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- /* The PyObject_ memory family: high-level object memory interfaces.
- See pymem.h for the low-level PyMem_ family.
- */
- #ifndef Py_OBJIMPL_H
- #define Py_OBJIMPL_H
- #include "pymem.h"
- #ifdef __cplusplus
- extern "C" {
- #endif
- /* BEWARE:
- Each interface exports both functions and macros. Extension modules should
- use the functions, to ensure binary compatibility across Python versions.
- Because the Python implementation is free to change internal details, and
- the macros may (or may not) expose details for speed, if you do use the
- macros you must recompile your extensions with each Python release.
- Never mix calls to PyObject_ memory functions with calls to the platform
- malloc/realloc/ calloc/free, or with calls to PyMem_.
- */
- /*
- Functions and macros for modules that implement new object types.
- - PyObject_New(type, typeobj) allocates memory for a new object of the given
- type, and initializes part of it. 'type' must be the C structure type used
- to represent the object, and 'typeobj' the address of the corresponding
- type object. Reference count and type pointer are filled in; the rest of
- the bytes of the object are *undefined*! The resulting expression type is
- 'type *'. The size of the object is determined by the tp_basicsize field
- of the type object.
- - PyObject_NewVar(type, typeobj, n) is similar but allocates a variable-size
- object with room for n items. In addition to the refcount and type pointer
- fields, this also fills in the ob_size field.
- - PyObject_Del(op) releases the memory allocated for an object. It does not
- run a destructor -- it only frees the memory. PyObject_Free is identical.
- - PyObject_Init(op, typeobj) and PyObject_InitVar(op, typeobj, n) don't
- allocate memory. Instead of a 'type' parameter, they take a pointer to a
- new object (allocated by an arbitrary allocator), and initialize its object
- header fields.
- Note that objects created with PyObject_{New, NewVar} are allocated using the
- specialized Python allocator (implemented in obmalloc.c), if WITH_PYMALLOC is
- enabled. In addition, a special debugging allocator is used if PYMALLOC_DEBUG
- is also #defined.
- In case a specific form of memory management is needed (for example, if you
- must use the platform malloc heap(s), or shared memory, or C++ local storage or
- operator new), you must first allocate the object with your custom allocator,
- then pass its pointer to PyObject_{Init, InitVar} for filling in its Python-
- specific fields: reference count, type pointer, possibly others. You should
- be aware that Python has no control over these objects because they don't
- cooperate with the Python memory manager. Such objects may not be eligible
- for automatic garbage collection and you have to make sure that they are
- released accordingly whenever their destructor gets called (cf. the specific
- form of memory management you're using).
- Unless you have specific memory management requirements, use
- PyObject_{New, NewVar, Del}.
- */
- /*
- * Raw object memory interface
- * ===========================
- */
- /* Functions to call the same malloc/realloc/free as used by Python's
- object allocator. If WITH_PYMALLOC is enabled, these may differ from
- the platform malloc/realloc/free. The Python object allocator is
- designed for fast, cache-conscious allocation of many "small" objects,
- and with low hidden memory overhead.
- PyObject_Malloc(0) returns a unique non-NULL pointer if possible.
- PyObject_Realloc(NULL, n) acts like PyObject_Malloc(n).
- PyObject_Realloc(p != NULL, 0) does not return NULL, or free the memory
- at p.
- Returned pointers must be checked for NULL explicitly; no action is
- performed on failure other than to return NULL (no warning it printed, no
- exception is set, etc).
- For allocating objects, use PyObject_{New, NewVar} instead whenever
- possible. The PyObject_{Malloc, Realloc, Free} family is exposed
- so that you can exploit Python's small-block allocator for non-object
- uses. If you must use these routines to allocate object memory, make sure
- the object gets initialized via PyObject_{Init, InitVar} after obtaining
- the raw memory.
