bpo-45947: Place dict and values pointer at fixed (negative) offset just before GC header. (GH-29879)

* Place __dict__ immediately before GC header for plain Python objects.

* Fix up lazy dict creation logic to use managed dict pointers.

* Manage values pointer, placing them directly before managed dict pointers.

* Convert hint-based load/store attr specialization target managed dict classes.

* Specialize LOAD_METHOD for managed dict objects.

* Remove unsafe _PyObject_GC_Calloc function.

* Remove unsafe _PyObject_GC_Malloc() function.

* Add comment explaning use of Py_TPFLAGS_MANAGED_DICT.
This commit is contained in:
Mark Shannon 2021-12-07 16:02:53 +00:00 committed by GitHub
parent c7e7a4b969
commit 8319114fee
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GPG key ID: 4AEE18F83AFDEB23
19 changed files with 260 additions and 285 deletions

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@ -5861,6 +5861,7 @@ test_tstate_capi(PyObject *self, PyObject *Py_UNUSED(args))
}
static PyObject *negative_dictoffset(PyObject *, PyObject *);
static PyObject *test_buildvalue_issue38913(PyObject *, PyObject *);
static PyObject *getargs_s_hash_int(PyObject *, PyObject *, PyObject*);
@ -5929,14 +5930,15 @@ static PyMethodDef TestMethods[] = {
#if (defined(__linux__) || defined(__FreeBSD__)) && defined(__GNUC__)
{"test_pep3118_obsolete_write_locks", (PyCFunction)test_pep3118_obsolete_write_locks, METH_NOARGS},
#endif
{"getbuffer_with_null_view", getbuffer_with_null_view, METH_O},
{"PyBuffer_SizeFromFormat", test_PyBuffer_SizeFromFormat, METH_VARARGS},
{"test_buildvalue_N", test_buildvalue_N, METH_NOARGS},
{"getbuffer_with_null_view", getbuffer_with_null_view, METH_O},
{"PyBuffer_SizeFromFormat", test_PyBuffer_SizeFromFormat, METH_VARARGS},
{"test_buildvalue_N", test_buildvalue_N, METH_NOARGS},
{"negative_dictoffset", negative_dictoffset, METH_NOARGS},
{"test_buildvalue_issue38913", test_buildvalue_issue38913, METH_NOARGS},
{"get_args", get_args, METH_VARARGS},
{"get_args", get_args, METH_VARARGS},
{"test_get_statictype_slots", test_get_statictype_slots, METH_NOARGS},
{"test_get_type_name", test_get_type_name, METH_NOARGS},
{"test_get_type_qualname", test_get_type_qualname, METH_NOARGS},
{"test_get_type_qualname", test_get_type_qualname, METH_NOARGS},
{"test_type_from_ephemeral_spec", test_type_from_ephemeral_spec, METH_NOARGS},
{"get_kwargs", (PyCFunction)(void(*)(void))get_kwargs,
METH_VARARGS|METH_KEYWORDS},
@ -7629,6 +7631,11 @@ PyInit__testcapi(void)
return m;
}
static PyObject *
negative_dictoffset(PyObject *self, PyObject *Py_UNUSED(ignored))
{
return PyType_FromSpec(&HeapCTypeWithNegativeDict_spec);
}
/* Test the C API exposed when PY_SSIZE_T_CLEAN is not defined */