mirror of
				https://github.com/KevinMidboe/Node-Com-Handler.git
				synced 2025-10-29 17:50:27 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			362 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			362 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* 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 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);
 | |
| PyAPI_FUNC(void *) PyObject_Realloc(void *ptr, size_t new_size);
 | |
| PyAPI_FUNC(void) PyObject_Free(void *ptr);
 | |
| 
 | |
| /* This function returns the number of allocated memory blocks, regardless of size */
 | |
| PyAPI_FUNC(Py_ssize_t) _Py_GetAllocatedBlocks(void);
 | |
| 
 | |
| /* Macros */
 | |
| #ifdef WITH_PYMALLOC
 | |
| #ifndef Py_LIMITED_API
 | |
| PyAPI_FUNC(void) _PyObject_DebugMallocStats(FILE *out);
 | |
| #endif /* #ifndef Py_LIMITED_API */
 | |
| #endif
 | |
| 
 | |
| /* 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) )
 | |
| #define PyObject_NewVar(type, typeobj, n) \
 | |
|                 ( (type *) _PyObject_NewVar((typeobj), (n)) )
 | |
| 
 | |
| /* Macros trading binary compatibility for speed. See also pymem.h.
 | |
|    Note that these macros expect non-NULL object pointers.*/
 | |
| #define PyObject_INIT(op, typeobj) \
 | |
|     ( Py_TYPE(op) = (typeobj), _Py_NewReference((PyObject *)(op)), (op) )
 | |
| #define PyObject_INIT_VAR(op, typeobj, size) \
 | |
|     ( Py_SIZE(op) = (size), PyObject_INIT((op), (typeobj)) )
 | |
| 
 | |
| #define _PyObject_SIZE(typeobj) ( (typeobj)->tp_basicsize )
 | |
| 
 | |
| /* _PyObject_VAR_SIZE returns the number of bytes (as size_t) allocated for a
 | |
|    vrbl-size object with nitems items, exclusive of gc overhead (if any).  The
 | |
|    value is rounded up to the closest multiple of sizeof(void *), in order to
 | |
|    ensure that pointer fields at the end of the object are correctly aligned
 | |
|    for the platform (this is of special importance for subclasses of, e.g.,
 | |
|    str or int, so that pointers can be stored after the embedded data).
 | |
| 
 | |
|    Note that there's no memory wastage in doing this, as malloc has to
 | |
|    return (at worst) pointer-aligned memory anyway.
 | |
| */
 | |
| #if ((SIZEOF_VOID_P - 1) & SIZEOF_VOID_P) != 0
 | |
| #   error "_PyObject_VAR_SIZE requires SIZEOF_VOID_P be a power of 2"
 | |
| #endif
 | |
| 
 | |
| #define _PyObject_VAR_SIZE(typeobj, nitems)     \
 | |
|     _Py_SIZE_ROUND_UP((typeobj)->tp_basicsize + \
 | |
|         (nitems)*(typeobj)->tp_itemsize,        \
 | |
|         SIZEOF_VOID_P)
 | |
| 
 | |
| #define PyObject_NEW(type, typeobj) \
 | |
| ( (type *) PyObject_Init( \
 | |
|     (PyObject *) PyObject_MALLOC( _PyObject_SIZE(typeobj) ), (typeobj)) )
 | |
| 
 | |
| #define PyObject_NEW_VAR(type, typeobj, n) \
 | |
| ( (type *) PyObject_InitVar( \
 | |
|       (PyVarObject *) PyObject_MALLOC(_PyObject_VAR_SIZE((typeobj),(n)) ),\
 | |
|       (typeobj), (n)) )
 | |
| 
 | |
| /* This example code implements an object constructor with a custom
 | |
|    allocator, where PyObject_New is inlined, and shows the important
 | |
|    distinction between two steps (at least):
 | |
|        1) the actual allocation of the object storage;
 | |
|        2) the initialization of the Python specific fields
 | |
|       in this storage with PyObject_{Init, InitVar}.
 | |
| 
 | |
|    PyObject *
 | |
|    YourObject_New(...)
