Merge branch 'master' of github.com:grpc/grpc into proto_interfaces
diff --git a/BUILD b/BUILD
index c02fb9d..2dd280f 100644
--- a/BUILD
+++ b/BUILD
@@ -784,6 +784,8 @@
     "include/grpc++/grpc++.h",
     "include/grpc++/impl/call.h",
     "include/grpc++/impl/client_unary_call.h",
+    "include/grpc++/impl/codegen/channel_interface.h",
+    "include/grpc++/impl/codegen/server_interface.h",
     "include/grpc++/impl/grpc_library.h",
     "include/grpc++/impl/proto_utils.h",
     "include/grpc++/impl/rpc_method.h",
@@ -877,6 +879,8 @@
     "include/grpc++/grpc++.h",
     "include/grpc++/impl/call.h",
     "include/grpc++/impl/client_unary_call.h",
+    "include/grpc++/impl/codegen/channel_interface.h",
+    "include/grpc++/impl/codegen/server_interface.h",
     "include/grpc++/impl/grpc_library.h",
     "include/grpc++/impl/proto_utils.h",
     "include/grpc++/impl/rpc_method.h",
diff --git a/Makefile b/Makefile
index 6d15a57..63ada73 100644
--- a/Makefile
+++ b/Makefile
@@ -2986,6 +2986,8 @@
     include/grpc++/grpc++.h \
     include/grpc++/impl/call.h \
     include/grpc++/impl/client_unary_call.h \
+    include/grpc++/impl/codegen/channel_interface.h \
+    include/grpc++/impl/codegen/server_interface.h \
     include/grpc++/impl/grpc_library.h \
     include/grpc++/impl/proto_utils.h \
     include/grpc++/impl/rpc_method.h \
@@ -3251,6 +3253,8 @@
     include/grpc++/grpc++.h \
     include/grpc++/impl/call.h \
     include/grpc++/impl/client_unary_call.h \
+    include/grpc++/impl/codegen/channel_interface.h \
+    include/grpc++/impl/codegen/server_interface.h \
     include/grpc++/impl/grpc_library.h \
     include/grpc++/impl/proto_utils.h \
     include/grpc++/impl/rpc_method.h \
diff --git a/build.yaml b/build.yaml
index 70a8dee..056a0c8 100644
--- a/build.yaml
+++ b/build.yaml
@@ -120,6 +120,7 @@
   - src/core/client_config/client_config.h
   - src/core/client_config/connector.h
   - src/core/client_config/initial_connect_string.h
+  - src/core/client_config/lb_policies/load_balancer_api.h
   - src/core/client_config/lb_policies/pick_first.h
   - src/core/client_config/lb_policies/round_robin.h
   - src/core/client_config/lb_policy.h
@@ -180,6 +181,7 @@
   - src/core/json/json_common.h
   - src/core/json/json_reader.h
   - src/core/json/json_writer.h
+  - src/core/proto/grpc/lb/v0/load_balancer.pb.h
   - src/core/statistics/census_interface.h
   - src/core/statistics/census_rpc_stats.h
   - src/core/surface/api_trace.h
@@ -235,6 +237,7 @@
   - src/core/client_config/connector.c
   - src/core/client_config/default_initial_connect_string.c
   - src/core/client_config/initial_connect_string.c
+  - src/core/client_config/lb_policies/load_balancer_api.c
   - src/core/client_config/lb_policies/pick_first.c
   - src/core/client_config/lb_policies/round_robin.c
   - src/core/client_config/lb_policy.c
@@ -298,6 +301,7 @@
   - src/core/json/json_reader.c
   - src/core/json/json_string.c
   - src/core/json/json_writer.c
+  - src/core/proto/grpc/lb/v0/load_balancer.pb.c
   - src/core/surface/api_trace.c
   - src/core/surface/byte_buffer.c
   - src/core/surface/byte_buffer_reader.c
@@ -364,6 +368,16 @@
   - test/core/util/port_posix.c
   - test/core/util/port_windows.c
   - test/core/util/slice_splitter.c
+- name: nanopb
+  headers:
+  - third_party/nanopb/pb.h
+  - third_party/nanopb/pb_common.h
+  - third_party/nanopb/pb_decode.h
+  - third_party/nanopb/pb_encode.h
+  src:
+  - third_party/nanopb/pb_common.c
+  - third_party/nanopb/pb_decode.c
+  - third_party/nanopb/pb_encode.c
 libs:
 - name: gpr
   build: all
@@ -512,6 +526,7 @@
   filegroups:
   - grpc_base
   - census
+  - nanopb
   secure: true
   vs_packages:
   - grpc.dependencies.openssl
@@ -558,6 +573,7 @@
   filegroups:
   - grpc_base
   - census
+  - nanopb
   secure: false
   vs_project_guid: '{46CEDFFF-9692-456A-AA24-38B5D6BCF4C5}'
 - name: grpc_zookeeper
@@ -2045,6 +2061,16 @@
   secure: false
   vs_config_type: Application
   vs_project_guid: '{069E9D05-B78B-4751-9252-D21EBAE7DE8E}'
+- name: grpclb_api_test
+  build: test
+  language: c++
+  src:
+  - src/proto/grpc/lb/v0/load_balancer.proto
+  - test/cpp/grpclb/grpclb_api_test.cc
+  deps:
+  - grpc++
+  - grpc
+  - gpr
 - name: interop_client
   build: test
   run: false
diff --git a/examples/cpp/helloworld/Makefile b/examples/cpp/helloworld/Makefile
index f2093af..8e0379c 100644
--- a/examples/cpp/helloworld/Makefile
+++ b/examples/cpp/helloworld/Makefile
@@ -55,6 +55,8 @@
 greeter_async_server: helloworld.pb.o helloworld.grpc.pb.o greeter_async_server.o
 	$(CXX) $^ $(LDFLAGS) -o $@
 
+.PRECIOUS: %.grpc.pb.cc %.pb.cc
+
 %.grpc.pb.cc: %.proto
 	$(PROTOC) -I $(PROTOS_PATH) --grpc_out=. --plugin=protoc-gen-grpc=$(GRPC_CPP_PLUGIN_PATH) $<
 
diff --git a/include/grpc++/channel.h b/include/grpc++/channel.h
index 541be13..7b54751 100644
--- a/include/grpc++/channel.h
+++ b/include/grpc++/channel.h
@@ -38,35 +38,16 @@
 
