[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: When should ralloc.c be used? (WAS: bug#24358)

From: Richard Stallman
Subject: Re: When should ralloc.c be used? (WAS: bug#24358)
Date: Thu, 27 Oct 2016 16:39:59 -0400

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > Eli has mentioned a simpler approach, where we build an .elc file when 
  > saving Emacs state and load the .elc file during normal startup. The 
  > main worry about this approach is performance.

There is no reason why we have to choose between C code and Lisp code.
It's worth developing a special-purpose format for this, if that would
be considerably faster.

However, reading a file that specifies construction of objects is
always going to be slower than copying a memory dump.  What part of the
time could we save with a different format?

Here's an idea.  We separate (1) creating objects from (2) storing them.
We define several operations.  We record all objects created
by sequence number.

We have these ways of creating an object.  That object is given
the next consecutive sequence number.

* intern (specify symbol name)
* variable value (specify variable name)
* string (specify contents)
* integer (specify value)
* cons (specify two sequence numbers)
* list (specify N sequence numbers)
* array (specify N sequence numbers)
* expression (specify the expression textually; it gets evalled)

And these ways of storing the last object.

* store in a variable (specify symbol name)
* store in a function cell (specify symbol name)
* store in car of cons cell (specify its sequence number)
* store in cdr of cons cell (specify its sequence number)
* store in array element (specify array sequence number and index)
* store in symbol property (specify symbol sequence number and property name)
* store using expression (specify a lambda expression with one arg, textually)
* store in special internal place (specify a code number to say which place)

And one storage reclaimer

* discard all sequence numbers back to N.

Dr Richard Stallman
President, Free Software Foundation (gnu.org, fsf.org)
Internet Hall-of-Famer (internethalloffame.org)
Skype: No way! See stallman.org/skype.html.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]