rebase: bump google.golang.org/grpc from 1.55.0 to 1.56.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.55.0 to 1.56.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.55.0...v1.56.0)

---
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/binarylog/binarylog.go

@@ -32,6 +32,9 @@ var grpclogLogger = grpclog.Component("binarylog")
 
 // Logger specifies MethodLoggers for method names with a Log call that
 // takes a context.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 type Logger interface {
 	GetMethodLogger(methodName string) MethodLogger
 }

vendor/google.golang.org/grpc/internal/binarylog/method_logger.go

@@ -49,6 +49,9 @@ func (g *callIDGenerator) reset() {
 var idGen callIDGenerator
 
 // MethodLogger is the sub-logger for each method.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 type MethodLogger interface {
 	Log(context.Context, LogEntryConfig)
 }
@@ -65,6 +68,9 @@ type TruncatingMethodLogger struct {
 }
 
 // NewTruncatingMethodLogger returns a new truncating method logger.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 func NewTruncatingMethodLogger(h, m uint64) *TruncatingMethodLogger {
 	return &TruncatingMethodLogger{
 		headerMaxLen:  h,
@@ -145,6 +151,9 @@ func (ml *TruncatingMethodLogger) truncateMessage(msgPb *binlogpb.Message) (trun
 }
 
 // LogEntryConfig represents the configuration for binary log entry.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 type LogEntryConfig interface {
 	toProto() *binlogpb.GrpcLogEntry
 }

vendor/google.golang.org/grpc/internal/buffer/unbounded.go

@@ -35,6 +35,7 @@ import "sync"
 // internal/transport/transport.go for an example of this.
 type Unbounded struct {
 	c       chan interface{}
+	closed  bool
 	mu      sync.Mutex
 	backlog []interface{}
 }
@@ -47,16 +48,18 @@ func NewUnbounded() *Unbounded {
 // Put adds t to the unbounded buffer.
 func (b *Unbounded) Put(t interface{}) {
 	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closed {
+		return
+	}
 	if len(b.backlog) == 0 {
 		select {
 		case b.c <- t:
-			b.mu.Unlock()
 			return
 		default:
 		}
 	}
 	b.backlog = append(b.backlog, t)
-	b.mu.Unlock()
 }
 
 // Load sends the earliest buffered data, if any, onto the read channel
@@ -64,6 +67,10 @@ func (b *Unbounded) Put(t interface{}) {
 // value from the read channel.
 func (b *Unbounded) Load() {
 	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closed {
+		return
+	}
 	if len(b.backlog) > 0 {
 		select {
 		case b.c <- b.backlog[0]:
@@ -72,7 +79,6 @@ func (b *Unbounded) Load() {
 		default:
 		}
 	}
-	b.mu.Unlock()
 }
 
 // Get returns a read channel on which values added to the buffer, via Put(),
@@ -80,6 +86,20 @@ func (b *Unbounded) Load() {
 //
 // Upon reading a value from this channel, users are expected to call Load() to
 // send the next buffered value onto the channel if there is any.
+//
+// If the unbounded buffer is closed, the read channel returned by this method
+// is closed.
 func (b *Unbounded) Get() <-chan interface{} {
 	return b.c
 }
+
+// Close closes the unbounded buffer.
+func (b *Unbounded) Close() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closed {
+		return
+	}
+	b.closed = true
+	close(b.c)
+}

vendor/google.golang.org/grpc/internal/envconfig/envconfig.go

@@ -36,6 +36,10 @@ var (
 	// "GRPC_RING_HASH_CAP".  This does not override the default bounds
 	// checking which NACKs configs specifying ring sizes > 8*1024*1024 (~8M).
 	RingHashCap = uint64FromEnv("GRPC_RING_HASH_CAP", 4096, 1, 8*1024*1024)
+	// PickFirstLBConfig is set if we should support configuration of the
+	// pick_first LB policy, which can be enabled by setting the environment
+	// variable "GRPC_EXPERIMENTAL_PICKFIRST_LB_CONFIG" to "true".
+	PickFirstLBConfig = boolFromEnv("GRPC_EXPERIMENTAL_PICKFIRST_LB_CONFIG", false)
 )
 
 func boolFromEnv(envVar string, def bool) bool {

vendor/google.golang.org/grpc/internal/envconfig/observability.go

@@ -28,9 +28,15 @@ const (
 var (
 	// ObservabilityConfig is the json configuration for the gcp/observability
 	// package specified directly in the envObservabilityConfig env var.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	ObservabilityConfig = os.Getenv(envObservabilityConfig)
 	// ObservabilityConfigFile is the json configuration for the
 	// gcp/observability specified in a file with the location specified in
 	// envObservabilityConfigFile env var.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	ObservabilityConfigFile = os.Getenv(envObservabilityConfigFile)
 )

