Active card removal monitoring issue when stopped

[amessara-billettiqueservices]

Hello team,

We have a specific use case, in which, when a type of card is detected we stop everything and let another application handle the card.

This revealed an issue in Keyple as we still keep interacting with the reader after a stopCardDetection() has been called.

finalizeCardProcessing() is called, switching the statemachine to WAIT_FOR_CARD_REMOVAL and starting an active card presence monitoring.

03-07-24 18:28:34.317 	 1 	 DEBUG 	 SmartcardNfcReader 	 Finishing handling the card
03-07-24 18:28:34.317 	 1 	 DEBUG 	 org.eclipse.keyple.core.service.ObservableLocalReaderAdapter 	 Reader 'BluebirdReader' of plugin 'BluebirdPlugin' starts the removal sequence of the card.
03-07-24 18:28:34.317 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.WaitForCardProcessingStateAdapter 	 [BluebirdReader] onInternalEvent => Event CARD_PROCESSED received in currentState WAIT_FOR_CARD_PROCESSING
03-07-24 18:28:34.318 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.ObservableReaderStateServiceAdapter 	 [BluebirdReader] Switch currentState from WAIT_FOR_CARD_PROCESSING to WAIT_FOR_CARD_REMOVAL
03-07-24 18:28:34.318 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.AbstractObservableStateAdapter 	 [BluebirdReader] onDeactivate => WAIT_FOR_CARD_PROCESSING
03-07-24 18:28:34.319 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.AbstractObservableStateAdapter 	 [BluebirdReader] onActivate => WAIT_FOR_CARD_REMOVAL

stopCardDetection() is called to stop all operations on the card and reader and let the other application work

03-07-24 18:28:34.320 	 1 	 DEBUG 	 SmartcardNfcReader 	 stopCardDetection()
03-07-24 18:28:34.321 	 1280 	 DEBUG 	 org.eclipse.keyple.core.service.CardRemovalActiveMonitoringJobAdapter 	 [BluebirdReader] Polling from isCardPresentPing
03-07-24 18:28:34.321 	 1 	 DEBUG 	 org.eclipse.keyple.core.service.ObservableLocalReaderAdapter 	 Reader 'BluebirdReader' of plugin 'BluebirdPlugin' stops the card detection.
03-07-24 18:28:34.322 	 1280 	 VERBOSE 	 org.eclipse.keyple.core.service.ObservableLocalReaderAdapter 	 [BluebirdReader] Ping card
03-07-24 18:28:34.322 	 1 	 DEBUG 	 BluebirdReaderAdapter 	 onStopDetection()
03-07-24 18:28:34.322 	 1280 	 DEBUG 	 BluebirdReaderAdapter 	 transmitApdu() apduIn=00C0000000
03-07-24 18:28:34.324 	 1 	 DEBUG 	 BluebirdReaderAdapter 	 extNfcReader.stopScan = 0
03-07-24 18:28:34.326 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.WaitForCardRemovalStateAdapter 	 [BluebirdReader] onInternalEvent => Event STOP_DETECT received in currentState WAIT_FOR_CARD_REMOVAL
03-07-24 18:28:34.327 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.LocalReaderAdapter 	 [BluebirdReader] closeLogicalChannel => Closing of the logical channel.
03-07-24 18:28:34.327 	 1 	 DEBUG 	 BluebirdReaderAdapter 	 closePhysicalChannel()
03-07-24 18:28:34.327 	 1 	 DEBUG 	 org.eclipse.keyple.core.service.ObservableLocalReaderAdapter 	 Reader 'BluebirdReader' notifies the reader event 'CARD_REMOVED' to 1 observer(s).

We see at the same time the state machine being "stopped" (WAIT_FOR_START_DETECTION) and the removal monitoring job requested to stop. (It's a simple request and not an interruption. Ongoing jobs are allowed to finish)

