run_cframe(PyFrameObject *f, int exc, PyObject *retval)

	PyThreadState *ts = PyThreadState_GET();

StacklessのPyCFrameObjectへキャスト

	PyCFrameObject *cf = (PyCFrameObject*) f;

Stackless拡張の.stからカレントTaskletを取得する

	PyTaskletObject *task = ts->st.current;
	int done = cf->i;

	ts->frame = f;

	if (retval == NULL || done)
	    goto exit_run_cframe;

	if (cf->ob2 == NULL)
		cf->ob2 = PyTuple_New(0);

参照の切り離し

	Py_DECREF(retval);

STACKLESS_PROPOSE_ALL()

	STACKLESS_PROPOSE_ALL();
	retval = PyObject_Call(cf->ob1, cf->ob2, cf->ob3);

STACKLESS_ASSERT()

	STACKLESS_ASSERT();
	cf->i = 1; /* mark ourself as done */

STACKLESS_UNWINDING(retval)

	if (STACKLESS_UNWINDING(retval)) {
		/* try to shortcut */
		if (ts->st.current == task && ts->frame != NULL &&
		    ts->frame->f_back == (PyFrameObject *) cf) {
			Py_DECREF(ts->frame->f_back);
			ts->frame->f_back = cf->f_back;
			Py_DECREF(cf); /* the exec reference */
		}
		return retval;
	}
	/* pop frame */

exit_run_cframe:
frameの繋がりを保存

	ts->frame = cf->f_back;
	Py_DECREF(cf);
	return retval;