| msg9693 - (view) |
Author: Adam M. Fass (afass) |
Date: 2002-03-14 04:52 |
| Call Py_Initialize(), create two objects that reference each other, then call Py_Finalize() and then Py_Intialize() again. This crashes Python with the following error message: Fatal Python error: UNREF invalid object The documentation on Py_Finalize() mentions that circular references will cause memory leaks, but it does not mention this behavior. Platform info: * Windows XP * Visual C++ 6.0 * Python 2.2 ------------------------------ #include "Python.h" int main(int argc, char* argv[]) { char *code1 = "class TestClass:\n\ti = 3\nt1 = TestClass()\nt2 = TestClass()\nt1.t = t2\nt2.t = t1"; Py_Initialize(); PyRun_SimpleString(code1); Py_Finalize(); Py_Initialize(); Py_Finalize(); } ------------------------------ The string "code1" contains this python code: class TestClass: i = 3 t1 = TestClass() t2 = TestClass() t1.t = t2 t2.t = t1 |
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| msg9694 - (view) |
Author: Neil Schemenauer (nascheme) *  |
Date: 2002-03-22 18:44 |
| Logged In: YES user_id=35752 I can't reproduce this on Linux with the latest CVS code. I tried with and without Py_DEBUG defined. |
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| msg9695 - (view) |
Author: Neal Norwitz (nnorwitz) * |
Date: 2002-09-06 22:54 |
| Logged In: YES user_id=33168 Adam, do you still have this problem, with 2.2.1+? |
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| msg9696 - (view) |
Author: Adam M. Fass (afass) |
Date: 2002-09-10 18:32 |
| Logged In: YES user_id=485533 I just tried my code with 2.2.1 and got the same exact result. My platform is still the same: Windows XP and Visual C++ 6.0. |
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| msg9697 - (view) |
Author: Neal Norwitz (nnorwitz) * |
Date: 2002-09-14 00:51 |
| Logged In: YES user_id=33168 I just tried the sample code on 2.3.0 and 2.2.1+ on Linux. This didn't crash or misbehave at all. Did you compile python or did you get a binary distribution? Could there be an incompatibility? Can you otherwise use python w/o problems? Could it be specific to your box or windows in general? Can you build python -with-pydebug? Can you test with the python versions in CVS 2.2.1+ or 2.3? |
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| msg9698 - (view) |
Author: Neal Norwitz (nnorwitz) * |
Date: 2002-11-03 03:21 |
| Logged In: YES user_id=33168 I just tested w/a debug build in 2.3 and it crashed on me. It's probably a problem in 2.2.2. Neil, could you try to look at this? I removed the second Py_Finalize() and it still crashed. (gdb) p *op $4 = {_ob_next = 0x4020a7b4, _ob_prev = 0x8124418, ob_refcnt = 0, ob_type = 0x8121140} Note: ob_refcnt == 0 |
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| msg9699 - (view) |
Author: Neil Schemenauer (nascheme) * |
Date: 2002-11-07 16:52 |
| Logged In: YES user_id=35752 A simpler bit of code to trigger the bug: Py_Initialize(); PyRun_SimpleString("x = []; x.append(x)\n"); Py_Finalize(); Py_Initialize(); Py_Finalize(); Py_DEBUG must be defined. I'm pretty sure the problem is caused by _Py_ResetReferences. It invalidates the invariant that _Py_ForgetReference is checking. The invariant check fails because the list lives across Py_Finalize and is freed the next time the GC is called. The correct fix is unclear to me. Maybe Guido has an idea. |
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| msg9700 - (view) |
Author: Guido van Rossum (gvanrossum) * |
Date: 2002-11-07 17:58 |
| Logged In: YES user_id=6380 How about we simply get rid of _Py_ResetReferences()? It's only a debugging thing, it only makes a difference when you call Py_Initialize() again, it's *wrong* in that case, so I see no need to keep it. |
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| msg9701 - (view) |
Author: Neil Schemenauer (nascheme) * |
Date: 2002-11-17 17:54 |
| Logged In: YES user_id=35752 Fixed by removing _Py_ResetReferences() as suggested by Guido. Objects/object.c 2.194 Python/pythonrun.c 2.169 Include/object.h 2.112 |
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| msg9702 - (view) |
Author: Neal Norwitz (nnorwitz) * |
Date: 2002-11-18 13:27 |
| Logged In: YES user_id=33168 Neil, this seems like it should be backported, do you agree? I suppose if so, we should leave the API in, but make it a no-op. I can fix it if you want. |
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| msg9703 - (view) |
Author: Neil Schemenauer (nascheme) * |
Date: 2002-11-18 15:28 |
| Logged In: YES user_id=35752 Yes please. Thanks. |
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| msg9704 - (view) |
Author: Neal Norwitz (nnorwitz) * |
Date: 2002-11-20 02:38 |
| Logged In: YES user_id=33168 Checked in bacport as: * Python/pythonrun.c 2.153.6.4 * Objects/object.c 2.162.6.7 |
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