From 9cf228b8a4f126e84eb62fc271d1b683703a61e5 Mon Sep 17 00:00:00 2001
From: "Mark D. Roth" <roth@google.com>
Date: Thu, 11 Jan 2024 17:47:26 -0800
Subject: [PATCH] [XdsClient] rename a bunch of internal classes, variables,
 and methods for clarity (#35531)

Closes #35531

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/35531 from markdroth:xds_client_cleanup 1b197cb90a0f8d21c9facccc583347f527898ee3
PiperOrigin-RevId: 597698967
---
 src/core/ext/xds/xds_client.cc | 602 ++++++++++++++++-----------------
 src/core/ext/xds/xds_client.h  |  32 +-
 2 files changed, 315 insertions(+), 319 deletions(-)

diff --git a/src/core/ext/xds/xds_client.cc b/src/core/ext/xds/xds_client.cc
index 7b125b771d2..f96bc95e5e3 100644
--- a/src/core/ext/xds/xds_client.cc
+++ b/src/core/ext/xds/xds_client.cc
@@ -70,10 +70,10 @@ TraceFlag grpc_xds_client_refcount_trace(false, "xds_client_refcount");
 // An xds call wrapper that can restart a call upon failure. Holds a ref to
 // the xds channel. The template parameter is the kind of wrapped xds call.
 template <typename T>
-class XdsClient::ChannelState::RetryableCall
+class XdsClient::XdsChannel::RetryableCall
     : public InternallyRefCounted<RetryableCall<T>> {
  public:
-  explicit RetryableCall(WeakRefCountedPtr<ChannelState> chand);
+  explicit RetryableCall(WeakRefCountedPtr<XdsChannel> xds_channel);
 
   // Disable thread-safety analysis because this method is called via
   // OrphanablePtr<>, but there's no way to pass the lock annotation
@@ -82,8 +82,8 @@ class XdsClient::ChannelState::RetryableCall
 
   void OnCallFinishedLocked() ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_);
 
-  T* calld() const { return calld_.get(); }
-  ChannelState* chand() const { return chand_.get(); }
+  T* call() const { return call_.get(); }
+  XdsChannel* xds_channel() const { return xds_channel_.get(); }
 
   bool IsCurrentCallOnChannel() const;
 
@@ -95,9 +95,9 @@ class XdsClient::ChannelState::RetryableCall
 
   // The wrapped xds call that talks to the xds server. It's instantiated
   // every time we start a new call. It's null during call retry backoff.
-  OrphanablePtr<T> calld_;
+  OrphanablePtr<T> call_;
   // The owning xds channel.
-  WeakRefCountedPtr<ChannelState> chand_;
+  WeakRefCountedPtr<XdsChannel> xds_channel_;
 
   // Retry state.
   BackOff backoff_;
@@ -108,17 +108,18 @@ class XdsClient::ChannelState::RetryableCall
 };
 
 // Contains an ADS call to the xds server.
-class XdsClient::ChannelState::AdsCallState
-    : public InternallyRefCounted<AdsCallState> {
+class XdsClient::XdsChannel::AdsCall : public InternallyRefCounted<AdsCall> {
  public:
   // The ctor and dtor should not be used directly.
-  explicit AdsCallState(RefCountedPtr<RetryableCall<AdsCallState>> parent);
+  explicit AdsCall(RefCountedPtr<RetryableCall<AdsCall>> retryable_call);
 
   void Orphan() override;
 
-  RetryableCall<AdsCallState>* parent() const { return parent_.get(); }
-  ChannelState* chand() const { return parent_->chand(); }
-  XdsClient* xds_client() const { return chand()->xds_client(); }
+  RetryableCall<AdsCall>* retryable_call() const {
+    return retryable_call_.get();
+  }
+  XdsChannel* xds_channel() const { return retryable_call_->xds_channel(); }
+  XdsClient* xds_client() const { return xds_channel()->xds_client(); }
   bool seen_response() const { return seen_response_; }
 
   void SubscribeLocked(const XdsResourceType* type, const XdsResourceName& name,
@@ -131,15 +132,7 @@ class XdsClient::ChannelState::AdsCallState
   bool HasSubscribedResources() const;
 
  private:
-  class AdsReadDelayHandle : public ReadDelayHandle {
-   public:
-    explicit AdsReadDelayHandle(RefCountedPtr<AdsCallState> ads_call_state)
-        : ads_call_state_(std::move(ads_call_state)) {}
-    ~AdsReadDelayHandle() override;
-
-   private:
-    RefCountedPtr<AdsCallState> ads_call_state_;
-  };
+  class AdsReadDelayHandle;
 
   class AdsResponseParser : public XdsApi::AdsResponseParserInterface {
    public:
@@ -155,8 +148,7 @@ class XdsClient::ChannelState::AdsCallState
       RefCountedPtr<ReadDelayHandle> read_delay_handle;
     };
 
-    explicit AdsResponseParser(AdsCallState* ads_call_state)
-        : ads_call_state_(ads_call_state) {}
+    explicit AdsResponseParser(AdsCall* ads_call) : ads_call_(ads_call) {}
 
     absl::Status ProcessAdsResponseFields(AdsResponseFields fields) override
         ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_);
@@ -172,9 +164,9 @@ class XdsClient::ChannelState::AdsCallState
     Result TakeResult() { return std::move(result_); }
 
    private:
-    XdsClient* xds_client() const { return ads_call_state_->xds_client(); }
+    XdsClient* xds_client() const { return ads_call_->xds_client(); }
 
-    AdsCallState* ads_call_state_;
+    AdsCall* ads_call_;
     const Timestamp update_time_ = Timestamp::Now();
     Result result_;
   };
@@ -197,10 +189,9 @@ class XdsClient::ChannelState::AdsCallState
       subscription_sent_ = true;
     }
 
-    void MaybeMarkSubscriptionSendComplete(
-        RefCountedPtr<AdsCallState> ads_calld)
+    void MaybeMarkSubscriptionSendComplete(RefCountedPtr<AdsCall> ads_call)
         ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_) {
-      if (subscription_sent_) MaybeStartTimer(std::move(ads_calld));
+      if (subscription_sent_) MaybeStartTimer(std::move(ads_call));
     }
 
     void MarkSeen() ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_) {
@@ -210,13 +201,13 @@ class XdsClient::ChannelState::AdsCallState
 
     void MaybeCancelTimer() ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_) {
       if (timer_handle_.has_value() &&
-          ads_calld_->xds_client()->engine()->Cancel(*timer_handle_)) {
+          ads_call_->xds_client()->engine()->Cancel(*timer_handle_)) {
         timer_handle_.reset();
       }
     }
 
    private:
-    void MaybeStartTimer(RefCountedPtr<AdsCallState> ads_calld)
+    void MaybeStartTimer(RefCountedPtr<AdsCall> ads_call)
         ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_) {
       // Don't start timer if we've already either seen the resource or
       // marked it as non-existing.
@@ -237,13 +228,13 @@ class XdsClient::ChannelState::AdsCallState
       // (a) we already have the resource and (b) the server may
       // optimize by not resending the resource that we already have.
       auto& authority_state =
-          ads_calld->xds_client()->authority_state_map_[name_.authority];
+          ads_call->xds_client()->authority_state_map_[name_.authority];
       ResourceState& state = authority_state.resource_map[type_][name_.key];
       if (state.resource != nullptr) return;
       // Start timer.
-      ads_calld_ = std::move(ads_calld);
-      timer_handle_ = ads_calld_->xds_client()->engine()->RunAfter(
-          ads_calld_->xds_client()->request_timeout_,
+      ads_call_ = std::move(ads_call);
+      timer_handle_ = ads_call_->xds_client()->engine()->RunAfter(
+          ads_call_->xds_client()->request_timeout_,
           [self = Ref(DEBUG_LOCATION, "timer")]() {
             ApplicationCallbackExecCtx callback_exec_ctx;
             ExecCtx exec_ctx;
@@ -256,32 +247,32 @@ class XdsClient::ChannelState::AdsCallState
         gpr_log(GPR_INFO,
                 "[xds_client %p] xds server %s: timeout obtaining resource "
                 "{type=%s name=%s} from xds server",
-                ads_calld_->xds_client(),
-                ads_calld_->chand()->server_.server_uri().c_str(),
+                ads_call_->xds_client(),
+                ads_call_->xds_channel()->server_.server_uri().c_str(),
                 std::string(type_->type_url()).c_str(),
                 XdsClient::ConstructFullXdsResourceName(
                     name_.authority, type_->type_url(), name_.key)
                     .c_str());
       }
       {
-        MutexLock lock(&ads_calld_->xds_client()->mu_);
+        MutexLock lock(&ads_call_->xds_client()->mu_);
         timer_handle_.reset();
         resource_seen_ = true;
         auto& authority_state =
-            ads_calld_->xds_client()->authority_state_map_[name_.authority];
+            ads_call_->xds_client()->authority_state_map_[name_.authority];
         ResourceState& state = authority_state.resource_map[type_][name_.key];
         state.meta.client_status = XdsApi::ResourceMetadata::DOES_NOT_EXIST;
-        ads_calld_->xds_client()->NotifyWatchersOnResourceDoesNotExist(
+        ads_call_->xds_client()->NotifyWatchersOnResourceDoesNotExist(
             state.watchers, ReadDelayHandle::NoWait());
       }
-      ads_calld_->xds_client()->work_serializer_.DrainQueue();
-      ads_calld_.reset();
+      ads_call_->xds_client()->work_serializer_.DrainQueue();
+      ads_call_.reset();
     }
 
     const XdsResourceType* type_;
     const XdsResourceName name_;
 
