Merge branch 'master' into rpc_mgr

53 files changed, 1241 insertions, 1048 deletions

diff --git a/include/grpc++/create_channel.h b/include/grpc++/create_channel.h
index e9ccb51503..0537695ed2 100644
--- a/include/grpc++/create_channel.h
+++ b/include/grpc++/create_channel.h
@@ -48,7 +48,6 @@ namespace grpc {
 /// \param target The URI of the endpoint to connect to.
 /// \param creds Credentials to use for the created channel. If it does not hold
 /// an object or is invalid, a lame channel is returned.
-/// \param args Options for channel creation.
 std::shared_ptr<Channel> CreateChannel(
     const grpc::string& target,
     const std::shared_ptr<ChannelCredentials>& creds);
diff --git a/include/grpc++/ext/reflection.grpc.pb.h b/include/grpc++/ext/reflection.grpc.pb.h
index 0b4ef86147..064117e303 100644
--- a/include/grpc++/ext/reflection.grpc.pb.h
+++ b/include/grpc++/ext/reflection.grpc.pb.h
@@ -74,6 +74,7 @@
 
 #include <grpc++/impl/codegen/async_stream.h>
 #include <grpc++/impl/codegen/async_unary_call.h>
+#include <grpc++/impl/codegen/method_handler_impl.h>
 #include <grpc++/impl/codegen/proto_utils.h>
 #include <grpc++/impl/codegen/rpc_method.h>
 #include <grpc++/impl/codegen/service_type.h>
@@ -174,6 +175,7 @@ class ServerReflection GRPC_FINAL {
       return ::grpc::Status(::grpc::StatusCode::UNIMPLEMENTED, "");
     }
   };
+  typedef Service StreamedUnaryService;
 };
 
 }  // namespace v1alpha
diff --git a/include/grpc++/grpc++.h b/include/grpc++/grpc++.h
index ef07e19975..afb1c555bb 100644
--- a/include/grpc++/grpc++.h
+++ b/include/grpc++/grpc++.h
@@ -51,6 +51,9 @@
 #ifndef GRPCXX_GRPCXX_H
 #define GRPCXX_GRPCXX_H
 
+// Pragma for http://include-what-you-use.org/ tool, tells that following
+// headers are not private for grpc++.h and are part of its interface.
+// IWYU pragma: begin_exports
 #include <grpc/grpc.h>
 
 #include <grpc++/channel.h>
@@ -62,5 +65,6 @@
 #include <grpc++/server_builder.h>
 #include <grpc++/server_context.h>
 #include <grpc++/server_posix.h>
+// IWYU pragma: end_exports
 
 #endif  // GRPCXX_GRPCXX_H
diff --git a/include/grpc++/impl/codegen/async_unary_call.h b/include/grpc++/impl/codegen/async_unary_call.h
index 5ceab73cea..87c94d6507 100644
--- a/include/grpc++/impl/codegen/async_unary_call.h
+++ b/include/grpc++/impl/codegen/async_unary_call.h
@@ -40,7 +40,6 @@
 #include <grpc++/impl/codegen/server_context.h>
 #include <grpc++/impl/codegen/service_type.h>
 #include <grpc++/impl/codegen/status.h>
-#include <grpc/impl/codegen/log.h>
 
 namespace grpc {
 
diff --git a/include/grpc++/impl/codegen/call.h b/include/grpc++/impl/codegen/call.h
index dfac177970..e211373e7d 100644
--- a/include/grpc++/impl/codegen/call.h
+++ b/include/grpc++/impl/codegen/call.h
@@ -46,9 +46,9 @@
 #include <grpc++/impl/codegen/core_codegen_interface.h>
 #include <grpc++/impl/codegen/serialization_traits.h>
 #include <grpc++/impl/codegen/status.h>
+#include <grpc++/impl/codegen/status_helper.h>
 #include <grpc++/impl/codegen/string_ref.h>
 
-#include <grpc/impl/codegen/alloc.h>
 #include <grpc/impl/codegen/compression_types.h>
 #include <grpc/impl/codegen/grpc_types.h>
 
@@ -175,7 +175,7 @@ template <int I>
 class CallNoOp {
  protected:
   void AddOp(grpc_op* ops, size_t* nops) {}
-  void FinishOp(bool* status, int max_message_size) {}
+  void FinishOp(bool* status, int max_receive_message_size) {}
 };
 
 class CallOpSendInitialMetadata {
@@ -213,7 +213,7 @@ class CallOpSendInitialMetadata {
     op->data.send_initial_metadata.maybe_compression_level.level =
         maybe_compression_level_.level;
   }
-  void FinishOp(bool* status, int max_message_size) {
+  void FinishOp(bool* status, int max_receive_message_size) {
     if (!send_) return;
     g_core_codegen_interface->gpr_free(initial_metadata_);
     send_ = false;
@@ -253,7 +253,7 @@ class CallOpSendMessage {
     // Flags are per-message: clear them after use.
     write_options_.Clear();
   }
-  void FinishOp(bool* status, int max_message_size) {
+  void FinishOp(bool* status, int max_receive_message_size) {
     if (own_buf_) g_core_codegen_interface->grpc_byte_buffer_destroy(send_buf_);
     send_buf_ = nullptr;
   }
@@ -301,13 +301,14 @@ class CallOpRecvMessage {
     op->data.recv_message = &recv_buf_;
   }
 
-  void FinishOp(bool* status, int max_message_size) {
+  void FinishOp(bool* status, int max_receive_message_size) {
     if (message_ == nullptr) return;
     if (recv_buf_) {
       if (*status) {
-        got_message = *status = SerializationTraits<R>::Deserialize(
-                                    recv_buf_, message_, max_message_size)
-                                    .ok();
+        got_message = *status =
+            SerializationTraits<R>::Deserialize(recv_buf_, message_,
+                                                max_receive_message_size)
+                .ok();
       } else {
         got_message = false;
         g_core_codegen_interface->grpc_byte_buffer_destroy(recv_buf_);
@@ -330,7 +331,8 @@ class CallOpRecvMessage {
 namespace CallOpGenericRecvMessageHelper {
 class DeserializeFunc {
  public:
-  virtual Status Deserialize(grpc_byte_buffer* buf, int max_message_size) = 0;
+  virtual Status Deserialize(grpc_byte_buffer* buf,
+                             int max_receive_message_size) = 0;
   virtual ~DeserializeFunc() {}
 };
 
@@ -339,8 +341,9 @@ class DeserializeFuncType GRPC_FINAL : public DeserializeFunc {
  public:
   DeserializeFuncType(R* message) : message_(message) {}
   Status Deserialize(grpc_byte_buffer* buf,
-                     int max_message_size) GRPC_OVERRIDE {
-    return SerializationTraits<R>::Deserialize(buf, message_, max_message_size);
+                     int max_receive_message_size) GRPC_OVERRIDE {
+    return SerializationTraits<R>::Deserialize(buf, message_,
+                                               max_receive_message_size);
   }
 
   ~DeserializeFuncType() GRPC_OVERRIDE {}
@@ -379,12 +382,13 @@ class CallOpGenericRecvMessage {
     op->data.recv_message = &recv_buf_;
   }
 
-  void FinishOp(bool* status, int max_message_size) {
+  void FinishOp(bool* status, int max_receive_message_size) {
     if (!deserialize_) return;
     if (recv_buf_) {
       if (*status) {
         got_message = true;
-        *status = deserialize_->Deserialize(recv_buf_, max_message_size).ok();
+        *status =
+            deserialize_->Deserialize(recv_buf_, max_receive_message_size).ok();
       } else {
         got_message = false;
         g_core_codegen_interface->grpc_byte_buffer_destroy(recv_buf_);
@@ -418,7 +422,7 @@ class CallOpClientSendClose {
     op->flags = 0;
     op->reserved = NULL;
   }
-  void FinishOp(bool* status, int max_message_size) { send_ = false; }
+  void FinishOp(bool* status, int max_receive_message_size) { send_ = false; }
 
  private:
   bool send_;
@@ -434,7 +438,7 @@ class CallOpServerSendStatus {
     trailing_metadata_count_ = trailing_metadata.size();
     trailing_metadata_ = FillMetadataArray(trailing_metadata);
     send_status_available_ = true;
-    send_status_code_ = static_cast<grpc_status_code>(status.error_code());
+    send_status_code_ = static_cast<grpc_status_code>(GetCanonicalCode(status));
     send_status_details_ = status.error_message();
   }
 
@@ -453,7 +457,7 @@ class CallOpServerSendStatus {
     op->reserved = NULL;
   }
 
-  void FinishOp(bool* status, int max_message_size) {
+  void FinishOp(bool* status, int max_receive_message_size) {
     if (!send_status_available_) return;
     g_core_codegen_interface->gpr_free(trailing_metadata_);
     send_status_available_ = false;
@@ -486,7 +490,7 @@ class CallOpRecvInitialMetadata {
     op->flags = 0;
     op->reserved = NULL;
   }
-  void FinishOp(bool* status, int max_message_size) {
+  void FinishOp(bool* status, int max_receive_message_size) {
     if (recv_initial_metadata_ == nullptr) return;
     FillMetadataMap(&recv_initial_metadata_arr_, recv_initial_metadata_);
     recv_initial_metadata_ = nullptr;
@@ -525,7 +529,7 @@ class CallOpClientRecvStatus {
     op->reserved = NULL;
   }
 
-  void FinishOp(bool* status, int max_message_size) {
+  void FinishOp(bool* status, int max_receive_message_size) {
     if (recv_status_ == nullptr) return;
     FillMetadataMap(&recv_trailing_metadata_arr_, recv_trailing_metadata_);
     *recv_status_ = Status(
@@ -562,13 +566,13 @@ class CallOpSetCollectionInterface
 /// API.
 class CallOpSetInterface : public CompletionQueueTag {
  public:
-  CallOpSetInterface() : max_message_size_(0) {}
+  CallOpSetInterface() : max_receive_message_size_(0) {}
   /// Fills in grpc_op, starting from ops[*nops] and moving
   /// upwards.
   virtual void FillOps(grpc_op* ops, size_t* nops) = 0;
 
-  void set_max_message_size(int max_message_size) {
-    max_message_size_ = max_message_size;
+  void set_max_receive_message_size(int max_receive_message_size) {
+    max_receive_message_size_ = max_receive_message_size;
   }
 
   /// Mark this as belonging to a collection if needed
@@ -577,7 +581,7 @@ class CallOpSetInterface : public CompletionQueueTag {
   }
 
  protected:
-  int max_message_size_;
+  int max_receive_message_size_;
   std::shared_ptr<CallOpSetCollectionInterface> collection_;
 };
 
@@ -609,12 +613,12 @@ class CallOpSet : public CallOpSetInterface,
   }
 
   bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE {
-    this->Op1::FinishOp(status, max_message_size_);
-    this->Op2::FinishOp(status, max_message_size_);
-    this->Op3::FinishOp(status, max_message_size_);
-    this->Op4::FinishOp(status, max_message_size_);
-    this->Op5::FinishOp(status, max_message_size_);
-    this->Op6::FinishOp(status, max_message_size_);
+    this->Op1::FinishOp(status, max_receive_message_size_);
+    this->Op2::FinishOp(status, max_receive_message_size_);
+    this->Op3::FinishOp(status, max_receive_message_size_);
+    this->Op4::FinishOp(status, max_receive_message_size_);
+    this->Op5::FinishOp(status, max_receive_message_size_);
+    this->Op6::FinishOp(status, max_receive_message_size_);
     *tag = return_tag_;
     collection_.reset();  // drop the ref at this point
     return true;
@@ -646,32 +650,35 @@ class Call GRPC_FINAL {
  public:
   /* call is owned by the caller */
   Call(grpc_call* call, CallHook* call_hook, CompletionQueue* cq)
-      : call_hook_(call_hook), cq_(cq), call_(call), max_message_size_(-1) {}
+      : call_hook_(call_hook),
+        cq_(cq),
+        call_(call),
+        max_receive_message_size_(-1) {}
 
   Call(grpc_call* call, CallHook* call_hook, CompletionQueue* cq,
-       int max_message_size)
+       int max_receive_message_size)
       : call_hook_(call_hook),
         cq_(cq),
         call_(call),
-        max_message_size_(max_message_size) {}
+        max_receive_message_size_(max_receive_message_size) {}
 
   void PerformOps(CallOpSetInterface* ops) {
-    if (max_message_size_ > 0) {
-      ops->set_max_message_size(max_message_size_);
+    if (max_receive_message_size_ > 0) {
+      ops->set_max_receive_message_size(max_receive_message_size_);
     }
     call_hook_->PerformOpsOnCall(ops, this);
   }
 
-  grpc_call* call() { return call_; }
-  CompletionQueue* cq() { return cq_; }
+  grpc_call* call() const { return call_; }
+  CompletionQueue* cq() const { return cq_; }
 
-  int max_message_size() { return max_message_size_; }
+  int max_receive_message_size() { return max_receive_message_size_; }
 
  private:
   CallHook* call_hook_;
   CompletionQueue* cq_;
   grpc_call* call_;
-  int max_message_size_;
+  int max_receive_message_size_;
 };
 
 }  // namespace grpc
diff --git a/include/grpc++/impl/codegen/client_context.h b/include/grpc++/impl/codegen/client_context.h
index 012bcc2bbe..387d807c4b 100644
--- a/include/grpc++/impl/codegen/client_context.h
+++ b/include/grpc++/impl/codegen/client_context.h
@@ -62,9 +62,7 @@
 #include <grpc++/impl/codegen/sync.h>
 #include <grpc++/impl/codegen/time.h>
 #include <grpc/impl/codegen/compression_types.h>
-#include <grpc/impl/codegen/log.h>
 #include <grpc/impl/codegen/propagation_bits.h>
-#include <grpc/impl/codegen/time.h>
 
 struct census_context;
 struct grpc_call;
@@ -225,6 +223,9 @@ class ClientContext {
   /// EXPERIMENTAL: Set this request to be idempotent
   void set_idempotent(bool idempotent) { idempotent_ = idempotent; }
 
+  /// EXPERIMENTAL: Set this request to be cacheable
+  void set_cacheable(bool cacheable) { cacheable_ = cacheable; }
+
   /// EXPERIMENTAL: Trigger fail-fast or not on this request
   void set_fail_fast(bool fail_fast) { fail_fast_ = fail_fast; }
 
@@ -271,7 +272,7 @@ class ClientContext {
 
   /// Set \a algorithm to be the compression algorithm used for the client call.
   ///
-  /// \param algorith The compression algorithm used for the client call.
+  /// \param algorithm The compression algorithm used for the client call.
   void set_compression_algorithm(grpc_compression_algorithm algorithm);
 
   /// Return the peer uri in a string.
@@ -307,6 +308,10 @@ class ClientContext {
   };
   static void SetGlobalCallbacks(GlobalCallbacks* callbacks);
 
+  // Should be used for framework-level extensions only.
+  // Applications never need to call this method.
+  grpc_call* c_call() { return call_; }
+
  private:
   // Disallow copy and assign.
   ClientContext(const ClientContext&);
@@ -342,7 +347,8 @@ class ClientContext {
 
   uint32_t initial_metadata_flags() const {
     return (idempotent_ ? GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST : 0) |
-           (fail_fast_ ? 0 : GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY);
+           (fail_fast_ ? 0 : GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY) |
+           (cacheable_ ? GRPC_INITIAL_METADATA_CACHEABLE_REQUEST : 0);
   }
 
   grpc::string authority() { return authority_; }
@@ -350,6 +356,7 @@ class ClientContext {
   bool initial_metadata_received_;
   bool fail_fast_;
   bool idempotent_;
+  bool cacheable_;
   std::shared_ptr<Channel> channel_;
   grpc::mutex mu_;
   grpc_call* call_;
diff --git a/include/grpc++/impl/codegen/completion_queue.h b/include/grpc++/impl/codegen/completion_queue.h
index 03009e0561..29bc97fdf7 100644
--- a/include/grpc++/impl/codegen/completion_queue.h
+++ b/include/grpc++/impl/codegen/completion_queue.h
@@ -52,7 +52,6 @@
 #include <grpc++/impl/codegen/grpc_library.h>
 #include <grpc++/impl/codegen/status.h>
 #include <grpc++/impl/codegen/time.h>
-#include <grpc/impl/codegen/time.h>
 
 struct grpc_completion_queue;
 
