[ python-Bugs-1225584 ] crash in gcmodule.c on python reinitialization

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Bugs item #1225584, was opened at 2005-06-22 16:43
Message generated for change (Comment added) made by amiseler
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Category: Python Interpreter Core
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Alexander Miseler (amiseler)
Assigned to: Nobody/Anonymous (nobody)
Summary: crash in gcmodule.c on python reinitialization

Initial Comment:
i have a c++ windows application with embedded python
interpreter.

this code crashs:

Py_Initialize();
PyRun_SimpleString("import gc");
Py_Finalize();
Py_Initialize();
PyRun_SimpleString("import gc");	// <--- BOOM


the problem seems to be the global var "garbage" in
gcmodule.c
the var isn't cleared in the reinitialization and
becomes an invalid pointer.
setting it to NULL in Py_Finalize fixes the crash.
i use python version 2.3.4 but a short look at the
2.4.1 source indicates that the problem is still there.

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>Comment By: Alexander Miseler (amiseler)
Date: 2005-06-23 10:11

Message:
Logged In: YES 
user_id=693638

yes, Neil Schemenauer (nascheme) added a Py_INCREF(garbage)
to initgc.
that *MIGHT* fix the crash. but only by simply never
releasing the garbage list. the garbage variable is still
never reset to NULL and therefore no new garbage list is
created after reinitialization.
besides: the incref is only in gcinit, but the list can be
created in gcinit OR in handle_finalizers (and while i was
looking at it in the debugger it always was handle_finalizers).

i guess the proper way to fix it would be a cleanup function
for the gcmodule that is called by Py_Finalize. the cleanup
function should do a decref (if Neils incref stays in, i'm
not sure if it is needed) and then reset the global vars.

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Comment By: Michael Hudson (mwh)
Date: 2005-06-22 17:59

Message:
Logged In: YES 
user_id=6656

Bizarrely, I think this got fixed in CVS HEAD just a few days ago.  Are you 
in a position to check that?

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