Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!mintaka!bloom-beacon!eru!hagbard!sunic!isgate!krafla!adamd
From: adamd@rhi.hi.is (Adam David)
Newsgroups: comp.os.minix
Subject: Re: Shared libraries with minix
Message-ID: <3186@krafla.rhi.hi.is>
Date: 25 May 91 16:25:08 GMT
References: <1991May24.015516.5698@watserv1.waterloo.edu>
Organization: University of Iceland
Lines: 41

hbetel@watserv1.uwaterloo.ca (Heather [actually Richard] Betel) writes:

>        b) How do parameters get passed? The  library  MUST  have
>access  to  all  processes' data space (can you feel your stomach
>churn?) On an MMU, this means all dataspaces  for  all  processes
>are mapped into the lib server's dataspace!

The library must have access to the dataspace of the current process.
This is essentially the same as if the library routine is included
in the codespace of the process like we use now.

>        d) where do you draw the line  between  what  is  put  in
>these  libraries,  and  what isn't? The pascal runtime library is
>just as important as the C libraries. Are you  going  to  put  in
>both?  How about the LISP, FORTH, ADA, etc libraries. How about C
>libraries that aren't in libc.a? (eg:curses) The list could go on
>forever...

What about a general purpose standard library which various
language libraries then use. Most of the primitives and other
general operations could be shared between different language
libraries.

Libraries can be categorised: system, application, user libraries.
It is a good idea to standardise the interface to the libraries so
that people can write custom libraries for their own use or for
distribution which use the same library handling routines as the
system does.

>        e) The original suggestion talks about putting in another
>trap.   Why  do  that  when messages work?

It is a question of efficiency. It is not desireable for a library
routine which is called often in a tight inner loop to require a
message rendevous each time it is called. It is only the first time,
if the library section is not already present, that a message call
is necessary so that the library section can be brought in from disk.

--
Adam David.
adamd@rhi.hi.is