cpython/Modules/xxmodule.c
Nick Coghlan d5cacbb1d9 PEP 489: Multi-phase extension module initialization
Known limitations of the current implementation:

- documentation changes are incomplete
- there's a reference leak I haven't tracked down yet

The leak is most visible by running:

  ./python -m test -R3:3 test_importlib

However, you can also see it by running:

  ./python -X showrefcount

Importing the array or _testmultiphase modules, and
then deleting them from both sys.modules and the local
namespace shows significant increases in the total
number of active references each cycle. By contrast,
with _testcapi (which continues to use single-phase
initialisation) the global refcounts stabilise after
a couple of cycles.
2015-05-23 22:24:10 +10:00

401 lines
12 KiB
C

/* Use this file as a template to start implementing a module that
also declares object types. All occurrences of 'Xxo' should be changed
to something reasonable for your objects. After that, all other
occurrences of 'xx' should be changed to something reasonable for your
module. If your module is named foo your sourcefile should be named
foomodule.c.
You will probably want to delete all references to 'x_attr' and add
your own types of attributes instead. Maybe you want to name your
local variables other than 'self'. If your object type is needed in
other files, you'll have to create a file "foobarobject.h"; see
floatobject.h for an example. */
/* Xxo objects */
#include "Python.h"
static PyObject *ErrorObject;
typedef struct {
PyObject_HEAD
PyObject *x_attr; /* Attributes dictionary */
} XxoObject;
static PyTypeObject Xxo_Type;
#define XxoObject_Check(v) (Py_TYPE(v) == &Xxo_Type)
static XxoObject *
newXxoObject(PyObject *arg)
{
XxoObject *self;
self = PyObject_New(XxoObject, &Xxo_Type);
if (self == NULL)
return NULL;
self->x_attr = NULL;
return self;
}
/* Xxo methods */
static void
Xxo_dealloc(XxoObject *self)
{
Py_XDECREF(self->x_attr);
PyObject_Del(self);
}
static PyObject *
Xxo_demo(XxoObject *self, PyObject *args)
{
if (!PyArg_ParseTuple(args, ":demo"))
return NULL;
Py_INCREF(Py_None);
return Py_None;
}
static PyMethodDef Xxo_methods[] = {
{"demo", (PyCFunction)Xxo_demo, METH_VARARGS,
PyDoc_STR("demo() -> None")},
{NULL, NULL} /* sentinel */
};
static PyObject *
Xxo_getattro(XxoObject *self, PyObject *name)
{
if (self->x_attr != NULL) {
PyObject *v = PyDict_GetItem(self->x_attr, name);
if (v != NULL) {
Py_INCREF(v);
return v;
}
}
return PyObject_GenericGetAttr((PyObject *)self, name);
}
static int
Xxo_setattr(XxoObject *self, char *name, PyObject *v)
{
if (self->x_attr == NULL) {
self->x_attr = PyDict_New();
if (self->x_attr == NULL)
return -1;
}
if (v == NULL) {
int rv = PyDict_DelItemString(self->x_attr, name);
if (rv < 0)
PyErr_SetString(PyExc_AttributeError,
"delete non-existing Xxo attribute");
return rv;
}
else
return PyDict_SetItemString(self->x_attr, name, v);
}
static PyTypeObject Xxo_Type = {
/* The ob_type field must be initialized in the module init function
* to be portable to Windows without using C++. */
PyVarObject_HEAD_INIT(NULL, 0)
"xxmodule.Xxo", /*tp_name*/
sizeof(XxoObject), /*tp_basicsize*/
0, /*tp_itemsize*/
/* methods */
(destructor)Xxo_dealloc, /*tp_dealloc*/
0, /*tp_print*/
(getattrfunc)0, /*tp_getattr*/
(setattrfunc)Xxo_setattr, /*tp_setattr*/
0, /*tp_reserved*/
0, /*tp_repr*/
0, /*tp_as_number*/
0, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
(getattrofunc)Xxo_getattro, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT, /*tp_flags*/
0, /*tp_doc*/
0, /*tp_traverse*/
0, /*tp_clear*/
0, /*tp_richcompare*/
0, /*tp_weaklistoffset*/
0, /*tp_iter*/
0, /*tp_iternext*/
Xxo_methods, /*tp_methods*/
0, /*tp_members*/
0, /*tp_getset*/
0, /*tp_base*/
0, /*tp_dict*/
0, /*tp_descr_get*/
0, /*tp_descr_set*/
0, /*tp_dictoffset*/
0, /*tp_init*/
0, /*tp_alloc*/
0, /*tp_new*/
0, /*tp_free*/
0, /*tp_is_gc*/
};
/* --------------------------------------------------------------------- */
/* Function of two integers returning integer */
PyDoc_STRVAR(xx_foo_doc,
"foo(i,j)\n\
\n\
Return the sum of i and j.");
static PyObject *
xx_foo(PyObject *self, PyObject *args)
{
long i, j;
long res;
if (!PyArg_ParseTuple(args, "ll:foo", &i, &j))
return NULL;
res = i+j; /* XXX Do something here */
return PyLong_FromLong(res);
}
/* Function of no arguments returning new Xxo object */
static PyObject *
xx_new(PyObject *self, PyObject *args)
