1 #ifndef Py_CPYTHON_OBJIMPL_H 2 # error "this header file must not be included directly" 3 #endif 4 5 #ifdef __cplusplus 6 extern "C" { 7 #endif 8 9 /* This function returns the number of allocated memory blocks, regardless of size */ 10 PyAPI_FUNC(Py_ssize_t) _Py_GetAllocatedBlocks(void); 11 12 /* Macros */ 13 #ifdef WITH_PYMALLOC 14 PyAPI_FUNC(int) _PyObject_DebugMallocStats(FILE *out); 15 #endif 16 17 18 typedef struct { 19 /* user context passed as the first argument to the 2 functions */ 20 void *ctx; 21 22 /* allocate an arena of size bytes */ 23 void* (*alloc) (void *ctx, size_t size); 24 25 /* free an arena */ 26 void (*free) (void *ctx, void *ptr, size_t size); 27 } PyObjectArenaAllocator; 28 29 /* Get the arena allocator. */ 30 PyAPI_FUNC(void) PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator); 31 32 /* Set the arena allocator. */ 33 PyAPI_FUNC(void) PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator); 34 35 36 PyAPI_FUNC(Py_ssize_t) _PyGC_CollectNoFail(void); 37 PyAPI_FUNC(Py_ssize_t) _PyGC_CollectIfEnabled(void); 38 39 40 /* Test if an object has a GC head */ 41 #define PyObject_IS_GC(o) \ 42 (PyType_IS_GC(Py_TYPE(o)) \ 43 && (Py_TYPE(o)->tp_is_gc == NULL || Py_TYPE(o)->tp_is_gc(o))) 44 45 /* GC information is stored BEFORE the object structure. */ 46 typedef struct { 47 // Pointer to next object in the list. 48 // 0 means the object is not tracked 49 uintptr_t _gc_next; 50 51 // Pointer to previous object in the list. 52 // Lowest two bits are used for flags documented later. 53 uintptr_t _gc_prev; 54 } PyGC_Head; 55 56 #define _Py_AS_GC(o) ((PyGC_Head *)(o)-1) 57 58 /* True if the object is currently tracked by the GC. */ 59 #define _PyObject_GC_IS_TRACKED(o) (_Py_AS_GC(o)->_gc_next != 0) 60 61 /* True if the object may be tracked by the GC in the future, or already is. 62 This can be useful to implement some optimizations. */ 63 #define _PyObject_GC_MAY_BE_TRACKED(obj) \ 64 (PyObject_IS_GC(obj) && \ 65 (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj))) 66 67 68 /* Bit flags for _gc_prev */ 69 /* Bit 0 is set when tp_finalize is called */ 70 #define _PyGC_PREV_MASK_FINALIZED (1) 71 /* Bit 1 is set when the object is in generation which is GCed currently. */ 72 #define _PyGC_PREV_MASK_COLLECTING (2) 73 /* The (N-2) most significant bits contain the real address. */ 74 #define _PyGC_PREV_SHIFT (2) 75 #define _PyGC_PREV_MASK (((uintptr_t) -1) << _PyGC_PREV_SHIFT) 76 77 // Lowest bit of _gc_next is used for flags only in GC. 78 // But it is always 0 for normal code. 79 #define _PyGCHead_NEXT(g) ((PyGC_Head*)(g)->_gc_next) 80 #define _PyGCHead_SET_NEXT(g, p) ((g)->_gc_next = (uintptr_t)(p)) 81 82 // Lowest two bits of _gc_prev is used for _PyGC_PREV_MASK_* flags. 83 #define _PyGCHead_PREV(g) ((PyGC_Head*)((g)->_gc_prev & _PyGC_PREV_MASK)) 84 #define _PyGCHead_SET_PREV(g, p) do { \ 85 assert(((uintptr_t)p & ~_PyGC_PREV_MASK) == 0); \ 86 (g)->_gc_prev = ((g)->_gc_prev & ~_PyGC_PREV_MASK) \ 87 | ((uintptr_t)(p)); \ 88 } while (0) 89 90 #define _PyGCHead_FINALIZED(g) \ 91 (((g)->_gc_prev & _PyGC_PREV_MASK_FINALIZED) != 0) 92 #define _PyGCHead_SET_FINALIZED(g) \ 93 ((g)->_gc_prev |= _PyGC_PREV_MASK_FINALIZED) 94 95 #define _PyGC_FINALIZED(o) \ 96 _PyGCHead_FINALIZED(_Py_AS_GC(o)) 97 #define _PyGC_SET_FINALIZED(o) \ 98 _PyGCHead_SET_FINALIZED(_Py_AS_GC(o)) 99 100 101 PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t size); 102 PyAPI_FUNC(PyObject *) _PyObject_GC_Calloc(size_t size); 103 104 105 /* Test if a type supports weak references */ 106 #define PyType_SUPPORTS_WEAKREFS(t) ((t)->tp_weaklistoffset > 0) 107 108 #define PyObject_GET_WEAKREFS_LISTPTR(o) \ 109 ((PyObject **) (((char *) (o)) + Py_TYPE(o)->tp_weaklistoffset)) 110 111 #ifdef __cplusplus 112 } 113 #endif 114