Crash on quit, Virtual Memory, and AppleScript
Crash on quit, Virtual Memory, and AppleScript
- Subject: Crash on quit, Virtual Memory, and AppleScript
- From: david craig <email@hidden>
- Date: Sat, 3 Nov 2001 20:32:59 -0500 (EST)
I've discovered an odd problem whose origin and resolution remains obscure
to me: when Fetch is launched by an AppleScript with virtual memory turned
off, it freezes my machine solid when you quit. Up to that point, Fetch
and everything else apparently behave normally. I am not sure if this is a
Fetch problem, an AppleScript problem, an OS problem, or some combination
of the above. Any help or insight would be appreciated.
Background: I recently took advantage of the current truly absurd memory
prices to upgrade my Mac OS 9.1 B&W G3/450 to 1GB of RAM (from 702). I
immediately concluded that one of the DIMM's I received was bad, because
the machine would lock up solid when I attempted to reboot or shut down.
The memory vendor sent me replacement chips right away. I was depressed to
find that the symptom remained with the new chips.
Over the course of the past week I've sorted out where the problem is
focused. The salient facts are these. First, I noticed after a few days
that it was always while the machine was trying to kill Fetch 4.0.1 that it
froze. Second, I noticed something I'd never known before, that the Mac OS
disables virtual memory if you have too much RAM (obviously a number
somewhere between 702 MB and 1 GB.) This has since been confirmed by
others. Third, I launch the applications I use most with an applescript in
my Startup Items folder that launches, then hides, each application.
Once I noticed that things were hanging up on Fetch, I experimented a bit
and discovered that the machine would only freeze when you attempt to quit
Fetch if it is launched by the applescript. If I launch Fetch by hand and
quit, there's no problem. If I launch all of the applications the
applescript launches in the same sequence, but by double-clicking in the
Finder, there's no problem. The problem only occurs if Fetch is launched
with the script, whether or not that script is run at startup, or after.
Having discovered this, I then removed half the machine's memory and
experimented some more. The symptom persisted, whether using my old pair
of 256's or one of the new pairs. However, with only 512 MB I could enable
virtual memory. With virtual memory enabled the problem disappears, no
matter what combination of RAM I tried.
The upshot is that I've now tried more or less all of the possible
combinations, and the machine only locks up when you attempt to quit Fetch
if *BOTH* (i) Fetch is launched with the applescript, and (ii) virtual
memory is off.
I tried three things to alleviate this crash: (i) increasing Fetch's memory
allocation; (ii) increasing the applescript's memory; and (iii) increasing
the memory available to the Finder with Reaper. None of these steps made
any discernible difference.
Any clues at all what's at issue here, or how to work around it? (There
are two obvious possibilities: don't include Fetch in my applescript, or
use another FTP client. I'm not thrilled about either choice, and besides,
if this isn't specifically a problem with Fetch, I'm likely to meet this
issue again, and I'd like to have some idea of what's going on.)
Thanks,
David Craig
<
http://www.panix.com/~dac/>