-    RefCountedPtr<AdsCallState> ads_calld_;
+    RefCountedPtr<AdsCall> ads_call_;
     // True if we have sent the initial subscription request for this
     // resource on this ADS stream.
     bool subscription_sent_ ABSL_GUARDED_BY(&XdsClient::mu_) = false;
@@ -296,19 +287,19 @@ class XdsClient::ChannelState::AdsCallState
   class StreamEventHandler
       : public XdsTransportFactory::XdsTransport::StreamingCall::EventHandler {
    public:
-    explicit StreamEventHandler(RefCountedPtr<AdsCallState> ads_calld)
-        : ads_calld_(std::move(ads_calld)) {}
+    explicit StreamEventHandler(RefCountedPtr<AdsCall> ads_call)
+        : ads_call_(std::move(ads_call)) {}
 
-    void OnRequestSent(bool ok) override { ads_calld_->OnRequestSent(ok); }
+    void OnRequestSent(bool ok) override { ads_call_->OnRequestSent(ok); }
     void OnRecvMessage(absl::string_view payload) override {
-      ads_calld_->OnRecvMessage(payload);
+      ads_call_->OnRecvMessage(payload);
     }
     void OnStatusReceived(absl::Status status) override {
-      ads_calld_->OnStatusReceived(std::move(status));
+      ads_call_->OnStatusReceived(std::move(status));
     }
 
    private:
-    RefCountedPtr<AdsCallState> ads_calld_;
+    RefCountedPtr<AdsCall> ads_call_;
   };
 
   struct ResourceTypeState {
@@ -337,9 +328,10 @@ class XdsClient::ChannelState::AdsCallState
       ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_);
 
   // The owning RetryableCall<>.
-  RefCountedPtr<RetryableCall<AdsCallState>> parent_;
+  RefCountedPtr<RetryableCall<AdsCall>> retryable_call_;
 
-  OrphanablePtr<XdsTransportFactory::XdsTransport::StreamingCall> call_;
+  OrphanablePtr<XdsTransportFactory::XdsTransport::StreamingCall>
+      streaming_call_;
 
   bool sent_initial_message_ = false;
   bool seen_response_ = false;
@@ -355,46 +347,45 @@ class XdsClient::ChannelState::AdsCallState
 };
 
 // Contains an LRS call to the xds server.
-class XdsClient::ChannelState::LrsCallState
-    : public InternallyRefCounted<LrsCallState> {
+class XdsClient::XdsChannel::LrsCall : public InternallyRefCounted<LrsCall> {
  public:
   // The ctor and dtor should not be used directly.
-  explicit LrsCallState(RefCountedPtr<RetryableCall<LrsCallState>> parent);
+  explicit LrsCall(RefCountedPtr<RetryableCall<LrsCall>> retryable_call);
 
   void Orphan() override;
 
   void MaybeStartReportingLocked()
       ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_);
 
-  RetryableCall<LrsCallState>* parent() { return parent_.get(); }
-  ChannelState* chand() const { return parent_->chand(); }
-  XdsClient* xds_client() const { return chand()->xds_client(); }
+  RetryableCall<LrsCall>* retryable_call() { return retryable_call_.get(); }
+  XdsChannel* xds_channel() const { return retryable_call_->xds_channel(); }
+  XdsClient* xds_client() const { return xds_channel()->xds_client(); }
   bool seen_response() const { return seen_response_; }
 
  private:
   class StreamEventHandler
       : public XdsTransportFactory::XdsTransport::StreamingCall::EventHandler {
    public:
-    explicit StreamEventHandler(RefCountedPtr<LrsCallState> lrs_calld)
-        : lrs_calld_(std::move(lrs_calld)) {}
+    explicit StreamEventHandler(RefCountedPtr<LrsCall> lrs_call)
+        : lrs_call_(std::move(lrs_call)) {}
 
-    void OnRequestSent(bool ok) override { lrs_calld_->OnRequestSent(ok); }
+    void OnRequestSent(bool ok) override { lrs_call_->OnRequestSent(ok); }
     void OnRecvMessage(absl::string_view payload) override {
-      lrs_calld_->OnRecvMessage(payload);
+      lrs_call_->OnRecvMessage(payload);
     }
     void OnStatusReceived(absl::Status status) override {
-      lrs_calld_->OnStatusReceived(std::move(status));
+      lrs_call_->OnStatusReceived(std::move(status));
     }
 
    private:
-    RefCountedPtr<LrsCallState> lrs_calld_;
+    RefCountedPtr<LrsCall> lrs_call_;
   };
 
   // Reports client-side load stats according to a fixed interval.
   class Reporter : public InternallyRefCounted<Reporter> {
    public:
-    Reporter(RefCountedPtr<LrsCallState> parent, Duration report_interval)
-        : parent_(std::move(parent)), report_interval_(report_interval) {
+    Reporter(RefCountedPtr<LrsCall> lrs_call, Duration report_interval)
+        : lrs_call_(std::move(lrs_call)), report_interval_(report_interval) {
       ScheduleNextReportLocked();
     }
 
@@ -412,12 +403,12 @@ class XdsClient::ChannelState::LrsCallState
     bool SendReportLocked() ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_);
 
     bool IsCurrentReporterOnCall() const {
-      return this == parent_->reporter_.get();
+      return this == lrs_call_->reporter_.get();
     }
-    XdsClient* xds_client() const { return parent_->xds_client(); }
+    XdsClient* xds_client() const { return lrs_call_->xds_client(); }
 
     // The owning LRS call.
-    RefCountedPtr<LrsCallState> parent_;
+    RefCountedPtr<LrsCall> lrs_call_;
 
     // The load reporting state.
     const Duration report_interval_;
@@ -433,9 +424,10 @@ class XdsClient::ChannelState::LrsCallState
   bool IsCurrentCallOnChannel() const;
 
   // The owning RetryableCall<>.
-  RefCountedPtr<RetryableCall<LrsCallState>> parent_;
+  RefCountedPtr<RetryableCall<LrsCall>> retryable_call_;
 
-  OrphanablePtr<XdsTransportFactory::XdsTransport::StreamingCall> call_;
+  OrphanablePtr<XdsTransportFactory::XdsTransport::StreamingCall>
+      streaming_call_;
 
   bool seen_response_ = false;
   bool send_message_pending_ ABSL_GUARDED_BY(&XdsClient::mu_) = false;
@@ -448,15 +440,14 @@ class XdsClient::ChannelState::LrsCallState
 };
 
 //
-// XdsClient::ChannelState
+// XdsClient::XdsChannel
 //
 
-XdsClient::ChannelState::ChannelState(WeakRefCountedPtr<XdsClient> xds_client,
-                                      const XdsBootstrap::XdsServer& server)
-    : DualRefCounted<ChannelState>(
-          GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_refcount_trace)
-              ? "ChannelState"
-              : nullptr),
+XdsClient::XdsChannel::XdsChannel(WeakRefCountedPtr<XdsClient> xds_client,
+                                  const XdsBootstrap::XdsServer& server)
+    : DualRefCounted<XdsChannel>(
+          GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_refcount_trace) ? "XdsChannel"
+                                                                  : nullptr),
       xds_client_(std::move(xds_client)),
       server_(server) {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
@@ -475,19 +466,19 @@ XdsClient::ChannelState::ChannelState(WeakRefCountedPtr<XdsClient> xds_client,
   if (!status.ok()) SetChannelStatusLocked(std::move(status));
 }
 
-XdsClient::ChannelState::~ChannelState() {
+XdsClient::XdsChannel::~XdsChannel() {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO, "[xds_client %p] destroying xds channel %p for server %s",
             xds_client(), this, server_.server_uri().c_str());
   }
-  xds_client_.reset(DEBUG_LOCATION, "ChannelState");
+  xds_client_.reset(DEBUG_LOCATION, "XdsChannel");
 }
 
 // This method should only ever be called when holding the lock, but we can't
 // use a ABSL_EXCLUSIVE_LOCKS_REQUIRED annotation, because Orphan() will be
 // called from DualRefCounted::Unref, which cannot have a lock annotation for
 // a lock in this subclass.
-void XdsClient::ChannelState::Orphan() ABSL_NO_THREAD_SAFETY_ANALYSIS {
+void XdsClient::XdsChannel::Orphan() ABSL_NO_THREAD_SAFETY_ANALYSIS {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO, "[xds_client %p] orphaning xds channel %p for server %s",
             xds_client(), this, server_.server_uri().c_str());
@@ -495,69 +486,67 @@ void XdsClient::ChannelState::Orphan() ABSL_NO_THREAD_SAFETY_ANALYSIS {
   shutting_down_ = true;
   transport_.reset();
   // At this time, all strong refs are removed, remove from channel map to
-  // prevent subsequent subscription from trying to use this ChannelState as
+  // prevent subsequent subscription from trying to use this XdsChannel as
   // it is shutting down.
   xds_client_->xds_server_channel_map_.erase(&server_);
-  ads_calld_.reset();
-  lrs_calld_.reset();
+  ads_call_.reset();
+  lrs_call_.reset();
 }
 
