From 726561ed062c6bb3635b48044bc5bb00de31e97e Mon Sep 17 00:00:00 2001
From: vjpai <vpai@google.com>
Date: Wed, 22 Jun 2016 11:14:24 -0700
Subject: [PATCH] Initial definition of flow-controlled unary type along with
 code generation for this type

---
 BUILD                                         |  5 +
 Makefile                                      |  6 ++
 build.yaml                                    |  2 +
 include/grpc++/impl/codegen/fc_unary.h        | 97 +++++++++++++++++++
 .../grpc++/impl/codegen/method_handler_impl.h | 35 +++++++
 include/grpc++/impl/codegen/rpc_method.h      |  3 +-
 include/grpc++/support/fc_unary.h             | 39 ++++++++
 src/compiler/cpp_generator.cc                 | 44 +++++++++
 src/cpp/server/server.cc                      |  1 +
 tools/doxygen/Doxyfile.c++                    |  2 +
 tools/doxygen/Doxyfile.c++.internal           |  2 +
 tools/run_tests/sources_and_headers.json      |  4 +
 vsprojects/vcxproj/grpc++/grpc++.vcxproj      |  2 +
 .../vcxproj/grpc++/grpc++.vcxproj.filters     |  6 ++
 .../grpc++_reflection.vcxproj                 |  1 +
 .../grpc++_reflection.vcxproj.filters         |  3 +
 .../grpc++_test_util/grpc++_test_util.vcxproj |  1 +
 .../grpc++_test_util.vcxproj.filters          |  3 +
 .../grpc++_unsecure/grpc++_unsecure.vcxproj   |  2 +
 .../grpc++_unsecure.vcxproj.filters           |  6 ++
 .../codegen_test_full.vcxproj                 |  1 +
 .../codegen_test_full.vcxproj.filters         |  3 +
 .../codegen_test_minimal.vcxproj              |  1 +
 .../codegen_test_minimal.vcxproj.filters      |  3 +
 24 files changed, 271 insertions(+), 1 deletion(-)
 create mode 100644 include/grpc++/impl/codegen/fc_unary.h
 create mode 100644 include/grpc++/support/fc_unary.h

diff --git a/BUILD b/BUILD
index ac0eb8e403..df77fea040 100644
--- a/BUILD
+++ b/BUILD
@@ -1301,6 +1301,7 @@ cc_library(
     "include/grpc++/support/byte_buffer.h",
     "include/grpc++/support/channel_arguments.h",
     "include/grpc++/support/config.h",
+    "include/grpc++/support/fc_unary.h",
     "include/grpc++/support/slice.h",
     "include/grpc++/support/status.h",
     "include/grpc++/support/status_code_enum.h",
@@ -1320,6 +1321,7 @@ cc_library(
     "include/grpc++/impl/codegen/config.h",
     "include/grpc++/impl/codegen/core_codegen_interface.h",
     "include/grpc++/impl/codegen/create_auth_context.h",
+    "include/grpc++/impl/codegen/fc_unary.h",
     "include/grpc++/impl/codegen/grpc_library.h",
     "include/grpc++/impl/codegen/method_handler_impl.h",
     "include/grpc++/impl/codegen/rpc_method.h",
@@ -1399,6 +1401,7 @@ cc_library(
     "include/grpc++/impl/codegen/config.h",
     "include/grpc++/impl/codegen/core_codegen_interface.h",
     "include/grpc++/impl/codegen/create_auth_context.h",
+    "include/grpc++/impl/codegen/fc_unary.h",
     "include/grpc++/impl/codegen/grpc_library.h",
     "include/grpc++/impl/codegen/method_handler_impl.h",
     "include/grpc++/impl/codegen/rpc_method.h",
@@ -1527,6 +1530,7 @@ cc_library(
     "include/grpc++/support/byte_buffer.h",
     "include/grpc++/support/channel_arguments.h",
     "include/grpc++/support/config.h",
+    "include/grpc++/support/fc_unary.h",
     "include/grpc++/support/slice.h",
     "include/grpc++/support/status.h",
     "include/grpc++/support/status_code_enum.h",
@@ -1546,6 +1550,7 @@ cc_library(
     "include/grpc++/impl/codegen/config.h",
     "include/grpc++/impl/codegen/core_codegen_interface.h",
     "include/grpc++/impl/codegen/create_auth_context.h",
+    "include/grpc++/impl/codegen/fc_unary.h",
     "include/grpc++/impl/codegen/grpc_library.h",
     "include/grpc++/impl/codegen/method_handler_impl.h",
     "include/grpc++/impl/codegen/rpc_method.h",
diff --git a/Makefile b/Makefile
index 9be3e5784c..05da53233e 100644
--- a/Makefile
+++ b/Makefile
@@ -3530,6 +3530,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/support/byte_buffer.h \
     include/grpc++/support/channel_arguments.h \
