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classification
Title: test_cpickle overflows stack on MacOS9
Type: Stage:
Components: None Versions:
process
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: jackjansen Nosy List: gvanrossum, jackjansen, tim.peters
Priority: normal Keywords:

Created on 2003-02-21 12:15 by jackjansen, last changed 2022-04-10 16:07 by admin. This issue is now closed.

Messages (6)
msg14765 - (view) Author: Jack Jansen (jackjansen) * (Python committer) Date: 2003-02-21 12:15
Test_cpickle overflows the stack and hangs the interpreter on MacOS9. This happens in test_nonrecursive_deep(), in the dumps() call.

I think there's a PyOS_CheckStack() call missing somewhere in cPickle.

Also, it's probably a good idea to lower the recursion to 50 (the test passes as long as the recusrion is less than 65 deep), at least on MacOS9. 
msg14766 - (view) Author: Tim Peters (tim.peters) * (Python committer) Date: 2003-02-21 19:55
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There are no PyOS_CheckStack()  calls in cPickle, and I'm 
not sure anyone really wants to bother adding them (cPickle 
is meant to be high-performance, not safe <wink>).

That test is consuming more stack frames than it used to, 
because each level of list pickling now bites another stack 
frame to call the new "batch list elements" routine.

Reducing to 50 doesn't fly because cPickle's internal 
PY_CPICKLE_FAST_LIMIT #define happens to be 50 now, 
and the purpose of test_nonrecursive_deep is to be sure that 
non-cyclic containers get pickled OK in a "fast" pickler even if 
they're nested as deeply as PY_CPICKLE_FAST_LIMIT.

Assigning to Guido for further cogitation on his day off <wink>.
msg14767 - (view) Author: Guido van Rossum (gvanrossum) * (Python committer) Date: 2003-02-21 20:01
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I agree that I'd rather not see CheckStack calls added to
cPickle. But using 60 instead of 100 should work for both of
you, right?
msg14768 - (view) Author: Tim Peters (tim.peters) * (Python committer) Date: 2003-02-21 20:04
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Right, AFAICT 60 is enough to test what this is trying to test 
(although I'm not the "fast pickler" expert -- but I think it's 
clear enough).  Jack, please confirm that 60 is OK for you?
msg14769 - (view) Author: Tim Peters (tim.peters) * (Python committer) Date: 2003-02-21 20:24
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I reduced the nesting depth to 60, in Lib/test/test_cpickle.py, 
rev 1.14.  Jack, please close this bug as Fixed if your 
problem goes away now.
msg14770 - (view) Author: Jack Jansen (jackjansen) * (Python committer) Date: 2003-03-16 23:07
Logged In: YES 
user_id=45365

It passes now. Closing.
History
Date User Action Args
2022-04-10 16:07:01adminsetgithub: 38027
2003-02-21 12:15:42jackjansencreate