-void XdsClient::ChannelState::ResetBackoff() { transport_->ResetBackoff(); }
+void XdsClient::XdsChannel::ResetBackoff() { transport_->ResetBackoff(); }
 
-XdsClient::ChannelState::AdsCallState* XdsClient::ChannelState::ads_calld()
-    const {
-  return ads_calld_->calld();
+XdsClient::XdsChannel::AdsCall* XdsClient::XdsChannel::ads_call() const {
+  return ads_call_->call();
 }
 
-XdsClient::ChannelState::LrsCallState* XdsClient::ChannelState::lrs_calld()
-    const {
-  return lrs_calld_->calld();
+XdsClient::XdsChannel::LrsCall* XdsClient::XdsChannel::lrs_call() const {
+  return lrs_call_->call();
 }
 
-void XdsClient::ChannelState::MaybeStartLrsCall() {
-  if (lrs_calld_ != nullptr) return;
-  lrs_calld_.reset(new RetryableCall<LrsCallState>(
-      WeakRef(DEBUG_LOCATION, "ChannelState+lrs")));
+void XdsClient::XdsChannel::MaybeStartLrsCall() {
+  if (lrs_call_ != nullptr) return;
+  lrs_call_.reset(
+      new RetryableCall<LrsCall>(WeakRef(DEBUG_LOCATION, "XdsChannel+lrs")));
 }
 
-void XdsClient::ChannelState::StopLrsCallLocked() {
+void XdsClient::XdsChannel::StopLrsCallLocked() {
   xds_client_->xds_load_report_server_map_.erase(&server_);
-  lrs_calld_.reset();
+  lrs_call_.reset();
 }
 
-void XdsClient::ChannelState::SubscribeLocked(const XdsResourceType* type,
-                                              const XdsResourceName& name) {
-  if (ads_calld_ == nullptr) {
+void XdsClient::XdsChannel::SubscribeLocked(const XdsResourceType* type,
+                                            const XdsResourceName& name) {
+  if (ads_call_ == nullptr) {
     // Start the ADS call if this is the first request.
-    ads_calld_.reset(new RetryableCall<AdsCallState>(
-        WeakRef(DEBUG_LOCATION, "ChannelState+ads")));
-    // Note: AdsCallState's ctor will automatically subscribe to all
+    ads_call_.reset(
+        new RetryableCall<AdsCall>(WeakRef(DEBUG_LOCATION, "XdsChannel+ads")));
+    // Note: AdsCall's ctor will automatically subscribe to all
     // resources that the XdsClient already has watchers for, so we can
     // return here.
     return;
   }
   // If the ADS call is in backoff state, we don't need to do anything now
   // because when the call is restarted it will resend all necessary requests.
-  if (ads_calld() == nullptr) return;
+  if (ads_call() == nullptr) return;
   // Subscribe to this resource if the ADS call is active.
-  ads_calld()->SubscribeLocked(type, name, /*delay_send=*/false);
-}
-
-void XdsClient::ChannelState::UnsubscribeLocked(const XdsResourceType* type,
-                                                const XdsResourceName& name,
-                                                bool delay_unsubscription) {
-  if (ads_calld_ != nullptr) {
-    auto* calld = ads_calld_->calld();
-    if (calld != nullptr) {
-      calld->UnsubscribeLocked(type, name, delay_unsubscription);
-      if (!calld->HasSubscribedResources()) {
-        ads_calld_.reset();
+  ads_call()->SubscribeLocked(type, name, /*delay_send=*/false);
+}
+
+void XdsClient::XdsChannel::UnsubscribeLocked(const XdsResourceType* type,
+                                              const XdsResourceName& name,
+                                              bool delay_unsubscription) {
+  if (ads_call_ != nullptr) {
+    auto* call = ads_call_->call();
+    if (call != nullptr) {
+      call->UnsubscribeLocked(type, name, delay_unsubscription);
+      if (!call->HasSubscribedResources()) {
+        ads_call_.reset();
       }
     }
   }
 }
 
-void XdsClient::ChannelState::OnConnectivityFailure(absl::Status status) {
+void XdsClient::XdsChannel::OnConnectivityFailure(absl::Status status) {
   {
     MutexLock lock(&xds_client_->mu_);
     SetChannelStatusLocked(std::move(status));
@@ -565,7 +554,7 @@ void XdsClient::ChannelState::OnConnectivityFailure(absl::Status status) {
   xds_client_->work_serializer_.DrainQueue();
 }
 
-void XdsClient::ChannelState::SetChannelStatusLocked(absl::Status status) {
+void XdsClient::XdsChannel::SetChannelStatusLocked(absl::Status status) {
   if (shutting_down_) return;
   status = absl::Status(status.code(), absl::StrCat("xDS channel for server ",
                                                     server_.server_uri(), ": ",
@@ -587,7 +576,7 @@ void XdsClient::ChannelState::SetChannelStatusLocked(absl::Status status) {
   // Find all watchers for this channel.
   std::set<RefCountedPtr<ResourceWatcherInterface>> watchers;
   for (const auto& a : xds_client_->authority_state_map_) {  // authority
-    if (a.second.channel_state != this) continue;
+    if (a.second.xds_channel != this) continue;
     for (const auto& t : a.second.resource_map) {  // type
       for (const auto& r : t.second) {             // resource id
         for (const auto& w : r.second.watchers) {  // watchers
@@ -608,13 +597,13 @@ void XdsClient::ChannelState::SetChannelStatusLocked(absl::Status status) {
 }
 
 //
-// XdsClient::ChannelState::RetryableCall<>
+// XdsClient::XdsChannel::RetryableCall<>
 //
 
 template <typename T>
-XdsClient::ChannelState::RetryableCall<T>::RetryableCall(
-    WeakRefCountedPtr<ChannelState> chand)
-    : chand_(std::move(chand)),
+XdsClient::XdsChannel::RetryableCall<T>::RetryableCall(
+    WeakRefCountedPtr<XdsChannel> xds_channel)
+    : xds_channel_(std::move(xds_channel)),
       backoff_(BackOff::Options()
                    .set_initial_backoff(Duration::Seconds(
                        GRPC_XDS_INITIAL_CONNECT_BACKOFF_SECONDS))
@@ -626,42 +615,43 @@ XdsClient::ChannelState::RetryableCall<T>::RetryableCall(
 }
 
 template <typename T>
-void XdsClient::ChannelState::RetryableCall<T>::Orphan() {
+void XdsClient::XdsChannel::RetryableCall<T>::Orphan() {
   shutting_down_ = true;
-  calld_.reset();
+  call_.reset();
   if (timer_handle_.has_value()) {
-    chand()->xds_client()->engine()->Cancel(*timer_handle_);
+    xds_channel()->xds_client()->engine()->Cancel(*timer_handle_);
     timer_handle_.reset();
   }
   this->Unref(DEBUG_LOCATION, "RetryableCall+orphaned");
 }
 
 template <typename T>
-void XdsClient::ChannelState::RetryableCall<T>::OnCallFinishedLocked() {
+void XdsClient::XdsChannel::RetryableCall<T>::OnCallFinishedLocked() {
   // If we saw a response on the current stream, reset backoff.
-  if (calld_->seen_response()) backoff_.Reset();
-  calld_.reset();
+  if (call_->seen_response()) backoff_.Reset();
+  call_.reset();
   // Start retry timer.
   StartRetryTimerLocked();
 }
 
 template <typename T>
-void XdsClient::ChannelState::RetryableCall<T>::StartNewCallLocked() {
+void XdsClient::XdsChannel::RetryableCall<T>::StartNewCallLocked() {
   if (shutting_down_) return;
-  GPR_ASSERT(chand_->transport_ != nullptr);
-  GPR_ASSERT(calld_ == nullptr);
+  GPR_ASSERT(xds_channel_->transport_ != nullptr);
+  GPR_ASSERT(call_ == nullptr);
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO,
             "[xds_client %p] xds server %s: start new call from retryable "
             "call %p",
-            chand()->xds_client(), chand()->server_.server_uri().c_str(), this);
+            xds_channel()->xds_client(),
+            xds_channel()->server_.server_uri().c_str(), this);
   }
-  calld_ = MakeOrphanable<T>(
+  call_ = MakeOrphanable<T>(
       this->Ref(DEBUG_LOCATION, "RetryableCall+start_new_call"));
 }
 