     include/grpc++/support/config.h \
+    include/grpc++/support/fc_unary.h \
     include/grpc++/support/slice.h \
     include/grpc++/support/status.h \
     include/grpc++/support/status_code_enum.h \
@@ -3549,6 +3550,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/config.h \
     include/grpc++/impl/codegen/core_codegen_interface.h \
     include/grpc++/impl/codegen/create_auth_context.h \
+    include/grpc++/impl/codegen/fc_unary.h \
     include/grpc++/impl/codegen/grpc_library.h \
     include/grpc++/impl/codegen/method_handler_impl.h \
     include/grpc++/impl/codegen/rpc_method.h \
@@ -3675,6 +3677,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/config.h \
     include/grpc++/impl/codegen/core_codegen_interface.h \
     include/grpc++/impl/codegen/create_auth_context.h \
+    include/grpc++/impl/codegen/fc_unary.h \
     include/grpc++/impl/codegen/grpc_library.h \
     include/grpc++/impl/codegen/method_handler_impl.h \
     include/grpc++/impl/codegen/rpc_method.h \
@@ -3853,6 +3856,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/config.h \
     include/grpc++/impl/codegen/core_codegen_interface.h \
     include/grpc++/impl/codegen/create_auth_context.h \
+    include/grpc++/impl/codegen/fc_unary.h \
     include/grpc++/impl/codegen/grpc_library.h \
     include/grpc++/impl/codegen/method_handler_impl.h \
     include/grpc++/impl/codegen/rpc_method.h \
@@ -4017,6 +4021,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/support/byte_buffer.h \
     include/grpc++/support/channel_arguments.h \
     include/grpc++/support/config.h \
+    include/grpc++/support/fc_unary.h \
     include/grpc++/support/slice.h \
     include/grpc++/support/status.h \
     include/grpc++/support/status_code_enum.h \
@@ -4036,6 +4041,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/config.h \
     include/grpc++/impl/codegen/core_codegen_interface.h \
     include/grpc++/impl/codegen/create_auth_context.h \
+    include/grpc++/impl/codegen/fc_unary.h \
     include/grpc++/impl/codegen/grpc_library.h \
     include/grpc++/impl/codegen/method_handler_impl.h \
     include/grpc++/impl/codegen/rpc_method.h \
diff --git a/build.yaml b/build.yaml
index 1f06e20cf9..27b6a1b058 100644
--- a/build.yaml
+++ b/build.yaml
@@ -676,6 +676,7 @@ filegroups:
   - include/grpc++/support/byte_buffer.h
   - include/grpc++/support/channel_arguments.h
   - include/grpc++/support/config.h
+  - include/grpc++/support/fc_unary.h
   - include/grpc++/support/slice.h
   - include/grpc++/support/status.h
   - include/grpc++/support/status_code_enum.h
@@ -733,6 +734,7 @@ filegroups:
   - include/grpc++/impl/codegen/config.h
   - include/grpc++/impl/codegen/core_codegen_interface.h
   - include/grpc++/impl/codegen/create_auth_context.h
+  - include/grpc++/impl/codegen/fc_unary.h
   - include/grpc++/impl/codegen/grpc_library.h
   - include/grpc++/impl/codegen/method_handler_impl.h
   - include/grpc++/impl/codegen/rpc_method.h
diff --git a/include/grpc++/impl/codegen/fc_unary.h b/include/grpc++/impl/codegen/fc_unary.h
new file mode 100644
index 0000000000..abb204939d
--- /dev/null
+++ b/include/grpc++/impl/codegen/fc_unary.h
@@ -0,0 +1,97 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPCXX_IMPL_CODEGEN_FC_UNARY_H
+#define GRPCXX_IMPL_CODEGEN_FC_UNARY_H
+
+#include <grpc++/impl/codegen/call.h>
+#include <grpc++/impl/codegen/core_codegen_interface.h>
+#include <grpc++/impl/codegen/server_context.h>
+
+namespace grpc {
+
+/// A class to represent a flow-controlled unary call. This is something
+/// of a hybrid between conventional unary and streaming. This is invoked
+/// through a unary call on the client side, but the server responds to it
+/// as though it were a single-ping-pong streaming call. The server can use
+/// the \a Size method to determine an upper-bound on the size of the message
+/// A key difference relative to streaming: an FCUnary must have exactly 1 Read
+/// and exactly 1 Write, in that order, to function correctly.