{
XxoObject *rv;
if (!PyArg_ParseTuple(args, ":new"))
return NULL;
rv = newXxoObject(args);
if (rv == NULL)
return NULL;
return (PyObject *)rv;
}
/* Example with subtle bug from extensions manual ("Thin Ice"). */
static PyObject *
xx_bug(PyObject *self, PyObject *args)
{
PyObject *list, *item;
if (!PyArg_ParseTuple(args, "O:bug", &list))
return NULL;
item = PyList_GetItem(list, 0);
/* Py_INCREF(item); */
PyList_SetItem(list, 1, PyLong_FromLong(0L));
PyObject_Print(item, stdout, 0);
printf("\n");
/* Py_DECREF(item); */
Py_INCREF(Py_None);
return Py_None;
}
/* Test bad format character */
static PyObject *
xx_roj(PyObject *self, PyObject *args)
{
PyObject *a;
long b;
if (!PyArg_ParseTuple(args, "O#:roj", &a, &b))
return NULL;
Py_INCREF(Py_None);
return Py_None;
}
/* ---------- */
static PyTypeObject Str_Type = {
/* The ob_type field must be initialized in the module init function
* to be portable to Windows without using C++. */
PyVarObject_HEAD_INIT(NULL, 0)
"xxmodule.Str", /*tp_name*/
0, /*tp_basicsize*/
0, /*tp_itemsize*/
/* methods */
0, /*tp_dealloc*/
0, /*tp_print*/
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_reserved*/
0, /*tp_repr*/
0, /*tp_as_number*/
0, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
0, /*tp_doc*/
0, /*tp_traverse*/
0, /*tp_clear*/
0, /*tp_richcompare*/
0, /*tp_weaklistoffset*/
0, /*tp_iter*/
0, /*tp_iternext*/
0, /*tp_methods*/
0, /*tp_members*/
0, /*tp_getset*/
0, /* see PyInit_xx */ /*tp_base*/
0, /*tp_dict*/
0, /*tp_descr_get*/
0, /*tp_descr_set*/
0, /*tp_dictoffset*/
0, /*tp_init*/
0, /*tp_alloc*/
0, /*tp_new*/
0, /*tp_free*/
0, /*tp_is_gc*/
};
/* ---------- */
static PyObject *
null_richcompare(PyObject *self, PyObject *other, int op)
{
Py_INCREF(Py_NotImplemented);
return Py_NotImplemented;
}
static PyTypeObject Null_Type = {
/* The ob_type field must be initialized in the module init function
* to be portable to Windows without using C++. */
PyVarObject_HEAD_INIT(NULL, 0)
"xxmodule.Null", /*tp_name*/
0, /*tp_basicsize*/
0, /*tp_itemsize*/
/* methods */
0, /*tp_dealloc*/
0, /*tp_print*/
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_reserved*/
0, /*tp_repr*/
0, /*tp_as_number*/
0, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
0, /*tp_doc*/
0, /*tp_traverse*/
0, /*tp_clear*/
null_richcompare, /*tp_richcompare*/
0, /*tp_weaklistoffset*/
0, /*tp_iter*/
0, /*tp_iternext*/
0, /*tp_methods*/
0, /*tp_members*/
0, /*tp_getset*/
0, /* see PyInit_xx */ /*tp_base*/
0, /*tp_dict*/
0, /*tp_descr_get*/
0, /*tp_descr_set*/
0, /*tp_dictoffset*/
0, /*tp_init*/
0, /*tp_alloc*/
0, /* see PyInit_xx */ /*tp_new*/
0, /*tp_free*/
0, /*tp_is_gc*/
};
/* ---------- */
/* List of functions defined in the module */
static PyMethodDef xx_methods[] = {
{"roj", xx_roj, METH_VARARGS,
PyDoc_STR("roj(a,b) -> None")},
{"foo", xx_foo, METH_VARARGS,
xx_foo_doc},
{"new", xx_new, METH_VARARGS,
PyDoc_STR("new() -> new Xx object")},
{"bug", xx_bug, METH_VARARGS,
PyDoc_STR("bug(o) -> None")},
{NULL, NULL} /* sentinel */
};
PyDoc_STRVAR(module_doc,
"This is a template module just for instruction.");
static int
xx_exec(PyObject *m)
{
/* Due to cross platform compiler issues the slots must be filled
* here. It's required for portability to Windows without requiring
* C++. */
Null_Type.tp_base = &PyBaseObject_Type;
Null_Type.tp_new = PyType_GenericNew;
Str_Type.tp_base = &PyUnicode_Type;
/* Finalize the type object including setting type of the new type
* object; doing it here is required for portability, too. */
if (PyType_Ready(&Xxo_Type) < 0)
goto fail;
/* Add some symbolic constants to the module */
if (ErrorObject == NULL) {
ErrorObject = PyErr_NewException("xx.error", NULL, NULL);
if (ErrorObject == NULL)
goto fail;
}
Py_INCREF(ErrorObject);
PyModule_AddObject(m, "error", ErrorObject);
/* Add Str */
if (PyType_Ready(&Str_Type) < 0)
goto fail;
PyModule_AddObject(m, "Str", (PyObject *)&Str_Type);
/* Add Null */
if (PyType_Ready(&Null_Type) < 0)
goto fail;
PyModule_AddObject(m, "Null", (PyObject *)&Null_Type);
return 0;
fail:
Py_XDECREF(m);
return -1;
}
static struct PyModuleDef_Slot xx_slots[] = {
{Py_mod_exec, xx_exec},
{0, NULL},
};
static struct PyModuleDef xxmodule = {
PyModuleDef_HEAD_INIT,
"xx",
module_doc,
0,
xx_methods,
xx_slots,
NULL,
NULL,
NULL
};
/* Export function for the module (*must* be called PyInit_xx) */
PyMODINIT_FUNC
PyInit_xx(void)
{
return PyModuleDef_Init(&xxmodule);
}