[self-interest] A paper on Images.
Jecel Assumpcao Jr.
jecel at merlintec.com
Tue Sep 27 19:03:38 UTC 2011
> Sorry, I'm currently doing a lot of learning ^^
That is always a good thing.
> Does anybody know a paper on the basics of Smalltalk and Self
> like Images? (One for the Self image would of course be best :D)
The problem is that they are essentially a memory dump with a header.
Being so simple, you couldn't get a paper about them published in any
conference. There are many interesting papers about going beyond the
image, however, and I will mention a few below.
David suggested the "blue book":
Chapters 26 to 30 are the ones that are interesting to implementors and
were available as html pages for many years before the whole book. While
that site is gone, you can still read it at
I thought I would see the code for reading or writting the image in the
part about primitives or about the object memory, but there doesn't seem
to be anything.
In the "green book"
(http://stephane.ducasse.free.fr/FreeBooks/BitsOfHistory/) the HP
chapter (6) describes the format they adopted for their images and how
it is different from the standard format.
Here are some details about the format of Squeak images:
One of the papers about going beyond the image is chapter 14 of the
green book: "LOOM - Large Object Oriented Memory for Smalltalk-80
Systems" by Ted Haehler and Gleen Krasner (pages 251 to 271). You can
also find an OOPSLA paper on LOOM.
"Annotating Objects for Transport to Other Worlds" by David Ungar shows
the issues that are not solved by images (or "snapshots", in Self):
You might find the predecessor for LOOM, OOZE, still has some
interesting ideas. Here is the 1981 Byte magazine article:
Releated to images, Squeak's ImageSegments are meant to save part of the
memory separately from the rest.
Note that there is a lot of research effort to replace these with more
general solutions like Fuel, SRP or Stomp. Here is a paper on Fuel:
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