From: Charles Oliver Nutter <charles.nutter@...>
Date: 2007-11-07T16:26:54+09:00
Subject: Re: JRuby performance questions answered

Clifford Heath wrote:
> Roger Pack wrote:
>> If you run multiple threads I assume there isn't an extra memory cost 
>> for that--is that right?
> 
> Every thread is going to need its own stack, but that'll be small
> compared to the startup overhead. I'm sure Charles will elaborate.

Our threads will be a lot more expensive than Ruby's, but a lot cheaper 
than a separate process in either world.

> I'm guessing that JRuby still doesn't support continuations...? I
> think that would require the "spaghetti stack" model, which would
> remove most of the per-thread initial stack overhead.

Our official stance is that JRuby won't support continuations until the 
JVM does. We could emulate them by forcing a stackless implementation, 
but it would be *drastically* slower than what we have now.

- Charlie