Clean up retry code (#25858)

src/core/ext/filters/client_channel/client_channel.cc

@@ -344,7 +344,7 @@ class DynamicTerminationFilter::CallData {
         calld->call_context_,    calld->path_,
         calld->call_start_time_, calld->deadline_,
         calld->arena_,           calld->call_combiner_};
-    calld->lb_call_ = client_channel->CreateLoadBalancedCall(args, pollent, 0);
+    calld->lb_call_ = client_channel->CreateLoadBalancedCall(args, pollent);
     if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p dynamic_termination_calld=%p: create lb_call=%p", chand,
@@ -1133,16 +1133,8 @@ ClientChannel::~ClientChannel() {
 
 RefCountedPtr<ClientChannel::LoadBalancedCall>
 ClientChannel::CreateLoadBalancedCall(const grpc_call_element_args& args,
-                                      grpc_polling_entity* pollent,
-                                      size_t parent_data_size) {
-  const size_t alloc_size =
-      parent_data_size > 0
-          ? (GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(LoadBalancedCall)) +
-             parent_data_size)
-          : sizeof(LoadBalancedCall);
-  auto* lb_call = static_cast<LoadBalancedCall*>(args.arena->Alloc(alloc_size));
-  new (lb_call) LoadBalancedCall(this, args, pollent);
-  return lb_call;
+                                      grpc_polling_entity* pollent) {
+  return args.arena->New<LoadBalancedCall>(this, args, pollent);
 }
 
 namespace {
@@ -1974,7 +1966,8 @@ void ClientChannel::CallData::SetPollent(grpc_call_element* elem,
 size_t ClientChannel::CallData::GetBatchIndex(
     grpc_transport_stream_op_batch* batch) {
   // Note: It is important the send_initial_metadata be the first entry
-  // here, since the code in pick_subchannel_locked() assumes it will be.
+  // here, since the code in ApplyServiceConfigToCallLocked() and
+  // CheckResolutionLocked() assumes it will be.
   if (batch->send_initial_metadata) return 0;
   if (batch->send_message) return 1;
   if (batch->send_trailing_metadata) return 2;
@@ -2515,15 +2508,10 @@ ClientChannel::LoadBalancedCall::~LoadBalancedCall() {
   }
 }
 
-void* ClientChannel::LoadBalancedCall::GetParentData() {
-  return reinterpret_cast<char*>(this) +
-         GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(LoadBalancedCall));
-}
-
 size_t ClientChannel::LoadBalancedCall::GetBatchIndex(
     grpc_transport_stream_op_batch* batch) {
   // Note: It is important the send_initial_metadata be the first entry
-  // here, since the code in pick_subchannel_locked() assumes it will be.
+  // here, since the code in PickSubchannelLocked() assumes it will be.
   if (batch->send_initial_metadata) return 0;
   if (batch->send_message) return 1;
   if (batch->send_trailing_metadata) return 2;

src/core/ext/filters/client_channel/client_channel.h

@@ -133,8 +133,7 @@ class ClientChannel {
       AsyncConnectivityStateWatcherInterface* watcher);
 
   RefCountedPtr<LoadBalancedCall> CreateLoadBalancedCall(
-      const grpc_call_element_args& args, grpc_polling_entity* pollent,
-      size_t parent_data_size);
+      const grpc_call_element_args& args, grpc_polling_entity* pollent);
 
  private:
   class CallData;
@@ -361,8 +360,6 @@ class ClientChannel::LoadBalancedCall
                    grpc_polling_entity* pollent);
   ~LoadBalancedCall() override;
 
-  void* GetParentData();
-
   void StartTransportStreamOpBatch(grpc_transport_stream_op_batch* batch);
 
   // Invoked by channel for queued LB picks when the picker is updated.