 #include <grpc/grpc.h>
 #include <grpc++/impl/call.h>
+#include <grpc++/impl/codegen/channel_interface.h>
 #include <grpc++/impl/grpc_library.h>
 #include <grpc++/support/config.h>
 
 struct grpc_channel;
 
 namespace grpc {
-class CallOpSetInterface;
-class ChannelArguments;
-class CompletionQueue;
-class ChannelCredentials;
-class SecureChannelCredentials;
-
-template <class R>
-class ClientReader;
-template <class W>
-class ClientWriter;
-template <class W, class R>
-class ClientReaderWriter;
-template <class R>
-class ClientAsyncReader;
-template <class W>
-class ClientAsyncWriter;
-template <class W, class R>
-class ClientAsyncReaderWriter;
-template <class R>
-class ClientAsyncResponseReader;
-
 /// Channels represent a connection to an endpoint. Created by \a CreateChannel.
-class Channel GRPC_FINAL : public GrpcLibrary,
+class Channel GRPC_FINAL : public ChannelInterface,
+                           public GrpcLibrary,
                            public CallHook,
                            public std::enable_shared_from_this<Channel> {
  public:
@@ -74,61 +55,28 @@
 
   /// Get the current channel state. If the channel is in IDLE and
   /// \a try_to_connect is set to true, try to connect.
-  grpc_connectivity_state GetState(bool try_to_connect);
-
-  /// Return the \a tag on \a cq when the channel state is changed or \a
-  /// deadline expires. \a GetState needs to called to get the current state.
-  template <typename T>
-  void NotifyOnStateChange(grpc_connectivity_state last_observed, T deadline,
-                           CompletionQueue* cq, void* tag) {
-    TimePoint<T> deadline_tp(deadline);
-    NotifyOnStateChangeImpl(last_observed, deadline_tp.raw_time(), cq, tag);
-  }
-
-  /// Blocking wait for channel state change or \a deadline expiration.
-  /// \a GetState needs to called to get the current state.
-  template <typename T>
-  bool WaitForStateChange(grpc_connectivity_state last_observed, T deadline) {
-    TimePoint<T> deadline_tp(deadline);
-    return WaitForStateChangeImpl(last_observed, deadline_tp.raw_time());
-  }
+  grpc_connectivity_state GetState(bool try_to_connect) override;
 
  private:
-  template <class R>
-  friend class ::grpc::ClientReader;
-  template <class W>
-  friend class ::grpc::ClientWriter;
-  template <class W, class R>
-  friend class ::grpc::ClientReaderWriter;
-  template <class R>
-  friend class ::grpc::ClientAsyncReader;
-  template <class W>
-  friend class ::grpc::ClientAsyncWriter;
-  template <class W, class R>
-  friend class ::grpc::ClientAsyncReaderWriter;
-  template <class R>
-  friend class ::grpc::ClientAsyncResponseReader;
   template <class InputMessage, class OutputMessage>
-  friend Status BlockingUnaryCall(Channel* channel, const RpcMethod& method,
+  friend Status BlockingUnaryCall(ChannelInterface* channel, const RpcMethod& method,
                                   ClientContext* context,
                                   const InputMessage& request,
                                   OutputMessage* result);
-  friend class ::grpc::RpcMethod;
   friend std::shared_ptr<Channel> CreateChannelInternal(
       const grpc::string& host, grpc_channel* c_channel);
-
   Channel(const grpc::string& host, grpc_channel* c_channel);
 
   Call CreateCall(const RpcMethod& method, ClientContext* context,
-                  CompletionQueue* cq);
-  void PerformOpsOnCall(CallOpSetInterface* ops, Call* call);
-  void* RegisterMethod(const char* method);
+                  CompletionQueue* cq) override;
+  void PerformOpsOnCall(CallOpSetInterface* ops, Call* call) override;
+  void* RegisterMethod(const char* method) override;
 
   void NotifyOnStateChangeImpl(grpc_connectivity_state last_observed,
                                gpr_timespec deadline, CompletionQueue* cq,
-                               void* tag);
+                               void* tag) override;
   bool WaitForStateChangeImpl(grpc_connectivity_state last_observed,
-                              gpr_timespec deadline);
+                              gpr_timespec deadline) override;
 
   const grpc::string host_;
   grpc_channel* const c_channel_;  // owned
diff --git a/include/grpc++/client_context.h b/include/grpc++/client_context.h
index 25eeb38..6ce1c85 100644
--- a/include/grpc++/client_context.h
+++ b/include/grpc++/client_context.h
@@ -69,6 +69,7 @@
 namespace grpc {
 
 class Channel;
+class ChannelInterface;
 class CompletionQueue;
 class CallCredentials;
 class RpcMethod;
@@ -315,7 +316,7 @@
   template <class R>
   friend class ::grpc::ClientAsyncResponseReader;
   template <class InputMessage, class OutputMessage>
-  friend Status BlockingUnaryCall(Channel* channel, const RpcMethod& method,
+  friend Status BlockingUnaryCall(ChannelInterface* channel, const RpcMethod& method,
                                   ClientContext* context,
                                   const InputMessage& request,
                                   OutputMessage* result);
diff --git a/include/grpc++/completion_queue.h b/include/grpc++/completion_queue.h
index 5c2bc20..adae926 100644
--- a/include/grpc++/completion_queue.h
+++ b/include/grpc++/completion_queue.h
@@ -68,6 +68,7 @@
 class UnknownMethodHandler;
 
 class Channel;
+class ChannelInterface;
 class ClientContext;
 class CompletionQueueTag;
 class CompletionQueue;
@@ -171,7 +172,7 @@
   friend class ::grpc::Server;
   friend class ::grpc::ServerContext;
   template <class InputMessage, class OutputMessage>
-  friend Status BlockingUnaryCall(Channel* channel, const RpcMethod& method,
+  friend Status BlockingUnaryCall(ChannelInterface* channel, const RpcMethod& method,
                                   ClientContext* context,
                                   const InputMessage& request,
                                   OutputMessage* result);
diff --git a/include/grpc++/generic/async_generic_service.h b/include/grpc++/generic/async_generic_service.h
index 57a2696..36ef8fc 100644
--- a/include/grpc++/generic/async_generic_service.h
+++ b/include/grpc++/generic/async_generic_service.h
@@ -51,6 +51,7 @@
 
  private:
   friend class Server;
+  friend class ServerInterface;
 
   grpc::string method_;
   grpc::string host_;
diff --git a/include/grpc++/generic/generic_stub.h b/include/grpc++/generic/generic_stub.h
index 1bb7900..cd8fb54 100644
--- a/include/grpc++/generic/generic_stub.h
+++ b/include/grpc++/generic/generic_stub.h
@@ -47,7 +47,7 @@
 // by name.
 class GenericStub GRPC_FINAL {
  public:
-  explicit GenericStub(std::shared_ptr<Channel> channel) : channel_(channel) {}
+  explicit GenericStub(std::shared_ptr<ChannelInterface> channel) : channel_(channel) {}
 
   // begin a call to a named method
   std::unique_ptr<GenericClientAsyncReaderWriter> Call(
@@ -55,7 +55,7 @@
       void* tag);
 
  private:
-  std::shared_ptr<Channel> channel_;
+  std::shared_ptr<ChannelInterface> channel_;
 };
 
