improvements

common/transport/mqtt/src/main/java/org/thingsboard/server/transport/mqtt/gateway/GatewayLatencyService.java

@@ -67,10 +67,7 @@ public class GatewayLatencyService {
     }
 
     public void onDeviceDelete(DeviceId deviceId) {
-        var state = states.remove(deviceId);
+        states.remove(deviceId);
-        if (state != null) {
-            state.clear();
-        }
     }
 
     public void onDeviceDisconnect(DeviceId deviceId) {
@@ -100,7 +97,6 @@ public class GatewayLatencyService {
             return;
         }
         var result = state.getLatencyStateResult();
-        state.clear();
         var kvProto = TransportProtos.KeyValueProto.newBuilder()
                 .setKey("latencyCheck")
                 .setType(TransportProtos.KeyValueType.JSON_V)

common/transport/mqtt/src/main/java/org/thingsboard/server/transport/mqtt/gateway/latency/GatewayLatencyState.java

@@ -54,13 +54,16 @@ public class GatewayLatencyState {
         }
     }
 
-    public void clear() {
-        connectors.clear();
-    }
-
     public Map<String, ConnectorLatencyResult> getLatencyStateResult() {
         Map<String, ConnectorLatencyResult> result = new HashMap<>();
-        connectors.forEach((name, state) -> result.put(name, state.getResult()));
+        updateLock.lock();
+        try {
+            connectors.forEach((name, state) -> result.put(name, state.getResult()));
+            connectors.clear();
+        } finally {
+            updateLock.unlock();
+        }
+
         return result;
     }