// capabilityLoop checks the cluster version every 500ms and updates // the enabledCapability when the cluster version increased. // capabilityLoop MUST be ran in a goroutine before checking capability // or using capabilityHandler. func capabilityLoop(s *etcdserver.EtcdServer) { stopped := s.StopNotify() var pv *semver.Version for { if v := s.ClusterVersion(); v != pv { if pv == nil { pv = v } else if v != nil && pv.LessThan(*v) { pv = v } enableMapMu.Lock() enabledMap = capabilityMaps[pv.String()] enableMapMu.Unlock() } select { case <-stopped: return case <-time.After(500 * time.Millisecond): } } }