@@ -68,8 +67,10 @@ template <class R>
 class ServerReader;
 template <class W>
 class ServerWriter;
+namespace internal {
 template <class W, class R>
-class ServerReaderWriter;
+class ServerReaderWriterBody;
+}
 template <class ServiceType, class RequestType, class ResponseType>
 class RpcMethodHandler;
 template <class ServiceType, class RequestType, class ResponseType>
@@ -178,15 +179,15 @@ class CompletionQueue : private GrpcLibraryCodegen {
   template <class W>
   friend class ::grpc::ServerWriter;
   template <class W, class R>
-  friend class ::grpc::ServerReaderWriter;
+  friend class ::grpc::internal::ServerReaderWriterBody;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class RpcMethodHandler;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class ClientStreamingHandler;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class ServerStreamingHandler;
-  template <class ServiceType, class RequestType, class ResponseType>
-  friend class BidiStreamingHandler;
+  template <class Streamer, bool WriteNeeded>
+  friend class TemplatedBidiStreamingHandler;
   friend class UnknownMethodHandler;
   friend class ::grpc::Server;
   friend class ::grpc::ServerContext;
@@ -217,7 +218,7 @@ class CompletionQueue : private GrpcLibraryCodegen {
   /// Performs a single polling pluck on \a tag.
   /// \warning Must not be mixed with calls to \a Next.
   void TryPluck(CompletionQueueTag* tag) {
-    auto deadline = gpr_time_0(GPR_CLOCK_REALTIME);
+    auto deadline = g_core_codegen_interface->gpr_time_0(GPR_CLOCK_REALTIME);
     auto ev = g_core_codegen_interface->grpc_completion_queue_pluck(
         cq_, tag, deadline, nullptr);
     if (ev.type == GRPC_QUEUE_TIMEOUT) return;
diff --git a/include/grpc++/impl/codegen/core_codegen.h b/include/grpc++/impl/codegen/core_codegen.h
index 2586b94504..0ce009e69d 100644
--- a/include/grpc++/impl/codegen/core_codegen.h
+++ b/include/grpc++/impl/codegen/core_codegen.h
@@ -55,6 +55,17 @@ class CoreCodegen : public CoreCodegenInterface {
   void* gpr_malloc(size_t size) GRPC_OVERRIDE;
   void gpr_free(void* p) GRPC_OVERRIDE;
 
+  void gpr_mu_init(gpr_mu* mu) GRPC_OVERRIDE;
+  void gpr_mu_destroy(gpr_mu* mu) GRPC_OVERRIDE;
+  void gpr_mu_lock(gpr_mu* mu) GRPC_OVERRIDE;
+  void gpr_mu_unlock(gpr_mu* mu) GRPC_OVERRIDE;
+  void gpr_cv_init(gpr_cv* cv) GRPC_OVERRIDE;
+  void gpr_cv_destroy(gpr_cv* cv) GRPC_OVERRIDE;
+  int gpr_cv_wait(gpr_cv* cv, gpr_mu* mu,
+                  gpr_timespec abs_deadline) GRPC_OVERRIDE;
+  void gpr_cv_signal(gpr_cv* cv) GRPC_OVERRIDE;
+  void gpr_cv_broadcast(gpr_cv* cv) GRPC_OVERRIDE;
+
   void grpc_byte_buffer_destroy(grpc_byte_buffer* bb) GRPC_OVERRIDE;
 
   int grpc_byte_buffer_reader_init(grpc_byte_buffer_reader* reader,
@@ -78,6 +89,7 @@ class CoreCodegen : public CoreCodegenInterface {
   void grpc_metadata_array_destroy(grpc_metadata_array* array) GRPC_OVERRIDE;
 
   gpr_timespec gpr_inf_future(gpr_clock_type type) GRPC_OVERRIDE;
+  gpr_timespec gpr_time_0(gpr_clock_type type) GRPC_OVERRIDE;
 
   virtual const Status& ok() GRPC_OVERRIDE;
   virtual const Status& cancelled() GRPC_OVERRIDE;
diff --git a/include/grpc++/impl/codegen/core_codegen_interface.h b/include/grpc++/impl/codegen/core_codegen_interface.h
index f9a8f9b980..68851f15c6 100644
--- a/include/grpc++/impl/codegen/core_codegen_interface.h
+++ b/include/grpc++/impl/codegen/core_codegen_interface.h
@@ -36,7 +36,13 @@
 
 #include <grpc++/impl/codegen/config.h>
 #include <grpc++/impl/codegen/status.h>
+#include <grpc/impl/codegen/byte_buffer_reader.h>
 #include <grpc/impl/codegen/grpc_types.h>
+#include <grpc/impl/codegen/sync.h>
+
+extern "C" {
+struct grpc_byte_buffer;
+}
 
 namespace grpc {
 
@@ -63,6 +69,17 @@ class CoreCodegenInterface {
   virtual void* gpr_malloc(size_t size) = 0;
   virtual void gpr_free(void* p) = 0;
 
+  virtual void gpr_mu_init(gpr_mu* mu) = 0;
+  virtual void gpr_mu_destroy(gpr_mu* mu) = 0;
+  virtual void gpr_mu_lock(gpr_mu* mu) = 0;
+  virtual void gpr_mu_unlock(gpr_mu* mu) = 0;
+  virtual void gpr_cv_init(gpr_cv* cv) = 0;
+  virtual void gpr_cv_destroy(gpr_cv* cv) = 0;
+  virtual int gpr_cv_wait(gpr_cv* cv, gpr_mu* mu,
+                          gpr_timespec abs_deadline) = 0;
+  virtual void gpr_cv_signal(gpr_cv* cv) = 0;
+  virtual void gpr_cv_broadcast(gpr_cv* cv) = 0;
+
   virtual void grpc_byte_buffer_destroy(grpc_byte_buffer* bb) = 0;
 
   virtual int grpc_byte_buffer_reader_init(grpc_byte_buffer_reader* reader,
@@ -89,6 +106,7 @@ class CoreCodegenInterface {
   virtual const Status& cancelled() = 0;
 
   virtual gpr_timespec gpr_inf_future(gpr_clock_type type) = 0;
+  virtual gpr_timespec gpr_time_0(gpr_clock_type type) = 0;
 };
 
 extern CoreCodegenInterface* g_core_codegen_interface;
diff --git a/include/grpc++/impl/codegen/grpc_library.h b/include/grpc++/impl/codegen/grpc_library.h
index 3cdc6f3f7c..2b11aff214 100644
--- a/include/grpc++/impl/codegen/grpc_library.h
+++ b/include/grpc++/impl/codegen/grpc_library.h
@@ -35,7 +35,6 @@
 #define GRPCXX_IMPL_CODEGEN_GRPC_LIBRARY_H
 
 #include <grpc++/impl/codegen/core_codegen_interface.h>
-#include <grpc/impl/codegen/log.h>
 
 namespace grpc {
 
diff --git a/include/grpc++/impl/codegen/method_handler_impl.h b/include/grpc++/impl/codegen/method_handler_impl.h
index 2f4be644ba..52f927631c 100644
--- a/include/grpc++/impl/codegen/method_handler_impl.h
+++ b/include/grpc++/impl/codegen/method_handler_impl.h
@@ -53,7 +53,7 @@ class RpcMethodHandler : public MethodHandler {
   void RunHandler(const HandlerParameter& param) GRPC_FINAL {
     RequestType req;
     Status status = SerializationTraits<RequestType>::Deserialize(
-        param.request, &req, param.max_message_size);
+        param.request, &req, param.max_receive_message_size);
     ResponseType rsp;
     if (status.ok()) {
       status = func_(service_, param.server_context, &req, &rsp);
@@ -139,7 +139,7 @@ class ServerStreamingHandler : public MethodHandler {
   void RunHandler(const HandlerParameter& param) GRPC_FINAL {
     RequestType req;
     Status status = SerializationTraits<RequestType>::Deserialize(
-        param.request, &req, param.max_message_size);
+        param.request, &req, param.max_receive_message_size);
 
     if (status.ok()) {
       ServerWriter<ResponseType> writer(param.call, param.server_context);
@@ -167,20 +167,22 @@ class ServerStreamingHandler : public MethodHandler {
 };
 
 // A wrapper class of an application provided bidi-streaming handler.
-template <class ServiceType, class RequestType, class ResponseType>
-class BidiStreamingHandler : public MethodHandler {
+// This also applies to server-streamed implementation of a unary method
+// with the additional requirement that such methods must have done a
+// write for status to be ok
+// Since this is used by more than 1 class, the service is not passed in.
+// Instead, it is expected to be an implicitly-captured argument of func
+// (through bind or something along those lines)
+template <class Streamer, bool WriteNeeded>
+class TemplatedBidiStreamingHandler : public MethodHandler {
  public:
-  BidiStreamingHandler(
-      std::function<Status(ServiceType*, ServerContext*,
-                           ServerReaderWriter<ResponseType, RequestType>*)>
-          func,
-      ServiceType* service)
-      : func_(func), service_(service) {}
+  TemplatedBidiStreamingHandler(
+      std::function<Status(ServerContext*, Streamer*)> func)
+      : func_(func), write_needed_(WriteNeeded) {}
 
   void RunHandler(const HandlerParameter& param) GRPC_FINAL {
-    ServerReaderWriter<ResponseType, RequestType> stream(param.call,
-                                                         param.server_context);
-    Status status = func_(service_, param.server_context, &stream);
+    Streamer stream(param.call, param.server_context);
+    Status status = func_(param.server_context, &stream);
 
     CallOpSet<CallOpSendInitialMetadata, CallOpServerSendStatus> ops;
     if (!param.server_context->sent_initial_metadata_) {
@@ -189,6 +191,12 @@ class BidiStreamingHandler : public MethodHandler {
       if (param.server_context->compression_level_set()) {
         ops.set_compression_level(param.server_context->compression_level());
       }
+      if (write_needed_ && status.ok()) {
+        // If we needed a write but never did one, we need to mark the
+        // status as a fail
+        status = Status(StatusCode::INTERNAL,
+                        "Service did not provide response message");
+      }
     }
     ops.ServerSendStatus(param.server_context->trailing_metadata_, status);
     param.call->PerformOps(&ops);
@@ -196,10 +204,36 @@ class BidiStreamingHandler : public MethodHandler {
   }
 
  private:
-  std::function<Status(ServiceType*, ServerContext*,
-                       ServerReaderWriter<ResponseType, RequestType>*)>
-      func_;
-  ServiceType* service_;
+  std::function<Status(ServerContext*, Streamer*)> func_;
+  const bool write_needed_;
+};
+
+template <class ServiceType, class RequestType, class ResponseType>
+class BidiStreamingHandler
+    : public TemplatedBidiStreamingHandler<
+          ServerReaderWriter<ResponseType, RequestType>, false> {
+ public:
+  BidiStreamingHandler(
+      std::function<Status(ServiceType*, ServerContext*,
+                           ServerReaderWriter<ResponseType, RequestType>*)>
+          func,
+      ServiceType* service)
+      : TemplatedBidiStreamingHandler<
+            ServerReaderWriter<ResponseType, RequestType>, false>(std::bind(
+            func, service, std::placeholders::_1, std::placeholders::_2)) {}
+};
+
+template <class RequestType, class ResponseType>
+class StreamedUnaryHandler
+    : public TemplatedBidiStreamingHandler<
+          ServerUnaryStreamer<RequestType, ResponseType>, true> {
+ public:
+  explicit StreamedUnaryHandler(
+      std::function<Status(ServerContext*,
+                           ServerUnaryStreamer<RequestType, ResponseType>*)>
+          func)
+      : TemplatedBidiStreamingHandler<
+            ServerUnaryStreamer<RequestType, ResponseType>, true>(func) {}
 };
 
 // Handle unknown method by returning UNIMPLEMENTED error.
diff --git a/include/grpc++/impl/codegen/proto_utils.h b/include/grpc++/impl/codegen/proto_utils.h
index d4599c5fff..6f4786b87b 100644
--- a/include/grpc++/impl/codegen/proto_utils.h
+++ b/include/grpc++/impl/codegen/proto_utils.h
@@ -40,9 +40,8 @@
 #include <grpc++/impl/codegen/core_codegen_interface.h>
 #include <grpc++/impl/codegen/serialization_traits.h>
 #include <grpc++/impl/codegen/status.h>
-#include <grpc/impl/codegen/byte_buffer.h>
 #include <grpc/impl/codegen/byte_buffer_reader.h>
-#include <grpc/impl/codegen/log.h>
+#include <grpc/impl/codegen/grpc_types.h>
 #include <grpc/impl/codegen/slice.h>
 
 namespace grpc {
@@ -205,7 +204,7 @@ class SerializationTraits<T, typename std::enable_if<std::is_base_of<
 
   static Status Deserialize(grpc_byte_buffer* buffer,
                             grpc::protobuf::Message* msg,
-                            int max_message_size) {
+                            int max_receive_message_size) {
     if (buffer == nullptr) {
       return Status(StatusCode::INTERNAL, "No payload");
     }
@@ -216,8 +215,9 @@ class SerializationTraits<T, typename std::enable_if<std::is_base_of<
         return reader.status();
       }
       ::grpc::protobuf::io::CodedInputStream decoder(&reader);
-      if (max_message_size > 0) {
-        decoder.SetTotalBytesLimit(max_message_size, max_message_size);
+      if (max_receive_message_size > 0) {
+        decoder.SetTotalBytesLimit(max_receive_message_size,
+                                   max_receive_message_size);
       }
       if (!msg->ParseFromCodedStream(&decoder)) {
         result = Status(StatusCode::INTERNAL, msg->InitializationErrorString());
diff --git a/include/grpc++/impl/codegen/rpc_method.h b/include/grpc++/impl/codegen/rpc_method.h
index 39cb4f75df..4897428074 100644
--- a/include/grpc++/impl/codegen/rpc_method.h
+++ b/include/grpc++/impl/codegen/rpc_method.h
@@ -60,11 +60,12 @@ class RpcMethod {
 
   const char* name() const { return name_; }
   RpcType method_type() const { return method_type_; }
+  void SetMethodType(RpcType type) { method_type_ = type; }
   void* channel_tag() const { return channel_tag_; }
 
  private:
   const char* const name_;
-  const RpcType method_type_;
+  RpcType method_type_;
   void* const channel_tag_;
 };
 
diff --git a/include/grpc++/impl/codegen/rpc_service_method.h b/include/grpc++/impl/codegen/rpc_service_method.h
index 8b1f026c91..78c54e3771 100644
--- a/include/grpc++/impl/codegen/rpc_service_method.h
+++ b/include/grpc++/impl/codegen/rpc_service_method.h
@@ -43,7 +43,10 @@
 #include <grpc++/impl/codegen/config.h>
 #include <grpc++/impl/codegen/rpc_method.h>
 #include <grpc++/impl/codegen/status.h>
-#include <grpc/impl/codegen/byte_buffer.h>
+
+extern "C" {
+struct grpc_byte_buffer;
+}
 
