+// Check for new services list every few minutes. Send the latest list
+// to the "latest" channel as needed.
+func (ent *cachedSvcList) poll() {
+ wakeup := make(chan struct{})
+
+ replace := make(chan svcList)
+ go func() {
+ wakeup <- struct{}{}
+ current := <-replace
+ for {
+ select {
+ case <-ent.clear:
+ wakeup <- struct{}{}
+ // Wait here for the next success, in
+ // order to avoid returning stale
+ // results on the "latest" channel.
+ current = <-replace
+ case current = <-replace:
+ case ent.latest <- current:
+ }
+ }
+ }()
+
+ okDelay := 5 * time.Minute
+ errDelay := 3 * time.Second
+ timer := time.NewTimer(okDelay)