Split C API docs in Py3k branch.

Doc/c-api/allocation.rst

@@ -0,0 +1,93 @@
+.. highlightlang:: c
+
+.. _allocating-objects:
+
+Allocating Objects on the Heap
+==============================
+
+
+.. cfunction:: PyObject* _PyObject_New(PyTypeObject *type)
+
+
+.. cfunction:: PyVarObject* _PyObject_NewVar(PyTypeObject *type, Py_ssize_t size)
+
+
+.. cfunction:: PyObject* PyObject_Init(PyObject *op, PyTypeObject *type)
+
+   Initialize a newly-allocated object *op* with its type and initial reference.
+   Returns the initialized object.  If *type* indicates that the object
+   participates in the cyclic garbage detector, it is added to the detector's set
+   of observed objects. Other fields of the object are not affected.
+
+
+.. cfunction:: PyVarObject* PyObject_InitVar(PyVarObject *op, PyTypeObject *type, Py_ssize_t size)
+
+   This does everything :cfunc:`PyObject_Init` does, and also initializes the
+   length information for a variable-size object.
+
+
+.. cfunction:: TYPE* PyObject_New(TYPE, PyTypeObject *type)
+
+   Allocate a new Python object using the C structure type *TYPE* and the Python
+   type object *type*.  Fields not defined by the Python object header are not
+   initialized; the object's reference count will be one.  The size of the memory
+   allocation is determined from the :attr:`tp_basicsize` field of the type object.
+
+
+.. cfunction:: TYPE* PyObject_NewVar(TYPE, PyTypeObject *type, Py_ssize_t size)
+
+   Allocate a new Python object using the C structure type *TYPE* and the Python
+   type object *type*.  Fields not defined by the Python object header are not
+   initialized.  The allocated memory allows for the *TYPE* structure plus *size*
+   fields of the size given by the :attr:`tp_itemsize` field of *type*.  This is
+   useful for implementing objects like tuples, which are able to determine their
+   size at construction time.  Embedding the array of fields into the same
+   allocation decreases the number of allocations, improving the memory management
+   efficiency.
+
+
+.. cfunction:: void PyObject_Del(PyObject *op)
+
+   Releases memory allocated to an object using :cfunc:`PyObject_New` or
+   :cfunc:`PyObject_NewVar`.  This is normally called from the :attr:`tp_dealloc`
+   handler specified in the object's type.  The fields of the object should not be
+   accessed after this call as the memory is no longer a valid Python object.
+
+
+.. cfunction:: PyObject* Py_InitModule(char *name, PyMethodDef *methods)
+
+   Create a new module object based on a name and table of functions, returning
+   the new module object; the *methods* argument can be *NULL* if no methods are
+   to be defined for the module.
+
+
+.. cfunction:: PyObject* Py_InitModule3(char *name, PyMethodDef *methods, char *doc)
+
+   Create a new module object based on a name and table of functions, returning
+   the new module object.  The *methods* argument can be *NULL* if no methods
+   are to be defined for the module.  If *doc* is non-*NULL*, it will be used to
+   define the docstring for the module.
+
+
+.. cfunction:: PyObject* Py_InitModule4(char *name, PyMethodDef *methods, char *doc, PyObject *self, int apiver)
+
+   Create a new module object based on a name and table of functions, returning
+   the new module object.  The *methods* argument can be *NULL* if no methods
+   are to be defined for the module.  If *doc* is non-*NULL*, it will be used to
+   define the docstring for the module.  If *self* is non-*NULL*, it will passed
+   to the functions of the module as their (otherwise *NULL*) first parameter.
+   (This was added as an experimental feature, and there are no known uses in
+   the current version of Python.)  For *apiver*, the only value which should be
+   passed is defined by the constant :const:`PYTHON_API_VERSION`.
+
+   .. note::
+
+      Most uses of this function should probably be using the :cfunc:`Py_InitModule3`
+      instead; only use this if you are sure you need it.
+
+
+.. cvar:: PyObject _Py_NoneStruct
+
+   Object which is visible in Python as ``None``.  This should only be accessed
+   using the :cmacro:`Py_None` macro, which evaluates to a pointer to this
+   object.