 template <typename T>
-void XdsClient::ChannelState::RetryableCall<T>::StartRetryTimerLocked() {
+void XdsClient::XdsChannel::RetryableCall<T>::StartRetryTimerLocked() {
   if (shutting_down_) return;
   const Timestamp next_attempt_time = backoff_.NextAttemptTime();
   const Duration timeout =
@@ -670,10 +660,10 @@ void XdsClient::ChannelState::RetryableCall<T>::StartRetryTimerLocked() {
     gpr_log(GPR_INFO,
             "[xds_client %p] xds server %s: call attempt failed; "
             "retry timer will fire in %" PRId64 "ms.",
-            chand()->xds_client(), chand()->server_.server_uri().c_str(),
-            timeout.millis());
+            xds_channel()->xds_client(),
+            xds_channel()->server_.server_uri().c_str(), timeout.millis());
   }
-  timer_handle_ = chand()->xds_client()->engine()->RunAfter(
+  timer_handle_ = xds_channel()->xds_client()->engine()->RunAfter(
       timeout,
       [self = this->Ref(DEBUG_LOCATION, "RetryableCall+retry_timer_start")]() {
         ApplicationCallbackExecCtx callback_exec_ctx;
@@ -683,8 +673,8 @@ void XdsClient::ChannelState::RetryableCall<T>::StartRetryTimerLocked() {
 }
 
 template <typename T>
-void XdsClient::ChannelState::RetryableCall<T>::OnRetryTimer() {
-  MutexLock lock(&chand_->xds_client()->mu_);
+void XdsClient::XdsChannel::RetryableCall<T>::OnRetryTimer() {
+  MutexLock lock(&xds_channel_->xds_client()->mu_);
   if (timer_handle_.has_value()) {
     timer_handle_.reset();
     if (shutting_down_) return;
@@ -692,45 +682,52 @@ void XdsClient::ChannelState::RetryableCall<T>::OnRetryTimer() {
       gpr_log(GPR_INFO,
               "[xds_client %p] xds server %s: retry timer fired (retryable "
               "call: %p)",
-              chand()->xds_client(), chand()->server_.server_uri().c_str(),
-              this);
+              xds_channel()->xds_client(),
+              xds_channel()->server_.server_uri().c_str(), this);
     }
     StartNewCallLocked();
   }
 }
 
 //
-// XdsClient::ChannelState::AdsCallState::AdsReadDelayHandle
+// XdsClient::XdsChannel::AdsCall::AdsReadDelayHandle
 //
 
-XdsClient::ChannelState::AdsCallState::AdsReadDelayHandle::
-    ~AdsReadDelayHandle() {
-  XdsClient* client = ads_call_state_->xds_client();
-  MutexLock lock(&client->mu_);
-  auto call = ads_call_state_->call_.get();
-  if (call != nullptr) {
-    call->StartRecvMessage();
+class XdsClient::XdsChannel::AdsCall::AdsReadDelayHandle
+    : public XdsClient::ReadDelayHandle {
+ public:
+  explicit AdsReadDelayHandle(RefCountedPtr<AdsCall> ads_call)
+      : ads_call_(std::move(ads_call)) {}
+
+  ~AdsReadDelayHandle() override {
+    MutexLock lock(&ads_call_->xds_client()->mu_);
+    auto call = ads_call_->streaming_call_.get();
+    if (call != nullptr) call->StartRecvMessage();
   }
-}
+
+ private:
+  RefCountedPtr<AdsCall> ads_call_;
+};
 
 //
-// XdsClient::ChannelState::AdsCallState::AdsResponseParser
+// XdsClient::XdsChannel::AdsCall::AdsResponseParser
 //
 
-absl::Status XdsClient::ChannelState::AdsCallState::AdsResponseParser::
-    ProcessAdsResponseFields(AdsResponseFields fields) {
+absl::Status
+XdsClient::XdsChannel::AdsCall::AdsResponseParser::ProcessAdsResponseFields(
+    AdsResponseFields fields) {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(
         GPR_INFO,
         "[xds_client %p] xds server %s: received ADS response: type_url=%s, "
         "version=%s, nonce=%s, num_resources=%" PRIuPTR,
-        ads_call_state_->xds_client(),
-        ads_call_state_->chand()->server_.server_uri().c_str(),
+        ads_call_->xds_client(),
+        ads_call_->xds_channel()->server_.server_uri().c_str(),
         fields.type_url.c_str(), fields.version.c_str(), fields.nonce.c_str(),
         fields.num_resources);
   }
   result_.type =
-      ads_call_state_->xds_client()->GetResourceTypeLocked(fields.type_url);
+      ads_call_->xds_client()->GetResourceTypeLocked(fields.type_url);
   if (result_.type == nullptr) {
     return absl::InvalidArgumentError(
         absl::StrCat("unknown resource type ", fields.type_url));
@@ -739,7 +736,7 @@ absl::Status XdsClient::ChannelState::AdsCallState::AdsResponseParser::
   result_.version = std::move(fields.version);
   result_.nonce = std::move(fields.nonce);
   result_.read_delay_handle =
-      MakeRefCounted<AdsReadDelayHandle>(ads_call_state_->Ref());
+      MakeRefCounted<AdsReadDelayHandle>(ads_call_->Ref());
   return absl::OkStatus();
 }
 
@@ -769,7 +766,7 @@ void UpdateResourceMetadataNacked(const std::string& version,
 
 }  // namespace
 
-void XdsClient::ChannelState::AdsCallState::AdsResponseParser::ParseResource(
+void XdsClient::XdsChannel::AdsCall::AdsResponseParser::ParseResource(
     upb_Arena* arena, size_t idx, absl::string_view type_url,
     absl::string_view resource_name, absl::string_view serialized_resource) {
   std::string error_prefix = absl::StrCat(
@@ -784,7 +781,7 @@ void XdsClient::ChannelState::AdsCallState::AdsResponseParser::ParseResource(
   }
   // Parse the resource.
   XdsResourceType::DecodeContext context = {
-      xds_client(), ads_call_state_->chand()->server_, &grpc_xds_client_trace,
+      xds_client(), ads_call_->xds_channel()->server_, &grpc_xds_client_trace,
       xds_client()->def_pool_.ptr(), arena};
   XdsResourceType::DecodeResult decode_result =
       result_.type->Decode(context, serialized_resource);
@@ -818,8 +815,8 @@ void XdsClient::ChannelState::AdsCallState::AdsResponseParser::ParseResource(
     return;
   }
   // Cancel resource-does-not-exist timer, if needed.
-  auto timer_it = ads_call_state_->state_map_.find(result_.type);
-  if (timer_it != ads_call_state_->state_map_.end()) {
+  auto timer_it = ads_call_->state_map_.find(result_.type);
+  if (timer_it != ads_call_->state_map_.end()) {
     auto it = timer_it->second.subscribed_resources.find(
         parsed_resource_name->authority);
     if (it != timer_it->second.subscribed_resources.end()) {
@@ -861,7 +858,7 @@ void XdsClient::ChannelState::AdsCallState::AdsResponseParser::ParseResource(
             "resource for which we previously ignored a deletion: type %s "
             "name %s",
             xds_client(),
-            ads_call_state_->chand()->server_.server_uri().c_str(),
+            ads_call_->xds_channel()->server_.server_uri().c_str(),
             std::string(type_url).c_str(), std::string(resource_name).c_str());
     resource_state.ignored_deletion = false;
   }
@@ -907,48 +904,47 @@ void XdsClient::ChannelState::AdsCallState::AdsResponseParser::ParseResource(
       DEBUG_LOCATION);
 }
 
-void XdsClient::ChannelState::AdsCallState::AdsResponseParser::
+void XdsClient::XdsChannel::AdsCall::AdsResponseParser::
     ResourceWrapperParsingFailed(size_t idx, absl::string_view message) {
   result_.errors.emplace_back(
       absl::StrCat("resource index ", idx, ": ", message));
 }
 
 //
-// XdsClient::ChannelState::AdsCallState
+// XdsClient::XdsChannel::AdsCall
 //
 