+/// Otherwise, the RPC is in error
+template <class RequestType, class ResponseType>
+  class FCUnary GRPC_FINAL {
+ public:
+ FCUnary(Call* call, ServerContext* ctx, int max_message_size): call_(call), ctx_(ctx), max_msg_size_(max_message_size), read_done_(false), write_done_(false) {}
+  ~FCUnary() {}
+  uint32_t Size() {return max_msg_size_;}
+  bool Read(RequestType *request) {
+    if (read_done_) {
+      return false;      
+    }
+    read_done_ = true;
+    CallOpSet<CallOpRecvMessage<RequestType>> ops;
+    ops.RecvMessage(request);
+    call_->PerformOps(&ops);
+    return call_->cq()->Pluck(&ops) && ops.got_message;
+  }
+  bool Write(const ResponseType& response) {return Write(response, WriteOptions());}
+  bool Write(const ResponseType& response, const WriteOptions& options) {
+    if (write_done_ || !read_done_) {
+      return false;      
+    }
+    write_done_ = true;
+    CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage> ops;
+    if (!ops.SendMessage(response, options).ok()) {
+      return false;
+    }
+    if (!ctx_->sent_initial_metadata_) {
+      ops.SendInitialMetadata(ctx_->initial_metadata_,
+                              ctx_->initial_metadata_flags());
+      ctx_->sent_initial_metadata_ = true;
+    } else {
+      return false;
+    }
+    call_->PerformOps(&ops);
+    return call_->cq()->Pluck(&ops);    
+  }
+ private:
+  Call* const call_;
+  ServerContext* const ctx_;
+  const int max_msg_size_;
+  bool read_done_;
+  bool write_done_;
+};
+
+}  // namespace grpc
+
+#endif  // GRPCXX_IMPL_CODEGEN_FC_UNARY_H
diff --git a/include/grpc++/impl/codegen/method_handler_impl.h b/include/grpc++/impl/codegen/method_handler_impl.h
index 21ac6c4fb5..ecf481ebb6 100644
--- a/include/grpc++/impl/codegen/method_handler_impl.h
+++ b/include/grpc++/impl/codegen/method_handler_impl.h
@@ -35,6 +35,7 @@
 #define GRPCXX_IMPL_CODEGEN_METHOD_HANDLER_IMPL_H
 
 #include <grpc++/impl/codegen/core_codegen_interface.h>
+#include <grpc++/impl/codegen/fc_unary.h>
 #include <grpc++/impl/codegen/rpc_service_method.h>
 #include <grpc++/impl/codegen/sync_stream.h>
 
@@ -190,6 +191,40 @@ class BidiStreamingHandler : public MethodHandler {
   ServiceType* service_;
 };
 
+// A wrapper class of an application provided rpc method handler
+// specifically to apply to the flow-controlled implementation of a unary
+// method
+template <class ServiceType, class RequestType, class ResponseType>
+class FCUnaryMethodHandler : public MethodHandler {
+ public:
+  FCUnaryMethodHandler(std::function<Status(ServiceType*, ServerContext*,
+					    FCUnary<RequestType,ResponseType>*)>
+                       func, ServiceType* service)
+    : func_(func), service_(service) {}
+
+  void RunHandler(const HandlerParameter& param) GRPC_FINAL {
+    FCUnary<RequestType, ResponseType> fc_unary(param.call,
+						param.server_context,
+						param.max_message_size);
+    Status status = func_(service_, param.server_context, &fc_unary);
+    if (!param.server_context->sent_initial_metadata_) {
+      // means that the write never happened, which is bad
+    } else {
+      CallOpSet<CallOpServerSendStatus> ops;
+      ops.ServerSendStatus(param.server_context->trailing_metadata_, status);
+      param.call->PerformOps(&ops);
+      param.call->cq()->Pluck(&ops);
+    }
+  }
+ private:
+  // Application provided rpc handler function.
