[Python-Dev] stack check on Unix: any suggestions?
Charles G Waldman
Sun, 3 Sep 2000 00:34:24 -0500 (CDT)
Skip Montanaro writes:
> When I configure --without-threads, the script runs much longer, making it
> past 18068. It conks out in the same spot, however, trying to print 18069.
> The fact that it occurs in the same place with and without threads (the
> addresses of the two different _IO_vfprintf functions are different, which
> implies different stdio libraries are active in the threading and
> non-threading versions as Thomas said), suggests to me that the problem may
> simply be that in the threading case each thread (even the main thread) is
> limited to a much smaller stack. Perhaps I'm seeing what I'm supposed to
> see. If the two versions were to crap out for different reasons, I doubt
> I'd see them failing in the same place.
Yes, libpthread defines it's own version of _IO_vprintf.
Try this experiment: do a "ulimit -a" to see what the stack size
limit is; start your Python process; find it's PID, and before you
start your test, go into another window and run the command
watch -n 0 "grep Stk /proc/<pythonpid>/status"
This will show exactly how much stack Python is using. Then start the
runaway-recursion test. If it craps out when the stack usage hits the
rlimit, you are seeing what you are supposed to see. If it craps out
anytime sooner, there is a real bug of some sort, as I'm 99% sure