[issue45879] Access violation

[vladexl]

New submission from vladexl :

It seems object.c hasn't taken into account possible nullptr:

object.c: ...else if (Py_TYPE(v)->tp_as_number != NULL &&...

It seems Py_TYPE(v) returns null

StackTrace:

> python310.dll!PyObject_IsTrue(_object * v=0x1d91e2d4) Line 1444 C
  python310.dll!_PyEval_EvalFrameDefault(_ts * tstate=0x1db76f50, _frame * 
f=0x1c064028, int throwflag=0) Line 3793 C
  [Inline Frame] python310.dll!_PyEval_EvalFrame(_ts *) Line 46 C
  python310.dll!_PyEval_Vector(_ts * tstate=0x1db76f50, PyFrameConstructor * 
con=0x1bd91858, _object * locals=0x, _object * const * args=0x1bdf86a8, 
unsigned int argcount=1, _object * kwnames=0x) Line 5080 C
  python310.dll!_PyFunction_Vectorcall(_object * func=0x1bd91850, _object * 
const * stack=0x1bdf86a8, unsigned int nargsf=2147483649, _object * 
kwnames=0x) Line 347 C
  [Inline Frame] python310.dll!_PyObject_VectorcallTstate(_ts *) Line 114 C
  python310.dll!PyObject_Vectorcall(_object * callable=0x1bd91850, _object * 
const * args, unsigned int nargsf=2147483649, _object * kwnames=0x) 
Line 123 C
  python310.dll!call_function(_ts * tstate=0x1db76f50, PyTraceInfo * 
trace_info=0x1bf3f7a0, _object * * * pp_stack=0x1bf3f774, int oparg=1, _object 
* kwnames=0x) Line 5888 C
  python310.dll!_PyEval_EvalFrameDefault(_ts * tstate=0x1db76f50, _frame * 
f=0x1bdf8568, int throwflag=0) Line 4222 C
  [Inline Frame] python310.dll!_PyEval_EvalFrame(_ts *) Line 46 C
  python310.dll!_PyEval_Vector(_ts * tstate=0x1db76f50, PyFrameConstructor * 
con=0x1bd918a0, _object * locals=0x, _object * const * args=0x1bde5334, 
unsigned int argcount=2, _object * kwnames=0x) Line 5080 C
  python310.dll!_PyFunction_Vectorcall(_object * func=0x1bd91898, _object * 
const * stack=0x1bde5334, unsigned int nargsf=2, _object * kwnames=0x) 
Line 347 C
  python310.dll!PyVectorcall_Call(_object * callable=0x1bd91898, _object * 
tuple=0x1bde5328, _object * kwargs=0x1ef3d618) Line 272 C
  python310.dll!_PyObject_Call(_ts * tstate=0x1db76f50, _object * 
callable=0x1bd91898, _object * args=0x1bde5328, _object * kwargs=0x1ef3d618) 
Line 290 C
  [Inline Frame] python310.dll!PyObject_Call(_object *) Line 317 C
  python310.dll!do_call_core(_ts * tstate=0x1db76f50, PyTraceInfo * 
trace_info=0x1bf3f93c, _object * func=0x1bd91898, _object * 
callargs=0x1bde5328, _object * kwdict=0x1ef3d618) Line 5940 C
  python310.dll!_PyEval_EvalFrameDefault(_ts * tstate=0x1db76f50, _frame * 
f=0x1bd7ab28, int throwflag=0) Line 4286 C
  [Inline Frame] python310.dll!_PyEval_EvalFrame(_ts *) Line 46 C
  python310.dll!_PyEval_Vector(_ts * tstate=0x1db76f50, PyFrameConstructor * 
con=0x1bdef930, _object * locals=0x, _object * const * args=0x1bdfa164, 
unsigned int argcount=1, _object * kwnames=0x) Line 5080 C
  python310.dll!_PyFunction_Vectorcall(_object * func=0x1bdef928, _object * 
const * stack=0x1bdfa164, unsigned int nargsf=2147483649, _object * 
kwnames=0x) Line 347 C
  [Inline Frame] python310.dll!_PyObject_VectorcallTstate(_ts *) Line 114 C
  python310.dll!PyObject_Vectorcall(_object * callable=0x1bdef928, _object * 
const * args, unsigned int nargsf=2147483649, _object * kwnames=0x) 
Line 123 C
  python310.dll!call_function(_ts * tstate=0x1db76f50, PyTraceInfo * 
trace_info=0x1bf3fa94, _object * * * pp_stack=0x1bf3fa70, int oparg=1, _object 
* kwnames=0x) Line 5888 C
  python310.dll!_PyEval_EvalFrameDefault(_ts * tstate=0x1db76f50, _frame * 
f=0x1bdfa028, int throwflag=0) Line 4207 C
  [Inline Frame] python310.dll!_PyEval_EvalFrame(_ts *) Line 46 C
  python310.dll!_PyEval_Vector(_ts * tstate=0x1db76f50, PyFrameConstructor * 
con=0x1bdefa98, _object * locals=0x, _object * const * args=0x1bc9db04, 
unsigned int argcount=1, _object * kwnames=0x) Line 5080 C
  python310.dll!_PyFunction_Vectorcall(_object * func=0x1bdefa90, _object * 
const * stack=0x1bc9db04, unsigned int nargsf=2147483649, _object * 
kwnames=0x) Line 347 C
  [Inline Frame] python310.dll!_PyObject_VectorcallTstate(_ts *) Line 114 C
  python310.dll!PyObject_Vectorcall(_object * callable=0x1bdefa90, _object * 
const * args, unsigned int nargsf=2147483649, _object * kwnames=0x) 
Line 123 C
  python310.dll!call_function(_ts * tstate=0x1db76f50, PyTraceInfo * 
trace_info=0x1bf3fbec, _object * * * pp_stack=0x1bf3fbc8, int oparg=1, _object 
* kwnames=0x) Line 5888 C
  python310.dll!_PyEval_EvalFrameDefault(_ts * tstate=0x1db76f50, _frame * 
f=0x1bc9d9c8, int throwflag=0) Line 4207 C
  [Inline Frame] python310.dll!_PyEval_EvalFrame(_ts *) Line 46 C
  python310.dll!_PyEval_Vector(_ts * tstate=0x1db76f50, PyFrameConstructor * 
con=0x1bdef978, _object * locals=0x, _object * const * args=0x1bf3fce8, 
unsigned int argcount=1, _object * kwnames=0x) Line 5080 C
  python310.dll!_PyFunction_Vectorcall(_object * func=0x1bdef970, _object * 
const * stack=0x1bf3fce8, unsigned int nargsf=1

