address comments

Author: yunhanw-google

src/app/InteractionModelEngine.h

@@ -236,8 +236,7 @@ class InteractionModelEngine : public Messaging::UnsolicitedMessageHandler,
     /**
      *  Activate the idle subscriptions.
      *
-     *  When subscribing to ICD and liveness timeout reached, the read client will move to `InactiveICDSubscription` state and
-     * resubscription can be triggered via OnActiveModeNotification().
+     *  See ReadClient::OnActiveModeNotification
      */
     void OnActiveModeNotification(ScopedNodeId aPeer);
 

src/app/ReadClient.cpp

@@ -484,8 +484,12 @@ CHIP_ERROR ReadClient::GenerateDataVersionFilterList(DataVersionFilterIBs::Build
 
 void ReadClient::OnActiveModeNotification()
 {
-    // Note: this API only works when issuing subscription via SendAutoResubscribeRequest.
     VerifyOrDie(mpImEngine->InActiveReadClientList(this));
+
+    // Note: this API only works when issuing subscription via SendAutoResubscribeRequest, when SendAutoResubscribeRequest is
+    // called, either mEventPathParamsListSize or mAttributePathParamsListSize is not 0.
+    VerifyOrDie(mReadPrepareParams.mEventPathParamsListSize != 0 || mReadPrepareParams.mAttributePathParamsListSize != 0);
+
     // When we reach here, the subscription definitely exceeded the liveness timeout. Just continue the unfinished resubscription
     // logic in `OnLivenessTimeoutCallback`.
     if (IsInactiveICDSubscription())
@@ -494,18 +498,19 @@ void ReadClient::OnActiveModeNotification()
         return;
     }
 
-    // If the server sends out check-in message, and there is no reschedule subscription yet in client side at the same time, it means
-    // current client does not realize subscription has gone, and we should forcibly timeout current subscription, and schedule a new one.
+    // If the server sends out check-in message, and there is no reschedule subscription yet in client side at the same time, it
+    // means current client does not realize subscription has gone, and we should forcibly timeout current subscription, and
+    // schedule a new one.
     if (!mIsResubscriptionScheduled)
     {
-        // Closing will ultimately trigger ScheduleResubscription with the aReestablishCASE argument set to true, effectively 
+        // Closing will ultimately trigger ScheduleResubscription with the aReestablishCASE argument set to true, effectively
         // rendering the session defunct.
         Close(CHIP_ERROR_TIMEOUT);
         return;
     }
 
-    // If the server sends a check-in message and a subscription is already scheduled, it indicates a client-side subscription timeout or failure.
-    // Cancel the scheduled subscription and initiate a new one immediately.
+    // If the server sends a check-in message and a subscription is already scheduled, it indicates a client-side subscription
+    // timeout or failure. Cancel the scheduled subscription and initiate a new one immediately.
     TriggerResubscribeIfScheduled("check-in message");
 }
 

src/app/ReadClient.h

@@ -351,11 +351,17 @@ class ReadClient : public Messaging::ExchangeDelegate
      *  Re-activate an inactive subscription.
      *
      *  When subscribing to LIT-ICD and liveness timeout reached and OnResubscriptionNeeded returns
-     * CHIP_ERROR_LIT_SUBSCRIBE_INACTIVE_TIMEOUT, the read client will move to the InactiveICDSubscription state and
-     * resubscription can be triggered via OnActiveModeNotification().
+     *  CHIP_ERROR_LIT_SUBSCRIBE_INACTIVE_TIMEOUT, the read client will move to the InactiveICDSubscription state and
+     *  resubscription can be triggered via OnActiveModeNotification().
      *
      *  If the subscription is not in the `InactiveICDSubscription` state, this function will do nothing. So it is always safe to
-     * call this function when a check-in message is received.
+     *  call this function when a check-in message is received.
+     *
+     *  If the server sends out check-in message, and there is no reschedule subscription yet in client side at the same time, it
+     *  means current client does not realize subscription has gone, and we should forcibly timeout current subscription, and
+     * schedule a new one.
+     *
+     *  This API only works when issuing subscription via SendAutoResubscribeRequest.
      */
     void OnActiveModeNotification();