-XdsClient::ChannelState::AdsCallState::AdsCallState(
-    RefCountedPtr<RetryableCall<AdsCallState>> parent)
-    : InternallyRefCounted<AdsCallState>(
-          GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_refcount_trace)
-              ? "AdsCallState"
-              : nullptr),
-      parent_(std::move(parent)) {
+XdsClient::XdsChannel::AdsCall::AdsCall(
+    RefCountedPtr<RetryableCall<AdsCall>> retryable_call)
+    : InternallyRefCounted<AdsCall>(
+          GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_refcount_trace) ? "AdsCall"
+                                                                  : nullptr),
+      retryable_call_(std::move(retryable_call)) {
   GPR_ASSERT(xds_client() != nullptr);
   // Init the ADS call.
   const char* method =
       "/envoy.service.discovery.v3.AggregatedDiscoveryService/"
       "StreamAggregatedResources";
-  call_ = chand()->transport_->CreateStreamingCall(
+  streaming_call_ = xds_channel()->transport_->CreateStreamingCall(
       method, std::make_unique<StreamEventHandler>(
                   // Passing the initial ref here.  This ref will go away when
                   // the StreamEventHandler is destroyed.
-                  RefCountedPtr<AdsCallState>(this)));
-  GPR_ASSERT(call_ != nullptr);
+                  RefCountedPtr<AdsCall>(this)));
+  GPR_ASSERT(streaming_call_ != nullptr);
   // Start the call.
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO,
             "[xds_client %p] xds server %s: starting ADS call "
-            "(calld: %p, call: %p)",
-            xds_client(), chand()->server_.server_uri().c_str(), this,
-            call_.get());
+            "(ads_call: %p, streaming_call: %p)",
+            xds_client(), xds_channel()->server_.server_uri().c_str(), this,
+            streaming_call_.get());
   }
   // If this is a reconnect, add any necessary subscriptions from what's
   // already in the cache.
   for (const auto& a : xds_client()->authority_state_map_) {
     const std::string& authority = a.first;
     // Skip authorities that are not using this xDS channel.
-    if (a.second.channel_state != chand()) continue;
+    if (a.second.xds_channel != xds_channel()) continue;
     for (const auto& t : a.second.resource_map) {
       const XdsResourceType* type = t.first;
       for (const auto& r : t.second) {
@@ -961,18 +957,19 @@ XdsClient::ChannelState::AdsCallState::AdsCallState(
   for (const auto& p : state_map_) {
     SendMessageLocked(p.first);
   }
-  call_->StartRecvMessage();
+  streaming_call_->StartRecvMessage();
 }
 
-void XdsClient::ChannelState::AdsCallState::Orphan() {
+void XdsClient::XdsChannel::AdsCall::Orphan() {
   state_map_.clear();
   // Note that the initial ref is held by the StreamEventHandler, which
-  // will be destroyed when call_ is destroyed, which may not happen
-  // here, since there may be other refs held to call_ by internal callbacks.
-  call_.reset();
+  // will be destroyed when streaming_call_ is destroyed, which may not happen
+  // here, since there may be other refs held to streaming_call_ by internal
+  // callbacks.
+  streaming_call_.reset();
 }
 
-void XdsClient::ChannelState::AdsCallState::SendMessageLocked(
+void XdsClient::XdsChannel::AdsCall::SendMessageLocked(
     const XdsResourceType* type)
     ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_) {
   // Buffer message sending if an existing message is in flight.
@@ -982,24 +979,25 @@ void XdsClient::ChannelState::AdsCallState::SendMessageLocked(
   }
   auto& state = state_map_[type];
   std::string serialized_message = xds_client()->api_.CreateAdsRequest(
-      type->type_url(), chand()->resource_type_version_map_[type], state.nonce,
-      ResourceNamesForRequest(type), state.status, !sent_initial_message_);
+      type->type_url(), xds_channel()->resource_type_version_map_[type],
+      state.nonce, ResourceNamesForRequest(type), state.status,
+      !sent_initial_message_);
   sent_initial_message_ = true;
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO,
             "[xds_client %p] xds server %s: sending ADS request: type=%s "
             "version=%s nonce=%s error=%s",
-            xds_client(), chand()->server_.server_uri().c_str(),
+            xds_client(), xds_channel()->server_.server_uri().c_str(),
             std::string(type->type_url()).c_str(),
-            chand()->resource_type_version_map_[type].c_str(),
+            xds_channel()->resource_type_version_map_[type].c_str(),
             state.nonce.c_str(), state.status.ToString().c_str());
   }
   state.status = absl::OkStatus();
-  call_->SendMessage(std::move(serialized_message));
+  streaming_call_->SendMessage(std::move(serialized_message));
   send_message_pending_ = type;
 }
 
-void XdsClient::ChannelState::AdsCallState::SubscribeLocked(
+void XdsClient::XdsChannel::AdsCall::SubscribeLocked(
     const XdsResourceType* type, const XdsResourceName& name, bool delay_send) {
   auto& state = state_map_[type].subscribed_resources[name.authority][name.key];
   if (state == nullptr) {
@@ -1008,7 +1006,7 @@ void XdsClient::ChannelState::AdsCallState::SubscribeLocked(
   }
 }
 
-void XdsClient::ChannelState::AdsCallState::UnsubscribeLocked(
+void XdsClient::XdsChannel::AdsCall::UnsubscribeLocked(
     const XdsResourceType* type, const XdsResourceName& name,
     bool delay_unsubscription) {
   auto& type_state_map = state_map_[type];
@@ -1025,14 +1023,14 @@ void XdsClient::ChannelState::AdsCallState::UnsubscribeLocked(
   }
 }
 
-bool XdsClient::ChannelState::AdsCallState::HasSubscribedResources() const {
+bool XdsClient::XdsChannel::AdsCall::HasSubscribedResources() const {
   for (const auto& p : state_map_) {
     if (!p.second.subscribed_resources.empty()) return true;
   }
   return false;
 }
 
-void XdsClient::ChannelState::AdsCallState::OnRequestSent(bool ok) {
+void XdsClient::XdsChannel::AdsCall::OnRequestSent(bool ok) {
   MutexLock lock(&xds_client()->mu_);
   // For each resource that was in the message we just sent, start the
   // resource timer if needed.
@@ -1064,8 +1062,7 @@ void XdsClient::ChannelState::AdsCallState::OnRequestSent(bool ok) {
   }
 }
 
-void XdsClient::ChannelState::AdsCallState::OnRecvMessage(
-    absl::string_view payload) {
+void XdsClient::XdsChannel::AdsCall::OnRecvMessage(absl::string_view payload) {
   // Needs to be destroyed after the mutex is released.
   RefCountedPtr<ReadDelayHandle> read_delay_handle;
   {
@@ -1082,11 +1079,11 @@ void XdsClient::ChannelState::AdsCallState::OnRecvMessage(
       gpr_log(GPR_ERROR,
               "[xds_client %p] xds server %s: error parsing ADS response (%s) "
               "-- ignoring",
-              xds_client(), chand()->server_.server_uri().c_str(),
+              xds_client(), xds_channel()->server_.server_uri().c_str(),
               status.ToString().c_str());
     } else {
       seen_response_ = true;
-      chand()->status_ = absl::OkStatus();
+      xds_channel()->status_ = absl::OkStatus();
       // Update nonce.
       auto& state = state_map_[result.type];
       state.nonce = result.nonce;
@@ -1099,7 +1096,7 @@ void XdsClient::ChannelState::AdsCallState::OnRecvMessage(
                 "[xds_client %p] xds server %s: ADS response invalid for "
                 "resource "
                 "type %s version %s, will NACK: nonce=%s status=%s",
-                xds_client(), chand()->server_.server_uri().c_str(),
+                xds_client(), xds_channel()->server_.server_uri().c_str(),
                 result.type_url.c_str(), result.version.c_str(),
                 state.nonce.c_str(), state.status.ToString().c_str());
       }
@@ -1109,7 +1106,7 @@ void XdsClient::ChannelState::AdsCallState::OnRecvMessage(
           const std::string& authority = a.first;
           AuthorityState& authority_state = a.second;
           // Skip authorities that are not using this xDS channel.
-          if (authority_state.channel_state != chand()) continue;
+          if (authority_state.xds_channel != xds_channel()) continue;
           auto seen_authority_it = result.resources_seen.find(authority);
           // Find this resource type.
           auto type_it = authority_state.resource_map.find(result.type);
@@ -1129,12 +1126,13 @@ void XdsClient::ChannelState::AdsCallState::OnRecvMessage(
               // that the resource does not exist.  For that case, we rely on
               // the request timeout instead.
               if (resource_state.resource == nullptr) continue;
-              if (chand()->server_.IgnoreResourceDeletion()) {
+              if (xds_channel()->server_.IgnoreResourceDeletion()) {
                 if (!resource_state.ignored_deletion) {
                   gpr_log(GPR_ERROR,
                           "[xds_client %p] xds server %s: ignoring deletion "
                           "for resource type %s name %s",
-                          xds_client(), chand()->server_.server_uri().c_str(),
+                          xds_client(),
+                          xds_channel()->server_.server_uri().c_str(),
                           result.type_url.c_str(),
                           XdsClient::ConstructFullXdsResourceName(
                               authority, result.type_url.c_str(), resource_key)
@@ -1154,13 +1152,13 @@ void XdsClient::ChannelState::AdsCallState::OnRecvMessage(
       }
       // If we had valid resources or the update was empty, update the version.
       if (result.have_valid_resources || result.errors.empty()) {
-        chand()->resource_type_version_map_[result.type] =
+        xds_channel()->resource_type_version_map_[result.type] =
             std::move(result.version);
         // Start load reporting if needed.
-        auto& lrs_call = chand()->lrs_calld_;
-        if (lrs_call != nullptr) {
-          LrsCallState* lrs_calld = lrs_call->calld();
-          if (lrs_calld != nullptr) lrs_calld->MaybeStartReportingLocked();
+        auto& lrs_retryable_call = xds_channel()->lrs_call_;
+        if (lrs_retryable_call != nullptr) {
+          LrsCall* lrs_call = lrs_retryable_call->call();
+          if (lrs_call != nullptr) lrs_call->MaybeStartReportingLocked();
         }
       }
       // Send ACK or NACK.
@@ -1170,16 +1168,16 @@ void XdsClient::ChannelState::AdsCallState::OnRecvMessage(
   xds_client()->work_serializer_.DrainQueue();
 }
 
