🚀 go-pugleaf

In article <724600898.9501@minster.york.ac.uk> mjl-b@minster.york.ac.uk (Mathew Lodge) writes:
>In article <1992Dec16.043917.1193@cc.umontreal.ca> kosmatoo@JSP.UMontreal.CA (Kosmatos Odisseas) writes:
>>Another topic I was wondering about was whether MiNT (and thus MultiTos)
>>does the following: When a program is loaded, say program X. If the program
>>is loaded again in another window / by another user / by a background shell
>>script, will the operating system notice that it is already loaded and just
>>use the copy in memory (but having a local stack and program pointers)
>>or will it load the program all over again (thus wasting precious primary
>>memory)?
>
>You mean sharable code segments? A good idea, but there are problems with
>programs that use self-modifying code. I hope that these are few and far
>between (because they'll cause problems with processor caches as well).
>Llamamtron is an example of such a program -- the sample replay routine is
>self modifying :-(
>
>Perhaps there could be a bit set in the program header to indicate that its
>code can be shared... Eric?

This feature was added to MiNT in version 0.96. It is supported by the
"-mbaserel" option in GCC 2.2.2 and 2.3.1. (GCC support by Yours Truly... }-)

All I'd like to add at this point, along these lines, is caching of text
images even after the process running it has exited. I.e., when a shared-text
program is loaded, the text stays in memory even after the process exits,
allowing it to be re-executed at a later time without needing to reload it.
(And of course, the memory can be reclaimed if necessary to satisfy some
other process's Malloc requirements...) Currently, the text image is freed
as soon as the last process using it exits.
-- 
  -- Howard Chu @ Jet Propulsion Laboratory, Pasadena, CA

All true wisdom is conveyed in one-line witticisms.