+  std::function<Status(ServiceType*, ServerContext*,
+                       FCUnary<RequestType, ResponseType>*)>
+    func_;
+  // The class the above handler function lives in.
+  ServiceType* service_;
+};
+
 // Handle unknown method by returning UNIMPLEMENTED error.
 class UnknownMethodHandler : public MethodHandler {
  public:
diff --git a/include/grpc++/impl/codegen/rpc_method.h b/include/grpc++/impl/codegen/rpc_method.h
index 39cb4f75df..53bee3727e 100644
--- a/include/grpc++/impl/codegen/rpc_method.h
+++ b/include/grpc++/impl/codegen/rpc_method.h
@@ -46,7 +46,8 @@ class RpcMethod {
     NORMAL_RPC = 0,
     CLIENT_STREAMING,  // request streaming
     SERVER_STREAMING,  // response streaming
-    BIDI_STREAMING
+    BIDI_STREAMING,
+    FC_UNARY // flow-controlled unary call
   };
 
   RpcMethod(const char* name, RpcType type)
diff --git a/include/grpc++/support/fc_unary.h b/include/grpc++/support/fc_unary.h
new file mode 100644
index 0000000000..7e7dea8feb
--- /dev/null
+++ b/include/grpc++/support/fc_unary.h
@@ -0,0 +1,39 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPCXX_SUPPORT_FC_UNARY_H
+#define GRPCXX_SUPPORT_FC_UNARY_H
+
+#include <grpc++/impl/codegen/fc_unary.h>
+
+#endif  // GRPCXX_SUPPORT_FC_UNARY_H
diff --git a/src/compiler/cpp_generator.cc b/src/compiler/cpp_generator.cc
index 2288ba4163..e5db84ab11 100644
--- a/src/compiler/cpp_generator.cc
+++ b/src/compiler/cpp_generator.cc
@@ -606,6 +606,50 @@ void PrintHeaderServerMethodAsync(
   printer->Print(*vars, "};\n");
 }
 
+void PrintHeaderServerMethodFCUnary(
+    Printer *printer,
+    const Method *method,
+    std::map<grpc::string, grpc::string> *vars) {
+  (*vars)["Method"] = method->name();
+  (*vars)["Request"] = method->input_type_name();
+  (*vars)["Response"] = method->output_type_name();
+  if (method->NoStreaming()) {
+    printer->Print(*vars, "template <class BaseClass>\n");
+    printer->Print(*vars,
+		   "class WithFCUnaryMethod_$Method$ : public BaseClass {\n");
+    printer->Print(
+      " private:\n"
+      "  void BaseClassMustBeDerivedFromService(const Service *service) {}\n");
+    printer->Print(" public:\n");
+    printer->Indent();
+    printer->Print(*vars,
+		   "WithFCUnaryMethod_$Method$() {\n"
+		   "}\n");
+    printer->Print(*vars,
+		   "~WithFCUnaryMethod_$Method$() GRPC_OVERRIDE {\n"
+		   "  BaseClassMustBeDerivedFromService(this);\n"
+		   "}\n");
+    printer->Print(
+        *vars,
+        "// disable regular version of this method\n"
+        "::grpc::Status $Method$("
+        "::grpc::ServerContext* context, const $Request$* request, "
+        "$Response$* response) GRPC_FINAL GRPC_OVERRIDE {\n"
+        "  abort();\n"
+        "  return ::grpc::Status(::grpc::StatusCode::UNIMPLEMENTED, \"\");\n"
+        "}\n");
+    printer->Print(
+        *vars,
+        "// replace default version of this method with FCUnary\n"
+        "::grpc::Status $Method$("
+        "::grpc::ServerContext* context, ::grpc::FCUnary<$Request$,$Response$>* streaming_unary)"
+        " GRPC_FINAL GRPC_OVERRIDE;\n");
+    printer->Print("}\n");
+    printer->Outdent();
+    printer->Print(*vars, "};\n");
+  }
+}
+
 void PrintHeaderServerMethodGeneric(
     Printer *printer,
     const Method *method,
diff --git a/src/cpp/server/server.cc b/src/cpp/server/server.cc
index fb4c68ebe4..68db9fb6df 100644
--- a/src/cpp/server/server.cc
+++ b/src/cpp/server/server.cc
@@ -341,6 +341,7 @@ static grpc_server_register_method_payload_handling PayloadHandlingForMethod(
       return GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER;
     case RpcMethod::CLIENT_STREAMING:
     case RpcMethod::BIDI_STREAMING:
+    case RpcMethod::FC_UNARY:
       return GRPC_SRM_PAYLOAD_NONE;
   }
   GPR_UNREACHABLE_CODE(return GRPC_SRM_PAYLOAD_NONE;);
diff --git a/tools/doxygen/Doxyfile.c++ b/tools/doxygen/Doxyfile.c++
index 7f9d2df6f6..ed46f8a2be 100644
--- a/tools/doxygen/Doxyfile.c++
+++ b/tools/doxygen/Doxyfile.c++
@@ -800,6 +800,7 @@ include/grpc++/support/async_unary_call.h \
 include/grpc++/support/byte_buffer.h \
 include/grpc++/support/channel_arguments.h \
 include/grpc++/support/config.h \
+include/grpc++/support/fc_unary.h \
 include/grpc++/support/slice.h \
 include/grpc++/support/status.h \
 include/grpc++/support/status_code_enum.h \
@@ -819,6 +820,7 @@ include/grpc++/impl/codegen/completion_queue_tag.h \
 include/grpc++/impl/codegen/config.h \
