gh-117376: Make `Py_DECREF` a macro in ceval.c in free-threaded build (#122975)

`Py_DECREF` and `PyStackRef_CLOSE` are now implemented as macros in the
free-threaded build in ceval.c. There are two motivations;

 * MSVC has problems inlining functions in ceval.c in the PGO build.

 * We will want to mark escaping calls in order to spill the stack
   pointer in ceval.c and we will want to do this around `_Py_Dealloc`
   (or `_Py_MergeZeroLocalRefcount` or `_Py_DecRefShared`), not around
   the entire `Py_DECREF` or `PyStackRef_CLOSE` call.
This commit is contained in:
Sam Gross 2024-08-23 15:36:14 -04:00 committed by GitHub
parent 67f2c84bff
commit 556e855684
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
2 changed files with 53 additions and 27 deletions

View File

@ -190,18 +190,15 @@ PyStackRef_FromPyObjectImmortal(PyObject *obj)
} while (0)
#ifdef Py_GIL_DISABLED
static inline void
PyStackRef_CLOSE(_PyStackRef stackref)
{
if (PyStackRef_IsDeferred(stackref)) {
// No assert for being immortal or deferred here.
// The GC unsets deferred objects right before clearing.
return;
}
Py_DECREF(PyStackRef_AsPyObjectBorrow(stackref));
}
# define PyStackRef_CLOSE(REF) \
do { \
_PyStackRef _close_tmp = (REF); \
if (!PyStackRef_IsDeferred(_close_tmp)) { \
Py_DECREF(PyStackRef_AsPyObjectBorrow(_close_tmp)); \
} \
} while (0)
#else
# define PyStackRef_CLOSE(stackref) Py_DECREF(PyStackRef_AsPyObjectBorrow(stackref));
# define PyStackRef_CLOSE(stackref) Py_DECREF(PyStackRef_AsPyObjectBorrow(stackref))
#endif
#define PyStackRef_XCLOSE(stackref) \
@ -227,7 +224,7 @@ PyStackRef_DUP(_PyStackRef stackref)
return stackref;
}
#else
# define PyStackRef_DUP(stackref) PyStackRef_FromPyObjectSteal(Py_NewRef(PyStackRef_AsPyObjectBorrow(stackref)));
# define PyStackRef_DUP(stackref) PyStackRef_FromPyObjectSteal(Py_NewRef(PyStackRef_AsPyObjectBorrow(stackref)))
#endif
static inline void

View File

@ -52,13 +52,27 @@
# error "ceval.c must be build with Py_BUILD_CORE define for best performance"
#endif
#if !defined(Py_DEBUG) && !defined(Py_TRACE_REFS) && !defined(Py_GIL_DISABLED)
#if !defined(Py_DEBUG) && !defined(Py_TRACE_REFS)
// GH-89279: The MSVC compiler does not inline these static inline functions
// in PGO build in _PyEval_EvalFrameDefault(), because this function is over
// the limit of PGO, and that limit cannot be configured.
// Define them as macros to make sure that they are always inlined by the
// preprocessor.
// TODO: implement Py_DECREF macro for Py_GIL_DISABLED
#undef Py_IS_TYPE
#define Py_IS_TYPE(ob, type) \
(_PyObject_CAST(ob)->ob_type == (type))
#undef Py_XDECREF
#define Py_XDECREF(arg) \
do { \
PyObject *xop = _PyObject_CAST(arg); \
if (xop != NULL) { \
Py_DECREF(xop); \
} \
} while (0)
#ifndef Py_GIL_DISABLED
#undef Py_DECREF
#define Py_DECREF(arg) \
@ -74,19 +88,6 @@
} \
} while (0)
#undef Py_XDECREF
#define Py_XDECREF(arg) \
do { \
PyObject *xop = _PyObject_CAST(arg); \
if (xop != NULL) { \
Py_DECREF(xop); \
} \
} while (0)
#undef Py_IS_TYPE
#define Py_IS_TYPE(ob, type) \
(_PyObject_CAST(ob)->ob_type == (type))
#undef _Py_DECREF_SPECIALIZED
#define _Py_DECREF_SPECIALIZED(arg, dealloc) \
do { \
@ -100,6 +101,34 @@
d(op); \
} \
} while (0)
#else // Py_GIL_DISABLED
#undef Py_DECREF
#define Py_DECREF(arg) \
do { \
PyObject *op = _PyObject_CAST(arg); \
uint32_t local = _Py_atomic_load_uint32_relaxed(&op->ob_ref_local); \
if (local == _Py_IMMORTAL_REFCNT_LOCAL) { \
break; \
} \
_Py_DECREF_STAT_INC(); \
if (_Py_IsOwnedByCurrentThread(op)) { \
local--; \
_Py_atomic_store_uint32_relaxed(&op->ob_ref_local, local); \
if (local == 0) { \
_Py_MergeZeroLocalRefcount(op); \
} \
} \
else { \
_Py_DecRefShared(op); \
} \
} while (0)
#undef _Py_DECREF_SPECIALIZED
#define _Py_DECREF_SPECIALIZED(arg, dealloc) Py_DECREF(arg)
#endif
#endif