 }  // namespace grpc
diff --git a/include/grpc++/impl/client_unary_call.h b/include/grpc++/impl/client_unary_call.h
index 4cdc800..554683a 100644
--- a/include/grpc++/impl/client_unary_call.h
+++ b/include/grpc++/impl/client_unary_call.h
@@ -35,6 +35,7 @@
 #define GRPCXX_IMPL_CLIENT_UNARY_CALL_H
 
 #include <grpc++/impl/call.h>
+#include <grpc++/impl/codegen/channel_interface.h>
 #include <grpc++/support/config.h>
 #include <grpc++/support/status.h>
 
@@ -47,7 +48,7 @@
 
 // Wrapper that performs a blocking unary call
 template <class InputMessage, class OutputMessage>
-Status BlockingUnaryCall(Channel* channel, const RpcMethod& method,
+Status BlockingUnaryCall(ChannelInterface* channel, const RpcMethod& method,
                          ClientContext* context, const InputMessage& request,
                          OutputMessage* result) {
   CompletionQueue cq;
diff --git a/include/grpc++/impl/codegen/channel_interface.h b/include/grpc++/impl/codegen/channel_interface.h
new file mode 100644
index 0000000..e294173
--- /dev/null
+++ b/include/grpc++/impl/codegen/channel_interface.h
@@ -0,0 +1,121 @@
+/*
+ *
+ * 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_CHANNEL_INTERFACE_H
+#define GRPCXX_CHANNEL_INTERFACE_H
+
+#include <grpc++/impl/grpc_library.h>
+#include <grpc++/support/status.h>
+#include <grpc++/support/time.h>
+
+namespace grpc {
+class Call;
+class ClientContext;
+class RpcMethod;
+class CallOpSetInterface;
+class CompletionQueue;
+
+template <class R>
+class ClientReader;
+template <class W>
+class ClientWriter;
+template <class W, class R>
+class ClientReaderWriter;
+template <class R>
+class ClientAsyncReader;
+template <class W>
+class ClientAsyncWriter;
+template <class W, class R>
+class ClientAsyncReaderWriter;
+template <class R>
+class ClientAsyncResponseReader;
+
+/// Codegen interface for \a grpc::Channel.
+class ChannelInterface {
+ public:
+  /// Get the current channel state. If the channel is in IDLE and
+  /// \a try_to_connect is set to true, try to connect.
+  virtual grpc_connectivity_state GetState(bool try_to_connect) = 0;
+
+  /// Return the \a tag on \a cq when the channel state is changed or \a
+  /// deadline expires. \a GetState needs to called to get the current state.
+  template <typename T>
+  void NotifyOnStateChange(grpc_connectivity_state last_observed, T deadline,
+                           CompletionQueue* cq, void* tag) {
+    TimePoint<T> deadline_tp(deadline);
+    NotifyOnStateChangeImpl(last_observed, deadline_tp.raw_time(), cq, tag);
+  }
+
+  /// Blocking wait for channel state change or \a deadline expiration.
+  /// \a GetState needs to called to get the current state.
+  template <typename T>
+  bool WaitForStateChange(grpc_connectivity_state last_observed, T deadline) {
+    TimePoint<T> deadline_tp(deadline);
+    return WaitForStateChangeImpl(last_observed, deadline_tp.raw_time());
+  }
+
+ private:
+  template <class R>
+  friend class ::grpc::ClientReader;
+  template <class W>
+  friend class ::grpc::ClientWriter;
+  template <class W, class R>
+  friend class ::grpc::ClientReaderWriter;
+  template <class R>
+  friend class ::grpc::ClientAsyncReader;
+  template <class W>
+  friend class ::grpc::ClientAsyncWriter;
+  template <class W, class R>
+  friend class ::grpc::ClientAsyncReaderWriter;
+  template <class R>
+  friend class ::grpc::ClientAsyncResponseReader;
+  template <class InputMessage, class OutputMessage>
+  friend Status BlockingUnaryCall(ChannelInterface* channel, const RpcMethod& method,
+                                  ClientContext* context,
+                                  const InputMessage& request,
+                                  OutputMessage* result);
+  friend class ::grpc::RpcMethod;
+  virtual Call CreateCall(const RpcMethod& method, ClientContext* context,
+                  CompletionQueue* cq) = 0;
+  virtual void PerformOpsOnCall(CallOpSetInterface* ops, Call* call) = 0;
+  virtual void* RegisterMethod(const char* method) = 0;
+  virtual void NotifyOnStateChangeImpl(grpc_connectivity_state last_observed,
+                               gpr_timespec deadline, CompletionQueue* cq,
+                               void* tag) = 0;
+  virtual bool WaitForStateChangeImpl(grpc_connectivity_state last_observed,
+                              gpr_timespec deadline) = 0;
+};
+
+}  // namespace grpc
+
+#endif  // GRPCXX_CHANNEL_INTERFACE_H
diff --git a/include/grpc++/impl/codegen/server_interface.h b/include/grpc++/impl/codegen/server_interface.h
new file mode 100644
index 0000000..8f7ce7b
--- /dev/null
+++ b/include/grpc++/impl/codegen/server_interface.h
@@ -0,0 +1,250 @@
+/*
+ *
+ * Copyright 2015, 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_SERVER_INTERFACE_H
+#define GRPCXX_SERVER_INTERFACE_H
+
+#include <grpc++/completion_queue.h>
+#include <grpc++/impl/call.h>
+
+namespace grpc {
+
+class ServerCredentials;
+class AsynchronousService;
+class GenericServerContext;
+class AsyncGenericService;
+class RpcService;
+class RpcServiceMethod;
+class ServerAsyncStreamingInterface;
+class ServerContext;
+class ThreadPoolInterface;
+
+/// Models a gRPC server.
+///
+/// Servers are configured and started via \a grpc::ServerBuilder.
+class ServerInterface : public CallHook {
+ public:
+  /// Shutdown the server, blocking until all rpc processing finishes.
+  /// Forcefully terminate pending calls after \a deadline expires.
+  ///
+  /// \param deadline How long to wait until pending rpcs are forcefully
+  /// terminated.
+  template <class T>
+  void Shutdown(const T& deadline) {
+    ShutdownInternal(TimePoint<T>(deadline).raw_time());
+  }
+
+  /// Shutdown the server, waiting for all rpc processing to finish.
+  void Shutdown() { ShutdownInternal(gpr_inf_future(GPR_CLOCK_MONOTONIC)); }
+
+  /// Block waiting for all work to complete.
+  ///
+  /// \warning The server must be either shutting down or some other thread must
+  /// call \a Shutdown for this function to ever return.
+  virtual void Wait() = 0;
+
+ protected:
+  friend class AsynchronousService;
+
+  /// Register a service. This call does not take ownership of the service.
+  /// The service must exist for the lifetime of the Server instance.
+  virtual bool RegisterService(const grpc::string* host, RpcService* service) = 0;
+
+  /// Register an asynchronous service. This call does not take ownership of the
+  /// service. The service must exist for the lifetime of the Server instance.
+  virtual bool RegisterAsyncService(const grpc::string* host,
+                            AsynchronousService* service) = 0;
+
+  /// Register a generic service. This call does not take ownership of the
+  /// service. The service must exist for the lifetime of the Server instance.
