Xref: utzoo comp.sys.amiga:47258 comp.sys.amiga.tech:9259
Path: utzoo!attcan!uunet!aplcen!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!usc!apple!well!ewhac
From: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab)
Newsgroups: comp.sys.amiga,comp.sys.amiga.tech
Subject: Re: Buggy Software Fix-It Kit
Keywords: none
Message-ID: <15486@well.UUCP>
Date: 12 Jan 90 10:07:25 GMT
References: <5289@blake.acs.washington.edu>
Reply-To: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab)
Organization: Shyster & Shaft Legal Services
Lines: 44
Quote: "You can't have everything.  Where would you put it?"  -- Steve Wright

In article <5289@blake.acs.washington.edu> dlarson@blake.acs.washington.edu (Dale Larson) writes:
>For example, WP has a lot of trouble dealing with low memory
>situations, so programs for creating low and fragmented memory situations
>would be helpful for them to have.  [ ... ]

	Let *me* tell ya about low memory....

	I've been pulling large quantities of hair off various part of my
body trying to combat system failures to low memory.  Despite whatever other
flaws it has, I really have to hand it to Dan Silva; it's tough to crash
DPaint with low memory.  We know.  We tried.

	Anyway, I've discovered that one rather important system function
goes belly-up in a big way when memory gets short.  It's AutoRequest(), and
I formally reported the bug on BIX last night.  "Okay," you say, "I won't
call AutoRequest()."

	Ha.  That's what you think.  Remember DOS?  It calls AutoRequest()
to throw up those "Please insert volume copy 32 of Empty: in any drive"
requesters.  "Okay," I hear you say, "I'll set the Process.pr_WindowPtr to
-1 and turn them off."  Oh yeah?  There are some DOS requesters you *can't*
shut off.  And what about other programs that may be running in the system
that may indirectly call up a requester?

	"Okay," I hear you saying, "I'll do an AvailMem() before I do
allocations or DOS calls and make sure there's enough memory left in the
system for AutoRequest() to work."  Uh huh.  Apart from the fact that this
will complicate your code beyond belief, you have no guarantee that other
programs in the system will do the same thing, that is, leave a little bit
for the OS.  So even if you keep 100K free, someone else may allocate it out
from under you, and you *still* end up looking at a flashing red box.  The
really irritating part of all this is that it looks like *your* program is
at fault.

	I've been trying to think of various ways of defending myself against
low memory, but I haven't been able to come up with a suitably elegant
solution.  If anyone has any suggestions, or can point to formal work on the
subject, I'd greatly appreciate it.

_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
Leo L. Schwab -- The Guy in The Cape	INET: well!ewhac@ucbvax.Berkeley.EDU
 \_ -_		Recumbent Bikes:	UUCP: pacbell > !{well,unicom}!ewhac
O----^o	      The Only Way To Fly.	      hplabs / (pronounced "AE-wack")
	 "Because you never know who might want to sit in your lap."