1 files changed, 32 insertions, 0 deletions
diff --git a/include/grpcpp/impl/codegen/channel_interface.h b/include/grpcpp/impl/codegen/channel_interface.h
index ec1c6c25d8..6ec1ffb8c7 100644
--- a/include/grpcpp/impl/codegen/channel_interface.h
+++ b/include/grpcpp/impl/codegen/channel_interface.h
@@ -20,6 +20,8 @@
 #define GRPCPP_IMPL_CODEGEN_CHANNEL_INTERFACE_H
 
 #include <grpc/impl/codegen/connectivity_state.h>
+#include <grpcpp/impl/codegen/call.h>
+#include <grpcpp/impl/codegen/client_context.h>
 #include <grpcpp/impl/codegen/status.h>
 #include <grpcpp/impl/codegen/time.h>
 
@@ -41,6 +43,8 @@ class CallOpSetInterface;
 class RpcMethod;
 template <class InputMessage, class OutputMessage>
 class BlockingUnaryCallImpl;
+template <class InputMessage, class OutputMessage>
+class CallbackUnaryCallImpl;
 template <class R>
 class ClientAsyncReaderFactory;
 template <class W>
@@ -49,6 +53,7 @@ template <class W, class R>
 class ClientAsyncReaderWriterFactory;
 template <class R>
 class ClientAsyncResponseReaderFactory;
+class InterceptedChannel;
 }  // namespace internal
 
 /// Codegen interface for \a grpc::Channel.
@@ -103,7 +108,10 @@ class ChannelInterface {
   friend class ::grpc::internal::ClientAsyncResponseReaderFactory;
   template <class InputMessage, class OutputMessage>
   friend class ::grpc::internal::BlockingUnaryCallImpl;
+  template <class InputMessage, class OutputMessage>
+  friend class ::grpc::internal::CallbackUnaryCallImpl;
   friend class ::grpc::internal::RpcMethod;
+  friend class ::grpc::internal::InterceptedChannel;
   virtual internal::Call CreateCall(const internal::RpcMethod& method,
                                     ClientContext* context,
                                     CompletionQueue* cq) = 0;
@@ -115,6 +123,30 @@ class ChannelInterface {
                                        CompletionQueue* cq, void* tag) = 0;
   virtual bool WaitForStateChangeImpl(grpc_connectivity_state last_observed,
                                       gpr_timespec deadline) = 0;
+
+  // EXPERIMENTAL
+  // This is needed to keep codegen_test_minimal happy. InterceptedChannel needs
+  // to make use of this but can't directly call Channel's implementation
+  // because of the test.
+  // Returns an empty Call object (rather than being pure) since this is a new
+  // method and adding a new pure method to an interface would be a breaking
+  // change (even though this is private and non-API)
+  virtual internal::Call CreateCallInternal(const internal::RpcMethod& method,
+                                            ClientContext* context,
+                                            CompletionQueue* cq,
+                                            size_t interceptor_pos) {
+    return internal::Call();
+  }
+
+  // EXPERIMENTAL
+  // A method to get the callbackable completion queue associated with this
+  // channel. If the return value is nullptr, this channel doesn't support
+  // callback operations.
+  // TODO(vjpai): Consider a better default like using a global CQ
+  // Returns nullptr (rather than being pure) since this is a post-1.0 method
+  // and adding a new pure method to an interface would be a breaking change
+  // (even though this is private and non-API)
+  virtual CompletionQueue* CallbackCQ() { return nullptr; }
 };
 }  // namespace grpc