Follow rate limit more closely by including update execution time (#108)

meters/device.go

@@ -21,12 +21,12 @@ type DeviceDescriptor struct {
 
 // Device is a modbus device that can be described, probed and queried
 type Device interface {
-	// Initialize prepares the device for usage. Any setup or initilization should be done here.
+	// Initialize prepares the device for usage. Any setup or initialization should be done here.
 	// It requires that the client has the correct device id applied.
 	Initialize(client modbus.Client) error
 
 	// Descriptor returns the device descriptor. Since this method does not have
-	// bus access the descriptor should be preared during initilization.
+	// bus access the descriptor should be prepared during initialization.
 	Descriptor() DeviceDescriptor
 
 	// Probe tests if a basic register, typically VoltageL1, can be read.

server/queryengine.go

@@ -85,6 +85,9 @@ func (q *QueryEngine) Run(
 	for _, h := range q.handlers {
 		wg.Add(1)
 		go func(h *Handler) {
+			ticker := time.NewTicker(rate)
+			defer ticker.Stop()
+
 			for {
 				// run handlers
 				h.Run(ctx, control, results)
@@ -95,7 +98,7 @@ func (q *QueryEngine) Run(
 					// abort if context is cancelled
 					wg.Done()
 					return
-				case <-time.After(rate):
+				case <-ticker.C:
 				}
 			}
 		}(h)