03-07-24 18:28:34.379 	 1280 	 DEBUG 	 BluebirdReaderAdapter 	 transmitApdu() result=6D00
03-07-24 18:28:34.381 	 1280 	 VERBOSE 	 org.eclipse.keyple.core.service.CardRemovalActiveMonitoringJobAdapter 	 [BluebirdReader] Polling retries : 1
03-07-24 18:28:34.556 	 1 	 DEBUG 	 PeripheralObserver 	 onChange(true,null
03-07-24 18:28:34.557 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.ObservableReaderStateServiceAdapter 	 [BluebirdReader] Switch currentState from WAIT_FOR_CARD_REMOVAL to WAIT_FOR_START_DETECTION
03-07-24 18:28:34.557 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.AbstractObservableStateAdapter 	 [BluebirdReader] onDeactivate => WAIT_FOR_CARD_REMOVAL
03-07-24 18:28:34.557 	 1 	 DEBUG 	 org.eclipse.keyple.core.service.CardRemovalActiveMonitoringJobAdapter 	 [BluebirdReader] Stop Polling 
03-07-24 18:28:34.558 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.AbstractObservableStateAdapter 	 [BluebirdReader] onDeactivate => cancel monitoring job CardRemovalActiveMonitoringJobAdapter by thread interruption true
03-07-24 18:28:34.558 	 1 	 VERBOSE 	 org.eclipse.keyple.core.service.AbstractObservableStateAdapter 	 [BluebirdReader] onActivate => WAIT_FOR_START_DETECTION
03-07-24 18:28:34.558 	 1 	 DEBUG 	 SmartcardNfcReader 	 remove observer
03-07-24 18:28:34.558 	 1 	 DEBUG 	 org.eclipse.keyple.core.service.ObservationManagerAdapter 	 Reader 'BluebirdReader' of plugin 'BluebirdPlugin' is removing the observer 'BluebirdNfcReader'.

200ms later the card removal monitoring job awakens from a Thread.sleep, understands that a stop has been requested BUT tries to close the physical channel and send a CARD_REMOVED event.

03-07-24 18:28:34.582 	 1280 	 DEBUG 	 org.eclipse.keyple.core.service.CardRemovalActiveMonitoringJobAdapter 	 [BluebirdReader] Polling loop has been stopped
03-07-24 18:28:34.583 	 1280 	 VERBOSE 	 org.eclipse.keyple.core.service.WaitForCardRemovalStateAdapter 	 [BluebirdReader] onInternalEvent => Event CARD_REMOVED received in currentState WAIT_FOR_CARD_REMOVAL
03-07-24 18:28:34.583 	 1280 	 VERBOSE 	 org.eclipse.keyple.core.service.LocalReaderAdapter 	 [BluebirdReader] closeLogicalChannel => Closing of the logical channel.
03-07-24 18:28:34.583 	 1280 	 DEBUG 	 BluebirdReaderAdapter 	 closePhysicalChannel()
03-07-24 18:28:34.585 	 1280 	 DEBUG 	 org.eclipse.keyple.core.service.ObservableLocalReaderAdapter 	 Reader 'BluebirdReader' notifies the reader event 'CARD_REMOVED' to 0 observer(s).
03-07-24 18:28:34.591 	 1280 	 VERBOSE 	 org.eclipse.keyple.core.service.ObservableReaderStateServiceAdapter 	 [BluebirdReader] Switch currentState from WAIT_FOR_START_DETECTION to WAIT_FOR_CARD_INSERTION
03-07-24 18:28:34.591 	 1280 	 VERBOSE 	 org.eclipse.keyple.core.service.AbstractObservableStateAdapter 	 [BluebirdReader] onDeactivate => WAIT_FOR_START_DETECTION
03-07-24 18:28:34.592 	 1280 	 VERBOSE 	 org.eclipse.keyple.core.service.AbstractObservableStateAdapter 	 [BluebirdReader] onActivate => WAIT_FOR_CARD_INSERTION

This behavior is very problematic as we have already stopped everything and the reader is currently used by another application.

I believe that the issue is in this finally block and simply checking if the loop has been stopped before should fix it.

keyple-service-java-lib/src/main/java/org/eclipse/keyple/core/service/CardRemovalActiveMonitoringJobAdapter.java

Lines 115 to 117 in df389b7

	} finally {
	monitoringState.onEvent(ObservableLocalReaderAdapter.InternalEvent.CARD_REMOVED);
	}

} finally {
          if(!loop.get()) {
            monitoringState.onEvent(ObservableLocalReaderAdapter.InternalEvent.CARD_REMOVED);
          }
}

[andrei-cristea]

Hi Aghilas,

There does seem to be a problem with the management of events in the card withdrawal waiting job.

However, I think the solution to your problem lies elsewhere.

If I understand correctly, the application detects the card, selects it, then realizes that it needs to be processed by another application that doesn't use Keyple.

In this case, can you tell us whether we need to close the physical channel with the card before handing over to the other application?

The call to the finalizeCardProcessing() method induces asynchronous processing to wait for the card to be withdrawn. This seems to be the problem.

Calling the stopCardDetection() method immediately closes the communication channel with the card and resets the state machine to the card detection waiting state.

Can you try to call only the stopCardDetection() method?

Regards

[amessara-billettiqueservices]

Hello Andrei,

Thank you for the reply. Not calling finalizeCardProcessing() would most likely fix the issue.

However finalizeCardProcessing() is called in a finally as advised by the documentation and changing that would require some not so great code.
I really think that the monitoring job should not be interacting with card when it has been explicitly requested to stop.

Regards,