- */
- PyAPI_FUNC(void *) PyObject_Malloc(size_t size);
- #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03050000
- PyAPI_FUNC(void *) PyObject_Calloc(size_t nelem, size_t elsize);
- #endif
- PyAPI_FUNC(void *) PyObject_Realloc(void *ptr, size_t new_size);
- PyAPI_FUNC(void) PyObject_Free(void *ptr);
- /* Macros */
- #define PyObject_MALLOC PyObject_Malloc
- #define PyObject_REALLOC PyObject_Realloc
- #define PyObject_FREE PyObject_Free
- #define PyObject_Del PyObject_Free
- #define PyObject_DEL PyObject_Free
- /*
- * Generic object allocator interface
- * ==================================
- */
- /* Functions */
- PyAPI_FUNC(PyObject *) PyObject_Init(PyObject *, PyTypeObject *);
- PyAPI_FUNC(PyVarObject *) PyObject_InitVar(PyVarObject *,
- PyTypeObject *, Py_ssize_t);
- PyAPI_FUNC(PyObject *) _PyObject_New(PyTypeObject *);
- PyAPI_FUNC(PyVarObject *) _PyObject_NewVar(PyTypeObject *, Py_ssize_t);
- #define PyObject_New(type, typeobj) ((type *)_PyObject_New(typeobj))
- // Alias to PyObject_New(). In Python 3.8, PyObject_NEW() called directly
- // PyObject_MALLOC() with _PyObject_SIZE().
- #define PyObject_NEW(type, typeobj) PyObject_New(type, typeobj)
- #define PyObject_NewVar(type, typeobj, n) \
- ( (type *) _PyObject_NewVar((typeobj), (n)) )
- // Alias to PyObject_New(). In Python 3.8, PyObject_NEW() called directly
- // PyObject_MALLOC() with _PyObject_VAR_SIZE().
- #define PyObject_NEW_VAR(type, typeobj, n) PyObject_NewVar(type, typeobj, n)
- #ifdef Py_LIMITED_API
- /* Define PyObject_INIT() and PyObject_INIT_VAR() as aliases to PyObject_Init()
- and PyObject_InitVar() in the limited C API for compatibility with the
- CPython C API. */
- # define PyObject_INIT(op, typeobj) \
- PyObject_Init(_PyObject_CAST(op), (typeobj))
- # define PyObject_INIT_VAR(op, typeobj, size) \
- PyObject_InitVar(_PyVarObject_CAST(op), (typeobj), (size))
- #else
- /* PyObject_INIT() and PyObject_INIT_VAR() are defined in cpython/objimpl.h */
- #endif
- /*
- * Garbage Collection Support
- * ==========================
- */
- /* C equivalent of gc.collect() which ignores the state of gc.enabled. */
- PyAPI_FUNC(Py_ssize_t) PyGC_Collect(void);
- /* Test if a type has a GC head */
- #define PyType_IS_GC(t) PyType_HasFeature((t), Py_TPFLAGS_HAVE_GC)
- PyAPI_FUNC(PyVarObject *) _PyObject_GC_Resize(PyVarObject *, Py_ssize_t);
- #define PyObject_GC_Resize(type, op, n) \
- ( (type *) _PyObject_GC_Resize(_PyVarObject_CAST(op), (n)) )
- 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) \
- ( (type *) _PyObject_GC_New(typeobj) )
- #define PyObject_GC_NewVar(type, typeobj, n) \
- ( (type *) _PyObject_GC_NewVar((typeobj), (n)) )
- PyAPI_FUNC(int) PyObject_GC_IsTracked(PyObject *);
- PyAPI_FUNC(int) PyObject_GC_IsFinalized(PyObject *);
- /* Utility macro to help write tp_traverse functions.
- * To use this macro, the tp_traverse function must name its arguments
- * "visit" and "arg". This is intended to keep tp_traverse functions
- * looking as much alike as possible.
- */
- #define Py_VISIT(op) \
- do { \
- if (op) { \
- int vret = visit(_PyObject_CAST(op), arg); \
- if (vret) \
- return vret; \
- } \
- } while (0)
- #ifndef Py_LIMITED_API
- # define Py_CPYTHON_OBJIMPL_H
- # include "cpython/objimpl.h"
- # undef Py_CPYTHON_OBJIMPL_H
- #endif
- #ifdef __cplusplus
- }
- #endif
- #endif /* !Py_OBJIMPL_H */
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