 namespace grpc {
 class ServerContext;
@@ -59,12 +62,12 @@ class MethodHandler {
         : call(c),
           server_context(context),
           request(req),
-          max_message_size(max_size) {}
+          max_receive_message_size(max_size) {}
     Call* call;
     ServerContext* server_context;
     // Handler required to grpc_byte_buffer_destroy this
     grpc_byte_buffer* request;
-    int max_message_size;
+    int max_receive_message_size;
   };
   virtual void RunHandler(const HandlerParameter& param) = 0;
 };
@@ -82,6 +85,7 @@ class RpcServiceMethod : public RpcMethod {
   // if MethodHandler is nullptr, then this is an async method
   MethodHandler* handler() const { return handler_.get(); }
   void ResetHandler() { handler_.reset(); }
+  void SetHandler(MethodHandler* handler) { handler_.reset(handler); }
 
  private:
   void* server_tag_;
diff --git a/include/grpc++/impl/codegen/serialization_traits.h b/include/grpc++/impl/codegen/serialization_traits.h
index fa99dbfa9c..54e5d47632 100644
--- a/include/grpc++/impl/codegen/serialization_traits.h
+++ b/include/grpc++/impl/codegen/serialization_traits.h
@@ -43,10 +43,10 @@ namespace grpc {
 /// functions:
 ///   static Status Serialize(const Message& msg,
 ///                           grpc_byte_buffer** buffer,
-//                            bool* own_buffer);
+///                           bool* own_buffer);
 ///   static Status Deserialize(grpc_byte_buffer* buffer,
 ///                             Message* msg,
-///                             int max_message_size);
+///                             int max_receive_message_size);
 ///
 /// Serialize is required to convert message to a grpc_byte_buffer, and
 /// to store a pointer to that byte buffer at *buffer. *own_buffer should
@@ -54,8 +54,8 @@ namespace grpc {
 /// ownership is retained elsewhere.
 ///
 /// Deserialize is required to convert buffer into the message stored at
-/// msg. max_message_size is passed in as a bound on the maximum number of
-/// message bytes Deserialize should accept.
+/// msg. max_receive_message_size is passed in as a bound on the maximum
+/// number of message bytes Deserialize should accept.
 ///
 /// Both functions return a Status, allowing them to explain what went
 /// wrong if required.
diff --git a/include/grpc++/impl/codegen/server_context.h b/include/grpc++/impl/codegen/server_context.h
index 08212af861..bce8d2c2f8 100644
--- a/include/grpc++/impl/codegen/server_context.h
+++ b/include/grpc++/impl/codegen/server_context.h
@@ -43,7 +43,6 @@
 #include <grpc++/impl/codegen/string_ref.h>
 #include <grpc++/impl/codegen/time.h>
 #include <grpc/impl/codegen/compression_types.h>
-#include <grpc/impl/codegen/time.h>
 
 struct gpr_timespec;
 struct grpc_metadata;
@@ -65,8 +64,10 @@ template <class R>
 class ServerReader;
 template <class W>
 class ServerWriter;
+namespace internal {
 template <class W, class R>
-class ServerReaderWriter;
+class ServerReaderWriterBody;
+}
 template <class ServiceType, class RequestType, class ResponseType>
 class RpcMethodHandler;
 template <class ServiceType, class RequestType, class ResponseType>
@@ -166,6 +167,10 @@ class ServerContext {
     async_notify_when_done_tag_ = tag;
   }
 
+  // Should be used for framework-level extensions only.
+  // Applications never need to call this method.
+  grpc_call* c_call() { return call_; }
+
  private:
   friend class ::grpc::testing::InteropServerContextInspector;
   friend class ::grpc::ServerInterface;
@@ -183,15 +188,15 @@ class ServerContext {
   template <class W>
   friend class ::grpc::ServerWriter;
   template <class W, class R>
-  friend class ::grpc::ServerReaderWriter;
+  friend class ::grpc::internal::ServerReaderWriterBody;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class RpcMethodHandler;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class ClientStreamingHandler;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class ServerStreamingHandler;
-  template <class ServiceType, class RequestType, class ResponseType>
-  friend class BidiStreamingHandler;
+  template <class Streamer, bool WriteNeeded>
+  friend class TemplatedBidiStreamingHandler;
   friend class UnknownMethodHandler;
   friend class ::grpc::ClientContext;
 
diff --git a/include/grpc++/impl/codegen/server_interface.h b/include/grpc++/impl/codegen/server_interface.h
index 3a3e052d9e..4a00d7a3a1 100644
--- a/include/grpc++/impl/codegen/server_interface.h
+++ b/include/grpc++/impl/codegen/server_interface.h
@@ -52,6 +52,8 @@ class ServerCredentials;
 class Service;
 class ThreadPoolInterface;
 
+extern CoreCodegenInterface* g_core_codegen_interface;
+
 /// Models a gRPC server.
 ///
 /// Servers are configured and started via \a grpc::ServerBuilder.
@@ -78,7 +80,10 @@ class ServerInterface : public CallHook {
   /// All completion queue associated with the server (for example, for async
   /// serving) must be shutdown *after* this method has returned:
   /// See \a ServerBuilder::AddCompletionQueue for details.
-  void Shutdown() { ShutdownInternal(gpr_inf_future(GPR_CLOCK_MONOTONIC)); }
+  void Shutdown() {
+    ShutdownInternal(
+        g_core_codegen_interface->gpr_inf_future(GPR_CLOCK_MONOTONIC));
+  }
 
   /// Block waiting for all work to complete.
   ///
@@ -129,7 +134,7 @@ class ServerInterface : public CallHook {
 
   virtual void ShutdownInternal(gpr_timespec deadline) = 0;
 
-  virtual int max_message_size() const = 0;
+  virtual int max_receive_message_size() const = 0;
 
   virtual grpc_server* server() = 0;
 
@@ -200,8 +205,8 @@ class ServerInterface : public CallHook {
     bool FinalizeResult(void** tag, bool* status) GRPC_OVERRIDE {
       bool serialization_status =
           *status && payload_ &&
-          SerializationTraits<Message>::Deserialize(payload_, request_,
-                                                    server_->max_message_size())
+          SerializationTraits<Message>::Deserialize(
+              payload_, request_, server_->max_receive_message_size())
               .ok();
       bool ret = RegisteredAsyncRequest::FinalizeResult(tag, status);
       *status = serialization_status && *status;
diff --git a/include/grpc++/impl/codegen/service_type.h b/include/grpc++/impl/codegen/service_type.h
index c19dfc7d45..72b2225312 100644
--- a/include/grpc++/impl/codegen/service_type.h
+++ b/include/grpc++/impl/codegen/service_type.h
@@ -147,6 +147,17 @@ class Service {
     methods_[index].reset();
   }
 
+  void MarkMethodStreamedUnary(int index,
+                               MethodHandler* streamed_unary_method) {
+    GPR_CODEGEN_ASSERT(methods_[index] && methods_[index]->handler() &&
+                       "Cannot mark an async or generic method Streamed Unary");
+    methods_[index]->SetHandler(streamed_unary_method);
+
+    // From the server's point of view, streamed unary is a special
+    // case of BIDI_STREAMING that has 1 read and 1 write, in that order.
+    methods_[index]->SetMethodType(::grpc::RpcMethod::BIDI_STREAMING);
+  }
+
  private:
   friend class Server;
   friend class ServerInterface;
diff --git a/include/grpc/impl/codegen/alloc.h b/include/grpc++/impl/codegen/status_helper.h
index 683c755f2c..bfe45d9e5b 100644
--- a/include/grpc/impl/codegen/alloc.h
+++ b/include/grpc++/impl/codegen/status_helper.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,44 +31,17 @@
  *
  */
 
-#ifndef GRPC_IMPL_CODEGEN_ALLOC_H
-#define GRPC_IMPL_CODEGEN_ALLOC_H
+#ifndef GRPCXX_IMPL_CODEGEN_STATUS_HELPER_H
+#define GRPCXX_IMPL_CODEGEN_STATUS_HELPER_H
 
-#include <stddef.h>
+#include <grpc++/impl/codegen/status.h>
 
-#include <grpc/impl/codegen/port_platform.h>
+namespace grpc {
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-typedef struct gpr_allocation_functions {
-  void *(*malloc_fn)(size_t size);
-  void *(*realloc_fn)(void *ptr, size_t size);
-  void (*free_fn)(void *ptr);
-} gpr_allocation_functions;
-
-/* malloc, never returns NULL */
-GPRAPI void *gpr_malloc(size_t size);
-/* free */
-GPRAPI void gpr_free(void *ptr);
-/* realloc, never returns NULL */
-GPRAPI void *gpr_realloc(void *p, size_t size);
-/* aligned malloc, never returns NULL, will align to 1 << alignment_log */
-GPRAPI void *gpr_malloc_aligned(size_t size, size_t alignment_log);
-/* free memory allocated by gpr_malloc_aligned */
-GPRAPI void gpr_free_aligned(void *ptr);
-
-/** Request the family of allocation functions in \a functions be used. NOTE
- * that this request will be honored in a *best effort* basis and that no
- * guarantees are made about the default functions (eg, malloc) being called. */
-GPRAPI void gpr_set_allocation_functions(gpr_allocation_functions functions);
-
-/** Return the family of allocation functions currently in effect. */
-GPRAPI gpr_allocation_functions gpr_get_allocation_functions();
-
-#ifdef __cplusplus
+inline StatusCode GetCanonicalCode(const Status& status) {
+  return status.error_code();
 }
-#endif
 
-#endif /* GRPC_IMPL_CODEGEN_ALLOC_H */
+}  // namespace grpc
+
+#endif  // GRPCXX_IMPL_CODEGEN_STATUS_HELPER_H
diff --git a/include/grpc++/impl/codegen/sync_no_cxx11.h b/include/grpc++/impl/codegen/sync_no_cxx11.h
index 55c059ede7..87a6594f7d 100644
--- a/include/grpc++/impl/codegen/sync_no_cxx11.h
+++ b/include/grpc++/impl/codegen/sync_no_cxx11.h
@@ -34,18 +34,20 @@
 #ifndef GRPCXX_IMPL_CODEGEN_SYNC_NO_CXX11_H
 #define GRPCXX_IMPL_CODEGEN_SYNC_NO_CXX11_H
 
-#include <grpc/impl/codegen/sync.h>
+#include <grpc++/impl/codegen/core_codegen_interface.h>
 
 namespace grpc {
 
+extern CoreCodegenInterface *g_core_codegen_interface;
+
 template <class mutex>
 class lock_guard;
 class condition_variable;
 
 class mutex {
  public:
-  mutex() { gpr_mu_init(&mu_); }
-  ~mutex() { gpr_mu_destroy(&mu_); }
+  mutex() { g_core_codegen_interface->gpr_mu_init(&mu_); }
+  ~mutex() { g_core_codegen_interface->gpr_mu_destroy(&mu_); }
 
  private:
   ::gpr_mu mu_;
@@ -57,16 +59,18 @@ class mutex {
 template <class mutex>
 class lock_guard {
  public:
-  lock_guard(mutex &mu) : mu_(mu), locked(true) { gpr_mu_lock(&mu.mu_); }
+  lock_guard(mutex &mu) : mu_(mu), locked(true) {
+    g_core_codegen_interface->gpr_mu_lock(&mu.mu_);
+  }
   ~lock_guard() { unlock_internal(); }
 
  protected:
   void lock_internal() {
-    if (!locked) gpr_mu_lock(&mu_.mu_);
+    if (!locked) g_core_codegen_interface->gpr_mu_lock(&mu_.mu_);
     locked = true;
   }
   void unlock_internal() {
-    if (locked) gpr_mu_unlock(&mu_.mu_);
+    if (locked) g_core_codegen_interface->gpr_mu_unlock(&mu_.mu_);
     locked = false;
   }
 
@@ -86,15 +90,17 @@ class unique_lock : public lock_guard<mutex> {
 
 class condition_variable {
  public:
-  condition_variable() { gpr_cv_init(&cv_); }
-  ~condition_variable() { gpr_cv_destroy(&cv_); }
+  condition_variable() { g_core_codegen_interface->gpr_cv_init(&cv_); }
+  ~condition_variable() { g_core_codegen_interface->gpr_cv_destroy(&cv_); }
   void wait(lock_guard<mutex> &mu) {
     mu.locked = false;
-    gpr_cv_wait(&cv_, &mu.mu_.mu_, gpr_inf_future(GPR_CLOCK_REALTIME));
+    g_core_codegen_interface->gpr_cv_wait(
+        &cv_, &mu.mu_.mu_,
+        g_core_codegen_interface->gpr_inf_future(GPR_CLOCK_REALTIME));
     mu.locked = true;
   }
-  void notify_one() { gpr_cv_signal(&cv_); }
-  void notify_all() { gpr_cv_broadcast(&cv_); }
+  void notify_one() { g_core_codegen_interface->gpr_cv_signal(&cv_); }
+  void notify_all() { g_core_codegen_interface->gpr_cv_broadcast(&cv_); }
 
  private:
   gpr_cv cv_;
diff --git a/include/grpc++/impl/codegen/sync_stream.h b/include/grpc++/impl/codegen/sync_stream.h
index b2b972760d..e3c5a919b1 100644
--- a/include/grpc++/impl/codegen/sync_stream.h
+++ b/include/grpc++/impl/codegen/sync_stream.h
@@ -42,7 +42,6 @@
 #include <grpc++/impl/codegen/server_context.h>
 #include <grpc++/impl/codegen/service_type.h>
 #include <grpc++/impl/codegen/status.h>
-#include <grpc/impl/codegen/log.h>
 
 namespace grpc {
 
@@ -64,12 +63,24 @@ class ClientStreamingInterface {
   virtual Status Finish() = 0;
 };
 
+/// Common interface for all synchronous server side streaming.
+class ServerStreamingInterface {
+ public:
+  virtual ~ServerStreamingInterface() {}
+
+  /// Blocking send initial metadata to client.
+  virtual void SendInitialMetadata() = 0;
+};
+
 /// An interface that yields a sequence of messages of type \a R.
 template <class R>
 class ReaderInterface {
  public:
   virtual ~ReaderInterface() {}
 
+  /// Upper bound on the next message size available for reading on this stream
+  virtual bool NextMessageSize(uint32_t* sz) = 0;
+
   /// Blocking read a message and parse to \a msg. Returns \a true on success.
   /// This is thread-safe with respect to \a Write or \WritesDone methods on
   /// the same stream. It should not be called concurrently with another \a
@@ -148,6 +159,11 @@ class ClientReader GRPC_FINAL : public ClientReaderInterface<R> {
     cq_.Pluck(&ops);  /// status ignored
   }
 
+  bool NextMessageSize(uint32_t* sz) GRPC_OVERRIDE {
+    *sz = call_.max_receive_message_size();
+    return true;
+  }
+
   bool Read(R* msg) GRPC_OVERRIDE {
     CallOpSet<CallOpRecvInitialMetadata, CallOpRecvMessage<R>> ops;
     if (!context_->initial_metadata_received_) {
@@ -293,6 +309,11 @@ class ClientReaderWriter GRPC_FINAL : public ClientReaderWriterInterface<W, R> {
     cq_.Pluck(&ops);  // status ignored
   }
 
+  bool NextMessageSize(uint32_t* sz) GRPC_OVERRIDE {
+    *sz = call_.max_receive_message_size();
+    return true;
+  }
+
   bool Read(R* msg) GRPC_OVERRIDE {
     CallOpSet<CallOpRecvInitialMetadata, CallOpRecvMessage<R>> ops;
     if (!context_->initial_metadata_received_) {
@@ -336,12 +357,17 @@ class ClientReaderWriter GRPC_FINAL : public ClientReaderWriterInterface<W, R> {
   Call call_;
 };
 
+/// Server-side interface for streaming reads of message of type \a R.
+template <class R>
+class ServerReaderInterface : public ServerStreamingInterface,
+                              public ReaderInterface<R> {};
+
 template <class R>
-class ServerReader GRPC_FINAL : public ReaderInterface<R> {
+class ServerReader GRPC_FINAL : public ServerReaderInterface<R> {
  public:
   ServerReader(Call* call, ServerContext* ctx) : call_(call), ctx_(ctx) {}
 