vendor/google.golang.org/grpc/internal/envconfig/xds.go

@@ -61,11 +61,10 @@ var (
 	// have a brand new API on the server-side and users explicitly need to use
 	// the new API to get security integration on the server.
 	XDSClientSideSecurity = boolFromEnv("GRPC_XDS_EXPERIMENTAL_SECURITY_SUPPORT", true)
-	// XDSAggregateAndDNS indicates whether processing of aggregated cluster
-	// and DNS cluster is enabled, which can be enabled by setting the
-	// environment variable
-	// "GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER" to
-	// "true".
+	// XDSAggregateAndDNS indicates whether processing of aggregated cluster and
+	// DNS cluster is enabled, which can be disabled by setting the environment
+	// variable "GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER"
+	// to "false".
 	XDSAggregateAndDNS = boolFromEnv("GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER", true)
 
 	// XDSRBAC indicates whether xDS configured RBAC HTTP Filter is enabled,
@@ -82,11 +81,15 @@ var (
 	XDSFederation = boolFromEnv("GRPC_EXPERIMENTAL_XDS_FEDERATION", true)
 
 	// XDSRLS indicates whether processing of Cluster Specifier plugins and
-	// support for the RLS CLuster Specifier is enabled, which can be enabled by
+	// support for the RLS CLuster Specifier is enabled, which can be disabled by
 	// setting the environment variable "GRPC_EXPERIMENTAL_XDS_RLS_LB" to
-	// "true".
-	XDSRLS = boolFromEnv("GRPC_EXPERIMENTAL_XDS_RLS_LB", false)
+	// "false".
+	XDSRLS = boolFromEnv("GRPC_EXPERIMENTAL_XDS_RLS_LB", true)
 
 	// C2PResolverTestOnlyTrafficDirectorURI is the TD URI for testing.
 	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv("GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI")
+	// XDSCustomLBPolicy indicates whether Custom LB Policies are enabled, which
+	// can be disabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_XDS_CUSTOM_LB_CONFIG" to "false".
+	XDSCustomLBPolicy = boolFromEnv("GRPC_EXPERIMENTAL_XDS_CUSTOM_LB_CONFIG", true)
 )

vendor/google.golang.org/grpc/internal/grpcrand/grpcrand.go

@@ -72,3 +72,17 @@ func Uint64() uint64 {
 	defer mu.Unlock()
 	return r.Uint64()
 }
+
+// Uint32 implements rand.Uint32 on the grpcrand global source.
+func Uint32() uint32 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Uint32()
+}
+
+// Shuffle implements rand.Shuffle on the grpcrand global source.
+var Shuffle = func(n int, f func(int, int)) {
+	mu.Lock()
+	defer mu.Unlock()
+	r.Shuffle(n, f)
+}

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

@@ -20,6 +20,7 @@ package grpcsync
 
 import (
 	"context"
+	"sync"
 
 	"google.golang.org/grpc/internal/buffer"
 )
@@ -31,15 +32,26 @@ import (
 //
 // This type is safe for concurrent access.
 type CallbackSerializer struct {
+	// 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{}
+
 	callbacks *buffer.Unbounded
+	closedMu  sync.Mutex
+	closed    bool
 }
 
 // NewCallbackSerializer returns a new CallbackSerializer instance. The provided
 // context will be passed to the scheduled callbacks. Users should cancel the
 // provided context to shutdown the CallbackSerializer. It is guaranteed that no
-// callbacks will be executed once this context is canceled.
+// 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{callbacks: buffer.NewUnbounded()}
+	t := &CallbackSerializer{
+		Done:      make(chan struct{}),
+		callbacks: buffer.NewUnbounded(),
+	}
 	go t.run(ctx)
 	return t
 }
@@ -48,18 +60,60 @@ func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
 //
 // Callbacks are expected to honor the context when performing any blocking
 // operations, and should return early when the context is canceled.
-func (t *CallbackSerializer) Schedule(f func(ctx context.Context)) {
+//
+// 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()
+
+	if t.closed {
+		return false
+	}
 	t.callbacks.Put(f)
+	return true
 }
 
 func (t *CallbackSerializer) run(ctx context.Context) {
+	var backlog []func(context.Context)
+
+	defer close(t.Done)
 	for ctx.Err() == nil {
 		select {
 		case <-ctx.Done():
-			return
-		case callback := <-t.callbacks.Get():
+			// 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():
+			if !ok {
+				return
+			}
 			t.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()
+	for _, b := range backlog {
+		b(ctx)
+	}
+}
+
+func (t *CallbackSerializer) fetchPendingCallbacks() []func(context.Context) {
+	var backlog []func(context.Context)
+	for {
+		select {
+		case b := <-t.callbacks.Get():
+			backlog = append(backlog, b.(func(context.Context)))
+			t.callbacks.Load()
+		default:
+			return backlog
+		}
+	}
 }

