+ it = TestOutputPortMessageIterator(graph, src.output_ports['out'])
+
+ # Three times the initial ref count of `None` iterations should
+ # be enough to catch the bug even if there are small differences
+ # between configurations.
+ none_ref_count = sys.getrefcount(None) * 3
+
+ for i in range(none_ref_count):
+ with self.assertRaises(bt2.TryAgain):
+ next(it)
+
+
+def _setup_seek_test(sink_cls, user_seek_beginning=None, user_can_seek_beginning=None):
+ class MySourceIter(bt2._UserMessageIterator):
+ def __init__(self, port):
+ tc, sc, ec = port.user_data
+ trace = tc()
+ stream = trace.create_stream(sc)
+ packet = stream.create_packet()
+
+ self._msgs = [
+ self._create_stream_beginning_message(stream),
+ self._create_packet_beginning_message(packet),
+ self._create_event_message(ec, packet),
+ self._create_event_message(ec, packet),
+ self._create_packet_end_message(packet),
+ self._create_stream_end_message(stream),
+ ]
+ self._at = 0
+
+ def __next__(self):
+ if self._at < len(self._msgs):
+ msg = self._msgs[self._at]
+ self._at += 1
+ return msg
+ else:
+ raise StopIteration
+
+ if user_seek_beginning is not None:
+ MySourceIter._user_seek_beginning = user_seek_beginning
+
+ if user_can_seek_beginning is not None:
+ MySourceIter._user_can_seek_beginning = property(user_can_seek_beginning)
+
+ class MySource(bt2._UserSourceComponent, message_iterator_class=MySourceIter):
+ def __init__(self, params, obj):
+ tc = self._create_trace_class()
+ sc = tc.create_stream_class(supports_packets=True)
+ ec = sc.create_event_class()
+
+ self._add_output_port('out', (tc, sc, ec))
+
+ class MyFilterIter(bt2._UserMessageIterator):
+ def __init__(self, port):
+ self._upstream_iter = self._create_input_port_message_iterator(
+ self._component._input_ports['in']
+ )
+
+ def __next__(self):
+ return next(self._upstream_iter)
+
+ @property
+ def _user_can_seek_beginning(self):
+ return self._upstream_iter.can_seek_beginning
+
+ def _user_seek_beginning(self):
+ self._upstream_iter.seek_beginning()
+
+ class MyFilter(bt2._UserFilterComponent, message_iterator_class=MyFilterIter):
+ def __init__(self, params, obj):
+ self._add_input_port('in')
+ self._add_output_port('out')