9/2.0

Does anybody know will there be support for both native and green
threads in Ruby 1.9/2.0?

I found letter with unanswered question in ruby-core:

2007/11/14, Berger, Daniel <Daniel.Berger@qwest.com>:
>  > -----Original Message-----
> > From: David Flanagan [mailto:david@davidflanagan.com]
> > Sent: Wednesday, November 14, 2007 11:31 AM
> > To: ruby-core@ruby-lang.org
> > Subject: Re: state of threads in 1.9
> >
> > Jordi wrote:
> > > Are Threads mapped to threads on the underlying operating system in
> > > 1.9 or still using green threads?
> > > If still using green threads, it is so because of a
> > designing decision
> > > or it is a limitation of the current implementation?
> > >
> >
> > As others have responded, Ruby 1.9 uses native threads.  But
> > you still don't get true concurrency.  The fear is that there
> > are extensions that are not thread-safe yet.  So even though
> > native threads are used, only one is allowed to run at a
> > time.  This means that you won't see increased performance
> > running a multi-threaded Ruby program on a multi-core CPU,
> > for example.
>
> Can't we have both native *and* green threads? There are advantages and
> disadvantages to both, yes? I know at least one user who says he won't
> be able to use Ruby 1.9/2.0 because he's using it on very old hardware
> (486's) for Point of Sale software. The native threads will be too
> heavy.
>
> Really, the only time that I've needed native thread support is for
> extending existing C libraries. I don't see the upside for general
> concurrency, since we're not getting multi-core support anyway.
>
> Have I missed something?
>
> Regards,
>
> Dan