-void XdsClient::ChannelState::AdsCallState::OnStatusReceived(
-    absl::Status status) {
+void XdsClient::XdsChannel::AdsCall::OnStatusReceived(absl::Status status) {
   {
     MutexLock lock(&xds_client()->mu_);
     if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
       gpr_log(GPR_INFO,
               "[xds_client %p] xds server %s: ADS call status received "
-              "(chand=%p, ads_calld=%p, call=%p): %s",
-              xds_client(), chand()->server_.server_uri().c_str(), chand(),
-              this, call_.get(), status.ToString().c_str());
+              "(xds_channel=%p, ads_call=%p, streaming_call=%p): %s",
+              xds_client(), xds_channel()->server_.server_uri().c_str(),
+              xds_channel(), this, streaming_call_.get(),
+              status.ToString().c_str());
     }
     // Cancel any does-not-exist timers that may be pending.
     for (const auto& p : state_map_) {
@@ -1192,12 +1190,12 @@ void XdsClient::ChannelState::AdsCallState::OnStatusReceived(
     // Ignore status from a stale call.
     if (IsCurrentCallOnChannel()) {
       // Try to restart the call.
-      parent_->OnCallFinishedLocked();
+      retryable_call_->OnCallFinishedLocked();
       // If we didn't receive a response on the stream, report the
       // stream failure as a connectivity failure, which will report the
       // error to all watchers of resources on this channel.
       if (!seen_response_) {
-        chand()->SetChannelStatusLocked(absl::UnavailableError(
+        xds_channel()->SetChannelStatusLocked(absl::UnavailableError(
             absl::StrCat("xDS call failed with no responses received; status: ",
                          status.ToString())));
       }
@@ -1206,15 +1204,15 @@ void XdsClient::ChannelState::AdsCallState::OnStatusReceived(
   xds_client()->work_serializer_.DrainQueue();
 }
 
-bool XdsClient::ChannelState::AdsCallState::IsCurrentCallOnChannel() const {
+bool XdsClient::XdsChannel::AdsCall::IsCurrentCallOnChannel() const {
   // If the retryable ADS call is null (which only happens when the xds
   // channel is shutting down), all the ADS calls are stale.
-  if (chand()->ads_calld_ == nullptr) return false;
-  return this == chand()->ads_calld_->calld();
+  if (xds_channel()->ads_call_ == nullptr) return false;
+  return this == xds_channel()->ads_call_->call();
 }
 
 std::vector<std::string>
-XdsClient::ChannelState::AdsCallState::ResourceNamesForRequest(
+XdsClient::XdsChannel::AdsCall::ResourceNamesForRequest(
     const XdsResourceType* type) {
   std::vector<std::string> resource_names;
   auto it = state_map_.find(type);
@@ -1234,10 +1232,10 @@ XdsClient::ChannelState::AdsCallState::ResourceNamesForRequest(
 }
 
 //
-// XdsClient::ChannelState::LrsCallState::Reporter
+// XdsClient::XdsChannel::LrsCall::Reporter
 //
 
-void XdsClient::ChannelState::LrsCallState::Reporter::Orphan() {
+void XdsClient::XdsChannel::LrsCall::Reporter::Orphan() {
   if (timer_handle_.has_value() &&
       xds_client()->engine()->Cancel(*timer_handle_)) {
     timer_handle_.reset();
@@ -1245,12 +1243,11 @@ void XdsClient::ChannelState::LrsCallState::Reporter::Orphan() {
   }
 }
 
-void XdsClient::ChannelState::LrsCallState::Reporter::
-    ScheduleNextReportLocked() {
+void XdsClient::XdsChannel::LrsCall::Reporter::ScheduleNextReportLocked() {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
-    gpr_log(GPR_INFO,
-            "[xds_client %p] xds server %s: scheduling load report timer",
-            xds_client(), parent_->chand()->server_.server_uri().c_str());
+    gpr_log(
+        GPR_INFO, "[xds_client %p] xds server %s: scheduling load report timer",
+        xds_client(), lrs_call_->xds_channel()->server_.server_uri().c_str());
   }
   timer_handle_ = xds_client()->engine()->RunAfter(report_interval_, [this]() {
     ApplicationCallbackExecCtx callback_exec_ctx;
@@ -1261,7 +1258,7 @@ void XdsClient::ChannelState::LrsCallState::Reporter::
   });
 }
 
-bool XdsClient::ChannelState::LrsCallState::Reporter::OnNextReportTimer() {
+bool XdsClient::XdsChannel::LrsCall::Reporter::OnNextReportTimer() {
   MutexLock lock(&xds_client()->mu_);
   timer_handle_.reset();
   if (!IsCurrentReporterOnCall()) return true;
@@ -1285,22 +1282,22 @@ bool LoadReportCountersAreZero(const XdsApi::ClusterLoadReportMap& snapshot) {
 
 }  // namespace
 
-bool XdsClient::ChannelState::LrsCallState::Reporter::SendReportLocked() {
+bool XdsClient::XdsChannel::LrsCall::Reporter::SendReportLocked() {
   // Construct snapshot from all reported stats.
   XdsApi::ClusterLoadReportMap snapshot =
-      xds_client()->BuildLoadReportSnapshotLocked(parent_->chand()->server_,
-                                                  parent_->send_all_clusters_,
-                                                  parent_->cluster_names_);
+      xds_client()->BuildLoadReportSnapshotLocked(
+          lrs_call_->xds_channel()->server_, lrs_call_->send_all_clusters_,
+          lrs_call_->cluster_names_);
   // Skip client load report if the counters were all zero in the last
   // report and they are still zero in this one.
   const bool old_val = last_report_counters_were_zero_;
   last_report_counters_were_zero_ = LoadReportCountersAreZero(snapshot);
   if (old_val && last_report_counters_were_zero_) {
     auto it = xds_client()->xds_load_report_server_map_.find(
-        &parent_->chand()->server_);
+        &lrs_call_->xds_channel()->server_);
     if (it == xds_client()->xds_load_report_server_map_.end() ||
         it->second.load_report_map.empty()) {
-      it->second.channel_state->StopLrsCallLocked();
+      it->second.xds_channel->StopLrsCallLocked();
       return true;
     }
     ScheduleNextReportLocked();
@@ -1309,12 +1306,12 @@ bool XdsClient::ChannelState::LrsCallState::Reporter::SendReportLocked() {
   // Send a request that contains the snapshot.
   std::string serialized_payload =
       xds_client()->api_.CreateLrsRequest(std::move(snapshot));
-  parent_->call_->SendMessage(std::move(serialized_payload));
-  parent_->send_message_pending_ = true;
+  lrs_call_->streaming_call_->SendMessage(std::move(serialized_payload));
+  lrs_call_->send_message_pending_ = true;
   return false;
 }
 
-void XdsClient::ChannelState::LrsCallState::Reporter::OnReportDoneLocked() {
+void XdsClient::XdsChannel::LrsCall::Reporter::OnReportDoneLocked() {
   // If a reporter starts a send_message op, then the reporting interval
   // changes and we destroy that reporter and create a new one, and then
   // the send_message op started by the old reporter finishes, this
@@ -1324,11 +1321,11 @@ void XdsClient::ChannelState::LrsCallState::Reporter::OnReportDoneLocked() {
   if (timer_handle_.has_value()) return;
   // If there are no more registered stats to report, cancel the call.
   auto it = xds_client()->xds_load_report_server_map_.find(
-      &parent_->chand()->server_);
+      &lrs_call_->xds_channel()->server_);
   if (it == xds_client()->xds_load_report_server_map_.end()) return;
   if (it->second.load_report_map.empty()) {
-    if (it->second.channel_state != nullptr) {
-      it->second.channel_state->StopLrsCallLocked();
+    if (it->second.xds_channel != nullptr) {
+      it->second.xds_channel->StopLrsCallLocked();
     }
     return;
   }
@@ -1337,77 +1334,77 @@ void XdsClient::ChannelState::LrsCallState::Reporter::OnReportDoneLocked() {
 }
 
 //
-// XdsClient::ChannelState::LrsCallState
+// XdsClient::XdsChannel::LrsCall
 //
 
