2 files changed, 51 insertions, 18 deletions

diff --git a/vendor/google.golang.org/grpc/balancer/balancer.go b/vendor/google.golang.org/grpc/balancer/balancer.go
index 8f00523c0..b6377f445 100644
--- a/vendor/google.golang.org/grpc/balancer/balancer.go
+++ b/vendor/google.golang.org/grpc/balancer/balancer.go
@@ -105,8 +105,8 @@ type SubConn interface {
 	//
 	// This will trigger a state transition for the SubConn.
 	//
-	// Deprecated: This method is now part of the ClientConn interface and will
-	// eventually be removed from here.
+	// Deprecated: this method will be removed.  Create new SubConns for new
+	// addresses instead.
 	UpdateAddresses([]resolver.Address)
 	// Connect starts the connecting for this SubConn.
 	Connect()
@@ -115,6 +115,13 @@ type SubConn interface {
 	// creates a new one and returns it.  Returns a close function which must
 	// be called when the Producer is no longer needed.
 	GetOrBuildProducer(ProducerBuilder) (p Producer, close func())
+	// Shutdown shuts down the SubConn gracefully.  Any started RPCs will be
+	// allowed to complete.  No future calls should be made on the SubConn.
+	// One final state update will be delivered to the StateListener (or
+	// UpdateSubConnState; deprecated) with ConnectivityState of Shutdown to
+	// indicate the shutdown operation.  This may be delivered before
+	// in-progress RPCs are complete and the actual connection is closed.
+	Shutdown()
 }
 
 // NewSubConnOptions contains options to create new SubConn.
@@ -129,6 +136,11 @@ type NewSubConnOptions struct {
 	// HealthCheckEnabled indicates whether health check service should be
 	// enabled on this SubConn
 	HealthCheckEnabled bool
+	// StateListener is called when the state of the subconn changes.  If nil,
+	// Balancer.UpdateSubConnState will be called instead.  Will never be
+	// invoked until after Connect() is called on the SubConn created with
+	// these options.
+	StateListener func(SubConnState)
 }
 
 // State contains the balancer's state relevant to the gRPC ClientConn.
@@ -150,16 +162,24 @@ type ClientConn interface {
 	// NewSubConn is called by balancer to create a new SubConn.
 	// It doesn't block and wait for the connections to be established.
 	// Behaviors of the SubConn can be controlled by options.
+	//
+	// Deprecated: please be aware that in a future version, SubConns will only
+	// support one address per SubConn.
 	NewSubConn([]resolver.Address, NewSubConnOptions) (SubConn, error)
 	// RemoveSubConn removes the SubConn from ClientConn.
 	// The SubConn will be shutdown.
+	//
+	// Deprecated: use SubConn.Shutdown instead.
 	RemoveSubConn(SubConn)
 	// UpdateAddresses updates the addresses used in the passed in SubConn.
 	// gRPC checks if the currently connected address is still in the new list.
 	// If so, the connection will be kept. Else, the connection will be
 	// gracefully closed, and a new connection will be created.
 	//
-	// This will trigger a state transition for the SubConn.
+	// This may trigger a state transition for the SubConn.
+	//
+	// Deprecated: this method will be removed.  Create new SubConns for new
+	// addresses instead.
 	UpdateAddresses(SubConn, []resolver.Address)
 
 	// UpdateState notifies gRPC that the balancer's internal state has
@@ -250,7 +270,7 @@ type DoneInfo struct {
 	// trailing metadata.
 	//
 	// The only supported type now is *orca_v3.LoadReport.
-	ServerLoad interface{}
+	ServerLoad any
 }
 
 var (
@@ -343,9 +363,13 @@ type Balancer interface {
 	ResolverError(error)
 	// UpdateSubConnState is called by gRPC when the state of a SubConn
 	// changes.
+	//
+	// Deprecated: Use NewSubConnOptions.StateListener when creating the
+	// SubConn instead.
 	UpdateSubConnState(SubConn, SubConnState)
-	// Close closes the balancer. The balancer is not required to call
-	// ClientConn.RemoveSubConn for its existing SubConns.
+	// Close closes the balancer. The balancer is not currently required to
+	// call SubConn.Shutdown for its existing SubConns; however, this will be
+	// required in a future release, so it is recommended.
 	Close()
 }
 