+  virtual void RegisterAsyncGenericService(AsyncGenericService* service) = 0;
+
+  /// Tries to bind \a server to the given \a addr.
+  ///
+  /// It can be invoked multiple times.
+  ///
+  /// \param addr The address to try to bind to the server (eg, localhost:1234,
+  /// 192.168.1.1:31416, [::1]:27182, etc.).
+  /// \params creds The credentials associated with the server.
+  ///
+  /// \return bound port number on sucess, 0 on failure.
+  ///
+  /// \warning It's an error to call this method on an already started server.
+  virtual int AddListeningPort(const grpc::string& addr, ServerCredentials* creds) = 0;
+
+  /// Start the server.
+  ///
+  /// \param cqs Completion queues for handling asynchronous services. The
+  /// caller is required to keep all completion queues live until the server is
+  /// destroyed.
+  /// \param num_cqs How many completion queues does \a cqs hold.
+  ///
+  /// \return true on a successful shutdown.
+  virtual bool Start(ServerCompletionQueue** cqs, size_t num_cqs) = 0;
+
+  /// Process one or more incoming calls.
+  virtual void RunRpc() = 0;
+
+  /// Schedule \a RunRpc to run in the threadpool.
+  virtual void ScheduleCallback() = 0;
+
+  virtual void ShutdownInternal(gpr_timespec deadline) = 0;
+
+  virtual int max_message_size() const = 0;
+
+  virtual grpc_server* server() = 0;
+
+  virtual void PerformOpsOnCall(CallOpSetInterface* ops, Call* call) = 0;
+
+  class BaseAsyncRequest : public CompletionQueueTag {
+   public:
+    BaseAsyncRequest(ServerInterface* server, ServerContext* context,
+                     ServerAsyncStreamingInterface* stream,
+                     CompletionQueue* call_cq, void* tag,
+                     bool delete_on_finalize);
+    virtual ~BaseAsyncRequest() {}
+
+    bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE;
+
+   protected:
+    ServerInterface* const server_;
+    ServerContext* const context_;
+    ServerAsyncStreamingInterface* const stream_;
+    CompletionQueue* const call_cq_;
+    void* const tag_;
+    const bool delete_on_finalize_;
+    grpc_call* call_;
+    grpc_metadata_array initial_metadata_array_;
+  };
+
+  class RegisteredAsyncRequest : public BaseAsyncRequest {
+   public:
+    RegisteredAsyncRequest(ServerInterface* server, ServerContext* context,
+                           ServerAsyncStreamingInterface* stream,
+                           CompletionQueue* call_cq, void* tag);
+
+    // uses BaseAsyncRequest::FinalizeResult
+
+   protected:
+    void IssueRequest(void* registered_method, grpc_byte_buffer** payload,
+                      ServerCompletionQueue* notification_cq);
+  };
+
+  class NoPayloadAsyncRequest GRPC_FINAL : public RegisteredAsyncRequest {
+   public:
+    NoPayloadAsyncRequest(void* registered_method, ServerInterface* server,
+                          ServerContext* context,
+                          ServerAsyncStreamingInterface* stream,
+                          CompletionQueue* call_cq,
+                          ServerCompletionQueue* notification_cq, void* tag)
+        : RegisteredAsyncRequest(server, context, stream, call_cq, tag) {
+      IssueRequest(registered_method, nullptr, notification_cq);
+    }
+
+    // uses RegisteredAsyncRequest::FinalizeResult
+  };
+
+  template <class Message>
+  class PayloadAsyncRequest GRPC_FINAL : public RegisteredAsyncRequest {
+   public:
+    PayloadAsyncRequest(void* registered_method, ServerInterface* server,
+                        ServerContext* context,
+                        ServerAsyncStreamingInterface* stream,
+                        CompletionQueue* call_cq,
+                        ServerCompletionQueue* notification_cq, void* tag,
+                        Message* request)
+        : RegisteredAsyncRequest(server, context, stream, call_cq, tag),
+          request_(request) {
+      IssueRequest(registered_method, &payload_, notification_cq);
+    }
+
+    bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE {
+      bool serialization_status =
+          *status && payload_ &&
+          SerializationTraits<Message>::Deserialize(
+              payload_, request_, server_->max_message_size()).ok();
+      bool ret = RegisteredAsyncRequest::FinalizeResult(tag, status);
+      *status = serialization_status&&* status;
+      return ret;
+    }
+
+   private:
+    grpc_byte_buffer* payload_;
+    Message* const request_;
+  };
+
+  class GenericAsyncRequest : public BaseAsyncRequest {
+   public:
+    GenericAsyncRequest(ServerInterface* server, GenericServerContext* context,
+                        ServerAsyncStreamingInterface* stream,
+                        CompletionQueue* call_cq,
+                        ServerCompletionQueue* notification_cq, void* tag,
+                        bool delete_on_finalize);
+
+    bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE;
+
+   private:
+    grpc_call_details call_details_;
+  };
+
+  template <class Message>
+  void RequestAsyncCall(void* registered_method, ServerContext* context,
+                        ServerAsyncStreamingInterface* stream,
+                        CompletionQueue* call_cq,
+                        ServerCompletionQueue* notification_cq, void* tag,
+                        Message* message) {
+    new PayloadAsyncRequest<Message>(registered_method, this, context, stream,
+                                     call_cq, notification_cq, tag, message);
+  }
+
+  void RequestAsyncCall(void* registered_method, ServerContext* context,
+                        ServerAsyncStreamingInterface* stream,
+                        CompletionQueue* call_cq,
+                        ServerCompletionQueue* notification_cq, void* tag) {
+    new NoPayloadAsyncRequest(registered_method, this, context, stream, call_cq,
+                              notification_cq, tag);
+  }
+
+  void RequestAsyncGenericCall(GenericServerContext* context,
+                               ServerAsyncStreamingInterface* stream,
+                               CompletionQueue* call_cq,
+                               ServerCompletionQueue* notification_cq,
+                               void* tag) {
+    new GenericAsyncRequest(this, context, stream, call_cq, notification_cq,
+                            tag, true);
+  }
+};
+
+}  // namespace grpc
+
+#endif  // GRPCXX_SERVER_INTERFACE_H
diff --git a/include/grpc++/impl/rpc_method.h b/include/grpc++/impl/rpc_method.h
index 9800268..cc29f6d 100644
--- a/include/grpc++/impl/rpc_method.h
+++ b/include/grpc++/impl/rpc_method.h
@@ -36,7 +36,7 @@
 
 #include <memory>
 
-#include <grpc++/channel.h>
+#include <grpc++/impl/codegen/channel_interface.h>
 
 namespace grpc {
 
@@ -53,7 +53,7 @@
       : name_(name), method_type_(type), channel_tag_(NULL) {}
 
