bpo-37140: Fix StructUnionType_paramfunc()#15612
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vstinner merged 3 commits intopython:masterfrom Aug 30, 2019
vstinner:ctypes_struct_param
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bpo-37140: Fix StructUnionType_paramfunc()#15612vstinner merged 3 commits intopython:masterfrom vstinner:ctypes_struct_param
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Fix a ctypes regression of Python 3.8. When a ctypes.Structure is passed by copy to a function, ctypes internals created a temporary object which had the side effect of calling the structure finalizer (__del__) twice. The Python semantics requires a finalizer to be called exactly once. Fix ctypes internals to no longer call the finalizer twice. Create a new internal StructParam_Type which is only used by _ctypes_callproc() to call PyMem_Free(ptr) on Py_DECREF(argument). StructUnionType_paramfunc() creates such object.
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I wrote an unit test. I made sure that the unit test fails without the fix: Without the fix, Test.del() is called once internally during the call to the C function ("func()"), and then a second time when the object is destroyed (s = None). |
| (PyObject *)Py_TYPE(self), new_ptr); | ||
| copied_self->b_needsfree = 1; | ||
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| obj = (&StructParam_Type)->tp_alloc(&StructParam_Type, 0); |
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s/obj/arg_obj/ to increase readability ?
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I chose "obj" name to get "parg->obj = obj" which looks nice to me :-)
| s = None | ||
| support.gc_collect() | ||
| self.assertEqual(finalizer_calls, ["called"]) | ||
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<3 the test case
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Thanks @vstinner for the PR 🌮🎉.. I'm working now to backport this PR to: 3.8. |
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GH-15613 is a backport of this pull request to the 3.8 branch. |
miss-islington
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Fix a ctypes regression of Python 3.8. When a ctypes.Structure is passed by copy to a function, ctypes internals created a temporary object which had the side effect of calling the structure finalizer (__del__) twice. The Python semantics requires a finalizer to be called exactly once. Fix ctypes internals to no longer call the finalizer twice. Create a new internal StructParam_Type which is only used by _ctypes_callproc() to call PyMem_Free(ptr) on Py_DECREF(argument). StructUnionType_paramfunc() creates such object. (cherry picked from commit 96b4087) Co-authored-by: Victor Stinner <[email protected]>
miss-islington
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Fix a ctypes regression of Python 3.8. When a ctypes.Structure is passed by copy to a function, ctypes internals created a temporary object which had the side effect of calling the structure finalizer (__del__) twice. The Python semantics requires a finalizer to be called exactly once. Fix ctypes internals to no longer call the finalizer twice. Create a new internal StructParam_Type which is only used by _ctypes_callproc() to call PyMem_Free(ptr) on Py_DECREF(argument). StructUnionType_paramfunc() creates such object. (cherry picked from commit 96b4087) Co-authored-by: Victor Stinner <[email protected]>
lisroach
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Fix a ctypes regression of Python 3.8. When a ctypes.Structure is passed by copy to a function, ctypes internals created a temporary object which had the side effect of calling the structure finalizer (__del__) twice. The Python semantics requires a finalizer to be called exactly once. Fix ctypes internals to no longer call the finalizer twice. Create a new internal StructParam_Type which is only used by _ctypes_callproc() to call PyMem_Free(ptr) on Py_DECREF(argument). StructUnionType_paramfunc() creates such object.
DinoV
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Jan 14, 2020
Fix a ctypes regression of Python 3.8. When a ctypes.Structure is passed by copy to a function, ctypes internals created a temporary object which had the side effect of calling the structure finalizer (__del__) twice. The Python semantics requires a finalizer to be called exactly once. Fix ctypes internals to no longer call the finalizer twice. Create a new internal StructParam_Type which is only used by _ctypes_callproc() to call PyMem_Free(ptr) on Py_DECREF(argument). StructUnionType_paramfunc() creates such object.
websurfer5
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Jul 20, 2020
Fix a ctypes regression of Python 3.8. When a ctypes.Structure is passed by copy to a function, ctypes internals created a temporary object which had the side effect of calling the structure finalizer (__del__) twice. The Python semantics requires a finalizer to be called exactly once. Fix ctypes internals to no longer call the finalizer twice. Create a new internal StructParam_Type which is only used by _ctypes_callproc() to call PyMem_Free(ptr) on Py_DECREF(argument). StructUnionType_paramfunc() creates such object.
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Fix a ctypes regression of Python 3.8. When a ctypes.Structure is
passed by copy to a function, ctypes internals created a temporary
object which had the side effect of calling the structure finalizer
(del) twice. The Python semantics requires a finalizer to be
called exactly once. Fix ctypes internals to no longer call the
finalizer twice.
Create a new internal StructParam_Type which is only used by
_ctypes_callproc() to call PyMem_Free(ptr) on Py_DECREF(argument).
StructUnionType_paramfunc() creates such object.
https://bugs.python.org/issue37140