-XdsClient::ChannelState::LrsCallState::LrsCallState(
-    RefCountedPtr<RetryableCall<LrsCallState>> parent)
-    : InternallyRefCounted<LrsCallState>(
-          GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_refcount_trace)
-              ? "LrsCallState"
-              : nullptr),
-      parent_(std::move(parent)) {
+XdsClient::XdsChannel::LrsCall::LrsCall(
+    RefCountedPtr<RetryableCall<LrsCall>> retryable_call)
+    : InternallyRefCounted<LrsCall>(
+          GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_refcount_trace) ? "LrsCall"
+                                                                  : nullptr),
+      retryable_call_(std::move(retryable_call)) {
   // Init the LRS call. Note that the call will progress every time there's
   // activity in xds_client()->interested_parties_, which is comprised of
   // the polling entities from client_channel.
   GPR_ASSERT(xds_client() != nullptr);
   const char* method =
       "/envoy.service.load_stats.v3.LoadReportingService/StreamLoadStats";
-  call_ = chand()->transport_->CreateStreamingCall(
+  streaming_call_ = xds_channel()->transport_->CreateStreamingCall(
       method, std::make_unique<StreamEventHandler>(
                   // Passing the initial ref here.  This ref will go away when
                   // the StreamEventHandler is destroyed.
-                  RefCountedPtr<LrsCallState>(this)));
-  GPR_ASSERT(call_ != nullptr);
+                  RefCountedPtr<LrsCall>(this)));
+  GPR_ASSERT(streaming_call_ != nullptr);
   // Start the call.
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO,
-            "[xds_client %p] xds server %s: starting LRS call (calld=%p, "
-            "call=%p)",
-            xds_client(), chand()->server_.server_uri().c_str(), this,
-            call_.get());
+            "[xds_client %p] xds server %s: starting LRS call (lrs_call=%p, "
+            "streaming_call=%p)",
+            xds_client(), xds_channel()->server_.server_uri().c_str(), this,
+            streaming_call_.get());
   }
   // Send the initial request.
   std::string serialized_payload = xds_client()->api_.CreateLrsInitialRequest();
-  call_->SendMessage(std::move(serialized_payload));
+  streaming_call_->SendMessage(std::move(serialized_payload));
   send_message_pending_ = true;
-  call_->StartRecvMessage();
+  streaming_call_->StartRecvMessage();
 }
 
-void XdsClient::ChannelState::LrsCallState::Orphan() {
+void XdsClient::XdsChannel::LrsCall::Orphan() {
   reporter_.reset();
   // Note that the initial ref is held by the StreamEventHandler, which
-  // will be destroyed when call_ is destroyed, which may not happen
-  // here, since there may be other refs held to call_ by internal callbacks.
-  call_.reset();
+  // will be destroyed when streaming_call_ is destroyed, which may not happen
+  // here, since there may be other refs held to streaming_call_ by internal
+  // callbacks.
+  streaming_call_.reset();
 }
 
-void XdsClient::ChannelState::LrsCallState::MaybeStartReportingLocked() {
+void XdsClient::XdsChannel::LrsCall::MaybeStartReportingLocked() {
   // Don't start again if already started.
   if (reporter_ != nullptr) return;
   // Don't start if the previous send_message op (of the initial request or
   // the last report of the previous reporter) hasn't completed.
-  if (call_ != nullptr && send_message_pending_) return;
+  if (streaming_call_ != nullptr && send_message_pending_) return;
   // Don't start if no LRS response has arrived.
   if (!seen_response()) return;
   // Don't start if the ADS call hasn't received any valid response. Note that
   // this must be the first channel because it is the current channel but its
   // ADS call hasn't seen any response.
-  if (chand()->ads_calld_ == nullptr ||
-      chand()->ads_calld_->calld() == nullptr ||
-      !chand()->ads_calld_->calld()->seen_response()) {
+  if (xds_channel()->ads_call_ == nullptr ||
+      xds_channel()->ads_call_->call() == nullptr ||
+      !xds_channel()->ads_call_->call()->seen_response()) {
     return;
   }
   // Start reporting.
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO, "[xds_client %p] xds server %s: creating load reporter",
-            xds_client(), chand()->server_.server_uri().c_str());
+            xds_client(), xds_channel()->server_.server_uri().c_str());
   }
   reporter_ = MakeOrphanable<Reporter>(
       Ref(DEBUG_LOCATION, "LRS+load_report+start"), load_reporting_interval_);
 }
 
-void XdsClient::ChannelState::LrsCallState::OnRequestSent(bool /*ok*/) {
+void XdsClient::XdsChannel::LrsCall::OnRequestSent(bool /*ok*/) {
   MutexLock lock(&xds_client()->mu_);
   send_message_pending_ = false;
   if (reporter_ != nullptr) {
@@ -1417,14 +1414,13 @@ void XdsClient::ChannelState::LrsCallState::OnRequestSent(bool /*ok*/) {
   }
 }
 
-void XdsClient::ChannelState::LrsCallState::OnRecvMessage(
-    absl::string_view payload) {
+void XdsClient::XdsChannel::LrsCall::OnRecvMessage(absl::string_view payload) {
   MutexLock lock(&xds_client()->mu_);
   // If we're no longer the current call, ignore the result.
   if (!IsCurrentCallOnChannel()) return;
   // Start recv after any code branch
-  auto cleanup =
-      absl::MakeCleanup([call = call_.get()]() { call->StartRecvMessage(); });
+  auto cleanup = absl::MakeCleanup(
+      [call = streaming_call_.get()]() { call->StartRecvMessage(); });
   // Parse the response.
   bool send_all_clusters = false;
   std::set<std::string> new_cluster_names;
@@ -1435,7 +1431,7 @@ void XdsClient::ChannelState::LrsCallState::OnRecvMessage(
   if (!status.ok()) {
     gpr_log(GPR_ERROR,
             "[xds_client %p] xds server %s: LRS response parsing failed: %s",
-            xds_client(), chand()->server_.server_uri().c_str(),
+            xds_client(), xds_channel()->server_.server_uri().c_str(),
             status.ToString().c_str());
     return;
   }
@@ -1446,7 +1442,7 @@ void XdsClient::ChannelState::LrsCallState::OnRecvMessage(
         "[xds_client %p] xds server %s: LRS response received, %" PRIuPTR
         " cluster names, send_all_clusters=%d, load_report_interval=%" PRId64
         "ms",
-        xds_client(), chand()->server_.server_uri().c_str(),
+        xds_client(), xds_channel()->server_.server_uri().c_str(),
         new_cluster_names.size(), send_all_clusters,
         new_load_reporting_interval.millis());
     size_t i = 0;
@@ -1463,7 +1459,7 @@ void XdsClient::ChannelState::LrsCallState::OnRecvMessage(
       gpr_log(GPR_INFO,
               "[xds_client %p] xds server %s: increased load_report_interval "
               "to minimum value %dms",
-              xds_client(), chand()->server_.server_uri().c_str(),
+              xds_client(), xds_channel()->server_.server_uri().c_str(),
               GRPC_XDS_MIN_CLIENT_LOAD_REPORTING_INTERVAL_MS);
     }
   }
@@ -1475,7 +1471,7 @@ void XdsClient::ChannelState::LrsCallState::OnRecvMessage(
       gpr_log(GPR_INFO,
               "[xds_client %p] xds server %s: incoming LRS response identical "
               "to current, ignoring.",
-              xds_client(), chand()->server_.server_uri().c_str());
+              xds_client(), xds_channel()->server_.server_uri().c_str());
     }
     return;
   }
@@ -1489,28 +1485,28 @@ void XdsClient::ChannelState::LrsCallState::OnRecvMessage(
   MaybeStartReportingLocked();
 }
 
-void XdsClient::ChannelState::LrsCallState::OnStatusReceived(
-    absl::Status status) {
+void XdsClient::XdsChannel::LrsCall::OnStatusReceived(absl::Status status) {
   MutexLock lock(&xds_client()->mu_);
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO,
             "[xds_client %p] xds server %s: LRS call status received "
-            "(chand=%p, calld=%p, call=%p): %s",
-            xds_client(), chand()->server_.server_uri().c_str(), chand(), this,
-            call_.get(), status.ToString().c_str());
+            "(xds_channel=%p, lrs_call=%p, streaming_call=%p): %s",
+            xds_client(), xds_channel()->server_.server_uri().c_str(),
+            xds_channel(), this, streaming_call_.get(),
+            status.ToString().c_str());
   }
   // Ignore status from a stale call.
   if (IsCurrentCallOnChannel()) {
     // Try to restart the call.
-    parent_->OnCallFinishedLocked();
+    retryable_call_->OnCallFinishedLocked();
   }
 }
 
-bool XdsClient::ChannelState::LrsCallState::IsCurrentCallOnChannel() const {
+bool XdsClient::XdsChannel::LrsCall::IsCurrentCallOnChannel() const {
   // If the retryable LRS call is null (which only happens when the xds
   // channel is shutting down), all the LRS calls are stale.
-  if (chand()->lrs_calld_ == nullptr) return false;
-  return this == chand()->lrs_calld_->calld();
+  if (xds_channel()->lrs_call_ == nullptr) return false;
+  return this == xds_channel()->lrs_call_->call();
 }
 
 //
@@ -1561,24 +1557,24 @@ void XdsClient::Orphan() {
   invalid_watchers_.clear();
   // We may still be sending lingering queued load report data, so don't
   // just clear the load reporting map, but we do want to clear the refs
-  // we're holding to the ChannelState objects, to make sure that
+  // we're holding to the XdsChannel objects, to make sure that
   // everything shuts down properly.
   for (auto& p : xds_load_report_server_map_) {
-    p.second.channel_state.reset(DEBUG_LOCATION, "XdsClient::Orphan()");
+    p.second.xds_channel.reset(DEBUG_LOCATION, "XdsClient::Orphan()");
   }
 }
 