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

@@ -60,6 +60,9 @@ var (
 	GetServerCredentials interface{} // func (*grpc.Server) credentials.TransportCredentials
 	// CanonicalString returns the canonical string of the code defined here:
 	// https://github.com/grpc/grpc/blob/master/doc/statuscodes.md.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	CanonicalString interface{} // func (codes.Code) string
 	// DrainServerTransports initiates a graceful close of existing connections
 	// on a gRPC server accepted on the provided listener address. An
@@ -69,20 +72,35 @@ var (
 	// AddGlobalServerOptions adds an array of ServerOption that will be
 	// effective globally for newly created servers. The priority will be: 1.
 	// user-provided; 2. this method; 3. default values.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	AddGlobalServerOptions interface{} // func(opt ...ServerOption)
 	// ClearGlobalServerOptions clears the array of extra ServerOption. This
 	// method is useful in testing and benchmarking.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	ClearGlobalServerOptions func()
 	// AddGlobalDialOptions adds an array of DialOption that will be effective
 	// globally for newly created client channels. The priority will be: 1.
 	// user-provided; 2. this method; 3. default values.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	AddGlobalDialOptions interface{} // func(opt ...DialOption)
 	// DisableGlobalDialOptions returns a DialOption that prevents the
 	// ClientConn from applying the global DialOptions (set via
 	// AddGlobalDialOptions).
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	DisableGlobalDialOptions interface{} // func() grpc.DialOption
 	// ClearGlobalDialOptions clears the array of extra DialOption. This
 	// method is useful in testing and benchmarking.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	ClearGlobalDialOptions func()
 	// JoinDialOptions combines the dial options passed as arguments into a
 	// single dial option.
@@ -93,9 +111,15 @@ var (
 
 	// WithBinaryLogger returns a DialOption that specifies the binary logger
 	// for a ClientConn.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	WithBinaryLogger interface{} // func(binarylog.Logger) grpc.DialOption
 	// BinaryLogger returns a ServerOption that can set the binary logger for a
 	// server.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	BinaryLogger interface{} // func(binarylog.Logger) grpc.ServerOption
 
 	// NewXDSResolverWithConfigForTesting creates a new xds resolver builder using

vendor/google.golang.org/grpc/internal/serviceconfig/duration.go

@@ -0,0 +1,130 @@
+/*
+ *
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package serviceconfig
+
+import (
+	"encoding/json"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Duration defines JSON marshal and unmarshal methods to conform to the
+// protobuf JSON spec defined [here].
+//
+// [here]: https://protobuf.dev/reference/protobuf/google.protobuf/#duration
+type Duration time.Duration
+
+func (d Duration) String() string {
+	return fmt.Sprint(time.Duration(d))
+}
+
+// MarshalJSON converts from d to a JSON string output.
+func (d Duration) MarshalJSON() ([]byte, error) {
+	ns := time.Duration(d).Nanoseconds()
+	sec := ns / int64(time.Second)
+	ns = ns % int64(time.Second)
+
+	var sign string
+	if sec < 0 || ns < 0 {
+		sign, sec, ns = "-", -1*sec, -1*ns
+	}
+
+	// Generated output always contains 0, 3, 6, or 9 fractional digits,
+	// depending on required precision.
+	str := fmt.Sprintf("%s%d.%09d", sign, sec, ns)
+	str = strings.TrimSuffix(str, "000")
+	str = strings.TrimSuffix(str, "000")
+	str = strings.TrimSuffix(str, ".000")
+	return []byte(fmt.Sprintf("\"%ss\"", str)), nil
+}
+
+// UnmarshalJSON unmarshals b as a duration JSON string into d.
+func (d *Duration) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	if !strings.HasSuffix(s, "s") {
+		return fmt.Errorf("malformed duration %q: missing seconds unit", s)
+	}
+	neg := false
+	if s[0] == '-' {
+		neg = true
+		s = s[1:]
+	}
+	ss := strings.SplitN(s[:len(s)-1], ".", 3)
+	if len(ss) > 2 {
+		return fmt.Errorf("malformed duration %q: too many decimals", s)
+	}
+	// hasDigits is set if either the whole or fractional part of the number is
+	// present, since both are optional but one is required.
+	hasDigits := false
+	var sec, ns int64
+	if len(ss[0]) > 0 {
+		var err error
+		if sec, err = strconv.ParseInt(ss[0], 10, 64); err != nil {
+			return fmt.Errorf("malformed duration %q: %v", s, err)
+		}
+		// Maximum seconds value per the durationpb spec.
+		const maxProtoSeconds = 315_576_000_000
+		if sec > maxProtoSeconds {
+			return fmt.Errorf("out of range: %q", s)
+		}
+		hasDigits = true
+	}
+	if len(ss) == 2 && len(ss[1]) > 0 {
+		if len(ss[1]) > 9 {
+			return fmt.Errorf("malformed duration %q: too many digits after decimal", s)
+		}
+		var err error
+		if ns, err = strconv.ParseInt(ss[1], 10, 64); err != nil {
+			return fmt.Errorf("malformed duration %q: %v", s, err)
+		}
+		for i := 9; i > len(ss[1]); i-- {
+			ns *= 10
+		}
+		hasDigits = true
+	}
+	if !hasDigits {
+		return fmt.Errorf("malformed duration %q: contains no numbers", s)
+	}
+
+	if neg {
+		sec *= -1
+		ns *= -1
+	}
+
+	// Maximum/minimum seconds/nanoseconds representable by Go's time.Duration.
+	const maxSeconds = math.MaxInt64 / int64(time.Second)
+	const maxNanosAtMaxSeconds = math.MaxInt64 % int64(time.Second)
+	const minSeconds = math.MinInt64 / int64(time.Second)
+	const minNanosAtMinSeconds = math.MinInt64 % int64(time.Second)
+
+	if sec > maxSeconds || (sec == maxSeconds && ns >= maxNanosAtMaxSeconds) {
+		*d = Duration(math.MaxInt64)
+	} else if sec < minSeconds || (sec == minSeconds && ns <= minNanosAtMinSeconds) {
+		*d = Duration(math.MinInt64)
+	} else {
+		*d = Duration(sec*int64(time.Second) + ns)
+	}
+	return nil
+}

