gwa@mentor.cc.purdue.edu (James D. Yegerlehner) (02/19/90)
A friend and I are developing a neural network simulation program
for the ST, but we've come to a grinding halt because our code
crashes from a bus error (2 bombs) and we can't figure out why.
We've observed several things about the crashes:
1. It occurs only when fprintf is called. By using the source
and assembly level debuggers (Mark Williams C), we've found that
it is happening within "lmalloc", which is called by malloc(), which is
called ultimately by fprintf. Specifically, there is a some symbol
in lmalloc called "_a_scanp_" which is used as a pointer, and which
apparrently gets clobbered or gets a bad value for some reason, which
results in the bus error.
2. It occurs consistently for any particular compilation of the
code, but is sensitive to things like changing the stack size or
otherwise rearranging memory; when this is done, it sometimes goes
away, only to come back later when still more changes are made.
Since I'm not an experienced GEM programmer, I thought that the above
symptoms might have implications of which I am oblivious. If any of you
GEM/TOS/C gurus have any suggestions for me, I would much appreciate it.
Thanks,
Jim
yegerleh@en.ecn.purdue.edu