From 1a6be91e6fd65ce9cb88cbbbb193db7e92ec6076 Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Tue, 13 Nov 2018 12:52:18 +0100 Subject: [PATCH] bpo-35081: Make some _PyGC macros internal (GH-10507) * Move "GC" macros together: * PyObject_IS_GC() * _Py_AS_GC() * _PyObject_GC_IS_TRACKED() * _PyObject_GC_MAY_BE_TRACKED() * Mark other GC macros as internal (#ifdef Py_BUILD_CORE): * _PyGCHead_NEXT(g), _PyGCHead_SET_NEXT(g, p) * _PyGCHead_PREV(g), _PyGCHead_SET_PREV(g, p) * _PyGCHead_FINALIZED(g), _PyGCHead_SET_FINALIZED(g) * _PyGC_FINALIZED(o), _PyGC_SET_FINALIZED(o) * _PyObject_GC_TRACK(o), _PyObject_GC_UNTRACK(o) * _PyGC_PREV_MASK_FINALIZED * _PyGC_PREV_MASK_COLLECTING * _PyGC_PREV_SHIFT * _PyGC_PREV_MASK * Replace _PyGC_generation0 with _PyRuntime.gc.generation0 * _queuemodule.c: replace _PyObject_GC_UNTRACK() with with PyObject_GC_UnTrack() * Document that _PyObject_GC_TRACK() _PyObject_GC_UNTRACK() macros have been removed from the public C API. --- Doc/c-api/gcsupport.rst | 11 +-- Include/internal/pycore_pymem.h | 2 - Include/objimpl.h | 73 ++++++++++++------- .../2018-11-13-12-13-04.bpo-35081.gFd85N.rst | 2 + Modules/_queuemodule.c | 2 +- 5 files changed, 52 insertions(+), 38 deletions(-) create mode 100644 Misc/NEWS.d/next/C API/2018-11-13-12-13-04.bpo-35081.gFd85N.rst diff --git a/Doc/c-api/gcsupport.rst b/Doc/c-api/gcsupport.rst index 7f54b6a9cf..b739aacea8 100644 --- a/Doc/c-api/gcsupport.rst +++ b/Doc/c-api/gcsupport.rst @@ -61,11 +61,6 @@ Constructors for container types must conform to two rules: end of the constructor. -.. c:function:: void _PyObject_GC_TRACK(PyObject *op) - - A macro version of :c:func:`PyObject_GC_Track`. It should not be used for - extension modules. - Similarly, the deallocator for the object must conform to a similar pair of rules: @@ -90,10 +85,10 @@ rules: the fields used by the :c:member:`~PyTypeObject.tp_traverse` handler become invalid. -.. c:function:: void _PyObject_GC_UNTRACK(PyObject *op) +.. versionchanged:: 3.8 - A macro version of :c:func:`PyObject_GC_UnTrack`. It should not be used for - extension modules. + The :c:func:`_PyObject_GC_TRACK` and :c:func:`_PyObject_GC_UNTRACK` macros + have been removed from the public C API. The :c:member:`~PyTypeObject.tp_traverse` handler accepts a function parameter of this type: diff --git a/Include/internal/pycore_pymem.h b/Include/internal/pycore_pymem.h index 247426afe7..1e7da87cd7 100644 --- a/Include/internal/pycore_pymem.h +++ b/Include/internal/pycore_pymem.h @@ -147,8 +147,6 @@ struct _gc_runtime_state { PyAPI_FUNC(void) _PyGC_Initialize(struct _gc_runtime_state *); -#define _PyGC_generation0 _PyRuntime.gc.generation0 - /* Set the memory allocator of the specified domain to the default. Save the old allocator into *old_alloc if it's non-NULL. diff --git a/Include/objimpl.h b/Include/objimpl.h index b3d3a81a6c..e1946c7456 100644 --- a/Include/objimpl.h +++ b/Include/objimpl.h @@ -256,18 +256,18 @@ PyAPI_FUNC(Py_ssize_t) _PyGC_CollectIfEnabled(void); /* Test