-  void SendInitialMetadata() {
+  void SendInitialMetadata() GRPC_OVERRIDE {
     GPR_CODEGEN_ASSERT(!ctx_->sent_initial_metadata_);
 
     CallOpSet<CallOpSendInitialMetadata> ops;
@@ -355,6 +381,11 @@ class ServerReader GRPC_FINAL : public ReaderInterface<R> {
     call_->cq()->Pluck(&ops);
   }
 
+  bool NextMessageSize(uint32_t* sz) GRPC_OVERRIDE {
+    *sz = call_->max_receive_message_size();
+    return true;
+  }
+
   bool Read(R* msg) GRPC_OVERRIDE {
     CallOpSet<CallOpRecvMessage<R>> ops;
     ops.RecvMessage(msg);
@@ -367,12 +398,17 @@ class ServerReader GRPC_FINAL : public ReaderInterface<R> {
   ServerContext* const ctx_;
 };
 
+/// Server-side interface for streaming writes of message of type \a W.
 template <class W>
-class ServerWriter GRPC_FINAL : public WriterInterface<W> {
+class ServerWriterInterface : public ServerStreamingInterface,
+                              public WriterInterface<W> {};
+
+template <class W>
+class ServerWriter GRPC_FINAL : public ServerWriterInterface<W> {
  public:
   ServerWriter(Call* call, ServerContext* ctx) : call_(call), ctx_(ctx) {}
 
-  void SendInitialMetadata() {
+  void SendInitialMetadata() GRPC_OVERRIDE {
     GPR_CODEGEN_ASSERT(!ctx_->sent_initial_metadata_);
 
     CallOpSet<CallOpSendInitialMetadata> ops;
@@ -411,10 +447,17 @@ class ServerWriter GRPC_FINAL : public WriterInterface<W> {
 
 /// Server-side interface for bi-directional streaming.
 template <class W, class R>
-class ServerReaderWriter GRPC_FINAL : public WriterInterface<W>,
-                                      public ReaderInterface<R> {
+class ServerReaderWriterInterface : public ServerStreamingInterface,
+                                    public WriterInterface<W>,
+                                    public ReaderInterface<R> {};
+
+// Actual implementation of bi-directional streaming
+namespace internal {
+template <class W, class R>
+class ServerReaderWriterBody GRPC_FINAL {
  public:
-  ServerReaderWriter(Call* call, ServerContext* ctx) : call_(call), ctx_(ctx) {}
+  ServerReaderWriterBody(Call* call, ServerContext* ctx)
+      : call_(call), ctx_(ctx) {}
 
   void SendInitialMetadata() {
     GPR_CODEGEN_ASSERT(!ctx_->sent_initial_metadata_);
@@ -430,15 +473,19 @@ class ServerReaderWriter GRPC_FINAL : public WriterInterface<W>,
     call_->cq()->Pluck(&ops);
   }
 
-  bool Read(R* msg) GRPC_OVERRIDE {
+  bool NextMessageSize(uint32_t* sz) {
+    *sz = call_->max_receive_message_size();
+    return true;
+  }
+
+  bool Read(R* msg) {
     CallOpSet<CallOpRecvMessage<R>> ops;
     ops.RecvMessage(msg);
     call_->PerformOps(&ops);
     return call_->cq()->Pluck(&ops) && ops.got_message;
   }
 
-  using WriterInterface<W>::Write;
-  bool Write(const W& msg, const WriteOptions& options) GRPC_OVERRIDE {
+  bool Write(const W& msg, const WriteOptions& options) {
     CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage> ops;
     if (!ops.SendMessage(msg, options).ok()) {
       return false;
@@ -459,6 +506,76 @@ class ServerReaderWriter GRPC_FINAL : public WriterInterface<W>,
   Call* const call_;
   ServerContext* const ctx_;
 };
+}
+
+// class to represent the user API for a bidirectional streaming call
+template <class W, class R>
+class ServerReaderWriter GRPC_FINAL : public ServerReaderWriterInterface<W, R> {
+ public:
+  ServerReaderWriter(Call* call, ServerContext* ctx) : body_(call, ctx) {}
+
+  void SendInitialMetadata() GRPC_OVERRIDE { body_.SendInitialMetadata(); }
+
+  bool NextMessageSize(uint32_t* sz) GRPC_OVERRIDE {
+    return body_.NextMessageSize(sz);
+  }
+
+  bool Read(R* msg) GRPC_OVERRIDE { return body_.Read(msg); }
+
+  using WriterInterface<W>::Write;
+  bool Write(const W& msg, const WriteOptions& options) GRPC_OVERRIDE {
+    return body_.Write(msg, options);
+  }
+
+ private:
+  internal::ServerReaderWriterBody<W, R> body_;
+};
+
+/// 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 NextMessageSize method to determine an upper-bound on the size of
+/// the message.
+/// A key difference relative to streaming: ServerUnaryStreamer
+///  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 ServerUnaryStreamer GRPC_FINAL
+    : public ServerReaderWriterInterface<ResponseType, RequestType> {
+ public:
+  ServerUnaryStreamer(Call* call, ServerContext* ctx)
+      : body_(call, ctx), read_done_(false), write_done_(false) {}
+
+  void SendInitialMetadata() GRPC_OVERRIDE { body_.SendInitialMetadata(); }
+
+  bool NextMessageSize(uint32_t* sz) GRPC_OVERRIDE {
+    return body_.NextMessageSize(sz);
+  }
+
+  bool Read(RequestType* request) GRPC_OVERRIDE {
+    if (read_done_) {
+      return false;
+    }
+    read_done_ = true;
+    return body_.Read(request);
+  }
+
+  using WriterInterface<ResponseType>::Write;
+  bool Write(const ResponseType& response,
+             const WriteOptions& options) GRPC_OVERRIDE {
+    if (write_done_ || !read_done_) {
+      return false;
+    }
+    write_done_ = true;
+    return body_.Write(response, options);
+  }
+
+ private:
+  internal::ServerReaderWriterBody<ResponseType, RequestType> body_;
+  bool read_done_;
+  bool write_done_;
+};
 
 }  // namespace grpc
 
diff --git a/include/grpc++/impl/codegen/thrift_serializer.h b/include/grpc++/impl/codegen/thrift_serializer.h
index 7308a1577c..fd324a994f 100644
--- a/include/grpc++/impl/codegen/thrift_serializer.h
+++ b/include/grpc++/impl/codegen/thrift_serializer.h
@@ -34,10 +34,8 @@
 #ifndef GRPCXX_IMPL_CODEGEN_THRIFT_SERIALIZER_H
 #define GRPCXX_IMPL_CODEGEN_THRIFT_SERIALIZER_H
 
-#include <grpc/impl/codegen/byte_buffer.h>
 #include <grpc/impl/codegen/byte_buffer_reader.h>
 #include <grpc/impl/codegen/slice.h>
-#include <grpc/impl/codegen/slice_buffer.h>
 #include <thrift/protocol/TBinaryProtocol.h>
 #include <thrift/protocol/TCompactProtocol.h>
 #include <thrift/protocol/TProtocolException.h>
@@ -216,4 +214,4 @@ typedef ThriftSerializer<void, TCompactProtocolT<TBufferBase>>
 }  // namespace thrift
 }  // namespace apache
 
-#endif
\ No newline at end of file
+#endif
diff --git a/include/grpc++/impl/codegen/thrift_utils.h b/include/grpc++/impl/codegen/thrift_utils.h
index 7d19b247f4..742d739703 100644
--- a/include/grpc++/impl/codegen/thrift_utils.h
+++ b/include/grpc++/impl/codegen/thrift_utils.h
@@ -40,10 +40,8 @@
 #include <grpc++/impl/codegen/status.h>
 #include <grpc++/impl/codegen/status_code_enum.h>
 #include <grpc++/impl/codegen/thrift_serializer.h>
-#include <grpc/impl/codegen/byte_buffer.h>
 #include <grpc/impl/codegen/byte_buffer_reader.h>
 #include <grpc/impl/codegen/slice.h>
-#include <grpc/impl/codegen/slice_buffer.h>
 #include <cstdint>
 #include <cstdlib>
 
@@ -66,7 +64,7 @@ class SerializationTraits<T, typename std::enable_if<std::is_base_of<
   }
 
   static Status Deserialize(grpc_byte_buffer* buffer, T* msg,
-                            int max_message_size) {
+                            int max_receive_message_size) {
     if (!buffer) {
       return Status(StatusCode::INTERNAL, "No payload");
     }
diff --git a/include/grpc++/impl/codegen/time.h b/include/grpc++/impl/codegen/time.h
index d9b19bce64..87c5112d0d 100644
--- a/include/grpc++/impl/codegen/time.h
+++ b/include/grpc++/impl/codegen/time.h
@@ -35,7 +35,7 @@
 #define GRPCXX_IMPL_CODEGEN_TIME_H
 
 #include <grpc++/impl/codegen/config.h>
-#include <grpc/impl/codegen/time.h>
+#include <grpc/impl/codegen/grpc_types.h>
 
 namespace grpc {
 
@@ -79,7 +79,7 @@ class TimePoint<gpr_timespec> {
 
 #include <chrono>
 
-#include <grpc/impl/codegen/time.h>
+#include <grpc/impl/codegen/grpc_types.h>
 
 namespace grpc {
 
diff --git a/include/grpc++/impl/server_builder_plugin.h b/include/grpc++/impl/server_builder_plugin.h
index 1e157efa11..61632e32fa 100644
--- a/include/grpc++/impl/server_builder_plugin.h
+++ b/include/grpc++/impl/server_builder_plugin.h
@@ -41,6 +41,7 @@
 namespace grpc {
 
 class ServerInitializer;
+class ChannelArguments;
 
 class ServerBuilderPlugin {
  public:
@@ -58,6 +59,10 @@ class ServerBuilderPlugin {
   // ServerBuilderOption::UpdatePlugins
   virtual void ChangeArguments(const grpc::string& name, void* value) = 0;
 
+  // UpdateChannelArguments will be called in ServerBuilder::BuildAndStart(),
+  // before the Server instance is created.
+  virtual void UpdateChannelArguments(ChannelArguments* args) {}
+
   virtual bool has_sync_methods() const { return false; }
   virtual bool has_async_methods() const { return false; }
 };
diff --git a/include/grpc++/server.h b/include/grpc++/server.h
index af0a15d7bd..6bbc265bc4 100644
--- a/include/grpc++/server.h
+++ b/include/grpc++/server.h
@@ -183,13 +183,15 @@ class Server GRPC_FINAL : public ServerInterface, private GrpcLibraryCodegen {
 
   void ShutdownInternal(gpr_timespec deadline) GRPC_OVERRIDE;
 
-  int max_message_size() const GRPC_OVERRIDE { return max_message_size_; };
+  int max_receive_message_size() const GRPC_OVERRIDE {
+    return max_receive_message_size_;
+  };
 
   grpc_server* server() GRPC_OVERRIDE { return server_; };
 
   ServerInitializer* initializer();
 
-  const int max_message_size_;
+  const int max_receive_message_size_;
 
   /// The following completion queues are ONLY used in case of Sync API i.e if
   /// the server has any services with sync methods. The server uses these
diff --git a/include/grpc++/server_builder.h b/include/grpc++/server_builder.h
index 847693d56f..d9a6878317 100644
--- a/include/grpc++/server_builder.h
+++ b/include/grpc++/server_builder.h
@@ -78,12 +78,23 @@ class ServerBuilder {
   /// Only matches requests with :authority \a host
   ServerBuilder& RegisterService(const grpc::string& host, Service* service);
 
-  /// Set max message size in bytes.
-  ServerBuilder& SetMaxMessageSize(int max_message_size) {
-    max_message_size_ = max_message_size;
+  /// Set max receive message size in bytes.
+  ServerBuilder& SetMaxReceiveMessageSize(int max_receive_message_size) {
+    max_receive_message_size_ = max_receive_message_size;
+    return *this;
+  }
+
+  /// Set max send message size in bytes.
+  ServerBuilder& SetMaxSendMessageSize(int max_send_message_size) {
+    max_send_message_size_ = max_send_message_size;
     return *this;
   }
 
+  /// \deprecated For backward compatibility.
+  ServerBuilder& SetMaxMessageSize(int max_message_size) {
+    return SetMaxReceiveMessageSize(max_message_size);
+  }
+
   /// Set the support status for compression algorithms. All algorithms are
   /// enabled by default.
   ///
@@ -174,7 +185,8 @@ class ServerBuilder {
     Service* service;
   };
 
-  int max_message_size_;
+  int max_receive_message_size_;
+  int max_send_message_size_;
   std::vector<std::unique_ptr<ServerBuilderOption>> options_;
   std::vector<std::unique_ptr<NamedService>> services_;
   std::vector<Port> ports_;
diff --git a/include/grpc++/support/byte_buffer.h b/include/grpc++/support/byte_buffer.h
index 01249a0b88..06f8969b70 100644
--- a/include/grpc++/support/byte_buffer.h
+++ b/include/grpc++/support/byte_buffer.h
@@ -96,7 +96,7 @@ template <>
 class SerializationTraits<ByteBuffer, void> {
  public:
   static Status Deserialize(grpc_byte_buffer* byte_buffer, ByteBuffer* dest,
-                            int max_message_size) {
+                            int max_receive_message_size) {
     dest->set_buffer(byte_buffer);
     return Status::OK;
   }
diff --git a/include/grpc/byte_buffer.h b/include/grpc/byte_buffer.h
index c3a394371d..f25c1d51d6 100644
--- a/include/grpc/byte_buffer.h
+++ b/include/grpc/byte_buffer.h
@@ -34,6 +34,69 @@
 #ifndef GRPC_BYTE_BUFFER_H
 #define GRPC_BYTE_BUFFER_H
 
-#include <grpc/impl/codegen/byte_buffer.h>
+#include <grpc/impl/codegen/grpc_types.h>
+#include <grpc/support/slice_buffer.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Returns a RAW byte buffer instance over the given slices (up to \a nslices).
+ *
+ * Increases the reference count for all \a slices processed. The user is
+ * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
+GRPCAPI grpc_byte_buffer *grpc_raw_byte_buffer_create(gpr_slice *slices,
+                                                      size_t nslices);
+
+/** Returns a *compressed* RAW byte buffer instance over the given slices (up to
+ * \a nslices). The \a compression argument defines the compression algorithm
+ * used to generate the data in \a slices.
+ *
+ * Increases the reference count for all \a slices processed. The user is
+ * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
+GRPCAPI grpc_byte_buffer *grpc_raw_compressed_byte_buffer_create(
+    gpr_slice *slices, size_t nslices, grpc_compression_algorithm compression);
+
+/** Copies input byte buffer \a bb.
+ *
+ * Increases the reference count of all the source slices. The user is
+ * responsible for calling grpc_byte_buffer_destroy over the returned copy. */
+GRPCAPI grpc_byte_buffer *grpc_byte_buffer_copy(grpc_byte_buffer *bb);
+
+/** Returns the size of the given byte buffer, in bytes. */
+GRPCAPI size_t grpc_byte_buffer_length(grpc_byte_buffer *bb);
+
+/** Destroys \a byte_buffer deallocating all its memory. */
+GRPCAPI void grpc_byte_buffer_destroy(grpc_byte_buffer *byte_buffer);
+
+/** Reader for byte buffers. Iterates over slices in the byte buffer */
+struct grpc_byte_buffer_reader;
+typedef struct grpc_byte_buffer_reader grpc_byte_buffer_reader;
+
+/** Initialize \a reader to read over \a buffer.
+ * Returns 1 upon success, 0 otherwise. */
+GRPCAPI int grpc_byte_buffer_reader_init(grpc_byte_buffer_reader *reader,
+                                         grpc_byte_buffer *buffer);
+
+/** Cleanup and destroy \a reader */
+GRPCAPI void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader);
+
+/** Updates \a slice with the next piece of data from from \a reader and returns
+ * 1. Returns 0 at the end of the stream. Caller is responsible for calling
+ * gpr_slice_unref on the result. */
+GRPCAPI int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
+                                         gpr_slice *slice);
+
+/** Merge all data from \a reader into single slice */
+GRPCAPI gpr_slice
+grpc_byte_buffer_reader_readall(grpc_byte_buffer_reader *reader);
+
+/** Returns a RAW byte buffer instance from the output of \a reader. */
+GRPCAPI grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
+    grpc_byte_buffer_reader *reader);
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* GRPC_BYTE_BUFFER_H */
diff --git a/include/grpc/compression.h b/include/grpc/compression.h
index 22bcf0e302..5f285cdcdf 100644
--- a/include/grpc/compression.h
+++ b/include/grpc/compression.h
@@ -36,9 +36,10 @@
 
