build: go 1.24

We were running behind and there were quite some deprecations to update.
This was mostly in the upstream copy/pasta package but seems quite
minimal.

vendor/google.golang.org/grpc/balancer_wrapper.go

@@ -26,6 +26,7 @@ import (
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/experimental/stats"
 	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/balancer/gracefulswitch"
 	"google.golang.org/grpc/internal/channelz"
@@ -34,7 +35,15 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-var setConnectedAddress = internal.SetConnectedAddress.(func(*balancer.SubConnState, resolver.Address))
+var (
+	setConnectedAddress = internal.SetConnectedAddress.(func(*balancer.SubConnState, resolver.Address))
+	// noOpRegisterHealthListenerFn is used when client side health checking is
+	// disabled. It sends a single READY update on the registered listener.
+	noOpRegisterHealthListenerFn = func(_ context.Context, listener func(balancer.SubConnState)) func() {
+		listener(balancer.SubConnState{ConnectivityState: connectivity.Ready})
+		return func() {}
+	}
+)
 
 // ccBalancerWrapper sits between the ClientConn and the Balancer.
 //
@@ -51,6 +60,7 @@ var setConnectedAddress = internal.SetConnectedAddress.(func(*balancer.SubConnSt
 // It uses the gracefulswitch.Balancer internally to ensure that balancer
 // switches happen in a graceful manner.
 type ccBalancerWrapper struct {
+	internal.EnforceClientConnEmbedding
 	// The following fields are initialized when the wrapper is created and are
 	// read-only afterwards, and therefore can be accessed without a mutex.
 	cc               *ClientConn
@@ -84,7 +94,6 @@ func newCCBalancerWrapper(cc *ClientConn) *ccBalancerWrapper {
 			CustomUserAgent: cc.dopts.copts.UserAgent,
 			ChannelzParent:  cc.channelz,
 			Target:          cc.parsedTarget,
-			MetricsRecorder: cc.metricsRecorderList,
 		},
 		serializer:       grpcsync.NewCallbackSerializer(ctx),
 		serializerCancel: cancel,
@@ -93,6 +102,10 @@ func newCCBalancerWrapper(cc *ClientConn) *ccBalancerWrapper {
 	return ccb
 }
 
+func (ccb *ccBalancerWrapper) MetricsRecorder() stats.MetricsRecorder {
+	return ccb.cc.metricsRecorderList
+}
+
 // updateClientConnState is invoked by grpc to push a ClientConnState update to
 // the underlying balancer.  This is always executed from the serializer, so
 // it is safe to call into the balancer here.
@@ -277,10 +290,17 @@ type healthData struct {
 	// to the LB policy. This is stored to avoid sending updates when the
 	// SubConn has already exited connectivity state READY.
 	connectivityState connectivity.State
+	// closeHealthProducer stores function to close the ref counted health
+	// producer. The health producer is automatically closed when the SubConn
+	// state changes.
+	closeHealthProducer func()
 }
 
 func newHealthData(s connectivity.State) *healthData {
-	return &healthData{connectivityState: s}
+	return &healthData{
+		connectivityState:   s,
+		closeHealthProducer: func() {},
+	}
 }
 
 // updateState is invoked by grpc to push a subConn state update to the
@@ -400,7 +420,7 @@ func (acbw *acBalancerWrapper) GetOrBuildProducer(pb balancer.ProducerBuilder) (
 		}
 		acbw.producersMu.Unlock()
 	}
-	return pData.producer, grpcsync.OnceFunc(unref)
+	return pData.producer, sync.OnceFunc(unref)
 }
 
 func (acbw *acBalancerWrapper) closeProducers() {
@@ -413,6 +433,37 @@ func (acbw *acBalancerWrapper) closeProducers() {
 	}
 }
 
+// healthProducerRegisterFn is a type alias for the health producer's function
+// for registering listeners.
+type healthProducerRegisterFn = func(context.Context, balancer.SubConn, string, func(balancer.SubConnState)) func()
+
+// healthListenerRegFn returns a function to register a listener for health
+// updates. If client side health checks are disabled, the registered listener
+// will get a single READY (raw connectivity state) update.
+//
+// Client side health checking is enabled when all the following
+// conditions are satisfied:
+// 1. Health checking is not disabled using the dial option.
+// 2. The health package is imported.
+// 3. The health check config is present in the service config.
+func (acbw *acBalancerWrapper) healthListenerRegFn() func(context.Context, func(balancer.SubConnState)) func() {
+	if acbw.ccb.cc.dopts.disableHealthCheck {
+		return noOpRegisterHealthListenerFn
+	}
+	regHealthLisFn := internal.RegisterClientHealthCheckListener
+	if regHealthLisFn == nil {
+		// The health package is not imported.
+		return noOpRegisterHealthListenerFn
+	}
+	cfg := acbw.ac.cc.healthCheckConfig()
+	if cfg == nil {
+		return noOpRegisterHealthListenerFn
+	}
+	return func(ctx context.Context, listener func(balancer.SubConnState)) func() {
+		return regHealthLisFn.(healthProducerRegisterFn)(ctx, acbw, cfg.ServiceName, listener)
+	}
+}
+
 // RegisterHealthListener accepts a health listener from the LB policy. It sends
 // updates to the health listener as long as the SubConn's connectivity state
 // doesn't change and a new health listener is not registered. To invalidate
@@ -421,6 +472,7 @@ func (acbw *acBalancerWrapper) closeProducers() {
 func (acbw *acBalancerWrapper) RegisterHealthListener(listener func(balancer.SubConnState)) {
 	acbw.healthMu.Lock()
 	defer acbw.healthMu.Unlock()
+	acbw.healthData.closeHealthProducer()
 	// listeners should not be registered when the connectivity state
 	// isn't Ready. This may happen when the balancer registers a listener
 	// after the connectivityState is updated, but before it is notified
@@ -436,6 +488,7 @@ func (acbw *acBalancerWrapper) RegisterHealthListener(listener func(balancer.Sub
 		return
 	}
 
+	registerFn := acbw.healthListenerRegFn()
 	acbw.ccb.serializer.TrySchedule(func(ctx context.Context) {
 		if ctx.Err() != nil || acbw.ccb.balancer == nil {
 			return
@@ -443,10 +496,25 @@ func (acbw *acBalancerWrapper) RegisterHealthListener(listener func(balancer.Sub
 		// Don't send updates if a new listener is registered.
 		acbw.healthMu.Lock()
 		defer acbw.healthMu.Unlock()
-		curHD := acbw.healthData
-		if curHD != hd {
+		if acbw.healthData != hd {
 			return
 		}
-		listener(balancer.SubConnState{ConnectivityState: connectivity.Ready})
+		// Serialize the health updates from the health producer with
+		// other calls into the LB policy.
+		listenerWrapper := func(scs balancer.SubConnState) {
+			acbw.ccb.serializer.TrySchedule(func(ctx context.Context) {
+				if ctx.Err() != nil || acbw.ccb.balancer == nil {
+					return
+				}
+				acbw.healthMu.Lock()
+				defer acbw.healthMu.Unlock()
+				if acbw.healthData != hd {
+					return
+				}
+				listener(scs)
+			})
+		}
+
+		hd.closeHealthProducer = registerFn(ctx, listenerWrapper)
 	})
 }