   RpcMethod(const char* name, RpcType type,
-            const std::shared_ptr<Channel>& channel)
+            const std::shared_ptr<ChannelInterface>& channel)
       : name_(name),
         method_type_(type),
         channel_tag_(channel->RegisterMethod(name)) {}
diff --git a/include/grpc++/impl/service_type.h b/include/grpc++/impl/service_type.h
index 3b6ac1d..123f889 100644
--- a/include/grpc++/impl/service_type.h
+++ b/include/grpc++/impl/service_type.h
@@ -35,7 +35,7 @@
 #define GRPCXX_IMPL_SERVICE_TYPE_H
 
 #include <grpc++/impl/serialization_traits.h>
-#include <grpc++/server.h>
+#include <grpc++/impl/codegen/server_interface.h>
 #include <grpc++/support/config.h>
 #include <grpc++/support/status.h>
 
@@ -45,6 +45,7 @@
 class CompletionQueue;
 class RpcService;
 class Server;
+class ServerInterface;
 class ServerCompletionQueue;
 class ServerContext;
 
@@ -61,7 +62,7 @@
   virtual void SendInitialMetadata(void* tag) = 0;
 
  private:
-  friend class Server;
+  friend class ServerInterface;
   virtual void BindCall(Call* call) = 0;
 };
 
@@ -112,7 +113,8 @@
 
  private:
   friend class Server;
-  Server* server_;
+  friend class ServerInterface;
+  ServerInterface* server_;
   const char** const method_names_;
   size_t method_count_;
   void** request_args_;
diff --git a/include/grpc++/server.h b/include/grpc++/server.h
index 644e66e..2c95bd8 100644
--- a/include/grpc++/server.h
+++ b/include/grpc++/server.h
@@ -41,6 +41,7 @@
 #include <grpc++/impl/call.h>
 #include <grpc++/impl/grpc_library.h>
 #include <grpc++/impl/sync.h>
+#include <grpc++/impl/codegen/server_interface.h>
 #include <grpc++/security/server_credentials.h>
 #include <grpc++/support/channel_arguments.h>
 #include <grpc++/support/config.h>
@@ -63,28 +64,16 @@
 /// Models a gRPC server.
 ///
 /// Servers are configured and started via \a grpc::ServerBuilder.
-class Server GRPC_FINAL : public GrpcLibrary, private CallHook {
+class Server GRPC_FINAL : public ServerInterface,
+                          public GrpcLibrary {
  public:
   ~Server();
 
-  /// Shutdown the server, blocking until all rpc processing finishes.
-  /// Forcefully terminate pending calls after \a deadline expires.
-  ///
-  /// \param deadline How long to wait until pending rpcs are forcefully
-  /// terminated.
-  template <class T>
-  void Shutdown(const T& deadline) {
-    ShutdownInternal(TimePoint<T>(deadline).raw_time());
-  }
-
-  /// Shutdown the server, waiting for all rpc processing to finish.
-  void Shutdown() { ShutdownInternal(gpr_inf_future(GPR_CLOCK_MONOTONIC)); }
-
   /// Block waiting for all work to complete.
   ///
   /// \warning The server must be either shutting down or some other thread must
   /// call \a Shutdown for this function to ever return.
-  void Wait();
+  void Wait() override;
 
   /// Global Callbacks
   ///
@@ -112,6 +101,10 @@
   class AsyncRequest;
   class ShutdownRequest;
 
+  class UnimplementedAsyncRequestContext;
+  class UnimplementedAsyncRequest;
+  class UnimplementedAsyncResponse;
+
   /// Server constructors. To be used by \a ServerBuilder only.
   ///
   /// \param thread_pool The threadpool instance to use for call processing.
@@ -123,16 +116,16 @@
 
   /// Register a service. This call does not take ownership of the service.
   /// The service must exist for the lifetime of the Server instance.
-  bool RegisterService(const grpc::string* host, RpcService* service);
+  bool RegisterService(const grpc::string* host, RpcService* service) override;
 
   /// Register an asynchronous service. This call does not take ownership of the
   /// service. The service must exist for the lifetime of the Server instance.
   bool RegisterAsyncService(const grpc::string* host,
-                            AsynchronousService* service);
+                            AsynchronousService* service) override;
 
   /// Register a generic service. This call does not take ownership of the
   /// service. The service must exist for the lifetime of the Server instance.
-  void RegisterAsyncGenericService(AsyncGenericService* service);
+  void RegisterAsyncGenericService(AsyncGenericService* service) override;
 
   /// Tries to bind \a server to the given \a addr.
   ///
@@ -145,7 +138,7 @@
   /// \return bound port number on sucess, 0 on failure.
   ///
   /// \warning It's an error to call this method on an already started server.
-  int AddListeningPort(const grpc::string& addr, ServerCredentials* creds);
+  int AddListeningPort(const grpc::string& addr, ServerCredentials* creds) override;
 
   /// Start the server.
   ///
@@ -155,141 +148,21 @@
   /// \param num_cqs How many completion queues does \a cqs hold.
   ///
   /// \return true on a successful shutdown.
-  bool Start(ServerCompletionQueue** cqs, size_t num_cqs);
-
-  void HandleQueueClosed();
+  bool Start(ServerCompletionQueue** cqs, size_t num_cqs) override;
 
   /// Process one or more incoming calls.
-  void RunRpc();
+  void RunRpc() override;
 
   /// Schedule \a RunRpc to run in the threadpool.
-  void ScheduleCallback();
+  void ScheduleCallback() override;
 
   void PerformOpsOnCall(CallOpSetInterface* ops, Call* call) GRPC_OVERRIDE;
 
-  void ShutdownInternal(gpr_timespec deadline);
+  void ShutdownInternal(gpr_timespec deadline) override;
 
-  class BaseAsyncRequest : public CompletionQueueTag {
-   public:
-    BaseAsyncRequest(Server* server, ServerContext* context,
-                     ServerAsyncStreamingInterface* stream,
-                     CompletionQueue* call_cq, void* tag,
-                     bool delete_on_finalize);
-    virtual ~BaseAsyncRequest();
+  int max_message_size() const override { return max_message_size_; };
 