-RefCountedPtr<XdsClient::ChannelState> XdsClient::GetOrCreateChannelStateLocked(
+RefCountedPtr<XdsClient::XdsChannel> XdsClient::GetOrCreateXdsChannelLocked(
     const XdsBootstrap::XdsServer& server, const char* reason) {
   auto it = xds_server_channel_map_.find(&server);
   if (it != xds_server_channel_map_.end()) {
     return it->second->Ref(DEBUG_LOCATION, reason);
   }
   // Channel not found, so create a new one.
-  auto channel_state = MakeRefCounted<ChannelState>(
-      WeakRef(DEBUG_LOCATION, "ChannelState"), server);
-  xds_server_channel_map_[&server] = channel_state.get();
-  return channel_state;
+  auto xds_channel =
+      MakeRefCounted<XdsChannel>(WeakRef(DEBUG_LOCATION, "XdsChannel"), server);
+  xds_server_channel_map_[&server] = xds_channel.get();
+  return xds_channel;
 }
 
 void XdsClient::WatchResource(const XdsResourceType* type,
@@ -1687,11 +1683,11 @@ void XdsClient::WatchResource(const XdsResourceType* type,
     }
     // If the authority doesn't yet have a channel, set it, creating it if
     // needed.
-    if (authority_state.channel_state == nullptr) {
-      authority_state.channel_state =
-          GetOrCreateChannelStateLocked(*xds_server, "start watch");
+    if (authority_state.xds_channel == nullptr) {
+      authority_state.xds_channel =
+          GetOrCreateXdsChannelLocked(*xds_server, "start watch");
     }
-    absl::Status channel_status = authority_state.channel_state->status();
+    absl::Status channel_status = authority_state.xds_channel->status();
     if (!channel_status.ok()) {
       if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
         gpr_log(GPR_INFO,
@@ -1706,7 +1702,7 @@ void XdsClient::WatchResource(const XdsResourceType* type,
               },
           DEBUG_LOCATION);
     }
-    authority_state.channel_state->SubscribeLocked(type, *resource_name);
+    authority_state.xds_channel->SubscribeLocked(type, *resource_name);
   }
   work_serializer_.DrainQueue();
 }
@@ -1744,13 +1740,13 @@ void XdsClient::CancelResourceWatch(const XdsResourceType* type,
               this, std::string(type->type_url()).c_str(),
               std::string(name).c_str());
     }
-    authority_state.channel_state->UnsubscribeLocked(type, *resource_name,
-                                                     delay_unsubscription);
+    authority_state.xds_channel->UnsubscribeLocked(type, *resource_name,
+                                                   delay_unsubscription);
     type_map.erase(resource_it);
     if (type_map.empty()) {
       authority_state.resource_map.erase(type_it);
       if (authority_state.resource_map.empty()) {
-        authority_state.channel_state.reset();
+        authority_state.xds_channel.reset();
       }
     }
   }
@@ -1834,9 +1830,9 @@ RefCountedPtr<XdsClusterDropStats> XdsClient::AddClusterDropStats(
     // in the load_report_map_ key, so that they have the same lifetime.
     auto server_it =
         xds_load_report_server_map_.emplace(server, LoadReportServer()).first;
-    if (server_it->second.channel_state == nullptr) {
-      server_it->second.channel_state = GetOrCreateChannelStateLocked(
-          *server, "load report map (drop stats)");
+    if (server_it->second.xds_channel == nullptr) {
+      server_it->second.xds_channel =
+          GetOrCreateXdsChannelLocked(*server, "load report map (drop stats)");
     }
     auto load_report_it = server_it->second.load_report_map
                               .emplace(std::move(key), LoadReportState())
@@ -1856,7 +1852,7 @@ RefCountedPtr<XdsClusterDropStats> XdsClient::AddClusterDropStats(
           load_report_it->first.second /*eds_service_name*/);
       load_report_state.drop_stats = cluster_drop_stats.get();
     }
-    server_it->second.channel_state->MaybeStartLrsCall();
+    server_it->second.xds_channel->MaybeStartLrsCall();
   }
   work_serializer_.DrainQueue();
   return cluster_drop_stats;
@@ -1902,8 +1898,8 @@ RefCountedPtr<XdsClusterLocalityStats> XdsClient::AddClusterLocalityStats(
     // in the load_report_map_ key, so that they have the same lifetime.
     auto server_it =
         xds_load_report_server_map_.emplace(server, LoadReportServer()).first;
-    if (server_it->second.channel_state == nullptr) {
-      server_it->second.channel_state = GetOrCreateChannelStateLocked(
+    if (server_it->second.xds_channel == nullptr) {
+      server_it->second.xds_channel = GetOrCreateXdsChannelLocked(
           *server, "load report map (locality stats)");
     }
     auto load_report_it = server_it->second.load_report_map
@@ -1927,7 +1923,7 @@ RefCountedPtr<XdsClusterLocalityStats> XdsClient::AddClusterLocalityStats(
           std::move(locality));
       locality_state.locality_stats = cluster_locality_stats.get();
     }
-    server_it->second.channel_state->MaybeStartLrsCall();
+    server_it->second.xds_channel->MaybeStartLrsCall();
   }
   work_serializer_.DrainQueue();
   return cluster_locality_stats;
diff --git a/src/core/ext/xds/xds_client.h b/src/core/ext/xds/xds_client.h
index 779198c581e..12c9d094b04 100644
--- a/src/core/ext/xds/xds_client.h
+++ b/src/core/ext/xds/xds_client.h
@@ -179,23 +179,23 @@ class XdsClient : public DualRefCounted<XdsClient> {
 
   // Contains a channel to the xds server and all the data related to the
   // channel.  Holds a ref to the xds client object.
-  class ChannelState : public DualRefCounted<ChannelState> {
+  class XdsChannel : public DualRefCounted<XdsChannel> {
    public:
     template <typename T>
     class RetryableCall;
 
-    class AdsCallState;
-    class LrsCallState;
+    class AdsCall;
+    class LrsCall;
 
-    ChannelState(WeakRefCountedPtr<XdsClient> xds_client,
-                 const XdsBootstrap::XdsServer& server);
-    ~ChannelState() override;
+    XdsChannel(WeakRefCountedPtr<XdsClient> xds_client,
+               const XdsBootstrap::XdsServer& server);
+    ~XdsChannel() override;
 
     void Orphan() override;
 
     XdsClient* xds_client() const { return xds_client_.get(); }
-    AdsCallState* ads_calld() const;
-    LrsCallState* lrs_calld() const;
+    AdsCall* ads_call() const;
+    LrsCall* lrs_call() const;
 
     void ResetBackoff();
 
@@ -231,9 +231,9 @@ class XdsClient : public DualRefCounted<XdsClient> {
 
     bool shutting_down_ = false;
 
-    // The retryable XDS calls.
-    OrphanablePtr<RetryableCall<AdsCallState>> ads_calld_;
-    OrphanablePtr<RetryableCall<LrsCallState>> lrs_calld_;
+    // The retryable ADS and LRS calls.
+    OrphanablePtr<RetryableCall<AdsCall>> ads_call_;
+    OrphanablePtr<RetryableCall<LrsCall>> lrs_call_;
 
     // Stores the most recent accepted resource version for each resource type.
     std::map<const XdsResourceType*, std::string /*version*/>
@@ -252,7 +252,7 @@ class XdsClient : public DualRefCounted<XdsClient> {
   };
 
   struct AuthorityState {
-    RefCountedPtr<ChannelState> channel_state;
+    RefCountedPtr<XdsChannel> xds_channel;
     std::map<const XdsResourceType*, std::map<XdsResourceKey, ResourceState>>
         resource_map;
   };
@@ -277,7 +277,7 @@ class XdsClient : public DualRefCounted<XdsClient> {
       LoadReportState>;
 
   struct LoadReportServer {
-    RefCountedPtr<ChannelState> channel_state;
+    RefCountedPtr<XdsChannel> xds_channel;
     LoadReportMap load_report_map;
   };
 
@@ -309,7 +309,7 @@ class XdsClient : public DualRefCounted<XdsClient> {
       const XdsBootstrap::XdsServer& xds_server, bool send_all_clusters,
       const std::set<std::string>& clusters) ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
 
-  RefCountedPtr<ChannelState> GetOrCreateChannelStateLocked(
+  RefCountedPtr<XdsChannel> GetOrCreateXdsChannelLocked(
       const XdsBootstrap::XdsServer& server, const char* reason)
       ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
 
@@ -330,8 +330,8 @@ class XdsClient : public DualRefCounted<XdsClient> {
 
   // Map of existing xDS server channels.
   // Key is owned by the bootstrap config.
-  std::map<const XdsBootstrap::XdsServer*, ChannelState*>
-      xds_server_channel_map_ ABSL_GUARDED_BY(mu_);
+  std::map<const XdsBootstrap::XdsServer*, XdsChannel*> xds_server_channel_map_
+      ABSL_GUARDED_BY(mu_);
 
   std::map<std::string /*authority*/, AuthorityState> authority_state_map_
       ABSL_GUARDED_BY(mu_);