mirror of
https://github.com/python/cpython.git
synced 2024-11-28 16:45:42 +01:00
123 lines
2.9 KiB
C
123 lines
2.9 KiB
C
/* Generator object implementation */
|
|
|
|
#include "Python.h"
|
|
#include "frameobject.h"
|
|
#include "genobject.h"
|
|
#include "ceval.h"
|
|
#include "structmember.h"
|
|
|
|
static int
|
|
gen_traverse(PyGenObject *gen, visitproc visit, void *arg)
|
|
{
|
|
return visit((PyObject *)gen->gi_frame, arg);
|
|
}
|
|
|
|
static void
|
|
gen_dealloc(PyGenObject *gen)
|
|
{
|
|
_PyObject_GC_UNTRACK(gen);
|
|
if (gen->gi_weakreflist != NULL)
|
|
PyObject_ClearWeakRefs((PyObject *) gen);
|
|
Py_DECREF(gen->gi_frame);
|
|
PyObject_GC_Del(gen);
|
|
}
|
|
|
|
static PyObject *
|
|
gen_iternext(PyGenObject *gen)
|
|
{
|
|
PyThreadState *tstate = PyThreadState_GET();
|
|
PyFrameObject *f = gen->gi_frame;
|
|
PyObject *result;
|
|
|
|
if (gen->gi_running) {
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"generator already executing");
|
|
return NULL;
|
|
}
|
|
if (f->f_stacktop == NULL)
|
|
return NULL;
|
|
|
|
/* Generators always return to their most recent caller, not
|
|
* necessarily their creator. */
|
|
Py_XINCREF(tstate->frame);
|
|
assert(f->f_back == NULL);
|
|
f->f_back = tstate->frame;
|
|
|
|
gen->gi_running = 1;
|
|
result = PyEval_EvalFrame(f);
|
|
gen->gi_running = 0;
|
|
|
|
/* Don't keep the reference to f_back any longer than necessary. It
|
|
* may keep a chain of frames alive or it could create a reference
|
|
* cycle. */
|
|
assert(f->f_back != NULL);
|
|
Py_CLEAR(f->f_back);
|
|
|
|
/* If the generator just returned (as opposed to yielding), signal
|
|
* that the generator is exhausted. */
|
|
if (result == Py_None && f->f_stacktop == NULL) {
|
|
Py_DECREF(result);
|
|
result = NULL;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
static PyMemberDef gen_memberlist[] = {
|
|
{"gi_frame", T_OBJECT, offsetof(PyGenObject, gi_frame), RO},
|
|
{"gi_running", T_INT, offsetof(PyGenObject, gi_running), RO},
|
|
{NULL} /* Sentinel */
|
|
};
|
|
|
|
PyTypeObject PyGen_Type = {
|
|
PyObject_HEAD_INIT(&PyType_Type)
|
|
0, /* ob_size */
|
|
"generator", /* tp_name */
|
|
sizeof(PyGenObject), /* tp_basicsize */
|
|
0, /* tp_itemsize */
|
|
/* methods */
|
|
(destructor)gen_dealloc, /* tp_dealloc */
|
|
0, /* tp_print */
|
|
0, /* tp_getattr */
|
|
0, /* tp_setattr */
|
|
0, /* tp_compare */
|
|
0, /* tp_repr */
|
|
0, /* tp_as_number */
|
|
0, /* tp_as_sequence */
|
|
0, /* tp_as_mapping */
|
|
0, /* tp_hash */
|
|
0, /* tp_call */
|
|
0, /* tp_str */
|
|
PyObject_GenericGetAttr, /* tp_getattro */
|
|
0, /* tp_setattro */
|
|
0, /* tp_as_buffer */
|
|
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
|
|
0, /* tp_doc */
|
|
(traverseproc)gen_traverse, /* tp_traverse */
|
|
0, /* tp_clear */
|
|
0, /* tp_richcompare */
|
|
offsetof(PyGenObject, gi_weakreflist), /* tp_weaklistoffset */
|
|
PyObject_SelfIter, /* tp_iter */
|
|
(iternextfunc)gen_iternext, /* tp_iternext */
|
|
0, /* tp_methods */
|
|
gen_memberlist, /* tp_members */
|
|
0, /* tp_getset */
|
|
0, /* tp_base */
|
|
0, /* tp_dict */
|
|
};
|
|
|
|
PyObject *
|
|
PyGen_New(PyFrameObject *f)
|
|
{
|
|
PyGenObject *gen = PyObject_GC_New(PyGenObject, &PyGen_Type);
|
|
if (gen == NULL) {
|
|
Py_DECREF(f);
|
|
return NULL;
|
|
}
|
|
gen->gi_frame = f;
|
|
gen->gi_running = 0;
|
|
gen->gi_weakreflist = NULL;
|
|
_PyObject_GC_TRACK(gen);
|
|
return (PyObject *)gen;
|
|
}
|