jstern@garnet.berkeley.edu (04/13/91)
We're having memory problems. ("Not enough memory to use painting
tools.") Our systems have 2.5 M (and have no inits but Disinfectant)
so I'm not willing to just accept the fact that we need more memory.
I can think of several things that I'm doing that could be contributing
to the problem, but would appreciate any guidance on what might be
the most fruitful attack to take. (There doesn't seem to be a whole
lot out there, published, on memory problems when using HyperCard.)
Here's what I see as potential problems:
1) Lots of stacks "in use" (6 currently).
Our basic setup is this: 12 machines (SEs & Pluses); each machine has
a stack that the students use, and add to throughout the semester. A
large percentage of the handlers for those stacks,however, reside in
the 6 stacks in use. These 6 stacks reside on our network server (in a
folder that's read only for the students). I need to do it this way so
that I can quickly and easily make changes to the handlers
(i.e. sometimes between class periods).
For simplicity's sake I "start using" all 6 stacks when the stack on
the local machine is first opened. I know that I probably should start
using stacks only when I need the handlers in each, and then stop using
each when I can, but it'll take me days to figure out which handlers get
called when, and then to do the appropriate moving around of handlers
amongst the 6 stacks.
Is it worth it for me to take the time to do this? I guess I question
if this is the biggest part of the problem because we don't run out
of memory when using the painting tools early in a session; it's
only after doing a bunch of stuff and then trying to use the painting
tools that we get the "Not enough memory to use painting tools"
message.
2) XCMDS--again lots. Some of these have been written by graduate
students specifically for this application. Could it be simply (ha!)
that some xcmd somewhere isn't de-allocating some specific block of
memory that the painting tools really want? Is there any way to figure
out what specifically Hypercard wants that it can't get? At one point I
was checking the heapspace each time before asking for the painting
tools, and didn't find any difference between the situation where it
wouldn't let me use the painting tools, and the situation where it
would, so it seems like it's not just a matter of finding enough
contiguous space in memory. (But then again, I don't know a whole lot
about memory allocation, obviously.) Should I take the time to test
each xcmd/xfcn, and then combos, to try to determine which one might be
causing the problem?
3) Globals -- probably too many of these as well (I think somewhere
around 40); many of them hold information from the server that's
referred to throughout the stack (nothing huge), but some of them
probably could be emptied. I doubt that this is the problem, but if
someone tells me otherwise, I'll get working on this right away.
I realize I'm being pretty vague, and if anyone thinks they can help
with more specific info (e.g. precise figures for heapspace; which xcmds
I use, etc.) , I'll be glad to provide it. Other than that, can anyone
provide general wisdom, enough to let me know which of the above things
(or something completely different) that I should try first?
Thanks for any advice,
Judy Stern
Instructional Technology Program
UCBerkeley
jstern@garnet.berkeley.edu