Xref: utzoo comp.os.msdos.programmer:1014 comp.lang.c:31965
Newsgroups: comp.os.msdos.programmer,comp.lang.c
Path: utzoo!utgpu!sarathy
From: sarathy@gpu.utcs.utoronto.ca (Rajiv Sarathy)
Subject: Child processes in Mess-DOS, and/or reducing code size
Message-ID: <1990Sep19.224551.27226@gpu.utcs.utoronto.ca>
Summary: spawn, exec, system,...?  Interesting problem for developers.
Organization: UTCS
Date: Wed, 19 Sep 90 22:45:51 GMT

Problem: a program that's too large to fit in memory.
Environment: C language in MS-DOS 3.x
Solution: break it down

	Options:
		- overlays (my #1 choice)
		- C spawn function (call another .exe module)
		- C exec function (call another .exe module)
		- C system function (call another .exe module)

What other options are there, and what are the pros and cons of these and
the ones listed above?

The problem with overlays (atleast with MSC 5.1) is that one module can't
appear in more than one overlay, so there's no way of guaranteeing that
a module isn't reloaded several times.  Or am I wrong?

The problem with the other three is that data passing becomes a hassle, and
is no longer transparent.  It forces us to decide EXACTLY what we want 
passed.  This is what we should be doing anyway, but can sometimes be a 
hassle.  (ie. if there are a lot of global constants/variables).

Any ideas?

-- 

 Rajiv Partha Sarathy         _  _ /@\    INTERNET sarathy@gpu.utcs.utoronto.ca
 ................ooooooooOOOO(_)(_)\@/      BITNET sarathy@utorgpu.bitnet
 University Of Toronto Computing Services     UUCP sarathy@utgpu.uucp