// 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):
}
}
}
