protected override void StopListening()
{
// disconnect the contact event for non-contact probes. this probe has already been marked as non-running, so
// there's no risk of a race condition in which the contact state changes to worn and the change event attempts
// to restart this probe after it has been stopped (we check Running during the change event).
if (!(this is MicrosoftBandContactProbe))
{
MicrosoftBandContactProbe contactProbe = Protocol.Probes.Single(probe => probe is MicrosoftBandContactProbe) as MicrosoftBandContactProbe;
contactProbe.ContactStateChanged -= ContactStateChanged;
}
StopReadings();
// only cancel the static health test if none of the band probes should be running.
if (BandProbesThatShouldBeRunning.Count == 0)
{
CancelHealthTest();
}
// disconnect the client if no band probes are actually running.
if (BandProbesThatAreRunning.Count == 0 && (BandClient?.IsConnected ?? false))
{
try
{
SensusServiceHelper.Get().Logger.Log("All Band probes have stopped. Disconnecting client.", LoggingLevel.Normal, GetType());
BandClient.DisconnectAsync().Wait();
BandClient = null;
}
catch (Exception ex)
{
SensusServiceHelper.Get().Logger.Log("Failed to disconnect client: " + ex.Message, LoggingLevel.Normal, GetType());
}
}
}
protected override void StartListening()
{
// we expect this probe to start successfully, but an exception may occur if no bands are paired with the device of if the
// connection with a paired band fails. so schedule a static repeating callback to check on all band probes and restart them
// if needed/possible. this is better than a non-static callback for each band probe because there are many band probes and
// the callbacks would be redundant, frequent, and power-hungry.
lock (HEALTH_TEST_LOCKER)
{
// only schedule the callback if we haven't done so already. the callback should be global across all band probes.
if (HEALTH_TEST_CALLBACK == null)
{
// the band health test is static, so it has no domain other than sensus.
HEALTH_TEST_CALLBACK = new ScheduledCallback(TestBandClientAsync, "BAND-HEALTH-TEST", null, null, HEALTH_TEST_TIMEOUT);
SensusContext.Current.CallbackScheduler.ScheduleRepeatingCallback(HEALTH_TEST_CALLBACK, HEALTH_TEST_DELAY, HEALTH_TEST_DELAY, false);
}
}
// hook up the contact event for non-contact probes. need to do this before the calls below because they might throw
// a band connect exception. such an exception will leave the probe in a running state in anticipation that the user
// might pair a band later. the band health test will start readings later for all band probes, but it will not use
// Start to do so (it will simply start the readings). so this is our only chance to hook up the contact event.
if (!(this is MicrosoftBandContactProbe))
{
MicrosoftBandContactProbe contactProbe = Protocol.Probes.Single(probe => probe is MicrosoftBandContactProbe) as MicrosoftBandContactProbe;
contactProbe.ContactStateChanged += ContactStateChanged;
}
ConnectClient();
Configure(BandClient);
StartReadings();
}