-    bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE;
-
-   protected:
-    Server* const server_;
-    ServerContext* const context_;
-    ServerAsyncStreamingInterface* const stream_;
-    CompletionQueue* const call_cq_;
-    void* const tag_;
-    const bool delete_on_finalize_;
-    grpc_call* call_;
-    grpc_metadata_array initial_metadata_array_;
-  };
-
-  class RegisteredAsyncRequest : public BaseAsyncRequest {
-   public:
-    RegisteredAsyncRequest(Server* server, ServerContext* context,
-                           ServerAsyncStreamingInterface* stream,
-                           CompletionQueue* call_cq, void* tag);
-
-    // uses BaseAsyncRequest::FinalizeResult
-
-   protected:
-    void IssueRequest(void* registered_method, grpc_byte_buffer** payload,
-                      ServerCompletionQueue* notification_cq);
-  };
-
-  class NoPayloadAsyncRequest GRPC_FINAL : public RegisteredAsyncRequest {
-   public:
-    NoPayloadAsyncRequest(void* registered_method, Server* server,
-                          ServerContext* context,
-                          ServerAsyncStreamingInterface* stream,
-                          CompletionQueue* call_cq,
-                          ServerCompletionQueue* notification_cq, void* tag)
-        : RegisteredAsyncRequest(server, context, stream, call_cq, tag) {
-      IssueRequest(registered_method, nullptr, notification_cq);
-    }
-
-    // uses RegisteredAsyncRequest::FinalizeResult
-  };
-
-  template <class Message>
-  class PayloadAsyncRequest GRPC_FINAL : public RegisteredAsyncRequest {
-   public:
-    PayloadAsyncRequest(void* registered_method, Server* server,
-                        ServerContext* context,
-                        ServerAsyncStreamingInterface* stream,
-                        CompletionQueue* call_cq,
-                        ServerCompletionQueue* notification_cq, void* tag,
-                        Message* request)
-        : RegisteredAsyncRequest(server, context, stream, call_cq, tag),
-          request_(request) {
-      IssueRequest(registered_method, &payload_, notification_cq);
-    }
-
-    bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE {
-      bool serialization_status =
-          *status && payload_ &&
-          SerializationTraits<Message>::Deserialize(
-              payload_, request_, server_->max_message_size_).ok();
-      bool ret = RegisteredAsyncRequest::FinalizeResult(tag, status);
-      *status = serialization_status&&* status;
-      return ret;
-    }
-
-   private:
-    grpc_byte_buffer* payload_;
-    Message* const request_;
-  };
-
-  class GenericAsyncRequest : public BaseAsyncRequest {
-   public:
-    GenericAsyncRequest(Server* server, GenericServerContext* context,
-                        ServerAsyncStreamingInterface* stream,
-                        CompletionQueue* call_cq,
-                        ServerCompletionQueue* notification_cq, void* tag,
-                        bool delete_on_finalize);
-
-    bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE;
-
-   private:
-    grpc_call_details call_details_;
-  };
-
-  class UnimplementedAsyncRequestContext;
-  class UnimplementedAsyncRequest;
-  class UnimplementedAsyncResponse;
-
-  template <class Message>
-  void RequestAsyncCall(void* registered_method, ServerContext* context,
-                        ServerAsyncStreamingInterface* stream,
-                        CompletionQueue* call_cq,
-                        ServerCompletionQueue* notification_cq, void* tag,
-                        Message* message) {
-    new PayloadAsyncRequest<Message>(registered_method, this, context, stream,
-                                     call_cq, notification_cq, tag, message);
-  }
-
-  void RequestAsyncCall(void* registered_method, ServerContext* context,
-                        ServerAsyncStreamingInterface* stream,
-                        CompletionQueue* call_cq,
-                        ServerCompletionQueue* notification_cq, void* tag) {
-    new NoPayloadAsyncRequest(registered_method, this, context, stream, call_cq,
-                              notification_cq, tag);
-  }
-
-  void RequestAsyncGenericCall(GenericServerContext* context,
-                               ServerAsyncStreamingInterface* stream,
-                               CompletionQueue* call_cq,
-                               ServerCompletionQueue* notification_cq,
-                               void* tag) {
-    new GenericAsyncRequest(this, context, stream, call_cq, notification_cq,
-                            tag, true);
-  }
+  grpc_server* server() override { return server_; };
 
   const int max_message_size_;
 
diff --git a/include/grpc++/server_context.h b/include/grpc++/server_context.h
index 8ba7348..1c3f39e 100644
--- a/include/grpc++/server_context.h
+++ b/include/grpc++/server_context.h
@@ -80,6 +80,7 @@
 class CallOpBuffer;
 class CompletionQueue;
 class Server;
+class ServerInterface;
 
 namespace testing {
 class InteropServerContextInspector;
@@ -138,6 +139,7 @@
 
  private:
   friend class ::grpc::testing::InteropServerContextInspector;
+  friend class ::grpc::ServerInterface;
   friend class ::grpc::Server;
   template <class W, class R>
   friend class ::grpc::ServerAsyncReader;
diff --git a/include/grpc++/support/async_stream.h b/include/grpc++/support/async_stream.h
index 0c96352..87c38a7 100644
--- a/include/grpc++/support/async_stream.h
+++ b/include/grpc++/support/async_stream.h
@@ -35,7 +35,7 @@
 #define GRPCXX_SUPPORT_ASYNC_STREAM_H
 
 #include <grpc/support/log.h>
-#include <grpc++/channel.h>
+#include <grpc++/impl/codegen/channel_interface.h>
 #include <grpc++/client_context.h>
 #include <grpc++/completion_queue.h>
 #include <grpc++/impl/call.h>
@@ -103,7 +103,7 @@
  public:
   /// Create a stream and write the first request out.
   template <class W>
-  ClientAsyncReader(Channel* channel, CompletionQueue* cq,
+  ClientAsyncReader(ChannelInterface* channel, CompletionQueue* cq,
                     const RpcMethod& method, ClientContext* context,
                     const W& request, void* tag)
       : context_(context), call_(channel->CreateCall(method, context, cq)) {
@@ -166,7 +166,7 @@
 class ClientAsyncWriter GRPC_FINAL : public ClientAsyncWriterInterface<W> {
  public:
   template <class R>
-  ClientAsyncWriter(Channel* channel, CompletionQueue* cq,
+  ClientAsyncWriter(ChannelInterface* channel, CompletionQueue* cq,
                     const RpcMethod& method, ClientContext* context,
                     R* response, void* tag)
       : context_(context), call_(channel->CreateCall(method, context, cq)) {
@@ -234,7 +234,7 @@
 class ClientAsyncReaderWriter GRPC_FINAL
     : public ClientAsyncReaderWriterInterface<W, R> {
  public:
-  ClientAsyncReaderWriter(Channel* channel, CompletionQueue* cq,
+  ClientAsyncReaderWriter(ChannelInterface* channel, CompletionQueue* cq,
                           const RpcMethod& method, ClientContext* context,
                           void* tag)
       : context_(context), call_(channel->CreateCall(method, context, cq)) {
diff --git a/include/grpc++/support/async_unary_call.h b/include/grpc++/support/async_unary_call.h
index 0f4ad26..396bd15 100644
--- a/include/grpc++/support/async_unary_call.h
+++ b/include/grpc++/support/async_unary_call.h
@@ -35,7 +35,7 @@
 #define GRPCXX_SUPPORT_ASYNC_UNARY_CALL_H
 
