rebase: Bump google.golang.org/grpc from 1.57.0 to 1.58.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.57.0 to 1.58.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.57.0...v1.58.0)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/google.golang.org/grpc/internal/grpcsync/callback_serializer.go

@@ -32,10 +32,10 @@ import (
 //
 // This type is safe for concurrent access.
 type CallbackSerializer struct {
-	// Done is closed once the serializer is shut down completely, i.e all
+	// done is closed once the serializer is shut down completely, i.e all
 	// scheduled callbacks are executed and the serializer has deallocated all
 	// its resources.
-	Done chan struct{}
+	done chan struct{}
 
 	callbacks *buffer.Unbounded
 	closedMu  sync.Mutex
@@ -48,12 +48,12 @@ type CallbackSerializer struct {
 // callbacks will be added once this context is canceled, and any pending un-run
 // callbacks will be executed before the serializer is shut down.
 func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
-	t := &CallbackSerializer{
-		Done:      make(chan struct{}),
+	cs := &CallbackSerializer{
+		done:      make(chan struct{}),
 		callbacks: buffer.NewUnbounded(),
 	}
-	go t.run(ctx)
-	return t
+	go cs.run(ctx)
+	return cs
 }
 
 // Schedule adds a callback to be scheduled after existing callbacks are run.
@@ -64,56 +64,62 @@ func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
 // Return value indicates if the callback was successfully added to the list of
 // callbacks to be executed by the serializer. It is not possible to add
 // callbacks once the context passed to NewCallbackSerializer is cancelled.
-func (t *CallbackSerializer) Schedule(f func(ctx context.Context)) bool {
-	t.closedMu.Lock()
-	defer t.closedMu.Unlock()
+func (cs *CallbackSerializer) Schedule(f func(ctx context.Context)) bool {
+	cs.closedMu.Lock()
+	defer cs.closedMu.Unlock()
 
-	if t.closed {
+	if cs.closed {
 		return false
 	}
-	t.callbacks.Put(f)
+	cs.callbacks.Put(f)
 	return true
 }
 
-func (t *CallbackSerializer) run(ctx context.Context) {
+func (cs *CallbackSerializer) run(ctx context.Context) {
 	var backlog []func(context.Context)
 
-	defer close(t.Done)
+	defer close(cs.done)
 	for ctx.Err() == nil {
 		select {
 		case <-ctx.Done():
 			// Do nothing here. Next iteration of the for loop will not happen,
 			// since ctx.Err() would be non-nil.
-		case callback, ok := <-t.callbacks.Get():
+		case callback, ok := <-cs.callbacks.Get():
 			if !ok {
 				return
 			}
-			t.callbacks.Load()
+			cs.callbacks.Load()
 			callback.(func(ctx context.Context))(ctx)
 		}
 	}
 
 	// Fetch pending callbacks if any, and execute them before returning from
-	// this method and closing t.Done.
-	t.closedMu.Lock()
-	t.closed = true
-	backlog = t.fetchPendingCallbacks()
-	t.callbacks.Close()
-	t.closedMu.Unlock()
+	// this method and closing cs.done.
+	cs.closedMu.Lock()
+	cs.closed = true
+	backlog = cs.fetchPendingCallbacks()
+	cs.callbacks.Close()
+	cs.closedMu.Unlock()
 	for _, b := range backlog {
 		b(ctx)
 	}
 }
 
-func (t *CallbackSerializer) fetchPendingCallbacks() []func(context.Context) {
+func (cs *CallbackSerializer) fetchPendingCallbacks() []func(context.Context) {
 	var backlog []func(context.Context)
 	for {
 		select {
-		case b := <-t.callbacks.Get():
+		case b := <-cs.callbacks.Get():
 			backlog = append(backlog, b.(func(context.Context)))
-			t.callbacks.Load()
+			cs.callbacks.Load()
 		default:
 			return backlog
 		}
 	}
 }
+
+// Done returns a channel that is closed after the context passed to
+// NewCallbackSerializer is canceled and all callbacks have been executed.
+func (cs *CallbackSerializer) Done() <-chan struct{} {
+	return cs.done
+}

vendor/google.golang.org/grpc/internal/grpcsync/pubsub.go

@@ -29,7 +29,7 @@ import (
 type Subscriber interface {
 	// OnMessage is invoked when a new message is published. Implementations
 	// must not block in this method.
-	OnMessage(msg interface{})
+	OnMessage(msg any)
 }
 
 // PubSub is a simple one-to-many publish-subscribe system that supports
@@ -40,25 +40,23 @@ type Subscriber interface {
 // subscribers interested in receiving these messages register a callback
 // via the Subscribe() method.
 //
-// Once a PubSub is stopped, no more messages can be published, and
-// it is guaranteed that no more subscriber callback will be invoked.
+// Once a PubSub is stopped, no more messages can be published, but any pending
+// published messages will be delivered to the subscribers.  Done may be used
+// to determine when all published messages have been delivered.
 type PubSub struct {
-	cs     *CallbackSerializer
-	cancel context.CancelFunc
+	cs *CallbackSerializer
 
 	// Access to the below fields are guarded by this mutex.
 	mu          sync.Mutex
-	msg         interface{}
+	msg         any
 	subscribers map[Subscriber]bool
-	stopped     bool
 }
 
-// NewPubSub returns a new PubSub instance.
-func NewPubSub() *PubSub {
-	ctx, cancel := context.WithCancel(context.Background())
+// NewPubSub returns a new PubSub instance.  Users should cancel the
+// provided context to shutdown the PubSub.
+func NewPubSub(ctx context.Context) *PubSub {
 	return &PubSub{
 		cs:          NewCallbackSerializer(ctx),
-		cancel:      cancel,
 		subscribers: map[Subscriber]bool{},
 	}
 }
@@ -75,10 +73,6 @@ func (ps *PubSub) Subscribe(sub Subscriber) (cancel func()) {
 	ps.mu.Lock()
 	defer ps.mu.Unlock()
 
-	if ps.stopped {
-		return func() {}
-	}
-
 	ps.subscribers[sub] = true
 
 	if ps.msg != nil {
@@ -102,14 +96,10 @@ func (ps *PubSub) Subscribe(sub Subscriber) (cancel func()) {
 
 // Publish publishes the provided message to the PubSub, and invokes
 // callbacks registered by subscribers asynchronously.
-func (ps *PubSub) Publish(msg interface{}) {
+func (ps *PubSub) Publish(msg any) {
 	ps.mu.Lock()
 	defer ps.mu.Unlock()
 
-	if ps.stopped {
-		return
-	}
-
 	ps.msg = msg
 	for sub := range ps.subscribers {
 		s := sub
@@ -124,13 +114,8 @@ func (ps *PubSub) Publish(msg interface{}) {
 	}
 }
 
-// Stop shuts down the PubSub and releases any resources allocated by it.
-// It is guaranteed that no subscriber callbacks would be invoked once this
-// method returns.
-func (ps *PubSub) Stop() {
-	ps.mu.Lock()
-	defer ps.mu.Unlock()
-	ps.stopped = true
-
-	ps.cancel()
+// Done returns a channel that is closed after the context passed to NewPubSub
+// is canceled and all updates have been sent to subscribers.
+func (ps *PubSub) Done() <-chan struct{} {
+	return ps.cs.Done()
 }