 #include <stdlib.h>
 
-#include <grpc/impl/codegen/compression_types.h>
 #include <grpc/impl/codegen/port_platform.h>
 
+#include <grpc/impl/codegen/compression_types.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/include/grpc/grpc.h b/include/grpc/grpc.h
index 4ca018edb3..587d86c98f 100644
--- a/include/grpc/grpc.h
+++ b/include/grpc/grpc.h
@@ -90,6 +90,9 @@ GRPCAPI void grpc_shutdown(void);
 /** Return a string representing the current version of grpc */
 GRPCAPI const char *grpc_version_string(void);
 
+/** Return a string specifying what the 'g' in gRPC stands for */
+GRPCAPI const char *grpc_g_stands_for(void);
+
 /** Create a completion queue */
 GRPCAPI grpc_completion_queue *grpc_completion_queue_create(void *reserved);
 
diff --git a/include/grpc/impl/codegen/atm.h b/include/grpc/impl/codegen/atm.h
index 5589d5d411..ae00fb0f16 100644
--- a/include/grpc/impl/codegen/atm.h
+++ b/include/grpc/impl/codegen/atm.h
@@ -75,6 +75,9 @@
    int gpr_atm_no_barrier_cas(gpr_atm *p, gpr_atm o, gpr_atm n);
    int gpr_atm_acq_cas(gpr_atm *p, gpr_atm o, gpr_atm n);
    int gpr_atm_rel_cas(gpr_atm *p, gpr_atm o, gpr_atm n);
+
+   // Atomically, set *p=n and return the old value of *p
+   gpr_atm gpr_atm_full_xchg(gpr_atm *p, gpr_atm n);
 */
 
 #include <grpc/impl/codegen/port_platform.h>
diff --git a/include/grpc/impl/codegen/atm_gcc_atomic.h b/include/grpc/impl/codegen/atm_gcc_atomic.h
index 8caf7edbde..7d4ae98cf7 100644
--- a/include/grpc/impl/codegen/atm_gcc_atomic.h
+++ b/include/grpc/impl/codegen/atm_gcc_atomic.h
@@ -69,4 +69,6 @@ static __inline int gpr_atm_rel_cas(gpr_atm *p, gpr_atm o, gpr_atm n) {
                                      __ATOMIC_RELAXED);
 }
 
+#define gpr_atm_full_xchg(p, n) __atomic_exchange_n((p), (n), __ATOMIC_ACQ_REL)
+
 #endif /* GRPC_IMPL_CODEGEN_ATM_GCC_ATOMIC_H */
diff --git a/include/grpc/impl/codegen/atm_gcc_sync.h b/include/grpc/impl/codegen/atm_gcc_sync.h
index 915b09fb0c..9aa2b43189 100644
--- a/include/grpc/impl/codegen/atm_gcc_sync.h
+++ b/include/grpc/impl/codegen/atm_gcc_sync.h
@@ -84,4 +84,12 @@ static __inline void gpr_atm_no_barrier_store(gpr_atm *p, gpr_atm value) {
 #define gpr_atm_acq_cas(p, o, n) (__sync_bool_compare_and_swap((p), (o), (n)))
 #define gpr_atm_rel_cas(p, o, n) gpr_atm_acq_cas((p), (o), (n))
 
+static __inline gpr_atm gpr_atm_full_xchg(gpr_atm *p, gpr_atm n) {
+  gpr_atm cur;
+  do {
+    cur = gpr_atm_acq_load(p);
+  } while (!gpr_atm_rel_cas(p, cur, n));
+  return cur;
+}
+
 #endif /* GRPC_IMPL_CODEGEN_ATM_GCC_SYNC_H */
diff --git a/include/grpc/impl/codegen/atm_windows.h b/include/grpc/impl/codegen/atm_windows.h
index d5fa8c0f62..0ab70b95c4 100644
--- a/include/grpc/impl/codegen/atm_windows.h
+++ b/include/grpc/impl/codegen/atm_windows.h
@@ -122,4 +122,8 @@ static __inline gpr_atm gpr_atm_full_fetch_add(gpr_atm *p, gpr_atm delta) {
   return old;
 }
 
+static __inline gpr_atm gpr_atm_full_xchg(gpr_atm *p, gpr_atm n) {
+  return (gpr_atm)InterlockedExchangePointer((PVOID *)p, (PVOID)n);
+}
+
 #endif /* GRPC_IMPL_CODEGEN_ATM_WINDOWS_H */
diff --git a/include/grpc/impl/codegen/byte_buffer.h b/include/grpc/impl/codegen/byte_buffer.h
deleted file mode 100644
index fe1e215979..0000000000
--- a/include/grpc/impl/codegen/byte_buffer.h
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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 GRPC_IMPL_CODEGEN_BYTE_BUFFER_H
-#define GRPC_IMPL_CODEGEN_BYTE_BUFFER_H
-
-#include <grpc/impl/codegen/compression_types.h>
-#include <grpc/impl/codegen/slice_buffer.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-typedef enum {
-  GRPC_BB_RAW
-  /* Future types may include GRPC_BB_PROTOBUF, etc. */
-} grpc_byte_buffer_type;
-
-struct grpc_byte_buffer {
-  void *reserved;
-  grpc_byte_buffer_type type;
-  union {
-    struct {
-      void *reserved[8];
-    } reserved;
-    struct {
-      grpc_compression_algorithm compression;
-      gpr_slice_buffer slice_buffer;
-    } raw;
-  } data;
-};
-typedef struct grpc_byte_buffer grpc_byte_buffer;
-
-/** Returns a RAW byte buffer instance over the given slices (up to \a nslices).
- *
- * Increases the reference count for all \a slices processed. The user is
- * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
-GRPCAPI grpc_byte_buffer *grpc_raw_byte_buffer_create(gpr_slice *slices,
-                                                      size_t nslices);
-
-/** Returns a *compressed* RAW byte buffer instance over the given slices (up to
- * \a nslices). The \a compression argument defines the compression algorithm
- * used to generate the data in \a slices.
- *
- * Increases the reference count for all \a slices processed. The user is
- * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
-GRPCAPI grpc_byte_buffer *grpc_raw_compressed_byte_buffer_create(
-    gpr_slice *slices, size_t nslices, grpc_compression_algorithm compression);
-
-/** Copies input byte buffer \a bb.
- *
- * Increases the reference count of all the source slices. The user is
- * responsible for calling grpc_byte_buffer_destroy over the returned copy. */
-GRPCAPI grpc_byte_buffer *grpc_byte_buffer_copy(grpc_byte_buffer *bb);
-
-/** Returns the size of the given byte buffer, in bytes. */
-GRPCAPI size_t grpc_byte_buffer_length(grpc_byte_buffer *bb);
-
-/** Destroys \a byte_buffer deallocating all its memory. */
-GRPCAPI void grpc_byte_buffer_destroy(grpc_byte_buffer *byte_buffer);
-
-/** Reader for byte buffers. Iterates over slices in the byte buffer */
-struct grpc_byte_buffer_reader;
-typedef struct grpc_byte_buffer_reader grpc_byte_buffer_reader;
-
-/** Initialize \a reader to read over \a buffer.
- * Returns 1 upon success, 0 otherwise. */
-GRPCAPI int grpc_byte_buffer_reader_init(grpc_byte_buffer_reader *reader,
-                                         grpc_byte_buffer *buffer);
-
-/** Cleanup and destroy \a reader */
-GRPCAPI void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader);
-
-/** Updates \a slice with the next piece of data from from \a reader and returns
- * 1. Returns 0 at the end of the stream. Caller is responsible for calling
- * gpr_slice_unref on the result. */
-GRPCAPI int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
-                                         gpr_slice *slice);
-
-/** Merge all data from \a reader into single slice */
-GRPCAPI gpr_slice
-grpc_byte_buffer_reader_readall(grpc_byte_buffer_reader *reader);
-
-/** Returns a RAW byte buffer instance from the output of \a reader. */
-GRPCAPI grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
-    grpc_byte_buffer_reader *reader);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* GRPC_IMPL_CODEGEN_BYTE_BUFFER_H */
diff --git a/include/grpc/impl/codegen/byte_buffer_reader.h b/include/grpc/impl/codegen/byte_buffer_reader.h
index 10c382924e..85a4864140 100644
--- a/include/grpc/impl/codegen/byte_buffer_reader.h
+++ b/include/grpc/impl/codegen/byte_buffer_reader.h
@@ -34,15 +34,15 @@
 #ifndef GRPC_IMPL_CODEGEN_BYTE_BUFFER_READER_H
 #define GRPC_IMPL_CODEGEN_BYTE_BUFFER_READER_H
 
-#include <grpc/impl/codegen/byte_buffer.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+struct grpc_byte_buffer;
+
 struct grpc_byte_buffer_reader {
-  grpc_byte_buffer *buffer_in;
-  grpc_byte_buffer *buffer_out;
+  struct grpc_byte_buffer *buffer_in;
+  struct grpc_byte_buffer *buffer_out;
   /* Different current objects correspond to different types of byte buffers */
   union {
     /* Index into a slice buffer's array of slices */
diff --git a/include/grpc/impl/codegen/compression_types.h b/include/grpc/impl/codegen/compression_types.h
index 3034182d4c..170d99f431 100644
--- a/include/grpc/impl/codegen/compression_types.h
+++ b/include/grpc/impl/codegen/compression_types.h
@@ -34,8 +34,8 @@
 #ifndef GRPC_IMPL_CODEGEN_COMPRESSION_TYPES_H
 #define GRPC_IMPL_CODEGEN_COMPRESSION_TYPES_H
 
-#include <grpc/impl/codegen/port_platform.h>
 #include <stdbool.h>
+#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/include/grpc/impl/codegen/gpr_types.h b/include/grpc/impl/codegen/gpr_types.h
new file mode 100644
index 0000000000..c8f0815f0b
--- /dev/null
+++ b/include/grpc/impl/codegen/gpr_types.h
@@ -0,0 +1,140 @@
+/*
+ *
+ * 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 GRPC_IMPL_CODEGEN_GPR_TYPES_H
+#define GRPC_IMPL_CODEGEN_GPR_TYPES_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* The clocks we support. */
+typedef enum {
+  /* Monotonic clock. Epoch undefined. Always moves forwards. */
+  GPR_CLOCK_MONOTONIC = 0,
+  /* Realtime clock. May jump forwards or backwards. Settable by
+     the system administrator. Has its epoch at 0:00:00 UTC 1 Jan 1970. */
+  GPR_CLOCK_REALTIME,
+  /* CPU cycle time obtained by rdtsc instruction on x86 platforms. Epoch
+     undefined. Degrades to GPR_CLOCK_REALTIME on other platforms. */
+  GPR_CLOCK_PRECISE,
+  /* Unmeasurable clock type: no base, created by taking the difference
+     between two times */
+  GPR_TIMESPAN
+} gpr_clock_type;
+
+/* Analogous to struct timespec. On some machines, absolute times may be in
+ * local time. */
+typedef struct gpr_timespec {
+  int64_t tv_sec;
+  int32_t tv_nsec;
+  /** Against which clock was this time measured? (or GPR_TIMESPAN if
+      this is a relative time meaure) */
+  gpr_clock_type clock_type;
+} gpr_timespec;
+
+/* Slice API
+
+   A slice represents a contiguous reference counted array of bytes.
+   It is cheap to take references to a slice, and it is cheap to create a
+   slice pointing to a subset of another slice.
+
+   The data-structure for slices is exposed here to allow non-gpr code to
+   build slices from whatever data they have available.
+
+   When defining interfaces that handle slices, care should be taken to define
+   reference ownership semantics (who should call unref?) and mutability
+   constraints (is the callee allowed to modify the slice?) */
+
+/* Reference count container for gpr_slice. Contains function pointers to
+   increment and decrement reference counts. Implementations should cleanup
+   when the reference count drops to zero.
+   Typically client code should not touch this, and use gpr_slice_malloc,
+   gpr_slice_new, or gpr_slice_new_with_len instead. */
+typedef struct gpr_slice_refcount {
+  void (*ref)(void *);
+  void (*unref)(void *);
+} gpr_slice_refcount;
+
+#define GPR_SLICE_INLINED_SIZE (sizeof(size_t) + sizeof(uint8_t *) - 1)
+
+/* A gpr_slice s, if initialized, represents the byte range
+   s.bytes[0..s.length-1].
+
+   It can have an associated ref count which has a destruction routine to be run
+   when the ref count reaches zero (see gpr_slice_new() and grp_slice_unref()).
+   Multiple gpr_slice values may share a ref count.
+
+   If the slice does not have a refcount, it represents an inlined small piece
+   of data that is copied by value. */
+typedef struct gpr_slice {
+  struct gpr_slice_refcount *refcount;
+  union {
+    struct {
+      uint8_t *bytes;
+      size_t length;
+    } refcounted;
+    struct {
+      uint8_t length;
+      uint8_t bytes[GPR_SLICE_INLINED_SIZE];
+    } inlined;
+  } data;
+} gpr_slice;
+
+#define GRPC_SLICE_BUFFER_INLINE_ELEMENTS 8
+
+/* Represents an expandable array of slices, to be interpreted as a
+   single item. */
+typedef struct {
+  /* slices in the array */
+  gpr_slice *slices;
+  /* the number of slices in the array */
+  size_t count;
+  /* the number of slices allocated in the array */
+  size_t capacity;
+  /* the combined length of all slices in the array */
+  size_t length;
+  /* inlined elements to avoid allocations */
+  gpr_slice inlined[GRPC_SLICE_BUFFER_INLINE_ELEMENTS];
+} gpr_slice_buffer;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_GPR_TYPES_H */
diff --git a/include/grpc/impl/codegen/grpc_types.h b/include/grpc/impl/codegen/grpc_types.h
index e5a82883be..a8e8ebe6ea 100644
--- a/include/grpc/impl/codegen/grpc_types.h
+++ b/include/grpc/impl/codegen/grpc_types.h
@@ -34,15 +34,37 @@
 #ifndef GRPC_IMPL_CODEGEN_GRPC_TYPES_H
 #define GRPC_IMPL_CODEGEN_GRPC_TYPES_H
 
-#include <grpc/impl/codegen/byte_buffer.h>
+#include <grpc/impl/codegen/gpr_types.h>
+
+#include <grpc/impl/codegen/compression_types.h>
 #include <grpc/impl/codegen/status.h>
 
