Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!sco!jamesm
From: jamesm@sco.COM (James M. Moore)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Debugger Info wanted
Message-ID: <7833@viscous.sco.COM>
Date: 4 Dec 89 17:17:19 GMT
References: <1262@castle.ed.ac.uk> <32962@ucbvax.BERKELEY.EDU>
Sender: news@sco.COM
Reply-To: jamesm@sco.COM (James M. Moore)
Organization: An tOibriu Santa Cruz
Lines: 24


In airteagal <32962@ucbvax.BERKELEY.EDU>, scriobhann oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster):
>The most common cause of complete lockup of the Macintosh by buggy programs
>is:
>
>Copying arbitrary data into low memory, for example:

My favorite way (discovered last night) is to be really lazy about
allocation of variables, and put too much stuff on the stack.  I was
allocating 2048 byes of chars (char bigstring[2048]) on entry into a
method, and whenever I entered the method I got a message from
Multifinder saying my application had quit unexpectedly.  At that
point, the mouse was usually frozen, and I had to reboot.  

Yes, I know this is a dumb thing, and I should have caught it immediately. 
And needless to say the code doesn't do this anymore.  Still, I burned at
least an hour and a half finding the thing, mostly because I also managed to
corrupt the resource file when it went down.  If you corrupt your resource
file, TCL tends to crash before you get into your own code.  Easy to fix once
you figure out what's going on.
-- 
James Moore                            | Nil aon .sig maith agam anois -
Santa Cruz Operation UNIX Tech Support |	B'fheidir an tseachtaine seo
jamesm@sco.com                         |		chugainn.