Date: Wed, 22 Apr 92 23:13:25 -0500
From: rcharif AT math DOT utexas DOT edu
Posted-Date: Wed, 22 Apr 92 23:13:25 -0500
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Ram disk, signal management
Reply-To: rcharif AT ma DOT utexas DOT edu
Status: O


go32 Memory management
----------------------
go32 frees all allocated memory when a child process is forked. A
solution for that is to have a delayed write cache like norton v6.01
of 1 meg minimum, this will speed up paging dramatically.  Another
alternative is to use a modified version of go32 v1.05 that can
reserves a minimum amount of memory for go32 to keep.  This
modification was made by M. Kobayashi and Y. Shibata, and can be ftped
from utsun.s.u-tokyo.ac.jp in /GNU/djgcc.  It supports a keep flag and
has an lru algorithm for paging.  The syntaxe is go32 keep=<# of bytes
to keep on system> <program name>.  It would be nice if these
modification are made to version 1.06, and better if DJ incorporates
them in the final product.

For those who want to use v1.06, you can try to edit the file
exphdlr.c and look for case 7 in the function turbo_assist at the end
of the file.  This is the call to start a child process.  You will
find a call to a function page_out_everything() before the system
call. You might try to trap this call and the page_in call following.

Signal management
-----------------

I am working to add signal handling to djgpp. An alpha version which
supports Ctrl-c (SIGINT) and limited SIGALRM handling is available.
The major part consists of a new interface function between go32 and
the user program.

For those who need signal handling for other signals and / or are
interested in developing these, I appreciate if you consider using a
common base so that I can incorporate your functions in my version as
I don't have the time to develop or simulate all unix style signals.

The patch is available for go32 v1.05 with the japanese patch or for
v1.06. It can be ftped from rascal.ics.utexas.edu:/tmp starting
Saturday, 04/25/92.