if a type has a GC head */ #define PyType_IS_GC(t) PyType_HasFeature((t), Py_TPFLAGS_HAVE_GC) -/* Test if an object has a GC head */ -#ifndef Py_LIMITED_API -#define PyObject_IS_GC(o) (PyType_IS_GC(Py_TYPE(o)) && \ - (Py_TYPE(o)->tp_is_gc == NULL || Py_TYPE(o)->tp_is_gc(o))) -#endif - PyAPI_FUNC(PyVarObject *) _PyObject_GC_Resize(PyVarObject *, Py_ssize_t); #define PyObject_GC_Resize(type, op, n) \ ( (type *) _PyObject_GC_Resize((PyVarObject *)(op), (n)) ) -/* GC information is stored BEFORE the object structure. */ + #ifndef Py_LIMITED_API +/* Test if an object has a GC head */ +#define PyObject_IS_GC(o) \ + (PyType_IS_GC(Py_TYPE(o)) \ + && (Py_TYPE(o)->tp_is_gc == NULL || Py_TYPE(o)->tp_is_gc(o))) + +/* GC information is stored BEFORE the object structure. */ typedef struct { // Pointer to next object in the list. // 0 means the object is not tracked @@ -278,10 +278,21 @@ typedef struct { uintptr_t _gc_prev; } PyGC_Head; -extern PyGC_Head *_PyGC_generation0; - #define _Py_AS_GC(o) ((PyGC_Head *)(o)-1) +/* True if the object is currently tracked by the GC. */ +#define _PyObject_GC_IS_TRACKED(o) (_Py_AS_GC(o)->_gc_next != 0) + +/* True if the object may be tracked by the GC in the future, or already is. + This can be useful to implement some optimizations. */ +#define _PyObject_GC_MAY_BE_TRACKED(obj) \ + (PyObject_IS_GC(obj) && \ + (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj))) +#endif + + +#if defined(Py_BUILD_CORE) || defined(Py_BUILD_CORE_BUILTIN) + /* Bit flags for _gc_prev */ /* Bit 0 is set when tp_finalize is called */ #define _PyGC_PREV_MASK_FINALIZED (1) @@ -304,20 +315,26 @@ extern PyGC_Head *_PyGC_generation0; | ((uintptr_t)(p)); \ } while (0) -#define _PyGCHead_FINALIZED(g) (((g)->_gc_prev & _PyGC_PREV_MASK_FINALIZED) != 0) -#define _PyGCHead_SET_FINALIZED(g) ((g)->_gc_prev |= _PyGC_PREV_MASK_FINALIZED) +#define _PyGCHead_FINALIZED(g) \ + (((g)->_gc_prev & _PyGC_PREV_MASK_FINALIZED) != 0) +#define _PyGCHead_SET_FINALIZED(g) \ + ((g)->_gc_prev |= _PyGC_PREV_MASK_FINALIZED) -#define _PyGC_FINALIZED(o) _PyGCHead_FINALIZED(_Py_AS_GC(o)) -#define _PyGC_SET_FINALIZED(o) _PyGCHead_SET_FINALIZED(_Py_AS_GC(o)) +#define _PyGC_FINALIZED(o) \ + _PyGCHead_FINALIZED(_Py_AS_GC(o)) +#define _PyGC_SET_FINALIZED(o) \ + _PyGCHead_SET_FINALIZED(_Py_AS_GC(o)) /* Tell the GC to track this object. * * NB: While the object is tracked by the collector, it must be safe to call the * ob_traverse method. * - * Internal note: _PyGC_generation0->_gc_prev doesn't have any bit flags + * Internal note: _PyRuntime.gc.generation0->_gc_prev doesn't have any bit flags * because it's not object header. So we don't use _PyGCHead_PREV() and * _PyGCHead_SET_PREV() for it to avoid unnecessary bitwise operations. + * + * The PyObject_GC_Track() function is the public version of this macro. */ #define _PyObject_GC_TRACK(o) do { \ PyGC_Head *g = _Py_AS_GC(o); \ @@ -325,17 +342,19 @@ extern PyGC_Head *_PyGC_generation0; Py_FatalError("GC object