 #include <stddef.h>
+#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+typedef enum {
+  GRPC_BB_RAW
+  /* Future types may include GRPC_BB_PROTOBUF, etc. */
+} grpc_byte_buffer_type;
+
+typedef struct grpc_byte_buffer {
+  void *reserved;
+  grpc_byte_buffer_type type;
+  union {
+    struct {
+      void *reserved[8];
+    } reserved;
+    struct {
+      grpc_compression_algorithm compression;
+      gpr_slice_buffer slice_buffer;
+    } raw;
+  } data;
+} grpc_byte_buffer;
+
 /** Completion Queues enable notification of the completion of asynchronous
     actions. */
 typedef struct grpc_completion_queue grpc_completion_queue;
@@ -127,7 +149,11 @@ typedef struct {
     connection. Int valued. */
 #define GRPC_ARG_MAX_CONCURRENT_STREAMS "grpc.max_concurrent_streams"
 /** Maximum message length that the channel can receive. Int valued, bytes. */
-#define GRPC_ARG_MAX_MESSAGE_LENGTH "grpc.max_message_length"
+#define GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH "grpc.max_receive_message_length"
+/** \deprecated For backward compatibility. */
+#define GRPC_ARG_MAX_MESSAGE_LENGTH GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH
+/** Maximum message length that the channel can send. Int valued, bytes. */
+#define GRPC_ARG_MAX_SEND_MESSAGE_LENGTH "grpc.max_send_message_length"
 /** Initial sequence number for http2 transports. Int valued. */
 #define GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER \
   "grpc.http2.initial_sequence_number"
@@ -142,6 +168,11 @@ typedef struct {
 /** How much memory to use for hpack encoding. Int valued, bytes. */
 #define GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_ENCODER \
   "grpc.http2.hpack_table_size.encoder"
+/** How big a frame are we willing to receive via HTTP2.
+    Min 16384, max 16777215.
+    Larger values give lower CPU usage for large messages, but more head of line
+    blocking for small messages. */
+#define GRPC_ARG_HTTP2_MAX_FRAME_SIZE "grpc.http2.max_frame_size"
 /** Default authority to pass if none specified on call construction. A string.
  * */
 #define GRPC_ARG_DEFAULT_AUTHORITY "grpc.default_authority"
@@ -222,10 +253,14 @@ typedef enum grpc_call_error {
 #define GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST (0x00000010u)
 /** Signal that the call should not return UNAVAILABLE before it has started */
 #define GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY (0x00000020u)
+/** Signal that the call is cacheable. GRPC is free to use GET verb */
+#define GRPC_INITIAL_METADATA_CACHEABLE_REQUEST (0x00000040u)
+
 /** Mask of all valid flags */
-#define GRPC_INITIAL_METADATA_USED_MASK       \
-  (GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST | \
-   GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY)
+#define GRPC_INITIAL_METADATA_USED_MASK        \
+  (GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST |  \
+   GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY | \
+   GRPC_INITIAL_METADATA_CACHEABLE_REQUEST)
 
 /** A single metadata element */
 typedef struct grpc_metadata {
@@ -327,6 +362,8 @@ typedef enum {
   GRPC_OP_RECV_CLOSE_ON_SERVER
 } grpc_op_type;
 
+struct grpc_byte_buffer;
+
 /** Operation data: one field for each op type (except SEND_CLOSE_FROM_CLIENT
    which has no arguments) */
 typedef struct grpc_op {
@@ -351,7 +388,7 @@ typedef struct grpc_op {
         grpc_compression_level level;
       } maybe_compression_level;
     } send_initial_metadata;
-    grpc_byte_buffer *send_message;
+    struct grpc_byte_buffer *send_message;
     struct {
       size_t trailing_metadata_count;
       grpc_metadata *trailing_metadata;
@@ -367,7 +404,7 @@ typedef struct grpc_op {
     /** ownership of the byte buffer is moved to the caller; the caller must
         call grpc_byte_buffer_destroy on this value, or reuse it in a future op.
        */
-    grpc_byte_buffer **recv_message;
+    struct grpc_byte_buffer **recv_message;
     struct {
       /** ownership of the array is with the caller, but ownership of the
           elements stays with the call object (ie key, value members are owned
diff --git a/include/grpc/impl/codegen/log.h b/include/grpc/impl/codegen/log.h
deleted file mode 100644
index e5010c29da..0000000000
--- a/include/grpc/impl/codegen/log.h
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- *
- * 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 GRPC_IMPL_CODEGEN_LOG_H
-#define GRPC_IMPL_CODEGEN_LOG_H
-
-#include <inttypes.h>
-#include <stdarg.h>
-#include <stdlib.h> /* for abort() */
-
-#include <grpc/impl/codegen/port_platform.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* GPR log API.
-
-   Usage (within grpc):
-
-   int argument1 = 3;
-   char* argument2 = "hello";
-   gpr_log(GPR_DEBUG, "format string %d", argument1);
-   gpr_log(GPR_INFO, "hello world");
-   gpr_log(GPR_ERROR, "%d %s!!", argument1, argument2); */
-
-/* The severity of a log message - use the #defines below when calling into
-   gpr_log to additionally supply file and line data */
-typedef enum gpr_log_severity {
-  GPR_LOG_SEVERITY_DEBUG,
-  GPR_LOG_SEVERITY_INFO,
-  GPR_LOG_SEVERITY_ERROR
-} gpr_log_severity;
-
-#define GPR_LOG_VERBOSITY_UNSET -1
-
-/* Returns a string representation of the log severity */
-const char *gpr_log_severity_string(gpr_log_severity severity);
-
-/* Macros to build log contexts at various severity levels */
-#define GPR_DEBUG __FILE__, __LINE__, GPR_LOG_SEVERITY_DEBUG
-#define GPR_INFO __FILE__, __LINE__, GPR_LOG_SEVERITY_INFO
-#define GPR_ERROR __FILE__, __LINE__, GPR_LOG_SEVERITY_ERROR
-
-/* Log a message. It's advised to use GPR_xxx above to generate the context
- * for each message */
-GPRAPI void gpr_log(const char *file, int line, gpr_log_severity severity,
-                    const char *format, ...) GPRC_PRINT_FORMAT_CHECK(4, 5);
-
-GPRAPI void gpr_log_message(const char *file, int line,
-                            gpr_log_severity severity, const char *message);
-
-/* Set global log verbosity */
-GPRAPI void gpr_set_log_verbosity(gpr_log_severity min_severity_to_print);
-
-GPRAPI void gpr_log_verbosity_init();
-
-/* Log overrides: applications can use this API to intercept logging calls
-   and use their own implementations */
-
-typedef struct {
-  const char *file;
-  int line;
-  gpr_log_severity severity;
-  const char *message;
-} gpr_log_func_args;
-
-typedef void (*gpr_log_func)(gpr_log_func_args *args);
-GPRAPI void gpr_set_log_function(gpr_log_func func);
-
-/* abort() the process if x is zero, having written a line to the log.
-
-   Intended for internal invariants.  If the error can be recovered from,
-   without the possibility of corruption, or might best be reflected via
-   an exception in a higher-level language, consider returning error code.  */
-#define GPR_ASSERT(x)                                 \
-  do {                                                \
-    if (!(x)) {                                       \
-      gpr_log(GPR_ERROR, "assertion failed: %s", #x); \
-      abort();                                        \
-    }                                                 \
-  } while (0)
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* GRPC_IMPL_CODEGEN_LOG_H */
diff --git a/include/grpc/impl/codegen/port_platform.h b/include/grpc/impl/codegen/port_platform.h
index 7c67bad5ae..f97e386289 100644
--- a/include/grpc/impl/codegen/port_platform.h
+++ b/include/grpc/impl/codegen/port_platform.h
@@ -234,6 +234,7 @@
 #define GPR_ARCH_32 1
 #endif /* _LP64 */
 #elif defined(__APPLE__)
+#include <Availability.h>
 #include <TargetConditionals.h>
 #ifndef _BSD_SOURCE
 #define _BSD_SOURCE
@@ -246,8 +247,18 @@
 #define GPR_PTHREAD_TLS 1
 #else /* TARGET_OS_IPHONE */
 #define GPR_PLATFORM_STRING "osx"
+#ifdef __MAC_OS_X_VERSION_MIN_REQUIRED
+#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_7
+#define GPR_CPU_IPHONE 1
+#define GPR_PTHREAD_TLS 1
+#else /* __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_7 */
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_TLS 1
+#endif
+#else /* __MAC_OS_X_VERSION_MIN_REQUIRED */
 #define GPR_CPU_POSIX 1
 #define GPR_GCC_TLS 1
+#endif
 #define GPR_POSIX_CRASH_HANDLER 1
 #endif
 #define GPR_GCC_ATOMIC 1
diff --git a/include/grpc/impl/codegen/slice.h b/include/grpc/impl/codegen/slice.h
index dfc0a774fc..a2637eea62 100644
--- a/include/grpc/impl/codegen/slice.h
+++ b/include/grpc/impl/codegen/slice.h
@@ -34,62 +34,8 @@
 #ifndef GRPC_IMPL_CODEGEN_SLICE_H
 #define GRPC_IMPL_CODEGEN_SLICE_H
 
-#include <grpc/impl/codegen/sync.h>
-
 #include <stddef.h>
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* Slice API
-
-   A slice represents a contiguous reference counted array of bytes.
-   It is cheap to take references to a slice, and it is cheap to create a
-   slice pointing to a subset of another slice.
-
-   The data-structure for slices is exposed here to allow non-gpr code to
-   build slices from whatever data they have available.
-
-   When defining interfaces that handle slices, care should be taken to define
-   reference ownership semantics (who should call unref?) and mutability
-   constraints (is the callee allowed to modify the slice?) */
-
-/* Reference count container for gpr_slice. Contains function pointers to
-   increment and decrement reference counts. Implementations should cleanup
-   when the reference count drops to zero.
-   Typically client code should not touch this, and use gpr_slice_malloc,
-   gpr_slice_new, or gpr_slice_new_with_len instead. */
-typedef struct gpr_slice_refcount {
-  void (*ref)(void *);
-  void (*unref)(void *);
-} gpr_slice_refcount;
-
-#define GPR_SLICE_INLINED_SIZE (sizeof(size_t) + sizeof(uint8_t *) - 1)
-
-/* A gpr_slice s, if initialized, represents the byte range
-   s.bytes[0..s.length-1].
-
-   It can have an associated ref count which has a destruction routine to be run
-   when the ref count reaches zero (see gpr_slice_new() and grp_slice_unref()).
-   Multiple gpr_slice values may share a ref count.
-
-   If the slice does not have a refcount, it represents an inlined small piece
-   of data that is copied by value. */
-typedef struct gpr_slice {
-  struct gpr_slice_refcount *refcount;
-  union {
-    struct {
-      uint8_t *bytes;
-      size_t length;
-    } refcounted;
-    struct {
-      uint8_t length;
-      uint8_t bytes[GPR_SLICE_INLINED_SIZE];
-    } inlined;
-  } data;
-} gpr_slice;
-
 #define GPR_SLICE_START_PTR(slice)                  \
   ((slice).refcount ? (slice).data.refcounted.bytes \
                     : (slice).data.inlined.bytes)
@@ -103,88 +49,4 @@ typedef struct gpr_slice {
   GPR_SLICE_START_PTR(slice) + GPR_SLICE_LENGTH(slice)
 #define GPR_SLICE_IS_EMPTY(slice) (GPR_SLICE_LENGTH(slice) == 0)
 
-/* Increment the refcount of s. Requires slice is initialized.
-   Returns s. */
-GPRAPI gpr_slice gpr_slice_ref(gpr_slice s);
-
-/* Decrement the ref count of s.  If the ref count of s reaches zero, all
-   slices sharing the ref count are destroyed, and considered no longer
-   initialized.  If s is ultimately derived from a call to gpr_slice_new(start,
-   len, dest) where dest!=NULL , then (*dest)(start) is called, else if s is
-   ultimately derived from a call to gpr_slice_new_with_len(start, len, dest)
-   where dest!=NULL , then (*dest)(start, len).  Requires s initialized.  */
-GPRAPI void gpr_slice_unref(gpr_slice s);
-
-/* Create a slice pointing at some data. Calls malloc to allocate a refcount
-   for the object, and arranges that destroy will be called with the pointer
-   passed in at destruction. */
-GPRAPI gpr_slice gpr_slice_new(void *p, size_t len, void (*destroy)(void *));
-
-/* Equivalent to gpr_slice_new, but with a separate pointer that is
-   passed to the destroy function.  This function can be useful when
-   the data is part of a larger structure that must be destroyed when
-   the data is no longer needed. */
-GPRAPI gpr_slice gpr_slice_new_with_user_data(void *p, size_t len,
-                                              void (*destroy)(void *),
-                                              void *user_data);
-
-/* Equivalent to gpr_slice_new, but with a two argument destroy function that
-   also takes the slice length. */
-GPRAPI gpr_slice gpr_slice_new_with_len(void *p, size_t len,
-                                        void (*destroy)(void *, size_t));
-
-/* Equivalent to gpr_slice_new(malloc(len), len, free), but saves one malloc()
-   call.
-   Aborts if malloc() fails. */
-GPRAPI gpr_slice gpr_slice_malloc(size_t length);
-
-/* Create a slice by copying a string.
-   Does not preserve null terminators.
-   Equivalent to:
-     size_t len = strlen(source);
-     gpr_slice slice = gpr_slice_malloc(len);
-     memcpy(slice->data, source, len); */
-GPRAPI gpr_slice gpr_slice_from_copied_string(const char *source);
-
-/* Create a slice by copying a buffer.
-   Equivalent to:
-     gpr_slice slice = gpr_slice_malloc(len);
-     memcpy(slice->data, source, len); */
-GPRAPI gpr_slice gpr_slice_from_copied_buffer(const char *source, size_t len);
-
-/* Create a slice pointing to constant memory */
-GPRAPI gpr_slice gpr_slice_from_static_string(const char *source);
-
-/* Return a result slice derived from s, which shares a ref count with s, where
-   result.data==s.data+begin, and result.length==end-begin.
-   The ref count of s is increased by one.
-   Requires s initialized, begin <= end, begin <= s.length, and
-   end <= source->length. */
-GPRAPI gpr_slice gpr_slice_sub(gpr_slice s, size_t begin, size_t end);
-
-/* The same as gpr_slice_sub, but without altering the ref count */
-GPRAPI gpr_slice gpr_slice_sub_no_ref(gpr_slice s, size_t begin, size_t end);
-
-/* Splits s into two: modifies s to be s[0:split], and returns a new slice,
-   sharing a refcount with s, that contains s[split:s.length].
-   Requires s intialized, split <= s.length */
-GPRAPI gpr_slice gpr_slice_split_tail(gpr_slice *s, size_t split);
-
-/* Splits s into two: modifies s to be s[split:s.length], and returns a new
-   slice, sharing a refcount with s, that contains s[0:split].
-   Requires s intialized, split <= s.length */
-GPRAPI gpr_slice gpr_slice_split_head(gpr_slice *s, size_t split);
-
-GPRAPI gpr_slice gpr_empty_slice(void);
-
-/* Returns <0 if a < b, ==0 if a == b, >0 if a > b
-   The order is arbitrary, and is not guaranteed to be stable across different
-   versions of the API. */
-GPRAPI int gpr_slice_cmp(gpr_slice a, gpr_slice b);
-GPRAPI int gpr_slice_str_cmp(gpr_slice a, const char *b);
-
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* GRPC_IMPL_CODEGEN_SLICE_H */
diff --git a/include/grpc/impl/codegen/slice_buffer.h b/include/grpc/impl/codegen/slice_buffer.h
deleted file mode 100644
index 7858021600..0000000000
--- a/include/grpc/impl/codegen/slice_buffer.h
+++ /dev/null
@@ -1,104 +0,0 @@
-/*
- *
- * 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 GRPC_IMPL_CODEGEN_SLICE_BUFFER_H
-#define GRPC_IMPL_CODEGEN_SLICE_BUFFER_H
-
-#include <grpc/impl/codegen/slice.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#define GRPC_SLICE_BUFFER_INLINE_ELEMENTS 8
-
-/* Represents an expandable array of slices, to be interpreted as a
-   single item. */
-typedef struct {
-  /* slices in the array */
-  gpr_slice *slices;
-  /* the number of slices in the array */
-  size_t count;
-  /* the number of slices allocated in the array */
-  size_t capacity;
-  /* the combined length of all slices in the array */
-  size_t length;
-  /* inlined elements to avoid allocations */
-  gpr_slice inlined[GRPC_SLICE_BUFFER_INLINE_ELEMENTS];
-} gpr_slice_buffer;
-
-/* initialize a slice buffer */
-GPRAPI void gpr_slice_buffer_init(gpr_slice_buffer *sb);
-/* destroy a slice buffer - unrefs any held elements */
-GPRAPI void gpr_slice_buffer_destroy(gpr_slice_buffer *sb);
-/* Add an element to a slice buffer - takes ownership of the slice.
-   This function is allowed to concatenate the passed in slice to the end of
-   some other slice if desired by the slice buffer. */
-GPRAPI void gpr_slice_buffer_add(gpr_slice_buffer *sb, gpr_slice slice);
-/* add an element to a slice buffer - takes ownership of the slice and returns
-   the index of the slice.
-   Guarantees that the slice will not be concatenated at the end of another
-   slice (i.e. the data for this slice will begin at the first byte of the
-   slice at the returned index in sb->slices)
-   The implementation MAY decide to concatenate data at the end of a small
-   slice added in this fashion. */
-GPRAPI size_t gpr_slice_buffer_add_indexed(gpr_slice_buffer *sb,
-                                           gpr_slice slice);
-GPRAPI void gpr_slice_buffer_addn(gpr_slice_buffer *sb, gpr_slice *slices,
-                                  size_t n);
-/* add a very small (less than 8 bytes) amount of data to the end of a slice
-   buffer: returns a pointer into which to add the data */
-GPRAPI uint8_t *gpr_slice_buffer_tiny_add(gpr_slice_buffer *sb, size_t len);
-/* pop the last buffer, but don't unref it */
-GPRAPI void gpr_slice_buffer_pop(gpr_slice_buffer *sb);
-/* clear a slice buffer, unref all elements */
-GPRAPI void gpr_slice_buffer_reset_and_unref(gpr_slice_buffer *sb);
-/* swap the contents of two slice buffers */
-GPRAPI void gpr_slice_buffer_swap(gpr_slice_buffer *a, gpr_slice_buffer *b);
-/* move all of the elements of src into dst */
-GPRAPI void gpr_slice_buffer_move_into(gpr_slice_buffer *src,
-                                       gpr_slice_buffer *dst);
-/* remove n bytes from the end of a slice buffer */
-GPRAPI void gpr_slice_buffer_trim_end(gpr_slice_buffer *src, size_t n,
-                                      gpr_slice_buffer *garbage);
-/* move the first n bytes of src into dst */
-GPRAPI void gpr_slice_buffer_move_first(gpr_slice_buffer *src, size_t n,
-                                        gpr_slice_buffer *dst);
-/* take the first slice in the slice buffer */
-GPRAPI gpr_slice gpr_slice_buffer_take_first(gpr_slice_buffer *src);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* GRPC_IMPL_CODEGEN_SLICE_BUFFER_H */
diff --git a/include/grpc/impl/codegen/sync.h b/include/grpc/impl/codegen/sync.h
index 5542482ed8..96aec0c2c0 100644
--- a/include/grpc/impl/codegen/sync.h
+++ b/include/grpc/impl/codegen/sync.h
@@ -64,257 +64,4 @@
 #error Unable to determine platform for sync
 #endif
 