 | |
|    {
 | |
|        PyObject *op;
 | |
| 
 | |
|        op = (PyObject *) Your_Allocator(_PyObject_SIZE(YourTypeStruct));
 | |
|        if (op == NULL)
 | |
|        return PyErr_NoMemory();
 | |
| 
 | |
|        PyObject_Init(op, &YourTypeStruct);
 | |
| 
 | |
|        op->ob_field = value;
 | |
|        ...
 | |
|        return op;
 | |
|    }
 | |
| 
 | |
|    Note that in C++, the use of the new operator usually implies that
 | |
|    the 1st step is performed automatically for you, so in a C++ class
 | |
|    constructor you would start directly with PyObject_Init/InitVar
 | |
| */
 | |
| 
 | |
| #ifndef Py_LIMITED_API
 | |
| typedef struct {
 | |
|     /* user context passed as the first argument to the 2 functions */
 | |
|     void *ctx;
 | |
| 
 | |
|     /* allocate an arena of size bytes */
 | |
|     void* (*alloc) (void *ctx, size_t size);
 | |
| 
 | |
|     /* free an arena */
 | |
|     void (*free) (void *ctx, void *ptr, size_t size);
 | |
| } PyObjectArenaAllocator;
 | |
| 
 | |
| /* Get the arena allocator. */
 | |
| PyAPI_FUNC(void) PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator);
 | |
| 
 | |
| /* Set the arena allocator. */
 | |
| PyAPI_FUNC(void) PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator);
 | |
| #endif
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Garbage Collection Support
 | |
|  * ==========================
 | |
|  */
 | |
| 
 | |
| /* C equivalent of gc.collect(). */
 | |
| PyAPI_FUNC(Py_ssize_t) PyGC_Collect(void);
 | |
| 
 | |
| #ifndef Py_LIMITED_API
 | |
| PyAPI_FUNC(Py_ssize_t) _PyGC_CollectNoFail(void);
 | |
| #endif
 | |
| 
 | |
| /* 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 */
 | |
| #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)))
 | |
| 
 | |
| 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
 | |
| typedef union _gc_head {
 | |
|     struct {
 | |
|         union _gc_head *gc_next;
 | |
|         union _gc_head *gc_prev;
 | |
|         Py_ssize_t gc_refs;
 | |
|     } gc;
 | |
|     double dummy;  /* force worst-case alignment */
 | |
| } PyGC_Head;
 | |
| 
 | |
| extern PyGC_Head *_PyGC_generation0;
 | |
| 
 | |
| #define _Py_AS_GC(o) ((PyGC_Head *)(o)-1)
 | |
| 
 | |
| /* Bit 0 is set when tp_finalize is called */
 | |
| #define _PyGC_REFS_MASK_FINALIZED  (1 << 0)
 | |
| /* The (N-1) most significant bits contain the gc state / refcount */
 | |
| #define _PyGC_REFS_SHIFT           (1)
 | |
| #define _PyGC_REFS_MASK            (((size_t) -1) << _PyGC_REFS_SHIFT)
 | |
| 
 | |
| #define _PyGCHead_REFS(g) ((g)->gc.gc_refs >> _PyGC_REFS_SHIFT)
 | |
| #define _PyGCHead_SET_REFS(g, v) do { \
 | |
|     (g)->gc.gc_refs = ((g)->gc.gc_refs & ~_PyGC_REFS_MASK) \
 | |
|         | (((size_t)(v)) << _PyGC_REFS_SHIFT);             \
 | |
|     } while (0)
 | |
| #define _PyGCHead_DECREF(g) ((g)->gc.gc_refs -= 1 << _PyGC_REFS_SHIFT)
 | |
| 
 | |
| #define _PyGCHead_FINALIZED(g) (((g)->gc.gc_refs & _PyGC_REFS_MASK_FINALIZED) != 0)
 | |
| #define _PyGCHead_SET_FINALIZED(g, v) do {  \
 | |