@@ -390,15 +414,14 @@ var ErrBadResolverState = errors.New("bad resolver state")
 type ProducerBuilder interface {
 	// Build creates a Producer.  The first parameter is always a
 	// grpc.ClientConnInterface (a type to allow creating RPCs/streams on the
-	// associated SubConn), but is declared as interface{} to avoid a
-	// dependency cycle.  Should also return a close function that will be
-	// called when all references to the Producer have been given up.
-	Build(grpcClientConnInterface interface{}) (p Producer, close func())
+	// associated SubConn), but is declared as `any` to avoid a dependency
+	// cycle.  Should also return a close function that will be called when all
+	// references to the Producer have been given up.
+	Build(grpcClientConnInterface any) (p Producer, close func())
 }
 
 // A Producer is a type shared among potentially many consumers.  It is
 // associated with a SubConn, and an implementation will typically contain
 // other methods to provide additional functionality, e.g. configuration or
 // subscription registration.
-type Producer interface {
-}
+type Producer any
diff --git a/vendor/google.golang.org/grpc/balancer/base/balancer.go b/vendor/google.golang.org/grpc/balancer/base/balancer.go
index 3929c26d3..a7f1eeec8 100644
--- a/vendor/google.golang.org/grpc/balancer/base/balancer.go
+++ b/vendor/google.golang.org/grpc/balancer/base/balancer.go
@@ -105,7 +105,12 @@ func (b *baseBalancer) UpdateClientConnState(s balancer.ClientConnState) error {
 		addrsSet.Set(a, nil)
 		if _, ok := b.subConns.Get(a); !ok {
 			// a is a new address (not existing in b.subConns).
-			sc, err := b.cc.NewSubConn([]resolver.Address{a}, balancer.NewSubConnOptions{HealthCheckEnabled: b.config.HealthCheck})
+			var sc balancer.SubConn
+			opts := balancer.NewSubConnOptions{
+				HealthCheckEnabled: b.config.HealthCheck,
+				StateListener:      func(scs balancer.SubConnState) { b.updateSubConnState(sc, scs) },
+			}
+			sc, err := b.cc.NewSubConn([]resolver.Address{a}, opts)
 			if err != nil {
 				logger.Warningf("base.baseBalancer: failed to create new SubConn: %v", err)
 				continue
@@ -121,10 +126,10 @@ func (b *baseBalancer) UpdateClientConnState(s balancer.ClientConnState) error {
 		sc := sci.(balancer.SubConn)
 		// a was removed by resolver.
 		if _, ok := addrsSet.Get(a); !ok {
-			b.cc.RemoveSubConn(sc)
+			sc.Shutdown()
 			b.subConns.Delete(a)
 			// Keep the state of this sc in b.scStates until sc's state becomes Shutdown.
-			// The entry will be deleted in UpdateSubConnState.
+			// The entry will be deleted in updateSubConnState.
 		}
 	}
 	// If resolver state contains no addresses, return an error so ClientConn
@@ -177,7 +182,12 @@ func (b *baseBalancer) regeneratePicker() {
 	b.picker = b.pickerBuilder.Build(PickerBuildInfo{ReadySCs: readySCs})
 }
 
+// UpdateSubConnState is a nop because a StateListener is always set in NewSubConn.
 func (b *baseBalancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	logger.Errorf("base.baseBalancer: UpdateSubConnState(%v, %+v) called unexpectedly", sc, state)
+}
+
+func (b *baseBalancer) updateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
 	s := state.ConnectivityState
 	if logger.V(2) {
 		logger.Infof("base.baseBalancer: handle SubConn state change: %p, %v", sc, s)
@@ -204,8 +214,8 @@ func (b *baseBalancer) UpdateSubConnState(sc balancer.SubConn, state balancer.Su
 	case connectivity.Idle:
 		sc.Connect()
 	case connectivity.Shutdown:
-		// When an address was removed by resolver, b called RemoveSubConn but
-		// kept the sc's state in scStates. Remove state for this sc here.
+		// When an address was removed by resolver, b called Shutdown but kept
+		// the sc's state in scStates. Remove state for this sc here.
 		delete(b.scStates, sc)
 	case connectivity.TransientFailure:
 		// Save error to be reported via picker.
@@ -226,7 +236,7 @@ func (b *baseBalancer) UpdateSubConnState(sc balancer.SubConn, state balancer.Su
 }
 
 // Close is a nop because base balancer doesn't have internal state to clean up,
-// and it doesn't need to call RemoveSubConn for the SubConns.
+// and it doesn't need to call Shutdown for the SubConns.
 func (b *baseBalancer) Close() {
 }