 #include <grpc/support/log.h>
-#include <grpc++/channel.h>
+#include <grpc++/impl/codegen/channel_interface.h>
 #include <grpc++/client_context.h>
 #include <grpc++/completion_queue.h>
 #include <grpc++/server_context.h>
@@ -58,7 +58,7 @@
     : public ClientAsyncResponseReaderInterface<R> {
  public:
   template <class W>
-  ClientAsyncResponseReader(Channel* channel, CompletionQueue* cq,
+  ClientAsyncResponseReader(ChannelInterface* channel, CompletionQueue* cq,
                             const RpcMethod& method, ClientContext* context,
                             const W& request)
       : context_(context), call_(channel->CreateCall(method, context, cq)) {
diff --git a/src/compiler/cpp_generator.cc b/src/compiler/cpp_generator.cc
index 3c8ca8a..e182d61 100644
--- a/src/compiler/cpp_generator.cc
+++ b/src/compiler/cpp_generator.cc
@@ -123,7 +123,6 @@
       "\n"
       "namespace grpc {\n"
       "class CompletionQueue;\n"
-      "class Channel;\n"
       "class RpcService;\n"
       "class ServerCompletionQueue;\n"
       "class ServerContext;\n"
@@ -557,14 +556,14 @@
       "class Stub GRPC_FINAL : public StubInterface"
       " {\n public:\n");
   printer->Indent();
-  printer->Print("Stub(const std::shared_ptr< ::grpc::Channel>& channel);\n");
+  printer->Print("Stub(const std::shared_ptr< ::grpc::ChannelInterface>& channel);\n");
   for (int i = 0; i < service->method_count(); ++i) {
     PrintHeaderClientMethod(printer, service->method(i), vars, true);
   }
   printer->Outdent();
   printer->Print("\n private:\n");
   printer->Indent();
-  printer->Print("std::shared_ptr< ::grpc::Channel> channel_;\n");
+  printer->Print("std::shared_ptr< ::grpc::ChannelInterface> channel_;\n");
   for (int i = 0; i < service->method_count(); ++i) {
     PrintHeaderClientMethod(printer, service->method(i), vars, false);
   }
@@ -575,7 +574,7 @@
   printer->Print("};\n");
   printer->Print(
       "static std::unique_ptr<Stub> NewStub(const std::shared_ptr< "
-      "::grpc::Channel>& channel, "
+      "::grpc::ChannelInterface>& channel, "
       "const ::grpc::StubOptions& options = ::grpc::StubOptions());\n");
 
   printer->Print("\n");
@@ -702,10 +701,10 @@
     grpc::protobuf::io::Printer printer(&output_stream, '$');
     std::map<grpc::string, grpc::string> vars;
 
-    printer.Print(vars, "#include <grpc++/channel.h>\n");
     printer.Print(vars, "#include <grpc++/impl/client_unary_call.h>\n");
     printer.Print(vars, "#include <grpc++/impl/rpc_service_method.h>\n");
     printer.Print(vars, "#include <grpc++/impl/service_type.h>\n");
+    printer.Print(vars, "#include <grpc++/impl/codegen/channel_interface.h>\n");
     printer.Print(vars, "#include <grpc++/support/async_unary_call.h>\n");
     printer.Print(vars, "#include <grpc++/support/async_stream.h>\n");
     printer.Print(vars, "#include <grpc++/support/sync_stream.h>\n");
@@ -967,7 +966,7 @@
 
   printer->Print(*vars,
                  "std::unique_ptr< $ns$$Service$::Stub> $ns$$Service$::NewStub("
-                 "const std::shared_ptr< ::grpc::Channel>& channel, "
+                 "const std::shared_ptr< ::grpc::ChannelInterface>& channel, "
                  "const ::grpc::StubOptions& options) {\n"
                  "  std::unique_ptr< $ns$$Service$::Stub> stub(new "
                  "$ns$$Service$::Stub(channel));\n"
@@ -975,7 +974,7 @@
                  "}\n\n");
   printer->Print(*vars,
                  "$ns$$Service$::Stub::Stub(const std::shared_ptr< "
-                 "::grpc::Channel>& channel)\n");
+                 "::grpc::ChannelInterface>& channel)\n");
   printer->Indent();
   printer->Print(": channel_(channel)");
   for (int i = 0; i < service->method_count(); ++i) {
diff --git a/src/cpp/server/server.cc b/src/cpp/server/server.cc
index 878775b..0e011e2 100644
--- a/src/cpp/server/server.cc
+++ b/src/cpp/server/server.cc
@@ -439,8 +439,8 @@
   GPR_ASSERT(GRPC_CALL_OK == result);
 }
 
-Server::BaseAsyncRequest::BaseAsyncRequest(
-    Server* server, ServerContext* context,
+ServerInterface::BaseAsyncRequest::BaseAsyncRequest(
+    ServerInterface* server, ServerContext* context,
     ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq, void* tag,
     bool delete_on_finalize)
     : server_(server),
@@ -453,9 +453,7 @@
   memset(&initial_metadata_array_, 0, sizeof(initial_metadata_array_));
 }
 
-Server::BaseAsyncRequest::~BaseAsyncRequest() {}
-
-bool Server::BaseAsyncRequest::FinalizeResult(void** tag, bool* status) {
+bool ServerInterface::BaseAsyncRequest::FinalizeResult(void** tag, bool* status) {
   if (*status) {
     for (size_t i = 0; i < initial_metadata_array_.count; i++) {
       context_->client_metadata_.insert(
@@ -469,7 +467,7 @@
   grpc_metadata_array_destroy(&initial_metadata_array_);
   context_->set_call(call_);
   context_->cq_ = call_cq_;
-  Call call(call_, server_, call_cq_, server_->max_message_size_);
+  Call call(call_, server_, call_cq_, server_->max_message_size());
   if (*status && call_) {
     context_->BeginCompletionOp(&call);
   }
@@ -482,22 +480,22 @@
   return true;
 }
 
-Server::RegisteredAsyncRequest::RegisteredAsyncRequest(
-    Server* server, ServerContext* context,
+ServerInterface::RegisteredAsyncRequest::RegisteredAsyncRequest(
+    ServerInterface* server, ServerContext* context,
     ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq, void* tag)
     : BaseAsyncRequest(server, context, stream, call_cq, tag, true) {}
 
-void Server::RegisteredAsyncRequest::IssueRequest(
+void ServerInterface::RegisteredAsyncRequest::IssueRequest(
     void* registered_method, grpc_byte_buffer** payload,
     ServerCompletionQueue* notification_cq) {
   grpc_server_request_registered_call(
-      server_->server_, registered_method, &call_, &context_->deadline_,
+      server_->server(), registered_method, &call_, &context_->deadline_,
       &initial_metadata_array_, payload, call_cq_->cq(), notification_cq->cq(),
       this);
 }
 