|     (g)->gc.gc_refs = ((g)->gc.gc_refs & ~_PyGC_REFS_MASK_FINALIZED) \
 | |
|         | (v != 0); \
 | |
|     } while (0)
 | |
| 
 | |
| #define _PyGC_FINALIZED(o) _PyGCHead_FINALIZED(_Py_AS_GC(o))
 | |
| #define _PyGC_SET_FINALIZED(o, v) _PyGCHead_SET_FINALIZED(_Py_AS_GC(o), v)
 | |
| 
 | |
| #define _PyGC_REFS(o) _PyGCHead_REFS(_Py_AS_GC(o))
 | |
| 
 | |
| #define _PyGC_REFS_UNTRACKED                    (-2)
 | |
| #define _PyGC_REFS_REACHABLE                    (-3)
 | |
| #define _PyGC_REFS_TENTATIVELY_UNREACHABLE      (-4)
 | |
| 
 | |
| /* Tell the GC to track this object.  NB: While the object is tracked the
 | |
|  * collector it must be safe to call the ob_traverse method. */
 | |
| #define _PyObject_GC_TRACK(o) do { \
 | |
|     PyGC_Head *g = _Py_AS_GC(o); \
 | |
|     if (_PyGCHead_REFS(g) != _PyGC_REFS_UNTRACKED) \
 | |
|         Py_FatalError("GC object already tracked"); \
 | |
|     _PyGCHead_SET_REFS(g, _PyGC_REFS_REACHABLE); \
 | |
|     g->gc.gc_next = _PyGC_generation0; \
 | |
|     g->gc.gc_prev = _PyGC_generation0->gc.gc_prev; \
 | |
|     g->gc.gc_prev->gc.gc_next = g; \
 | |
|     _PyGC_generation0->gc.gc_prev = g; \
 | |
|     } while (0);
 | |
| 
 | |
| /* Tell the GC to stop tracking this object.
 | |
|  * gc_next doesn't need to be set to NULL, but doing so is a good
 | |
|  * way to provoke memory errors if calling code is confused.
 | |
|  */
 | |
| #define _PyObject_GC_UNTRACK(o) do { \
 | |
|     PyGC_Head *g = _Py_AS_GC(o); \
 | |
|     assert(_PyGCHead_REFS(g) != _PyGC_REFS_UNTRACKED); \
 | |
|     _PyGCHead_SET_REFS(g, _PyGC_REFS_UNTRACKED); \
 | |
|     g->gc.gc_prev->gc.gc_next = g->gc.gc_next; \
 | |
|     g->gc.gc_next->gc.gc_prev = g->gc.gc_prev; \
 | |
|     g->gc.gc_next = NULL; \
 | |
|     } while (0);
 | |
| 
 | |
| /* True if the object is currently tracked by the GC. */
 | |
| #define _PyObject_GC_IS_TRACKED(o) \
 | |
|     (_PyGC_REFS(o) != _PyGC_REFS_UNTRACKED)
 | |
| 
 | |
| /* 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 */
 | |
| 
 | |
| PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t);
 | |
| PyAPI_FUNC(PyObject *) _PyObject_GC_New(PyTypeObject *);
 | |
| PyAPI_FUNC(PyVarObject *) _PyObject_GC_NewVar(PyTypeObject *, Py_ssize_t);
 | |
| PyAPI_FUNC(void) PyObject_GC_Track(void *);
 | |
| 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)) )
 | |
| 
 | |
| 
 | |
| /* 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 *)(op), arg);                    \
 | |
|             if (vret)                                                   \
 | |
|                 return vret;                                            \
 | |
|         }                                                               \
 | |
|     } while (0)
 | |
| 
 | |
| 
 | |
| /* Test if a type supports weak references */
 | |
| #define PyType_SUPPORTS_WEAKREFS(t) ((t)->tp_weaklistoffset > 0)
 | |
| 
 | |
| #define PyObject_GET_WEAKREFS_LISTPTR(o) \
 | |
|     ((PyObject **) (((char *) (o)) + Py_TYPE(o)->tp_weaklistoffset))
 | |
| 
 | |
| #ifdef __cplusplus
 | |
| }
 | |
| #endif
 | |
| #endif /* !Py_OBJIMPL_H */
 |