-#include <grpc/impl/codegen/time.h> /* for gpr_timespec */
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* --- Mutex interface ---
-
-   At most one thread may hold an exclusive lock on a mutex at any given time.
-   Actions taken by a thread that holds a mutex exclusively happen after
-   actions taken by all previous holders of the mutex.  Variables of type
-   gpr_mu are uninitialized when first declared.  */
-
-/* Initialize *mu.  Requires:  *mu uninitialized.  */
-GPRAPI void gpr_mu_init(gpr_mu *mu);
-
-/* Cause *mu no longer to be initialized, freeing any memory in use.  Requires:
-   *mu initialized; no other concurrent operation on *mu.  */
-GPRAPI void gpr_mu_destroy(gpr_mu *mu);
-
-/* Wait until no thread has a lock on *mu, cause the calling thread to own an
-   exclusive lock on *mu, then return.  May block indefinitely or crash if the
-   calling thread has a lock on *mu.  Requires:  *mu initialized.  */
-GPRAPI void gpr_mu_lock(gpr_mu *mu);
-
-/* Release an exclusive lock on *mu held by the calling thread.  Requires:  *mu
-   initialized; the calling thread holds an exclusive lock on *mu.  */
-GPRAPI void gpr_mu_unlock(gpr_mu *mu);
-
-/* Without blocking, attempt to acquire an exclusive lock on *mu for the
-   calling thread, then return non-zero iff success.  Fail, if any thread holds
-   the lock; succeeds with high probability if no thread holds the lock.
-   Requires:  *mu initialized.  */
-GPRAPI int gpr_mu_trylock(gpr_mu *mu);
-
-/* --- Condition variable interface ---
-
-   A while-loop should be used with gpr_cv_wait() when waiting for conditions
-   to become true.  See the example below.  Variables of type gpr_cv are
-   uninitialized when first declared.  */
-
-/* Initialize *cv.  Requires:  *cv uninitialized.  */
-GPRAPI void gpr_cv_init(gpr_cv *cv);
-
-/* Cause *cv no longer to be initialized, freeing any memory in use.  Requires:
-   *cv initialized; no other concurrent operation on *cv.*/
-GPRAPI void gpr_cv_destroy(gpr_cv *cv);
-
-/* Atomically release *mu and wait on *cv.  When the calling thread is woken
-   from *cv or the deadline abs_deadline is exceeded, execute gpr_mu_lock(mu)
-   and return whether the deadline was exceeded.  Use
-   abs_deadline==gpr_inf_future for no deadline.  abs_deadline can be either
-   an absolute deadline, or a GPR_TIMESPAN.  May return even when not
-   woken explicitly.  Requires:  *mu and *cv initialized; the calling thread
-   holds an exclusive lock on *mu.  */
-GPRAPI int gpr_cv_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline);
-
-/* If any threads are waiting on *cv, wake at least one.
-   Clients may treat this as an optimization of gpr_cv_broadcast()
-   for use in the case where waking more than one waiter is not useful.
-   Requires:  *cv initialized.  */
-GPRAPI void gpr_cv_signal(gpr_cv *cv);
-
-/* Wake all threads waiting on *cv.  Requires:  *cv initialized.  */
-GPRAPI void gpr_cv_broadcast(gpr_cv *cv);
-
-/* --- One-time initialization ---
-
-   gpr_once must be declared with static storage class, and initialized with
-   GPR_ONCE_INIT.  e.g.,
-     static gpr_once once_var = GPR_ONCE_INIT;     */
-
-/* Ensure that (*init_routine)() has been called exactly once (for the
-   specified gpr_once instance) and then return.
-   If multiple threads call gpr_once() on the same gpr_once instance, one of
-   them will call (*init_routine)(), and the others will block until that call
-   finishes.*/
-GPRAPI void gpr_once_init(gpr_once *once, void (*init_routine)(void));
-
-/* --- One-time event notification ---
-
-  These operations act on a gpr_event, which should be initialized with
-  gpr_ev_init(), or with GPR_EVENT_INIT if static, e.g.,
-       static gpr_event event_var = GPR_EVENT_INIT;
-  It requires no destruction.  */
-
-/* Initialize *ev. */
-GPRAPI void gpr_event_init(gpr_event *ev);
-
-/* Set *ev so that gpr_event_get() and gpr_event_wait() will return value.
-   Requires:  *ev initialized; value != NULL; no prior or concurrent calls to
-   gpr_event_set(ev, ...) since initialization.  */
-GPRAPI void gpr_event_set(gpr_event *ev, void *value);
-
-/* Return the value set by gpr_event_set(ev, ...), or NULL if no such call has
-   completed.  If the result is non-NULL, all operations that occurred prior to
-   the gpr_event_set(ev, ...) set will be visible after this call returns.
-   Requires:  *ev initialized.  This operation is faster than acquiring a mutex
-   on most platforms.  */
-GPRAPI void *gpr_event_get(gpr_event *ev);
-
-/* Wait until *ev is set by gpr_event_set(ev, ...), or abs_deadline is
-   exceeded, then return gpr_event_get(ev).  Requires:  *ev initialized.  Use
-   abs_deadline==gpr_inf_future for no deadline.  When the event has been
-   signalled before the call, this operation is faster than acquiring a mutex
-   on most platforms.  */
-GPRAPI void *gpr_event_wait(gpr_event *ev, gpr_timespec abs_deadline);
-
-/* --- Reference counting ---
-
-   These calls act on the type gpr_refcount.  It requires no destruction.  */
-
-/* Initialize *r to value n.  */
-GPRAPI void gpr_ref_init(gpr_refcount *r, int n);
-
-/* Increment the reference count *r.  Requires *r initialized. */
-GPRAPI void gpr_ref(gpr_refcount *r);
-
-/* Increment the reference count *r.  Requires *r initialized.
-   Crashes if refcount is zero */
-GPRAPI void gpr_ref_non_zero(gpr_refcount *r);
-
-/* Increment the reference count *r by n.  Requires *r initialized, n > 0. */
-GPRAPI void gpr_refn(gpr_refcount *r, int n);
-
-/* Decrement the reference count *r and return non-zero iff it has reached
-   zero. .  Requires *r initialized. */
-GPRAPI int gpr_unref(gpr_refcount *r);
-
-/* --- Stats counters ---
-
-   These calls act on the integral type gpr_stats_counter.  It requires no
-   destruction.  Static instances may be initialized with
-       gpr_stats_counter c = GPR_STATS_INIT;
-   Beware:  These operations do not imply memory barriers.  Do not use them to
-   synchronize other events.  */
-
-/* Initialize *c to the value n. */
-GPRAPI void gpr_stats_init(gpr_stats_counter *c, intptr_t n);
-
-/* *c += inc.  Requires: *c initialized. */
-GPRAPI void gpr_stats_inc(gpr_stats_counter *c, intptr_t inc);
-
-/* Return *c.  Requires: *c initialized. */
-GPRAPI intptr_t gpr_stats_read(const gpr_stats_counter *c);
-
-/* ==================Example use of interface===================
-   A producer-consumer queue of up to N integers,
-   illustrating the use of the calls in this interface. */
-#if 0
-
-#define N 4
-
-   typedef struct queue {
-     gpr_cv non_empty;  /* Signalled when length becomes non-zero. */
-     gpr_cv non_full;   /* Signalled when length becomes non-N. */
-     gpr_mu mu;         /* Protects all fields below.
-                            (That is, except during initialization or
-                            destruction, the fields below should be accessed
-                            only by a thread that holds mu.) */
-     int head;           /* Index of head of queue 0..N-1. */
-     int length;         /* Number of valid elements in queue 0..N. */
-     int elem[N];        /* elem[head .. head+length-1] are queue elements. */
-   } queue;
-
-   /* Initialize *q. */
-   void queue_init(queue *q) {
-     gpr_mu_init(&q->mu);
-     gpr_cv_init(&q->non_empty);
-     gpr_cv_init(&q->non_full);
-     q->head = 0;
-     q->length = 0;
-   }
-
-   /* Free storage associated with *q. */
-   void queue_destroy(queue *q) {
-     gpr_mu_destroy(&q->mu);
-     gpr_cv_destroy(&q->non_empty);
-     gpr_cv_destroy(&q->non_full);
-   }
-
-   /* Wait until there is room in *q, then append x to *q. */
-   void queue_append(queue *q, int x) {
-     gpr_mu_lock(&q->mu);
-     /* To wait for a predicate without a deadline, loop on the negation of the
-        predicate, and use gpr_cv_wait(..., gpr_inf_future) inside the loop
-        to release the lock, wait, and reacquire on each iteration.  Code that
-        makes the condition true should use gpr_cv_broadcast() on the
-        corresponding condition variable.  The predicate must be on state
-        protected by the lock.  */
-     while (q->length == N) {
-       gpr_cv_wait(&q->non_full, &q->mu, gpr_inf_future);
-     }
-     if (q->length == 0) {  /* Wake threads blocked in queue_remove(). */
-       /* It's normal to use gpr_cv_broadcast() or gpr_signal() while
-          holding the lock. */
-       gpr_cv_broadcast(&q->non_empty);
-     }
-     q->elem[(q->head + q->length) % N] = x;
-     q->length++;
-     gpr_mu_unlock(&q->mu);
-   }
-
-   /* If it can be done without blocking, append x to *q and return non-zero.
-      Otherwise return 0. */
-   int queue_try_append(queue *q, int x) {
-     int result = 0;
-     if (gpr_mu_trylock(&q->mu)) {
-       if (q->length != N) {
-         if (q->length == 0) {  /* Wake threads blocked in queue_remove(). */
-           gpr_cv_broadcast(&q->non_empty);
-         }
-         q->elem[(q->head + q->length) % N] = x;
-         q->length++;
-         result = 1;
-       }
-       gpr_mu_unlock(&q->mu);
-     }
-     return result;
-   }
-
-   /* Wait until the *q is non-empty or deadline abs_deadline passes.  If the
-      queue is non-empty, remove its head entry, place it in *head, and return
-      non-zero.  Otherwise return 0.  */
-   int queue_remove(queue *q, int *head, gpr_timespec abs_deadline) {
-     int result = 0;
-     gpr_mu_lock(&q->mu);
-     /* To wait for a predicate with a deadline, loop on the negation of the
-        predicate or until gpr_cv_wait() returns true.  Code that makes
-        the condition true should use gpr_cv_broadcast() on the corresponding
-        condition variable.  The predicate must be on state protected by the
-        lock. */
-     while (q->length == 0 &&
-            !gpr_cv_wait(&q->non_empty, &q->mu, abs_deadline)) {
-     }
-     if (q->length != 0) {    /* Queue is non-empty. */
-       result = 1;
-       if (q->length == N) {  /* Wake threads blocked in queue_append(). */
-         gpr_cv_broadcast(&q->non_full);
-       }
-       *head = q->elem[q->head];
-       q->head = (q->head + 1) % N;
-       q->length--;
-     } /* else deadline exceeded */
-     gpr_mu_unlock(&q->mu);
-     return result;
-   }
-#endif /* 0 */
-
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* GRPC_IMPL_CODEGEN_SYNC_H */
diff --git a/include/grpc/impl/codegen/time.h b/include/grpc/impl/codegen/time.h
deleted file mode 100644
index 381e267259..0000000000
--- a/include/grpc/impl/codegen/time.h
+++ /dev/null
@@ -1,130 +0,0 @@
-/*
- *
- * 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 GRPC_IMPL_CODEGEN_TIME_H
-#define GRPC_IMPL_CODEGEN_TIME_H
-/* Time support.
-   We use gpr_timespec, which is analogous to struct timespec.  On some
-   machines, absolute times may be in local time.  */
-
-#include <grpc/impl/codegen/port_platform.h>
-#include <stddef.h>
-#include <time.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* The clocks we support. */
-typedef enum {
-  /* Monotonic clock. Epoch undefined. Always moves forwards. */
-  GPR_CLOCK_MONOTONIC = 0,
-  /* Realtime clock. May jump forwards or backwards. Settable by
-     the system administrator. Has its epoch at 0:00:00 UTC 1 Jan 1970. */
-  GPR_CLOCK_REALTIME,
-  /* CPU cycle time obtained by rdtsc instruction on x86 platforms. Epoch
-     undefined. Degrades to GPR_CLOCK_REALTIME on other platforms. */
-  GPR_CLOCK_PRECISE,
-  /* Unmeasurable clock type: no base, created by taking the difference
-     between two times */
-  GPR_TIMESPAN
-} gpr_clock_type;
-
-typedef struct gpr_timespec {
-  int64_t tv_sec;
-  int32_t tv_nsec;
-  /** Against which clock was this time measured? (or GPR_TIMESPAN if
-      this is a relative time meaure) */
-  gpr_clock_type clock_type;
-} gpr_timespec;
-
-/* Time constants. */
-GPRAPI gpr_timespec
-gpr_time_0(gpr_clock_type type); /* The zero time interval. */
-GPRAPI gpr_timespec gpr_inf_future(gpr_clock_type type); /* The far future */
-GPRAPI gpr_timespec gpr_inf_past(gpr_clock_type type);   /* The far past. */
-
-#define GPR_MS_PER_SEC 1000
-#define GPR_US_PER_SEC 1000000
-#define GPR_NS_PER_SEC 1000000000
-#define GPR_NS_PER_MS 1000000
-#define GPR_NS_PER_US 1000
-#define GPR_US_PER_MS 1000
-
-/* initialize time subsystem */
-GPRAPI void gpr_time_init(void);
-
-/* Return the current time measured from the given clocks epoch. */
-GPRAPI gpr_timespec gpr_now(gpr_clock_type clock);
-
-/* Convert a timespec from one clock to another */
-GPRAPI gpr_timespec gpr_convert_clock_type(gpr_timespec t,
-                                           gpr_clock_type target_clock);
-
-/* Return -ve, 0, or +ve according to whether a < b, a == b, or a > b
-   respectively.  */
-GPRAPI int gpr_time_cmp(gpr_timespec a, gpr_timespec b);
-
-GPRAPI gpr_timespec gpr_time_max(gpr_timespec a, gpr_timespec b);
-GPRAPI gpr_timespec gpr_time_min(gpr_timespec a, gpr_timespec b);
-
-/* Add and subtract times.  Calculations saturate at infinities. */
-GPRAPI gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b);
-GPRAPI gpr_timespec gpr_time_sub(gpr_timespec a, gpr_timespec b);
-
-/* Return a timespec representing a given number of time units. INT64_MIN is
-   interpreted as gpr_inf_past, and INT64_MAX as gpr_inf_future.  */
-GPRAPI gpr_timespec gpr_time_from_micros(int64_t x, gpr_clock_type clock_type);
-GPRAPI gpr_timespec gpr_time_from_nanos(int64_t x, gpr_clock_type clock_type);
-GPRAPI gpr_timespec gpr_time_from_millis(int64_t x, gpr_clock_type clock_type);
-GPRAPI gpr_timespec gpr_time_from_seconds(int64_t x, gpr_clock_type clock_type);
-GPRAPI gpr_timespec gpr_time_from_minutes(int64_t x, gpr_clock_type clock_type);
-GPRAPI gpr_timespec gpr_time_from_hours(int64_t x, gpr_clock_type clock_type);
-
-GPRAPI int32_t gpr_time_to_millis(gpr_timespec timespec);
-
-/* Return 1 if two times are equal or within threshold of each other,
-   0 otherwise */
-GPRAPI int gpr_time_similar(gpr_timespec a, gpr_timespec b,
-                            gpr_timespec threshold);
-
-/* Sleep until at least 'until' - an absolute timeout */
-GPRAPI void gpr_sleep_until(gpr_timespec until);
-
-GPRAPI double gpr_timespec_to_micros(gpr_timespec t);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* GRPC_IMPL_CODEGEN_TIME_H */
diff --git a/include/grpc/module.modulemap b/include/grpc/module.modulemap
index 02fb2f39b2..51bfef2cc9 100644
--- a/include/grpc/module.modulemap
+++ b/include/grpc/module.modulemap
@@ -4,8 +4,6 @@ framework module grpc {
   header "byte_buffer_reader.h"
   header "grpc_security.h"
   header "grpc_security_constants.h"
-  header "impl/codegen/alloc.h"
-  header "impl/codegen/byte_buffer_reader.h"
   header "support/alloc.h"
   header "support/port_platform.h"
   header "support/string_util.h"
diff --git a/include/grpc/support/alloc.h b/include/grpc/support/alloc.h
index 8d03af8424..327a9ff9f0 100644
--- a/include/grpc/support/alloc.h
+++ b/include/grpc/support/alloc.h
@@ -34,6 +34,41 @@
 #ifndef GRPC_SUPPORT_ALLOC_H
 #define GRPC_SUPPORT_ALLOC_H
 
