From: David Flanagan <david@...>
Date: 2007-11-15T03:31:26+09:00
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.

> By the way, except for eigenclass there is no official changelog of
> changes in 1.9 ?
> It would be great (for the news, the people getting excited / start
> deprecating code, etc)

I posted this list to my blog back in August. Probably a bit out of date 
now, but it hits the major points:

http://www.davidflanagan.com/blog/2007_08.html#000137

	David

> --
> Jordi
>