[Python-Dev] PyObject_New vs PyObject_NEW
David Abrahams
dave@boost-consulting.com
Wed, 12 Mar 2003 13:03:35 -0500
Tim Peters <tim.one@comcast.net> writes:
> [Guido]
>> You can read the source code as well as I can.
>
> Possibly, but not as well as I can <wink> -- the memory API's
> implementation is monumentally convoluted, especially before 2.3.
> Speaking of which, David, which version of Python was "someone"
> using?
I was the one who discovered the problem, using Python 2.2.2.
Curiously, "someone" missed it because he was using vc6 instead of
vc7.
> Did they enable pymalloc?
I don't think I did that. I don't exactly know what pymalloc is.
> Did they give you a traceback (showing from where free() was
> called)?
I can get one for you. Here:
> MSVCRTD.DLL!_free_dbg_lk(void * pUserData=0x00c46338, int nBlockUse=1) Line 1044 + 0x30 C
MSVCRTD.DLL!_free_dbg(void * pUserData=0x00c46338, int nBlockUse=1) Line 1001 + 0xd C
MSVCRTD.DLL!free(void * pUserData=0x00c46338) Line 956 + 0xb C
python22_d.dll!_PyObject_Del(_object * op=0x00c46338) Line 146 + 0xa C
opaque_ext_d.pyd!dealloc(_object * self=0x00c46338) Line 12 + 0xa C++
python22_d.dll!_Py_Dealloc(_object * op=0x00c46338) Line 1837 + 0x7 C
python22_d.dll!tupledealloc(PyTupleObject * op=0x0093c9a8) Line 147 + 0x70 C
python22_d.dll!_Py_Dealloc(_object * op=0x0093c9a8) Line 1837 + 0x7 C
python22_d.dll!do_call(_object * func=0x00c45e00, _object * * * pp_stack=0x0012edf8, int na=1, int nk=0) Line 3273 + 0x43 C
python22_d.dll!eval_frame(_frame * f=0x008c2e68) Line 2038 + 0x1e C
python22_d.dll!PyEval_EvalCodeEx(PyCodeObject * co=0x00963068, _object * globals=0x008e65a8, _object * locals=0x008e65a8, _object * * args=0x00000000, int argcount=0, _object * * kws=0x00000000, int kwcount=0, _object * * defs=0x00000000, int defcount=0, _object * closure=0x00000000) Line 2595 + 0x9 C
python22_d.dll!PyEval_EvalCode(PyCodeObject * co=0x00963068, _object * globals=0x008e65a8, _object * locals=0x008e65a8) Line 486 + 0x1f C
python22_d.dll!exec_statement(_frame * f=0x008efbf0, _object * prog=0x00963068, _object * globals=0x008e65a8, _object * locals=0x008e65a8) Line 3668 + 0x11 C
python22_d.dll!eval_frame(_frame * f=0x008efbf0) Line 1482 + 0x15 C
python22_d.dll!PyEval_EvalCodeEx(PyCodeObject * co=0x008c79a8, _object * globals=0x008e5940, _object * locals=0x00000000, _object * * args=0x00965a7c, int argcount=7, _object * * kws=0x00965a98, int kwcount=0, _object * * defs=0x00000000, int defcount=0, _object * closure=0x00000000) Line 2595 + 0x9 C
python22_d.dll!fast_function(_object * func=0x0095cc98, _object * * * pp_stack=0x0012f268, int n=7, int na=7, int nk=0) Line 3173 + 0x41 C
python22_d.dll!eval_frame(_frame * f=0x00965900) Line 2035 + 0x25 C
python22_d.dll!PyEval_EvalCodeEx(PyCodeObject * co=0x008c6fd8, _object * globals=0x008e5940, _object * locals=0x00000000, _object * * args=0x008d8c64, int argcount=5, _object * * kws=0x008d8c78, int kwcount=0, _object * * defs=0x00000000, int defcount=0, _object * closure=0x00000000) Line 2595 + 0x9 C
python22_d.dll!fast_function(_object * func=0x009551a8, _object * * * pp_stack=0x0012f494, int n=5, int na=5, int nk=0) Line 3173 + 0x41 C
python22_d.dll!eval_frame(_frame * f=0x008d8af0) Line 2035 + 0x25 C
python22_d.dll!PyEval_EvalCodeEx(PyCodeObject * co=0x008cee50, _object * globals=0x008e5940, _object * locals=0x00000000, _object * * args=0x008c75d8, int argcount=5, _object * * kws=0x008c75ec, int kwcount=0, _object * * defs=0x0092d7a4, int defcount=3, _object * closure=0x00000000) Line 2595 + 0x9 C
python22_d.dll!fast_function(_object * func=0x00955220, _object * * * pp_stack=0x0012f6c0, int n=5, int na=5, int nk=0) Line 3173 + 0x41 C
