Exception in Python 2.3.3 Interpreter

[Saravanan]

Hello,


Im running Python Application as a Windows Service (using windows
extensions). But, sporadically the application crashes (crash in
Python23.dll) and this stops the service. This problem cann't be
reproduced easily in my system and the call stack generated by the
application is given below. Please note that the call stack generation
is taken from crash dump file.

The crash occured at the following line:
c = strcmp(vname, wname) (object.c)

# ChildEBP RetAddr Args to Child
00 023ffa58 1e05c6da 055b1250 00637470 00000000
python23!default_3way_compare(struct _object * v = 0x053f2bfc, struct
_object * w = 0x00000001)+0x102
[F:\Python-2.3.3\Python-2.3.3\Objects\object.c @ 689]
01 023ffa74 1e05c5ee 055b1250 00637470 00000000
python23!do_richcmp(struct _object * v = 0x1e0b9fb8, struct _object * w
= 0x00000000, int op = 0)+0x4a
02 023ffa94 1e0174d9 055b1250 00637470 00000000
python23!PyObject_RichCompare(struct _object * v = 0x053f2bfc, struct
_object * w = 0x00000001, int op = 0)+0x1ae
[F:\Python-2.3.3\Python-2.3.3\Objects\object.c @ 1044]
03 023ffaa4 1e013182 00000000 055b1250 00637470
python23!cmp_outcome(int op = 88026108, struct _object * v =
0x00000001, struct _object * w = 0x00000000)+0xa9
[F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 3880]
04 023ffb18 1e016ba4 014f3318 00000002 0099f170
python23!eval_frame(struct _frame * f = 0x053f2bfc)+0x542
[F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 1965]
05 023ffb30 1e016a69 0099f170 023ffb7c 00000002
python23!fast_function(struct _object * func = <Memory access error>,
struct _object *** pp_stack = <Memory access error>, int n = <Memory
access error>, int na = <Memory access error>, int nk = <Memory access
error>)+0x94 [F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 3520]
06 023ffb5c 1e014b65 00a280d0 00000002 00000008
python23!call_function(struct _object *** pp_stack = 0x00000001, int
oparg = 0)+0x159 [F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 3458]
07 023ffbcc 1e016ba4 006ea160 00000001 0099f1b0
python23!eval_frame(struct _frame * f = <Memory access error>)+0x1f25
[F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 2117]
08 023ffbe4 1e016a69 0099f1b0 023ffc30 00000001
python23!fast_function(struct _object * func = <Memory access error>,
struct _object *** pp_stack = <Memory access error>, int n = <Memory
access error>, int na = <Memory access error>, int nk = <Memory access
error>)+0x94 [F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 3520]
09 023ffc10 1e014b65 00a280d0 00000001 00000000
python23!call_function(struct _object *** pp_stack = 0x00000000, int
oparg = 0)+0x159 [F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 3458]
0a 023ffc80 1e015b6f 006cf6d0 00000000 00a1df9c
python23!eval_frame(struct _frame * f = <Memory access error>)+0x1f25
[F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 2117]
0b 023ffcac 1e040978 0096b720 00000001 006cf6d0
python23!PyEval_EvalCodeEx(struct PyCodeObject * co = <Memory access
error>, struct _object * globals = <Memory access error>, struct
_object * locals = <Memory access error>, struct _object ** args =
<Memory access error>, int argcount = <Memory access error>, struct
_object ** kws = <Memory access error>, int kwcount = <Memory access
error>, struct _object ** defs = <Memory access error>, int defcount =
<Memory access error>, struct _object * closure = <Memory access
error>)+0x70f [F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 2663]
0c 023ffcf0 1e0078ec 009788b0 00a1df90 00000000
python23!function_call(struct _object * func = 0x1e0baa50, struct
_object * arg = 0x0096b720, struct _object * kw = 0x00954390)+0x138
[F:\Python-2.3.3\Python-2.3.3\Objects\funcobject.c @ 512]
0d 023ffd04 1e01be03 009788b0 00a1df90 00000000
python23!PyObject_Call(struct _object * func = 0x1e0d7608, struct
_object * arg = 0x00000001, struct _object * kw = 0x00a280d0)+0x1c
[F:\Python-2.3.3\Python-2.3.3\Objects\abstract.c @ 1755]
0e 023fff24 1e0078ec 00a20f08 00671030 00000000
python23!instancemethod_call(struct _object * func = 0x1e0d7608, struct
_object * arg = 0x00000001, struct _object * kw = 0x00a280d0)+0x133
[F:\Python-2.3.3\Python-2.3.3\Objects\classobject.c @ 2433]
0f 023fff38 1e016827 00a20f08 00671030 00000000
python23!PyObject_Call(struct _object * func = 0x77e4a990, struct
_object * arg = 0x01415bd8, struct _object * kw = 0x00000000)+0x1c
[F:\Python-2.3.3\Python-2.3.3\Objects\abstract.c @ 1755]
10 023fff50 1e080c77 00a20f08 00671030 00000000
python23!PyEval_CallObjectWithKeywords(struct _object * func =
0x77e4a990, struct _object * arg = 0x01415bd8, struct _object * kw =
0x00000000)+0xa7 [F:\Python-2.3.3\Python-2.3.3\Python\ceval.c @ 3346]
11 023fff70 1e080675 013d8ba0 00000000 014161a8
python23!t_bootstrap(void * boot_raw = 0x77e4a990)+0x37
[F:\Python-2.3.3\Python-2.3.3\Modules\threadmodule.c @ 183]
12 023fff84 77bc90a2 0086f32c 00000000 00000000
python23!PyThread_get_thread_ident(void)+0x5
[F:\Python-2.3.3\Python-2.3.3\Python\thread_nt.h @ 213]
13 023fffb8 77e4a990 01415bd8 00000000 00000000 msvcrt!_endthread+0xa6
14 023fffec 00000000 77bc9032 01415bd8 00000000
kernel32!BaseThreadStart+0x34

Any clues about the problem ?

- Saravanan D

 

[Terry Reedy]

Im running Python Application as a Windows Service (using windows
extensions). But, sporadically the application crashes (crash in
Python23.dll) and this stops the service. This problem cann't be
reproduced easily in my system and the call stack generated by the
application is given below. Please note that the call stack generation
is taken from crash dump file.

The crash occured at the following line:
c = strcmp(vname, wname) (object.c)

I am puzzled by this line. I can't see how it could execute.
Is this C or Python code? from the distribution or your code?
How is the result of strcmp (-1, 0, 1 ?) supposed to be callable?
Is this guarded by a rarely triggered condition?

Terry J. Reedy

 

[Saravanan D]

I am puzzled by this line. I can't see how it could execute.
Is this C or Python code? from the distribution or your code?
How is the result of strcmp (-1, 0, 1 ?) supposed to be callable?
Is this guarded by a rarely triggered condition?

Terry J. Reedy

The above one is C Code. The same line is present in object.c file of
Python Interpreter Source and the function name is default_3way_compare().

Windows debugger points to above line in the event of crash of my
application.

Saravanan D

 

[Terry Reedy]

The above one is C Code. The same line is present in object.c file of
Python Interpreter Source and the function name is
default_3way_compare().

Ok, much clearer, you actually meant:

c = strcmp(vname, wname) /* in file object.c */

TJR