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<p>I'm not 100% sure, but I don't believe that ITS/Tops-20/TENEX
Emacs quite does this. It is built on top of TECO, which you will
recall as a language that is so terse that it looks like line
noise. I don't think it's a very big stretch to compare it a byte
code interpreter.</p>
<p>I do not recall that the EMACS libraries that are loaded are not
<i>quite</i> compiled. They have all the comments and unnecessary
white space stripped out, which would, of course speed execution.</p>
<p>gnuEmacs does a similar thing for the LISP code; it's still
interpreted as I recall.<br>
</p>
<div class="moz-cite-prefix">On 11/12/21 10:59 AM, Johnny Billquist
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:0a969799-b6a6-3904-514b-0270e807039a@softjar.se">RMS
kept the idea alive in Emacs, where even today you fire up the
core system, load all kind of libraries, and then you do a memory
dump, which is the runnable Emacs image.
<br>
<br>
JOhnny
<br>
<br>
On 2021-11-12 16:06, Thomas DeBellis wrote:
<br>
<blockquote type="cite">It's not uncommon or it least it didn't
used to be. Here are three examples:
<br>
<br>
First, I believe early versions of Smalltalk did exactly this.
<br>
<br>
Second, at WPI, we implemented two commands called freeze and
thaw, which would take all the information in the currently
running job (AC's, PC, open files, Etc.) and write them into a
file. You could ^C, freeze, come back later, thaw the .ICE file
(frozen job, get it?) and be right where you were. One common
use was when a dial up was abruptly disconnected by call
waiting. The monitor would notice you were detached and perform
a freeze on your behalf, thus both freeing up the job slot and
not losing your work. Saved me a bunch of TECO'ing. It could
have been extended to batch jobs running out of processor time,
but I don't remember if it was.
<br>
<br>
I liked it so much that I tried to implement it at Columbia for
Tops-20. Tried... I think the problem I ran into was that I
couldn't find out timers and get the same fork handles. Or one
of the problems. Another was security, which I'll discuss
below.
<br>
<br>
Third, at Columbia, it was used extensively in our chronically
CPU starved environment:
<br>
<br>
* The EXEC could save the PCL environment (but I think this
originally
<br>
was part of the CMU implementation)
<br>
* The mailing system keeps a binary file of forwarding
bindings. If
<br>
you edit the text source, the newer write date is noticed
and the
<br>
binary is 'recompiled'
<br>
* I lifted the feature for LPTSPL's LPFORM.INI parser when I
realized
<br>
how often it was getting reparsed (basically after any idle
period
<br>
between jobs)
<br>
<br>
From the information security standpoint, you have to consider
the usage of these kinds of files. Obviously, you wouldn't want
to thaw something with JACCT set unless the existing job had the
ability to get that, was [1,2] without some fairly careful
checking. Ditto Tops-20, if the fork had capabilities. I mean,
if somebody could get write access to the binary, then they
could potentially compromise system security with a little
strategic FILDDT'ing (or EXAMINE and DEPOSIT, if it came to
that).
<br>
<br>
A 'legitimately' corrupt binary could also crash the fork on
start up, but I don't recall as we ever fully addressed that. I
think a checksum would have been the obvious start, but I guess
we didn't want to spend the cycles.
<br>
<br>
In these days of multi-gigahertz processors, I don't see the
children discussing it much at all.
<br>
<br>
<blockquote type="cite">------------------------------------------------------------------------
<br>
On 11/12/21 9:24 AM, Paul Koning wrote:
<br>
<br>
That's a bit like how RSX-11/D and IAS boot -- by reloading
the image of memory when you issued the SAV command. Pretty
clever: you set things up the way you want them to be, and
then you make that state persistent.
<br>
paul
<br>
<blockquote type="cite">------------------------------------------------------------------------
<br>
<br>
On Nov 11, 2021, at 6:22 PM, Johnny Billquist
<a class="moz-txt-link-rfc2396E" href="mailto:bqt@softjar.se"><bqt@softjar.se></a> wrote: I must admit that I hadn't
considered the possibility of just saving the core. Which of
course can accomplish the same thing in a neat way.
<br>
<br>
</blockquote>
</blockquote>
</blockquote>
<br>
</blockquote>
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