vendor/google.golang.org/grpc/internal/transport/handler_server.go

@@ -453,7 +453,7 @@ func (ht *serverHandlerTransport) IncrMsgSent() {}
 
 func (ht *serverHandlerTransport) IncrMsgRecv() {}
 
-func (ht *serverHandlerTransport) Drain() {
+func (ht *serverHandlerTransport) Drain(debugData string) {
 	panic("Drain() is not implemented")
 }
 

vendor/google.golang.org/grpc/internal/transport/http2_client.go

@@ -1337,7 +1337,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 
 // setGoAwayReason sets the value of t.goAwayReason based
 // on the GoAway frame received.
-// It expects a lock on transport's mutext to be held by
+// It expects a lock on transport's mutex to be held by
 // the caller.
 func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
 	t.goAwayReason = GoAwayNoReason

vendor/google.golang.org/grpc/internal/transport/http2_server.go

@@ -1166,12 +1166,12 @@ func (t *http2Server) keepalive() {
 			if val <= 0 {
 				// The connection has been idle for a duration of keepalive.MaxConnectionIdle or more.
 				// Gracefully close the connection.
-				t.Drain()
+				t.Drain("max_idle")
 				return
 			}
 			idleTimer.Reset(val)
 		case <-ageTimer.C:
-			t.Drain()
+			t.Drain("max_age")
 			ageTimer.Reset(t.kp.MaxConnectionAgeGrace)
 			select {
 			case <-ageTimer.C:
@@ -1318,14 +1318,14 @@ func (t *http2Server) RemoteAddr() net.Addr {
 	return t.remoteAddr
 }
 
-func (t *http2Server) Drain() {
+func (t *http2Server) Drain(debugData string) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	if t.drainEvent != nil {
 		return
 	}
 	t.drainEvent = grpcsync.NewEvent()
-	t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte{}, headsUp: true})
+	t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte(debugData), headsUp: true})
 }
 
 var goAwayPing = &ping{data: [8]byte{1, 6, 1, 8, 0, 3, 3, 9}}
@@ -1367,7 +1367,7 @@ func (t *http2Server) outgoingGoAwayHandler(g *goAway) (bool, error) {
 	// originated before the GoAway reaches the client.
 	// After getting the ack or timer expiration send out another GoAway this
 	// time with an ID of the max stream server intends to process.
-	if err := t.framer.fr.WriteGoAway(math.MaxUint32, http2.ErrCodeNo, []byte{}); err != nil {
+	if err := t.framer.fr.WriteGoAway(math.MaxUint32, http2.ErrCodeNo, g.debugData); err != nil {
 		return false, err
 	}
 	if err := t.framer.fr.WritePing(false, goAwayPing.data); err != nil {

vendor/google.golang.org/grpc/internal/transport/transport.go

@@ -726,7 +726,7 @@ type ServerTransport interface {
 	RemoteAddr() net.Addr
 
 	// Drain notifies the client this ServerTransport stops accepting new RPCs.
-	Drain()
+	Drain(debugData string)
 
 	// IncrMsgSent increments the number of message sent through this transport.
 	IncrMsgSent()