 include/grpc++/impl/codegen/core_codegen_interface.h \
 include/grpc++/impl/codegen/create_auth_context.h \
+include/grpc++/impl/codegen/fc_unary.h \
 include/grpc++/impl/codegen/grpc_library.h \
 include/grpc++/impl/codegen/method_handler_impl.h \
 include/grpc++/impl/codegen/rpc_method.h \
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index dcf1a4c8c4..005f4f2b3f 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -800,6 +800,7 @@ include/grpc++/support/async_unary_call.h \
 include/grpc++/support/byte_buffer.h \
 include/grpc++/support/channel_arguments.h \
 include/grpc++/support/config.h \
+include/grpc++/support/fc_unary.h \
 include/grpc++/support/slice.h \
 include/grpc++/support/status.h \
 include/grpc++/support/status_code_enum.h \
@@ -819,6 +820,7 @@ include/grpc++/impl/codegen/completion_queue_tag.h \
 include/grpc++/impl/codegen/config.h \
 include/grpc++/impl/codegen/core_codegen_interface.h \
 include/grpc++/impl/codegen/create_auth_context.h \
+include/grpc++/impl/codegen/fc_unary.h \
 include/grpc++/impl/codegen/grpc_library.h \
 include/grpc++/impl/codegen/method_handler_impl.h \
 include/grpc++/impl/codegen/rpc_method.h \
diff --git a/tools/run_tests/sources_and_headers.json b/tools/run_tests/sources_and_headers.json
index 00018834af..21bd776c6d 100644
--- a/tools/run_tests/sources_and_headers.json
+++ b/tools/run_tests/sources_and_headers.json
@@ -6555,6 +6555,7 @@
       "include/grpc++/support/byte_buffer.h", 
       "include/grpc++/support/channel_arguments.h", 
       "include/grpc++/support/config.h", 
+      "include/grpc++/support/fc_unary.h", 
       "include/grpc++/support/slice.h", 
       "include/grpc++/support/status.h", 
       "include/grpc++/support/status_code_enum.h", 
@@ -6609,6 +6610,7 @@
       "include/grpc++/support/byte_buffer.h", 
       "include/grpc++/support/channel_arguments.h", 
       "include/grpc++/support/config.h", 
+      "include/grpc++/support/fc_unary.h", 
       "include/grpc++/support/slice.h", 
       "include/grpc++/support/status.h", 
       "include/grpc++/support/status_code_enum.h", 
@@ -6666,6 +6668,7 @@
       "include/grpc++/impl/codegen/config.h", 
       "include/grpc++/impl/codegen/core_codegen_interface.h", 
       "include/grpc++/impl/codegen/create_auth_context.h", 
+      "include/grpc++/impl/codegen/fc_unary.h", 
       "include/grpc++/impl/codegen/grpc_library.h", 
       "include/grpc++/impl/codegen/method_handler_impl.h", 
       "include/grpc++/impl/codegen/rpc_method.h", 
@@ -6700,6 +6703,7 @@
       "include/grpc++/impl/codegen/config.h", 
       "include/grpc++/impl/codegen/core_codegen_interface.h", 
       "include/grpc++/impl/codegen/create_auth_context.h", 
+      "include/grpc++/impl/codegen/fc_unary.h", 
       "include/grpc++/impl/codegen/grpc_library.h", 
       "include/grpc++/impl/codegen/method_handler_impl.h", 
       "include/grpc++/impl/codegen/rpc_method.h", 
diff --git a/vsprojects/vcxproj/grpc++/grpc++.vcxproj b/vsprojects/vcxproj/grpc++/grpc++.vcxproj
index cb9e41ea22..730e6c0c6c 100644
--- a/vsprojects/vcxproj/grpc++/grpc++.vcxproj
+++ b/vsprojects/vcxproj/grpc++/grpc++.vcxproj
@@ -298,6 +298,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\byte_buffer.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\channel_arguments.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\config.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\fc_unary.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\slice.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\status.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\status_code_enum.h" />
@@ -317,6 +318,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\config.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
diff --git a/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters b/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
index a9051182b3..c444cf0cb6 100644
--- a/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
@@ -222,6 +222,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\config.h">
       <Filter>include\grpc++\support</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\fc_unary.h">
+      <Filter>include\grpc++\support</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\slice.h">
       <Filter>include\grpc++\support</Filter>
     </ClInclude>
