Struct lbPicker

balancer/grpclb/grpclb_picker.go:136–144

lbPicker does two layers of picks: First layer: roundrobin on all servers in serverList, including drops and backends. - If it picks a drop, the RPC will fail as being dropped. - If it picks a backend, do a second layer pick to pick the real backend. Second layer: roundrobin on all READY backends.

//
// It's guaranteed that len(serverList) > 0.
type lbPicker struct {
	mu             sync.Mutex
	serverList     []*lbpb.Server
	serverListNext int
	subConns       []balancer.SubConn // The subConns that were READY when taking the snapshot.
	subConnsNext   int

	stats *rpcStats
}

func newLBPicker(serverList []*lbpb.Server, readySCs []balancer.SubConn, stats *rpcStats) *lbPicker {
	return &lbPicker{