commit 885a294646703a537c37cd2a5ac9aa8728561744 Author: Damian Johnson atagar@torproject.org Date: Sat Dec 8 12:35:34 2012 -0800

Re-attaching event listeners

When a controller disconnects then reconnects we want our event listeners to resume getting events. There's a couple things about this commit that I really don't like...

* It includes a hack in our msg() method to add the hook. * Our tests include sleep() calls. This sucks since it makes our tests take considerably longer, and can break on systems under heavy load. --- stem/control.py | 40 +++++++++++++++++++++++++++++-------- test/integ/control/controller.py | 38 ++++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+), 9 deletions(-)

diff --git a/stem/control.py b/stem/control.py index 0803ad4..79ad70f 100644 --- a/stem/control.py +++ b/stem/control.py @@ -299,6 +299,13 @@ class BaseController(object): if isinstance(response, stem.ControllerError): raise response else: + # I really, really don't like putting hooks into this method, but + # this is the most reliable method I can think of for taking actions + # immediately after successfully authenticating to a connection. + + if message.upper().startswith("AUTHENTICATE"): + self._post_authentication() + return response except stem.SocketClosed, exc: # If the recv() thread caused the SocketClosed then we could still be @@ -435,6 +442,11 @@ class BaseController(object): self._notify_status_listeners(State.CLOSED, False) self._socket_close()

+ def _post_authentication(self): + # actions to be taken after we have a newly authenticated connection + + pass + def _notify_status_listeners(self, state, expect_alive = None): """ Informs our status listeners that a state change occurred. @@ -548,9 +560,6 @@ class Controller(BaseController): BaseController and provides a more user friendly API for library users. """

- # TODO: We need a set_up() (and maybe tear_down()?) method, so we can - # reattach listeners and set VERBOSE_NAMES. - def from_port(control_addr = "127.0.0.1", control_port = 9051): """ Constructs a :class:`~stem.socket.ControlPort` based Controller. @@ -653,12 +662,7 @@ class Controller(BaseController): with self._event_listeners_lock: for event_type in events: self._event_listeners.setdefault(event_type, []).append(listener) - - if self.is_alive(): - response = self.msg("SETEVENTS %s" % " ".join(self._event_listeners.keys())) - - if not response.is_ok(): - raise stem.socket.ProtocolError("SETEVENTS received unexpected response\n%s" % response) + self._attach_listeners()

def remove_event_listener(self, listener): """ @@ -1484,6 +1488,14 @@ class Controller(BaseController):

return response.entries

+ def _post_authentication(self): + # try to re-attach event listeners to the new instance + + try: + self._attach_listeners() + except stem.ProtocolError, exc: + log.warn("We were unable to re-attach our event listeners to the new tor instance (%s)" % exc) + def _handle_event(self, event_message): stem.response.convert("EVENT", event_message, arrived_at = time.time())

@@ -1492,6 +1504,16 @@ class Controller(BaseController): if event_type == event_message.type: for listener in event_listeners: listener(event_message) + + def _attach_listeners(self): + # issues the SETEVENTS call for our event listeners + + with self._event_listeners_lock: + if self.is_alive(): + response = self.msg("SETEVENTS %s" % " ".join(self._event_listeners.keys())) + + if not response.is_ok(): + raise stem.ProtocolError("SETEVENTS received unexpected response\n%s" % response)

def _parse_circ_path(path): """ diff --git a/test/integ/control/controller.py b/test/integ/control/controller.py index 7c424cf..0ecece3 100644 --- a/test/integ/control/controller.py +++ b/test/integ/control/controller.py @@ -98,6 +98,44 @@ class TestController(unittest.TestCase): self.assertTrue(hasattr(event, 'read')) self.assertTrue(hasattr(event, 'written'))

+ def test_reattaching_listeners(self): + """ + Checks that event listeners are re-attached when a controller disconnects + then reconnects to tor. + """ + + if test.runner.require_control(self): return + + event_buffer = [] + + def listener(event): + event_buffer.append(event) + + runner = test.runner.get_runner() + with runner.get_tor_controller() as controller: + controller.add_event_listener(listener, EventType.BW) + + # get a BW event or two + + time.sleep(2) + self.assertTrue(len(event_buffer) >= 1) + + # disconnect and check that we stop getting events + + controller.close() + event_buffer = [] + + time.sleep(2) + self.assertTrue(len(event_buffer) == 0) + + # reconnect and check that we get events again + + controller.connect() + controller.authenticate() + + time.sleep(2) + self.assertTrue(len(event_buffer) >= 1) + def test_getinfo(self): """ Exercises GETINFO with valid and invalid queries.