already tracked"); \ } \ assert((g->_gc_prev & _PyGC_PREV_MASK_COLLECTING) == 0); \ - PyGC_Head *last = (PyGC_Head*)(_PyGC_generation0->_gc_prev); \ + PyGC_Head *last = (PyGC_Head*)(_PyRuntime.gc.generation0->_gc_prev); \ _PyGCHead_SET_NEXT(last, g); \ _PyGCHead_SET_PREV(g, last); \ - _PyGCHead_SET_NEXT(g, _PyGC_generation0); \ - _PyGC_generation0->_gc_prev = (uintptr_t)g; \ + _PyGCHead_SET_NEXT(g, _PyRuntime.gc.generation0); \ + _PyRuntime.gc.generation0->_gc_prev = (uintptr_t)g; \ } while (0); /* Tell the GC to stop tracking this object. * * Internal note: This may be called while GC. So _PyGC_PREV_MASK_COLLECTING must * be cleared. But _PyGC_PREV_MASK_FINALIZED bit is kept. + * + * The PyObject_GC_UnTrack() function is the public version of this macro. */ #define _PyObject_GC_UNTRACK(o) do { \ PyGC_Head *g = _Py_AS_GC(o); \ @@ -347,16 +366,7 @@ extern PyGC_Head *_PyGC_generation0; g->_gc_next = 0; \ g->_gc_prev &= _PyGC_PREV_MASK_FINALIZED; \ } while (0); - -/* True if the object is currently tracked by the GC. */ -#define _PyObject_GC_IS_TRACKED(o) (_Py_AS_GC(o)->_gc_next != 0) - -/* True if the object may be tracked by the GC in the future, or already is. - This can be useful to implement some optimizations. */ -#define _PyObject_GC_MAY_BE_TRACKED(obj) \ - (PyObject_IS_GC(obj) && \ - (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj))) -#endif /* Py_LIMITED_API */ +#endif /* defined(Py_BUILD_CORE) || defined(Py_BUILD_CORE_BUILTIN) */ #ifndef Py_LIMITED_API PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t size); @@ -364,8 +374,17 @@ PyAPI_FUNC(PyObject *) _PyObject_GC_Calloc(size_t size); #endif /* !Py_LIMITED_API */ PyAPI_FUNC(PyObject *) _PyObject_GC_New(PyTypeObject *); PyAPI_FUNC(PyVarObject *) _PyObject_GC_NewVar(PyTypeObject *, Py_ssize_t); + +/* Tell the GC to track this object. + * + * See also private _PyObject_GC_TRACK() macro. */ PyAPI_FUNC(void) PyObject_GC_Track(void *); + +/* Tell the GC to stop tracking this object. + * + * See also private _PyObject_GC_UNTRACK() macro. */ PyAPI_FUNC(void) PyObject_GC_UnTrack(void *); + PyAPI_FUNC(void) PyObject_GC_Del(void *); #define PyObject_GC_New(type, typeobj) \ diff --git a/Misc/NEWS.d/next/C API/2018-11-13-12-13-04.bpo-35081.gFd85N.rst b/Misc/NEWS.d/next/C API/2018-11-13-12-13-04.bpo-35081.gFd85N.rst new file mode 100644 index 0000000000..34aa742012 --- /dev/null +++ b/Misc/NEWS.d/next/C API/2018-11-13-12-13-04.bpo-35081.gFd85N.rst @@ -0,0 +1,2 @@ +The :c:func:`_PyObject_GC_TRACK` and :c:func:`_PyObject_GC_UNTRACK` macros +have been removed from the public C API. diff --git a/Modules/_queuemodule.c b/Modules/_queuemodule.c index 2a9406cc47..35906f08c1 100644 --- a/Modules/_queuemodule.c +++ b/Modules/_queuemodule.c @@ -26,7 +26,7 @@ typedef struct { static void simplequeue_dealloc(simplequeueobject *self) { - _PyObject_GC_UNTRACK(self); + PyObject_GC_UnTrack(self); if (self->lock != NULL) { /* Unlock the lock so it's safe to free it */ if (self->locked > 0) -- 2.40.0