在此节中的宏用于管理 Python 对象的引用计数。
Py_INCREF
(
PyObject
*o
)
¶
递增引用计数为对象
o
。对象不得为
NULL
; if you aren’t sure that it isn’t
NULL
，使用
Py_XINCREF()
.
Py_DECREF
(
PyObject
*o
)
¶
递减引用计数为对象
o
。对象不得为
NULL
; if you aren’t sure that it isn’t
NULL
，使用
Py_XDECREF()
. If the reference count reaches zero, the object’s type’s deallocation function (which must not be
NULL
) is invoked.
警告
The deallocation function can cause arbitrary Python code to be invoked (e.g. when a class instance with a
__del__()
method is deallocated). While exceptions in such code are not propagated, the executed code has free access to all Python global variables. This means that any object that is reachable from a global variable should be in a consistent state before
Py_DECREF()
is invoked. For example, code to delete an object from a list should copy a reference to the deleted object in a temporary variable, update the list data structure, and then call
Py_DECREF()
for the temporary variable.
Py_XDECREF
(
PyObject
*o
)
¶
递减引用计数为对象
o
。对象可能是
NULL
, in which case the macro has no effect; otherwise the effect is the same as for
Py_DECREF()
, and the same warning applies.
Py_CLEAR
(
PyObject
*o
)
¶
递减引用计数为对象
o
。对象可能是
NULL
, in which case the macro has no effect; otherwise the effect is the same as for
Py_DECREF()
, except that the argument is also set to
NULL
. The warning for
Py_DECREF()
does not apply with respect to the object passed because the macro carefully uses a temporary variable and sets the argument to
NULL
before decrementing its reference count.
It is a good idea to use this macro whenever decrementing the value of a variable that might be traversed during garbage collection.
以下函数在 Python 运行时动态嵌入：
Py_IncRef(PyObject
*o)
,
Py_DecRef(PyObject
*o)
. They are simply exported function versions of
Py_XINCREF()
and
Py_XDECREF()
，分别。
以下函数或宏仅用于解释器核心：
_Py_Dealloc()
,
_Py_ForgetReference()
,
_Py_NewReference()
，及全局变量
_Py_RefTotal
.