VOL-2138 Use v2 import paths for voltha-lib-go;
migrate from voltha-go to voltha-lib-go

Change-Id: I3db6759f3c0cea3c2164889b3d36eae708b19bde
diff --git a/vendor/google.golang.org/grpc/resolver_conn_wrapper.go b/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
index 50991ea..6934905 100644
--- a/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
+++ b/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
@@ -21,6 +21,7 @@
 import (
 	"fmt"
 	"strings"
+	"sync/atomic"
 
 	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/internal/channelz"
@@ -30,12 +31,12 @@
 // ccResolverWrapper is a wrapper on top of cc for resolvers.
 // It implements resolver.ClientConnection interface.
 type ccResolverWrapper struct {
-	cc                 *ClientConn
-	resolver           resolver.Resolver
-	addrCh             chan []resolver.Address
-	scCh               chan string
-	done               chan struct{}
-	lastAddressesCount int
+	cc       *ClientConn
+	resolver resolver.Resolver
+	addrCh   chan []resolver.Address
+	scCh     chan string
+	done     uint32 // accessed atomically; set to 1 when closed.
+	curState resolver.State
 }
 
 // split2 returns the values from strings.SplitN(s, sep, 2).
@@ -82,7 +83,6 @@
 		cc:     cc,
 		addrCh: make(chan []resolver.Address, 1),
 		scCh:   make(chan string, 1),
-		done:   make(chan struct{}),
 	}
 
 	var err error
@@ -99,57 +99,70 @@
 
 func (ccr *ccResolverWrapper) close() {
 	ccr.resolver.Close()
-	close(ccr.done)
+	atomic.StoreUint32(&ccr.done, 1)
 }
 
-// NewAddress is called by the resolver implemenetion to send addresses to gRPC.
-func (ccr *ccResolverWrapper) NewAddress(addrs []resolver.Address) {
-	select {
-	case <-ccr.done:
+func (ccr *ccResolverWrapper) isDone() bool {
+	return atomic.LoadUint32(&ccr.done) == 1
+}
+
+func (ccr *ccResolverWrapper) UpdateState(s resolver.State) {
+	if ccr.isDone() {
 		return
-	default:
+	}
+	grpclog.Infof("ccResolverWrapper: sending update to cc: %v", s)
+	if channelz.IsOn() {
+		ccr.addChannelzTraceEvent(s)
+	}
+	ccr.cc.updateResolverState(s)
+	ccr.curState = s
+}
+
+// NewAddress is called by the resolver implementation to send addresses to gRPC.
+func (ccr *ccResolverWrapper) NewAddress(addrs []resolver.Address) {
+	if ccr.isDone() {
+		return
 	}
 	grpclog.Infof("ccResolverWrapper: sending new addresses to cc: %v", addrs)
 	if channelz.IsOn() {
-		ccr.addChannelzTraceEvent(addrs)
+		ccr.addChannelzTraceEvent(resolver.State{Addresses: addrs, ServiceConfig: ccr.curState.ServiceConfig})
 	}
-	ccr.cc.handleResolvedAddrs(addrs, nil)
+	ccr.curState.Addresses = addrs
+	ccr.cc.updateResolverState(ccr.curState)
 }
 
-// NewServiceConfig is called by the resolver implemenetion to send service
+// NewServiceConfig is called by the resolver implementation to send service
 // configs to gRPC.
 func (ccr *ccResolverWrapper) NewServiceConfig(sc string) {
-	select {
-	case <-ccr.done:
+	if ccr.isDone() {
 		return
-	default:
 	}
 	grpclog.Infof("ccResolverWrapper: got new service config: %v", sc)
-	ccr.cc.handleServiceConfig(sc)
+	c, err := parseServiceConfig(sc)
+	if err != nil {
+		return
+	}
+	if channelz.IsOn() {
+		ccr.addChannelzTraceEvent(resolver.State{Addresses: ccr.curState.Addresses, ServiceConfig: c})
+	}
+	ccr.curState.ServiceConfig = c
+	ccr.cc.updateResolverState(ccr.curState)
 }
 
-func (ccr *ccResolverWrapper) addChannelzTraceEvent(addrs []resolver.Address) {
-	if len(addrs) == 0 && ccr.lastAddressesCount != 0 {
-		channelz.AddTraceEvent(ccr.cc.channelzID, &channelz.TraceEventDesc{
-			Desc:     "Resolver returns an empty address list",
-			Severity: channelz.CtWarning,
-		})
-	} else if len(addrs) != 0 && ccr.lastAddressesCount == 0 {
-		var s string
-		for i, a := range addrs {
-			if a.ServerName != "" {
-				s += a.Addr + "(" + a.ServerName + ")"
-			} else {
-				s += a.Addr
-			}
-			if i != len(addrs)-1 {
-				s += " "
-			}
-		}
-		channelz.AddTraceEvent(ccr.cc.channelzID, &channelz.TraceEventDesc{
-			Desc:     fmt.Sprintf("Resolver returns a non-empty address list (previous one was empty) %q", s),
-			Severity: channelz.CtINFO,
-		})
+func (ccr *ccResolverWrapper) addChannelzTraceEvent(s resolver.State) {
+	var updates []string
+	oldSC, oldOK := ccr.curState.ServiceConfig.(*ServiceConfig)
+	newSC, newOK := s.ServiceConfig.(*ServiceConfig)
+	if oldOK != newOK || (oldOK && newOK && oldSC.rawJSONString != newSC.rawJSONString) {
+		updates = append(updates, "service config updated")
 	}
-	ccr.lastAddressesCount = len(addrs)
+	if len(ccr.curState.Addresses) > 0 && len(s.Addresses) == 0 {
+		updates = append(updates, "resolver returned an empty address list")
+	} else if len(ccr.curState.Addresses) == 0 && len(s.Addresses) > 0 {
+		updates = append(updates, "resolver returned new addresses")
+	}
+	channelz.AddTraceEvent(ccr.cc.channelzID, &channelz.TraceEventDesc{
+		Desc:     fmt.Sprintf("Resolver state updated: %+v (%v)", s, strings.Join(updates, "; ")),
+		Severity: channelz.CtINFO,
+	})
 }