Mercurial > repos > rliterman > csp2
diff CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/include/python3.8/objimpl.h @ 69:33d812a61356
planemo upload commit 2e9511a184a1ca667c7be0c6321a36dc4e3d116d
author | jpayne |
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date | Tue, 18 Mar 2025 17:55:14 -0400 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/include/python3.8/objimpl.h Tue Mar 18 17:55:14 2025 -0400 @@ -0,0 +1,284 @@ +/* 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) ) +#define PyObject_NewVar(type, typeobj, n) \ + ( (type *) _PyObject_NewVar((typeobj), (n)) ) + +/* Inline functions trading binary compatibility for speed: + PyObject_INIT() is the fast version of PyObject_Init(), and + PyObject_INIT_VAR() is the fast version of PyObject_InitVar. + See also pymem.h. + + These inline functions expect non-NULL object pointers. */ +static inline PyObject* +_PyObject_INIT(PyObject *op, PyTypeObject *typeobj) +{ + assert(op != NULL); + Py_TYPE(op) = typeobj; + if (PyType_GetFlags(typeobj) & Py_TPFLAGS_HEAPTYPE) { + Py_INCREF(typeobj); + } + _Py_NewReference(op); + return op; +} + +#define PyObject_INIT(op, typeobj) \ + _PyObject_INIT(_PyObject_CAST(op), (typeobj)) + +static inline PyVarObject* +_PyObject_INIT_VAR(PyVarObject *op, PyTypeObject *typeobj, Py_ssize_t size) +{ + assert(op != NULL); + Py_SIZE(op) = size; + PyObject_INIT((PyObject *)op, typeobj); + return op; +} + +#define PyObject_INIT_VAR(op, typeobj, size) \ + _PyObject_INIT_VAR(_PyVarObject_CAST(op), (typeobj), (size)) + +#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 +*/ + + + +/* + * 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)) ) + + +/* 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 */