From: "Anthony.Appleyard" <MCLSSAA2 AT fs2 DOT mt DOT umist DOT ac DOT uk>
Organization: Materials Science Centre
To: DJGPP AT DELORIE DOT COM
Date: Mon, 14 Apr 1997 09:36:21 GMT-1
Subject: djgpp DLL's?; The generation gap
Reply-to: Anthony DOT Appleyard AT umist DOT ac DOT uk
Message-ID: <F16E6D00CE@fs2.mt.umist.ac.uk>

  When will djgpp C+ and also C++ have some sort of overlay program system!?,
so that (code which not obeyed much) needn't stay in RAM all the time.

  The nearest to this that I can use now seems to be calling a child process
by one of the spawn() functions. But the only way that the parent can talk to
the child is via call parameters, which must be ascii and are limited in
length. If I write two programs, A.EXE and B.EXE, can I do this?:-
  A reserves some conventional memory and keeps its address in a variable x.
  A writes varions matter to that conventional memory.
  A calls B as a child process, and in a call parameter tells B the value of
x.
  B reads x from that parameter.
  B looks for its data at conventional memory address x etseq.
  B writes matter into conventional memory address x etseq.
  B exits and returns to A.
  A expects B's results to be at conventional memory address x etseq.

  Would that work? Or is A's conventional memory allocation swopped out to
disk while B is running?