独仗剑

 1 [object.h]
 2 #ifdef Py_TRACE_REFS
 3 /* Define pointers to support a doubly-linked list of all live heap objects. */
 4 #define _PyObject_HEAD_EXTRA            \
 5     struct _object *_ob_next;           \
 6     struct _object *_ob_prev;
 7  
 8 #define _PyObject_EXTRA_INIT 0, 0,
 9  
10 #else
11 #define _PyObject_HEAD_EXTRA
12 #define _PyObject_EXTRA_INIT
13 #endif
14  
15 /* PyObject_HEAD defines the initial segment of every PyObject. */
16 #define PyObject_HEAD                   \
17     _PyObject_HEAD_EXTRA                \
18     Py_ssize_t ob_refcnt;               \            //引用计数
19     struct _typeobject *ob_type;
20  
21 #define PyObject_HEAD_INIT(type)        \
22     _PyObject_EXTRA_INIT                \
23     1, type,
24  
25 #define PyVarObject_HEAD_INIT(type, size)       \
26     PyObject_HEAD_INIT(type) size,
27 ....
28  
29 typedef struct _object {
30     PyObject_HEAD
31 } PyObject;
32  
33 typedef struct {
34     PyObject_VAR_HEAD
35 } PyVarObject;

 1 [object.h]
 2 typedef struct _typeobject{
 3     PyObject_VAR_HEAD            //注意这里也有对象头
 4     char *tp_name;                        //for printing 
 5     int tp_basicsize, tp_itmesize;
 6  
 7  
 8     //methods
 9     destructor tp_dealloc;
10     printfunc   tp_print;
11     .....
12  
13  
14    //more 
15     hashfunc   tp_hash;
16     ternaryfunc  tp_call;
17     ....
18  
19 }  PyTypeObject;

 1 [typeobject.c]
 2  
 3 PyTypeObject PyType_Type ={
 4     PyObject_HEAD_INIT(&PyType_Type)
 5     0,
 6     "type",
 7     sizeof(PyHeadTypeObject),
 8     sizeof(PyMemberDef),
 9     ....
10     PyObject_GC_Del,
11     (inquiry) type_is_gc,
12  
13 };
14 //以一个整数对象为例：
15 PyTypeObject  PyInt_Type = {
16     PyObject_HEAD_INIT(&PyType_Type)
17     0,
18     "int",
19     sizeof(PyIntObject),
20     ...
21 };

 1 #define _Py_NewReference(op) (                          \
 2     _Py_INC_TPALLOCS(op) _Py_COUNT_ALLOCS_COMMA         \
 3     _Py_INC_REFTOTAL  _Py_REF_DEBUG_COMMA               \
 4     Py_REFCNT(op) = 1)
 5  
 6 #define _Py_ForgetReference(op) _Py_INC_TPFREES(op)
 7  
 8 #define _Py_Dealloc(op) (                               \
 9     _Py_INC_TPFREES(op) _Py_COUNT_ALLOCS_COMMA          \
10     (*Py_TYPE(op)->tp_dealloc)((PyObject *)(op)))
11 #endif /* !Py_TRACE_REFS */
12  
13 #define Py_INCREF(op) (                         \
14     _Py_INC_REFTOTAL  _Py_REF_DEBUG_COMMA       \
15     ((PyObject*)(op))->ob_refcnt++)
16  
17 #define Py_DECREF(op)                                   \
18     do {                                                \
19         if (_Py_DEC_REFTOTAL  _Py_REF_DEBUG_COMMA       \
20         --((PyObject*)(op))->ob_refcnt != 0)            \
21             _Py_CHECK_REFCNT(op)                        \
22         else                                            \
23         _Py_Dealloc((PyObject *)(op));                  \
24     } while (0)
25  

1 #define _Py_INC_TPFREES(OP)     dec_count(Py_TYPE(OP))