python22_d.dll!eval_frame(_frame * f=0x008c7450) Line 2035 + 0x25 C
python22_d.dll!PyEval_EvalCodeEx(PyCodeObject * co=0x008ddba0, _object * globals=0x008e5940, _object * locals=0x00000000, _object * * args=0x0089582c, int argcount=3, _object * * kws=0x00895838, int kwcount=0, _object * * defs=0x0092e2cc, int defcount=1, _object * closure=0x00000000) Line 2595 + 0x9 C
python22_d.dll!fast_function(_object * func=0x0095a850, _object * * * pp_stack=0x0012f8ec, int n=3, int na=3, int nk=0) Line 3173 + 0x41 C
python22_d.dll!eval_frame(_frame * f=0x008956a8) Line 2035 + 0x25 C
python22_d.dll!PyEval_EvalCodeEx(PyCodeObject * co=0x008e3848, _object * globals=0x008e5940, _object * locals=0x00000000, _object * * args=0x008787f4, int argcount=1, _object * * kws=0x008787f8, int kwcount=0, _object * * defs=0x0092eaa4, int defcount=5, _object * closure=0x00000000) Line 2595 + 0x9 C
python22_d.dll!fast_function(_object * func=0x0095e620, _object * * * pp_stack=0x0012fb18, int n=1, int na=1, int nk=0) Line 3173 + 0x41 C
python22_d.dll!eval_frame(_frame * f=0x00878690) Line 2035 + 0x25 C
python22_d.dll!PyEval_EvalCodeEx(PyCodeObject * co=0x008ce618, _object * globals=0x0086f780, _object * locals=0x00000000, _object * * args=0x008777bc, int argcount=0, _object * * kws=0x008777bc, int kwcount=0, _object * * defs=0x0084e56c, int defcount=1, _object * closure=0x00000000) Line 2595 + 0x9 C
python22_d.dll!fast_function(_object * func=0x008736e8, _object * * * pp_stack=0x0012fd44, int n=0, int na=0, int nk=0) Line 3173 + 0x41 C
python22_d.dll!eval_frame(_frame * f=0x00877660) Line 2035 + 0x25 C
python22_d.dll!PyEval_EvalCodeEx(PyCodeObject * co=0x0084d8a8, _object * globals=0x0086f780, _object * locals=0x0086f780, _object * * args=0x00000000, int argcount=0, _object * * kws=0x00000000, int kwcount=0, _object * * defs=0x00000000, int defcount=0, _object * closure=0x00000000) Line 2595 + 0x9 C
python22_d.dll!PyEval_EvalCode(PyCodeObject * co=0x0084d8a8, _object * globals=0x0086f780, _object * locals=0x0086f780) Line 486 + 0x1f C
python22_d.dll!run_node(_node * n=0x0088e730, char * filename=0x00842def, _object * globals=0x0086f780, _object * locals=0x0086f780, PyCompilerFlags * flags=0x0012ff38) Line 1079 + 0x11 C
python22_d.dll!run_err_node(_node * n=0x0088e730, char * filename=0x00842def, _object * globals=0x0086f780, _object * locals=0x0086f780, PyCompilerFlags * flags=0x0012ff38) Line 1066 + 0x19 C
python22_d.dll!PyRun_FileExFlags(_iobuf * fp=0x10261888, char * filename=0x00842def, int start=257, _object * globals=0x0086f780, _object * locals=0x0086f780, int closeit=1, PyCompilerFlags * flags=0x0012ff38) Line 1057 + 0x19 C
python22_d.dll!PyRun_SimpleFileExFlags(_iobuf * fp=0x10261888, char * filename=0x00842def, int closeit=1, PyCompilerFlags * flags=0x0012ff38) Line 686 + 0x22 C
python22_d.dll!PyRun_AnyFileExFlags(_iobuf * fp=0x10261888, char * filename=0x00842def, int closeit=1, PyCompilerFlags * flags=0x0012ff38) Line 495 + 0x15 C
python22_d.dll!Py_Main(int argc=2, char * * argv=0x00842db8) Line 367 + 0x30 C
python_d.exe!main(int argc=2, char * * argv=0x00842db8) Line 10 + 0xd C
python_d.exe!mainCRTStartup() Line 338 + 0x11 C
kernel32.dll!77e814c7()
> Was it even freeing a Python object at the time?
Yup.
> In what code base did someone make this substitution (e.g., Python
> core, Boost sources, someone's own extension module, someone else's
> extension module)?
Boost sources
> The straight answer to your question is no. A nastier answer is
> that many memory mgmt screwups are shy, and can be triggered by
> seemingly irrelevant changes.
Both answers seem to amount to "'someone' must have a bug in his
code". Am I reading that correctly?
--
Dave Abrahams
Boost Consulting
www.boost-consulting.com