Print gap between collector ticks. (viamrobotics#710)

data/collector.go

@@ -100,26 +100,32 @@ func (c *collector) Collect() error {
 }
 
 func (c *collector) capture() {
-	_, span := trace.StartSpan(c.cancelCtx, "data::collector::capture")
-	defer span.End()
-
 	ticker := time.NewTicker(c.interval)
 	defer ticker.Stop()
+	var wg sync.WaitGroup
+	lastTick := time.Now()
 
 	for {
 		select {
 		case <-c.cancelCtx.Done():
+			wg.Wait()
 			close(c.queue)
 			return
 		case <-ticker.C:
-			c.getAndPushNextReading()
+			currTick := time.Now()
+			diff := currTick.Sub(lastTick).Microseconds()
+			if diff > 1800 {
+				c.logger.Debugf("took %d microseconds between ticks", diff)
+			}
+			lastTick = currTick
+			wg.Add(1)
+			go c.getAndPushNextReading(&wg)
 		}
 	}
 }
 
-func (c *collector) getAndPushNextReading() {
-	_, span := trace.StartSpan(c.cancelCtx, "data::collector::getAndPushNextReading")
-	defer span.End()
+func (c *collector) getAndPushNextReading(wg *sync.WaitGroup) {
+	defer wg.Done()
 
 	timeRequested := timestamppb.New(time.Now().UTC())
 	reading, err := c.capturer.Capture(c.cancelCtx, c.params)