Connected channel has ref to channelz

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

@@ -659,7 +659,7 @@ static bool publish_transport_locked(grpc_subchannel* c) {
 
   /* publish */
   c->connected_subchannel.reset(grpc_core::New<grpc_core::ConnectedSubchannel>(
-      stk, c->channelz_subchannel.get(), socket_uuid));
+      stk, c->channelz_subchannel, socket_uuid));
   gpr_log(GPR_INFO, "New connected subchannel at %p for subchannel %p",
           c->connected_subchannel.get(), c);
 
@@ -891,13 +891,16 @@ namespace grpc_core {
 
 ConnectedSubchannel::ConnectedSubchannel(
     grpc_channel_stack* channel_stack,
-    channelz::SubchannelNode* channelz_subchannel, intptr_t socket_uuid)
+    grpc_core::RefCountedPtr<grpc_core::channelz::SubchannelNode>
+        channelz_subchannel,
+    intptr_t socket_uuid)
     : RefCountedWithTracing<ConnectedSubchannel>(&grpc_trace_stream_refcount),
       channel_stack_(channel_stack),
-      channelz_subchannel_(channelz_subchannel),
+      channelz_subchannel_(std::move(channelz_subchannel)),
       socket_uuid_(socket_uuid) {}
 
 ConnectedSubchannel::~ConnectedSubchannel() {
+  channelz_subchannel_.reset();
   GRPC_CHANNEL_STACK_UNREF(channel_stack_, "connected_subchannel_dtor");
 }
 

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

@@ -85,9 +85,11 @@ class ConnectedSubchannel : public RefCountedWithTracing<ConnectedSubchannel> {
     size_t parent_data_size;
   };
 
-  explicit ConnectedSubchannel(grpc_channel_stack* channel_stack,
+  explicit ConnectedSubchannel(
-                               channelz::SubchannelNode* channelz_subchannel,
+      grpc_channel_stack* channel_stack,
-                               intptr_t socket_uuid);
+      grpc_core::RefCountedPtr<grpc_core::channelz::SubchannelNode>
+          channelz_subchannel,
+      intptr_t socket_uuid);
   ~ConnectedSubchannel();
 
   grpc_channel_stack* channel_stack() { return channel_stack_; }
@@ -97,15 +99,16 @@ class ConnectedSubchannel : public RefCountedWithTracing<ConnectedSubchannel> {
   void Ping(grpc_closure* on_initiate, grpc_closure* on_ack);
   grpc_error* CreateCall(const CallArgs& args, grpc_subchannel_call** call);
   channelz::SubchannelNode* channelz_subchannel() {
-    return channelz_subchannel_;
+    return channelz_subchannel_.get();
   }
   intptr_t socket_uuid() { return socket_uuid_; }
 
  private:
   grpc_channel_stack* channel_stack_;
-  // backpointer to the channelz node in this connected subchannel's
+  // ref counted pointer to the channelz node in this connected subchannel's
   // owning subchannel.
-  channelz::SubchannelNode* channelz_subchannel_;
+  grpc_core::RefCountedPtr<grpc_core::channelz::SubchannelNode>
+      channelz_subchannel_;
   // uuid of this subchannel's socket. 0 if this subchannel is not connected.
   const intptr_t socket_uuid_;
 };