[issue45879] Access violation

[vladexl]

vladexl  added the comment:

Sorry i can't provide simple example, but will describe steps. And also i found 
reason of such behavior.
It was a function from pythonwin: PyWinObject_FromHANDLE.  When i removed it 
from code - issue gone.

So, in order to start 2 python scripts simultaneously:
1. 2 interpreters was created (Py_NewInterpreter)
2. 2 windows threads started and 2 python scripts inside 
(PyRun_AnyFileExFlags(hFile, filePath, true, nullptr);
3. Python scripts like this:  (i started additional thread inside python 
script, it's necessary)
@entry
def main():
import time
i = 100
while i < 103 :
print("iter {0} ".format(i))
time.sleep(1)
i = i +1
def entry(function):
def entry_decorator():
import threading
thread = threading.Thread(target=_threadmain, args=(function,))
thread.start()
return entry_decorator
def _threadmain(function):
# call entry point from primary script
function()
myevent = __mymodule.GetStopEvent()
while True:
rc = win32event.MsgWaitForMultipleObjects((myevent,), 1, 1000, 
win32event.QS_ALLINPUT);
if rc == win32event.WAIT_OBJECT_0:
break
pythoncom.PumpWaitingMessages()
pythoncom.CoUninitialize() 
4. GetStopEvent like this:
PyObject* GetStopEvent(PyObject *self, PyObject *args)
{
 HANDLE hEvent = CreateEvent(...);
 return PyWinObject_FromHANDLE(hEvent);
}
5. Exception appears after starting/stopping(firing event) 3..4 times. It works 
fine in case of single starting.

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