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Date: Sat, 14 May 2005 08:00:32 -0600
To: harmony-dev@incubator.apache.org
Subject: Re: Against using Java to implement Java (Was: Java)
References: <BAY103-F27186DCCF1B133CCB0C70A9110@phx.gbl>
 <5AB4C453-4FEA-445E-91B6-B0FE3ACF0212@mac.com>
From: "Ravi kiran Gorrepati" <ravi@cs.unm.edu>
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Check the design of Jikes at,
http://www.research.ibm.com/journal/sj/391/alpern.pdf

Though the memory subsytem section is a little outdated,
that should not prevent you from understanding how it
works.

--
Ravi

On Thu, 12 May 2005 10:30:12 -0600, <tumnus@mac.com> wrote:

>
> On 12 May 2005, at 12:17, theUser BL wrote:
>
>> I hope you use C to write the VM for Harmony.
>>
>
> Forgive me if I am repeating what others have already said - I'm a bit  
> late to this.
>
> Bootstrapping the whole thing in Java is a very clever idea, but what  
> about the management of the heap (GC etc)? Presumably that would have to  
> be done in some layered system, with a very simplistic GC in the  
> bootstrap VM, with layers of extra logic on top of it? Or am I missing  
> something?
>
> If so, what sort of performance hit would this have? I agree that in  
> many ways it is a Good Thing, but so was Sun's handle redirection stuff  
> (where an object reference referred to a table, that referred to the  
> object) but Microsoft's Bad Way of simply linking to the object ran much  
> quicker. In fact, didn't Sun eventually switch to that way of working? I  
> think there was something about it in Simon Ritter's talk on GC at last  
> year's London Java Tech days.
>
> I know very little about all this (so please beat me only with a very  
> small stick and in a loving manner) but would it be possible to start  
> with an existing(?) JVM written in C/C++ and then start to migrate it  
> part by part into Java? Taking the baby steps approach, couldn't we work  
> out exactly where the log-jams are likely to be? And then get as much as  
> we can in Java, so long as it doesn't have a significant impact on  
> performance?
>
> Would taking the C/C++ --> Java approach mean that we could base our  
> discussions upon the evidence of the code, and less upon subjective  
> belief? More ground up and less BUFD?
>
> DG