@@ -279,6 +282,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc++_reflection/grpc++_reflection.vcxproj b/vsprojects/vcxproj/grpc++_reflection/grpc++_reflection.vcxproj
index 7c3e63b208..e7f504fc2b 100644
--- a/vsprojects/vcxproj/grpc++_reflection/grpc++_reflection.vcxproj
+++ b/vsprojects/vcxproj/grpc++_reflection/grpc++_reflection.vcxproj
@@ -163,6 +163,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\config.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
diff --git a/vsprojects/vcxproj/grpc++_reflection/grpc++_reflection.vcxproj.filters b/vsprojects/vcxproj/grpc++_reflection/grpc++_reflection.vcxproj.filters
index d9cd49cc30..edc8866420 100644
--- a/vsprojects/vcxproj/grpc++_reflection/grpc++_reflection.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++_reflection/grpc++_reflection.vcxproj.filters
@@ -63,6 +63,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj b/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj
index d0fca9ba65..026952c1bd 100644
--- a/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj
+++ b/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj
@@ -159,6 +159,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\config.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
diff --git a/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj.filters b/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj.filters
index cc98c60408..cc3fb70fa4 100644
--- a/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj.filters
@@ -69,6 +69,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
index 03be485b29..0b97b1ebc3 100644
--- a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
+++ b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
@@ -298,6 +298,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\byte_buffer.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\channel_arguments.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\config.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\fc_unary.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\slice.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\status.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\status_code_enum.h" />
@@ -317,6 +318,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\config.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
diff --git a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
index ba99bc53c8..85cc8f7814 100644
--- a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
@@ -207,6 +207,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\config.h">
       <Filter>include\grpc++\support</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\fc_unary.h">
+      <Filter>include\grpc++\support</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\support\slice.h">
       <Filter>include\grpc++\support</Filter>
     </ClInclude>
@@ -264,6 +267,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj b/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj
index e608f7ed3a..0e2b0d8adb 100644
--- a/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj
+++ b/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj
@@ -172,6 +172,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\config.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
diff --git a/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj.filters b/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj.filters
index 8fc8f3901b..098c89cdcc 100644
--- a/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj.filters
+++ b/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj.filters
@@ -57,6 +57,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj b/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj
index 3331c61847..d5133f7238 100644
--- a/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj
+++ b/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj
@@ -172,6 +172,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\config.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
diff --git a/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj.filters b/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj.filters
index a8ff115317..e4e68de185 100644
--- a/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj.filters
+++ b/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj.filters
@@ -60,6 +60,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\fc_unary.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
-- 
GitLab