[Vm-dev] I need an idea. I know you have some. Give.

Mariano Martinez Peck marianopeck at gmail.com
Fri Mar 8 16:29:35 UTC 2013


On Fri, Mar 8, 2013 at 12:15 PM, Louis LaBrunda
<Lou at keystone-software.com>wrote:

>
> Hi Casey,
>
> Since you are posting the to VM news group I will give you an idea I had a
> while ago that requires a little VM work.  The goal is an object database
> that doesn't require serializing the objects.
>
> This would be done by replacing the normal memory pointers in objects with
> offsets from the beginning of the database.  Persistent objects (those from
> the database) would have an indicator to distinguish them form
> non-persistent objects.  When accessing persistent objects the VM would use
> the database offset pointer as a key into a virtual memory lookup table
> whose value would be the real memory address of the object.  If not present
> in the table, the object would be read from the database.  Remember,
> everything else about the object would look the same as it does now in
> memory.  From time to time the VM would save all changed (DB) objects to
> the database.  If this sounds familiar it should, it is the way most caches
> work.
>
>
That sounds quite similar to what Gemstone does. It tags persistent objects
with a bit in the object reference. I think
Gemstone 32 used the combination 10 for the last bits (because of
4 alignment all object pointers ended up with 00 and SmallIntegers with 01
or 11, so 10 was free).
Gemstone 64 uses several bits for tagging (6 or 8 or something like that).
Besides tagging persisten objects they can also embed immediate objects
like characters, small flotas, nil, and stuff like that.

Best,


> I have no experience with the VM (and not very much experience with Squeak)
> but I think this would be a cool project and it could be useful.  I'm not
> is much better shape than you are but I could contribute some time and
> ideas.
>
> Lou
>
>
> >Hello Squeakers!
> >
> >My job search is turning up dead ends, hurry up and wait, and
> unfathomably boring prospects.
> >
> >Screw all that! I want to do something cool.
> >
> >I'm thinking about doing a KickStarter, but almost all of my ideas are
> either a) stuff no one else wants which only I could possibly think would
> be cool, or b) overly ambitious. The words Andreas used to describe my last
> idea: "a bit grandiose." Gift for understatement at times.
> >
> >So I'm looking for something which could be completed by one or two geeks
> in six months to a year, which people actually want, to be implemented (at
> least in part) using Squeak, and to be released at the end under the MIT
> license.
> >
> >I've floored my expenses, so I can make my own labor (relatively, for a
> guy living in Seattle) very cheap. By floored, I mean the room I sleep in
> isn't even tall enough to stand up in -- I do not presently meet the
> definition of a free-range chicken -- and I've disconnected my cellular
> service. I want to be an efficient engine for getting things that matter to
> me and other people done, rather than go on being some tool used to ship
> lucrative enterprise crapware.
> >
> >So here's the $x question: what do you want me to do? I have a Raspberry
> Pi on order, so bonus points if you can work that in somehow.
> >
> >The person with the best (realistic) idea will be credited for it.
> >
> >Inspire me! And thanks for reading all the way down to the bottom of this
> message.
> >
> >Casey
> -----------------------------------------------------------
> Louis LaBrunda
> Keystone Software Corp.
> SkypeMe callto://PhotonDemon
> mailto:Lou at Keystone-Software.com http://www.Keystone-Software.com
>
>


-- 
Mariano
http://marianopeck.wordpress.com
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