modules on CD (was: full isolation)

[Jecel Assumpcao Jr]

Craig Latta wrote on Sat, 05 Mar 2005 22:21:17 -0800
>  > [need to ship modules on a CD]
> 
> 	You could populate the CD-ROMs with object memory snapshots that, when 
> resumed, start servers on 'localhost'. Message-based negotiation still 
> happens, it's just that the clients and servers are all on the same 
> machine. The CD-ROM object memories could have all the modules you want 
> to convey in them.

I guess there are two ways this could be done:

 1) for each module we would have a memory snapshot containing the
module itself, any modules it depends on including the very basic stuff

 2) a single memory snapshot containing all the modules we want to ship,
any modules they depend on including the very basic stuff

Option 1 wastes some of the CD-ROM, just like in Unix before dynamic
linking each executable file had a copy of the basic libraries. Running
each image separately doesn't take up much memory. Option 2, however,
does take up quite a bit of (virtual) memory... if less than 650MB can
be considered quite a bit in this era of 1GB RAMs.

In any case, after message-based negotiation the local Squeak(s) get the
modules they need and that will be saved to local disk automatically
when the image is saved.

This system is certainly usable and has many advantages, but takes up
more RAM and disk than alternatives which allow images to be split into
chunks which can then be lumped together again.

-- Jecel