PyObject *
PyWeakref_NewRef(PyObject *ob, PyObject *callback)
{
PyWeakReference *result = NULL;
PyWeakReference **list;
PyWeakReference *ref, *proxy;
if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) {
PyErr_Format(PyExc_TypeError,
"cannot create weak reference to '%s' object",
ob->ob_type->tp_name);
return NULL;
}
list = GET_WEAKREFS_LISTPTR(ob);
get_basic_refs(*list, &ref, &proxy);
if (callback == Py_None)
callback = NULL;
if (callback == NULL)
/* return existing weak reference if it exists */
result = ref;
if (result != NULL)
Py_INCREF(result);
else {
/* Note: new_weakref() can trigger cyclic GC, so the weakref
list on ob can be mutated. This means that the ref and
proxy pointers we got back earlier may have been collected,
so we need to compute these values again before we use
them. */
result = new_weakref(ob, callback);
if (result != NULL) {
get_basic_refs(*list, &ref, &proxy);
if (callback == NULL) {
if (ref == NULL)
insert_head(result, list);
else {
/* Someone else added a ref without a callback
during GC. Return that one instead of this one
to avoid violating the invariants of the list
of weakrefs for ob. */
Py_DECREF(result);
Py_INCREF(ref);
result = ref;
}
}
else {
PyWeakReference *prev;
prev = (proxy == NULL) ? ref : proxy;
if (prev == NULL)
insert_head(result, list);
else
insert_after(result, prev);
}
}
}
return (PyObject *) result;
}
PyObject *
PyWeakref_NewProxy(PyObject *ob, PyObject *callback)
{
PyWeakReference *result = NULL;
PyWeakReference **list;
PyWeakReference *ref, *proxy;
if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) {
PyErr_Format(PyExc_TypeError,
"cannot create weak reference to '%s' object",
ob->ob_type->tp_name);
return NULL;
}
list = GET_WEAKREFS_LISTPTR(ob);
get_basic_refs(*list, &ref, &proxy);
if (callback == NULL)
/* attempt to return an existing weak reference if it exists */
result = proxy;
if (result != NULL)
Py_XINCREF(result);
else {
result = new_weakref(ob, callback);
if (result != NULL) {
PyWeakReference *prev;
if (PyCallable_Check(ob))
result->ob_type = &_PyWeakref_CallableProxyType;
else
result->ob_type = &_PyWeakref_ProxyType;
if (callback == NULL)
prev = ref;
else
prev = (proxy == NULL) ? ref : proxy;
if (prev == NULL)
insert_head(result, list);
else
insert_after(result, prev);
}
}
return (PyObject *) result;
}
PyObject *
PyWeakref_NewProxy(PyObject *ob, PyObject *callback)
{
PyWeakReference *result = NULL;
PyWeakReference **list;
PyWeakReference *ref, *proxy;
if (!PyType_SUPPORTS_WEAKREFS(Py_TYPE(ob))) {
PyErr_Format(PyExc_TypeError,
"cannot create weak reference to '%s' object",
Py_TYPE(ob)->tp_name);
return NULL;
}
list = GET_WEAKREFS_LISTPTR(ob);
get_basic_refs(*list, &ref, &proxy);
if (callback == Py_None)
callback = NULL;
if (callback == NULL)
/* attempt to return an existing weak reference if it exists */
result = proxy;
if (result != NULL)
Py_INCREF(result);
else {
/* Note: new_weakref() can trigger cyclic GC, so the weakref
list on ob can be mutated. This means that the ref and
proxy pointers we got back earlier may have been collected,
so we need to compute these values again before we use
them. */
if (PyCallable_Check(ob))
result = new_weakref(ob, callback, &_PyWeakref_CallableProxyType);
else
result = new_weakref(ob, callback, &_PyWeakref_ProxyType);
if (result != NULL) {
PyWeakReference *prev;
//JyNI-note: These lines mess up JyNI-initialization.
//In new_weakref _PyObject_GC_New(&_PyWeakref_RefType) is
//called, which caches the tme for _PyWeakref_RefType in
//jy->jy. Now the type is altered afterwards leading to
//a wrong tme. Shall we fix it here, or implement a
//lookup in unconsistent case?
//(Better fix it here)
// if (PyCallable_Check(ob))
// Py_TYPE(result) = &_PyWeakref_CallableProxyType;
// else
// Py_TYPE(result) = &_PyWeakref_ProxyType;
get_basic_refs(*list, &ref, &proxy);
if (callback == NULL) {
if (proxy != NULL) {
/* Someone else added a proxy without a callback
during GC. Return that one instead of this one
to avoid violating the invariants of the list
of weakrefs for ob. */
Py_DECREF(result);
Py_INCREF(result = proxy);
goto skip_insert;
}
prev = ref;
}
else
prev = (proxy == NULL) ? ref : proxy;
if (prev == NULL)
insert_head(result, list);
else
insert_after(result, prev);
skip_insert:
;
}
}
return (PyObject *) result;
}
