[Vm-dev] how to identify objects ? (hash?)

[Dave Raymer]

Sent from my iPad

On Jul 19, 2010, at 7:25, Mariano Martinez Peck <marianopeck at gmail.com> wrote:

> 
> Hi folks. I have a simple question. Suppose I have a file in disk that has a "pointer" to an object X that is in the image. What can I store from X in the file?  Two options: the address in memory or the hash.
> 
> If I savethe address, the object X can be moved by the GC, and thus, the address can become incorrect in the file.  I don't want to update the disk files in case objects are moved.
> If I save the hash of X, how can I then localize that object in memory?  Hash is 12 bits...so it is not enough to find that object...(otherwise there would be only 4096 objects)
> 
> So....the question is, what should I save from object X in the file and what should I do to be able to localize it, some time after (even when the X is moved by the GC).
> 
> Sorry for my ignorance about the hash. 
> 
> Thank you very much in advance,
> 
> Mariano