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From "Pavel Pervov" <pmcfi...@gmail.com>
Subject Re: [drlvm] Class unloading support
Date Fri, 27 Oct 2006 14:42:36 GMT
I think I know where the idea of additional reference to j/l/Class in every
object came from.

Lets look at original proposal:

"...

*Automatic class unloading approach.*
...
To do that we need to provide two conditions:

  1. Introduce reference from object to its j.l.Class instance.
..."

Lets rephrase the latter the following way:

"1. Make j.l.Class reachable from all objects of that class."

As everybody agrees that adding one more pointer into object overhead is not
a good idea, the only way is making j.l.Class reachable through available
data - in other words through VTable, which becomes regular Java object.

That is it.

Resume: no direct reference to j.l.Class in object of that class, no
additional object overhead, no MMTk incompatibility.

On 10/27/06, Weldon Washburn <weldonwjw@gmail.com> wrote:
>
> Steve Blackburn was in Portland Oregon today.  I mentioned the idea of
> adding a  reference pointer from object to its j.l.Class instance.  MMTk
> was
> not designed with this idea in mind.  It looks like you will need to fix
> this part of MMTk and maintain it yourself.  Steve did not seem thrilled
> at
> adding this support to MMTk code base.


<SNIP>

-- 
Pavel Pervov,
Intel Enterprise Solutions Software Division

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