gh-121528: Fix _PyObject_Init() assertion for stable ABI (#121725)

Add _Py_IsImmortalLoose() function for assertions.
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Victor Stinner 2024-07-17 21:49:37 +02:00 committed by GitHub
parent f4bc84d261
commit b826e459ca
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1 changed files with 26 additions and 2 deletions

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@ -15,6 +15,30 @@ extern "C" {
#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_STORE_PTR_RELAXED
#include "pycore_pystate.h" // _PyInterpreterState_GET()
#define _Py_IMMORTAL_REFCNT_LOOSE ((_Py_IMMORTAL_REFCNT >> 1) + 1)
// gh-121528, gh-118997: Similar to _Py_IsImmortal() but be more loose when
// comparing the reference count to stay compatible with C extensions built
// with the stable ABI 3.11 or older. Such extensions implement INCREF/DECREF
// as refcnt++ and refcnt-- without taking in account immortal objects. For
// example, the reference count of an immortal object can change from
// _Py_IMMORTAL_REFCNT to _Py_IMMORTAL_REFCNT+1 (INCREF) or
// _Py_IMMORTAL_REFCNT-1 (DECREF).
//
// This function should only be used in assertions. Otherwise, _Py_IsImmortal()
// must be used instead.
static inline int _Py_IsImmortalLoose(PyObject *op)
{
#if defined(Py_GIL_DISABLED)
return _Py_IsImmortal(op);
#else
return (op->ob_refcnt >= _Py_IMMORTAL_REFCNT_LOOSE);
#endif
}
#define _Py_IsImmortalLoose(op) _Py_IsImmortalLoose(_PyObject_CAST(op))
/* Check if an object is consistent. For example, ensure that the reference
counter is greater than or equal to 1, and ensure that ob_type is not NULL.
@ -134,7 +158,7 @@ PyAPI_FUNC(void) _Py_SetImmortalUntracked(PyObject *op);
static inline void _Py_SetMortal(PyObject *op, Py_ssize_t refcnt)
{
if (op) {
assert(_Py_IsImmortal(op));
assert(_Py_IsImmortalLoose(op));
#ifdef Py_GIL_DISABLED
op->ob_tid = _Py_UNOWNED_TID;
op->ob_ref_local = 0;
@ -266,7 +290,7 @@ _PyObject_Init(PyObject *op, PyTypeObject *typeobj)
{
assert(op != NULL);
Py_SET_TYPE(op, typeobj);
assert(_PyType_HasFeature(typeobj, Py_TPFLAGS_HEAPTYPE) || _Py_IsImmortal(typeobj));
assert(_PyType_HasFeature(typeobj, Py_TPFLAGS_HEAPTYPE) || _Py_IsImmortalLoose(typeobj));
Py_INCREF(typeobj);
_Py_NewReference(op);
}