-Server::GenericAsyncRequest::GenericAsyncRequest(
-    Server* server, GenericServerContext* context,
+ServerInterface::GenericAsyncRequest::GenericAsyncRequest(
+    ServerInterface* server, GenericServerContext* context,
     ServerAsyncStreamingInterface* stream, CompletionQueue* call_cq,
     ServerCompletionQueue* notification_cq, void* tag, bool delete_on_finalize)
     : BaseAsyncRequest(server, context, stream, call_cq, tag,
@@ -505,12 +503,12 @@
   grpc_call_details_init(&call_details_);
   GPR_ASSERT(notification_cq);
   GPR_ASSERT(call_cq);
-  grpc_server_request_call(server->server_, &call_, &call_details_,
+  grpc_server_request_call(server->server(), &call_, &call_details_,
                            &initial_metadata_array_, call_cq->cq(),
                            notification_cq->cq(), this);
 }
 
-bool Server::GenericAsyncRequest::FinalizeResult(void** tag, bool* status) {
+bool ServerInterface::GenericAsyncRequest::FinalizeResult(void** tag, bool* status) {
   // TODO(yangg) remove the copy here.
   if (*status) {
     static_cast<GenericServerContext*>(context_)->method_ =
diff --git a/tools/doxygen/Doxyfile.c++ b/tools/doxygen/Doxyfile.c++
index 500d110..d288dce 100644
--- a/tools/doxygen/Doxyfile.c++
+++ b/tools/doxygen/Doxyfile.c++
@@ -769,6 +769,8 @@
 include/grpc++/grpc++.h \
 include/grpc++/impl/call.h \
 include/grpc++/impl/client_unary_call.h \
+include/grpc++/impl/codegen/channel_interface.h \
+include/grpc++/impl/codegen/server_interface.h \
 include/grpc++/impl/grpc_library.h \
 include/grpc++/impl/proto_utils.h \
 include/grpc++/impl/rpc_method.h \
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index ba1dec0..f93084c 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -769,6 +769,8 @@
 include/grpc++/grpc++.h \
 include/grpc++/impl/call.h \
 include/grpc++/impl/client_unary_call.h \
+include/grpc++/impl/codegen/channel_interface.h \
+include/grpc++/impl/codegen/server_interface.h \
 include/grpc++/impl/grpc_library.h \
 include/grpc++/impl/proto_utils.h \
 include/grpc++/impl/rpc_method.h \
diff --git a/tools/run_tests/sources_and_headers.json b/tools/run_tests/sources_and_headers.json
index 3e42c59..0c1f2d2 100644
--- a/tools/run_tests/sources_and_headers.json
+++ b/tools/run_tests/sources_and_headers.json
@@ -3828,6 +3828,8 @@
       "include/grpc++/grpc++.h", 
       "include/grpc++/impl/call.h", 
       "include/grpc++/impl/client_unary_call.h", 
+      "include/grpc++/impl/codegen/channel_interface.h", 
+      "include/grpc++/impl/codegen/server_interface.h", 
       "include/grpc++/impl/grpc_library.h", 
       "include/grpc++/impl/proto_utils.h", 
       "include/grpc++/impl/rpc_method.h", 
@@ -3882,6 +3884,8 @@
       "include/grpc++/grpc++.h", 
       "include/grpc++/impl/call.h", 
       "include/grpc++/impl/client_unary_call.h", 
+      "include/grpc++/impl/codegen/channel_interface.h", 
+      "include/grpc++/impl/codegen/server_interface.h", 
       "include/grpc++/impl/grpc_library.h", 
       "include/grpc++/impl/proto_utils.h", 
       "include/grpc++/impl/rpc_method.h", 
@@ -4014,6 +4018,8 @@
       "include/grpc++/grpc++.h", 
       "include/grpc++/impl/call.h", 
       "include/grpc++/impl/client_unary_call.h", 
+      "include/grpc++/impl/codegen/channel_interface.h", 
+      "include/grpc++/impl/codegen/server_interface.h", 
       "include/grpc++/impl/grpc_library.h", 
       "include/grpc++/impl/proto_utils.h", 
       "include/grpc++/impl/rpc_method.h", 
@@ -4065,6 +4071,8 @@
       "include/grpc++/grpc++.h", 
       "include/grpc++/impl/call.h", 
       "include/grpc++/impl/client_unary_call.h", 
+      "include/grpc++/impl/codegen/channel_interface.h", 
+      "include/grpc++/impl/codegen/server_interface.h", 
       "include/grpc++/impl/grpc_library.h", 
       "include/grpc++/impl/proto_utils.h", 
       "include/grpc++/impl/rpc_method.h", 
diff --git a/vsprojects/vcxproj/grpc++/grpc++.vcxproj b/vsprojects/vcxproj/grpc++/grpc++.vcxproj
index 886d415..071e002 100644
--- a/vsprojects/vcxproj/grpc++/grpc++.vcxproj
+++ b/vsprojects/vcxproj/grpc++/grpc++.vcxproj
@@ -267,6 +267,8 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\grpc++.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\call.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\client_unary_call.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\channel_interface.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\server_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\grpc_library.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\proto_utils.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\rpc_method.h" />
diff --git a/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters b/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
index abd39c7..e918200 100644
--- a/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
@@ -126,6 +126,12 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\client_unary_call.h">
       <Filter>include\grpc++\impl</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\channel_interface.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\server_interface.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\grpc_library.h">
       <Filter>include\grpc++\impl</Filter>
     </ClInclude>
@@ -266,6 +272,9 @@
     <Filter Include="include\grpc++\impl">
       <UniqueIdentifier>{0da8cd95-314f-da1b-5ce7-7791a5be1f1a}</UniqueIdentifier>
     </Filter>
+    <Filter Include="include\grpc++\impl\codegen">
+      <UniqueIdentifier>{a3e7f28b-a7c7-7364-d402-edb1bfa414a4}</UniqueIdentifier>
+    </Filter>
     <Filter Include="include\grpc++\security">
       <UniqueIdentifier>{a80eb32b-1be9-1187-5f40-30d92accecc8}</UniqueIdentifier>
     </Filter>
diff --git a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
index 2193321..2101f8f 100644
--- a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
+++ b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
@@ -267,6 +267,8 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\grpc++.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\call.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\client_unary_call.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\channel_interface.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\server_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\grpc_library.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\proto_utils.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\rpc_method.h" />
diff --git a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
index 073b181..d19d8eb 100644
--- a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
@@ -111,6 +111,12 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\client_unary_call.h">
       <Filter>include\grpc++\impl</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\channel_interface.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\server_interface.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\grpc_library.h">
       <Filter>include\grpc++\impl</Filter>
     </ClInclude>
@@ -242,6 +248,9 @@
     <Filter Include="include\grpc++\impl">
       <UniqueIdentifier>{dadc0002-f2ac-451b-a9b8-33b8de10b5fc}</UniqueIdentifier>
     </Filter>
+    <Filter Include="include\grpc++\impl\codegen">
+      <UniqueIdentifier>{ccc364e2-3f28-8bfc-c26e-800dd6f9a9af}</UniqueIdentifier>
+    </Filter>
     <Filter Include="include\grpc++\security">
       <UniqueIdentifier>{64bf60ff-9192-bb59-dcc8-8a0021e1d016}</UniqueIdentifier>
     </Filter>