-#include <grpc/impl/codegen/alloc.h>
+#include <stddef.h>
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct gpr_allocation_functions {
+  void *(*malloc_fn)(size_t size);
+  void *(*realloc_fn)(void *ptr, size_t size);
+  void (*free_fn)(void *ptr);
+} gpr_allocation_functions;
+
+/* malloc, never returns NULL */
+GPRAPI void *gpr_malloc(size_t size);
+/* free */
+GPRAPI void gpr_free(void *ptr);
+/* realloc, never returns NULL */
+GPRAPI void *gpr_realloc(void *p, size_t size);
+/* aligned malloc, never returns NULL, will align to 1 << alignment_log */
+GPRAPI void *gpr_malloc_aligned(size_t size, size_t alignment_log);
+/* free memory allocated by gpr_malloc_aligned */
+GPRAPI void gpr_free_aligned(void *ptr);
+
+/** Request the family of allocation functions in \a functions be used. NOTE
+ * that this request will be honored in a *best effort* basis and that no
+ * guarantees are made about the default functions (eg, malloc) being called. */
+GPRAPI void gpr_set_allocation_functions(gpr_allocation_functions functions);
+
+/** Return the family of allocation functions currently in effect. */
+GPRAPI gpr_allocation_functions gpr_get_allocation_functions();
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* GRPC_SUPPORT_ALLOC_H */
diff --git a/include/grpc/support/log.h b/include/grpc/support/log.h
index 3fdba04943..5acf17fc2c 100644
--- a/include/grpc/support/log.h
+++ b/include/grpc/support/log.h
@@ -34,6 +34,85 @@
 #ifndef GRPC_SUPPORT_LOG_H
 #define GRPC_SUPPORT_LOG_H
 
-#include <grpc/impl/codegen/log.h>
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdlib.h> /* for abort() */
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* GPR log API.
+
+   Usage (within grpc):
+
+   int argument1 = 3;
+   char* argument2 = "hello";
+   gpr_log(GPR_DEBUG, "format string %d", argument1);
+   gpr_log(GPR_INFO, "hello world");
+   gpr_log(GPR_ERROR, "%d %s!!", argument1, argument2); */
+
+/* The severity of a log message - use the #defines below when calling into
+   gpr_log to additionally supply file and line data */
+typedef enum gpr_log_severity {
+  GPR_LOG_SEVERITY_DEBUG,
+  GPR_LOG_SEVERITY_INFO,
+  GPR_LOG_SEVERITY_ERROR
+} gpr_log_severity;
+
+#define GPR_LOG_VERBOSITY_UNSET -1
+
+/* Returns a string representation of the log severity */
+const char *gpr_log_severity_string(gpr_log_severity severity);
+
+/* Macros to build log contexts at various severity levels */
+#define GPR_DEBUG __FILE__, __LINE__, GPR_LOG_SEVERITY_DEBUG
+#define GPR_INFO __FILE__, __LINE__, GPR_LOG_SEVERITY_INFO
+#define GPR_ERROR __FILE__, __LINE__, GPR_LOG_SEVERITY_ERROR
+
+/* Log a message. It's advised to use GPR_xxx above to generate the context
+ * for each message */
+GPRAPI void gpr_log(const char *file, int line, gpr_log_severity severity,
+                    const char *format, ...) GPRC_PRINT_FORMAT_CHECK(4, 5);
+
+GPRAPI void gpr_log_message(const char *file, int line,
+                            gpr_log_severity severity, const char *message);
+
+/* Set global log verbosity */
+GPRAPI void gpr_set_log_verbosity(gpr_log_severity min_severity_to_print);
+
+GPRAPI void gpr_log_verbosity_init();
+
+/* Log overrides: applications can use this API to intercept logging calls
+   and use their own implementations */
+
+typedef struct {
+  const char *file;
+  int line;
+  gpr_log_severity severity;
+  const char *message;
+} gpr_log_func_args;
+
+typedef void (*gpr_log_func)(gpr_log_func_args *args);
+GPRAPI void gpr_set_log_function(gpr_log_func func);
+
+/* abort() the process if x is zero, having written a line to the log.
+
+   Intended for internal invariants.  If the error can be recovered from,
+   without the possibility of corruption, or might best be reflected via
+   an exception in a higher-level language, consider returning error code.  */
+#define GPR_ASSERT(x)                                 \
+  do {                                                \
+    if (!(x)) {                                       \
+      gpr_log(GPR_ERROR, "assertion failed: %s", #x); \
+      abort();                                        \
+    }                                                 \
+  } while (0)
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* GRPC_SUPPORT_LOG_H */
diff --git a/include/grpc/support/slice.h b/include/grpc/support/slice.h
index b45db03389..b31fe6c0c5 100644
--- a/include/grpc/support/slice.h
+++ b/include/grpc/support/slice.h
@@ -35,5 +35,94 @@
 #define GRPC_SUPPORT_SLICE_H
 
 #include <grpc/impl/codegen/slice.h>
+#include <grpc/support/sync.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Increment the refcount of s. Requires slice is initialized.
+   Returns s. */
+GPRAPI gpr_slice gpr_slice_ref(gpr_slice s);
+
+/* Decrement the ref count of s.  If the ref count of s reaches zero, all
+   slices sharing the ref count are destroyed, and considered no longer
+   initialized.  If s is ultimately derived from a call to gpr_slice_new(start,
+   len, dest) where dest!=NULL , then (*dest)(start) is called, else if s is
+   ultimately derived from a call to gpr_slice_new_with_len(start, len, dest)
+   where dest!=NULL , then (*dest)(start, len).  Requires s initialized.  */
+GPRAPI void gpr_slice_unref(gpr_slice s);
+
+/* Create a slice pointing at some data. Calls malloc to allocate a refcount
+   for the object, and arranges that destroy will be called with the pointer
+   passed in at destruction. */
+GPRAPI gpr_slice gpr_slice_new(void *p, size_t len, void (*destroy)(void *));
+
+/* Equivalent to gpr_slice_new, but with a separate pointer that is
+   passed to the destroy function.  This function can be useful when
+   the data is part of a larger structure that must be destroyed when
+   the data is no longer needed. */
+GPRAPI gpr_slice gpr_slice_new_with_user_data(void *p, size_t len,
+                                              void (*destroy)(void *),
+                                              void *user_data);
+
+/* Equivalent to gpr_slice_new, but with a two argument destroy function that
+   also takes the slice length. */
+GPRAPI gpr_slice gpr_slice_new_with_len(void *p, size_t len,
+                                        void (*destroy)(void *, size_t));
+
+/* Equivalent to gpr_slice_new(malloc(len), len, free), but saves one malloc()
+   call.
+   Aborts if malloc() fails. */
+GPRAPI gpr_slice gpr_slice_malloc(size_t length);
+
+/* Create a slice by copying a string.
+   Does not preserve null terminators.
+   Equivalent to:
+     size_t len = strlen(source);
+     gpr_slice slice = gpr_slice_malloc(len);
+     memcpy(slice->data, source, len); */
+GPRAPI gpr_slice gpr_slice_from_copied_string(const char *source);
+
+/* Create a slice by copying a buffer.
+   Equivalent to:
+     gpr_slice slice = gpr_slice_malloc(len);
+     memcpy(slice->data, source, len); */
+GPRAPI gpr_slice gpr_slice_from_copied_buffer(const char *source, size_t len);
+
+/* Create a slice pointing to constant memory */
+GPRAPI gpr_slice gpr_slice_from_static_string(const char *source);
+
+/* Return a result slice derived from s, which shares a ref count with s, where
+   result.data==s.data+begin, and result.length==end-begin.
+   The ref count of s is increased by one.
+   Requires s initialized, begin <= end, begin <= s.length, and
+   end <= source->length. */
+GPRAPI gpr_slice gpr_slice_sub(gpr_slice s, size_t begin, size_t end);
+
+/* The same as gpr_slice_sub, but without altering the ref count */
+GPRAPI gpr_slice gpr_slice_sub_no_ref(gpr_slice s, size_t begin, size_t end);
+
+/* Splits s into two: modifies s to be s[0:split], and returns a new slice,
+   sharing a refcount with s, that contains s[split:s.length].
+   Requires s intialized, split <= s.length */
+GPRAPI gpr_slice gpr_slice_split_tail(gpr_slice *s, size_t split);
+
+/* Splits s into two: modifies s to be s[split:s.length], and returns a new
+   slice, sharing a refcount with s, that contains s[0:split].
+   Requires s intialized, split <= s.length */
+GPRAPI gpr_slice gpr_slice_split_head(gpr_slice *s, size_t split);
+
+GPRAPI gpr_slice gpr_empty_slice(void);
+
+/* Returns <0 if a < b, ==0 if a == b, >0 if a > b
+   The order is arbitrary, and is not guaranteed to be stable across different
+   versions of the API. */
+GPRAPI int gpr_slice_cmp(gpr_slice a, gpr_slice b);
+GPRAPI int gpr_slice_str_cmp(gpr_slice a, const char *b);
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* GRPC_SUPPORT_SLICE_H */
diff --git a/include/grpc/support/slice_buffer.h b/include/grpc/support/slice_buffer.h
index cf7a89f8f1..3920432b02 100644
--- a/include/grpc/support/slice_buffer.h
+++ b/include/grpc/support/slice_buffer.h
@@ -34,6 +34,54 @@
 #ifndef GRPC_SUPPORT_SLICE_BUFFER_H
 #define GRPC_SUPPORT_SLICE_BUFFER_H
 
-#include <grpc/impl/codegen/slice_buffer.h>
+#include <grpc/support/slice.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* initialize a slice buffer */
+GPRAPI void gpr_slice_buffer_init(gpr_slice_buffer *sb);
+/* destroy a slice buffer - unrefs any held elements */
+GPRAPI void gpr_slice_buffer_destroy(gpr_slice_buffer *sb);
+/* Add an element to a slice buffer - takes ownership of the slice.
+   This function is allowed to concatenate the passed in slice to the end of
+   some other slice if desired by the slice buffer. */
+GPRAPI void gpr_slice_buffer_add(gpr_slice_buffer *sb, gpr_slice slice);
+/* add an element to a slice buffer - takes ownership of the slice and returns
+   the index of the slice.
+   Guarantees that the slice will not be concatenated at the end of another
+   slice (i.e. the data for this slice will begin at the first byte of the
+   slice at the returned index in sb->slices)
+   The implementation MAY decide to concatenate data at the end of a small
+   slice added in this fashion. */
+GPRAPI size_t gpr_slice_buffer_add_indexed(gpr_slice_buffer *sb,
+                                           gpr_slice slice);
+GPRAPI void gpr_slice_buffer_addn(gpr_slice_buffer *sb, gpr_slice *slices,
+                                  size_t n);
+/* add a very small (less than 8 bytes) amount of data to the end of a slice
+   buffer: returns a pointer into which to add the data */
+GPRAPI uint8_t *gpr_slice_buffer_tiny_add(gpr_slice_buffer *sb, size_t len);
+/* pop the last buffer, but don't unref it */
+GPRAPI void gpr_slice_buffer_pop(gpr_slice_buffer *sb);
+/* clear a slice buffer, unref all elements */
+GPRAPI void gpr_slice_buffer_reset_and_unref(gpr_slice_buffer *sb);
+/* swap the contents of two slice buffers */
+GPRAPI void gpr_slice_buffer_swap(gpr_slice_buffer *a, gpr_slice_buffer *b);
+/* move all of the elements of src into dst */
+GPRAPI void gpr_slice_buffer_move_into(gpr_slice_buffer *src,
+                                       gpr_slice_buffer *dst);
+/* remove n bytes from the end of a slice buffer */
+GPRAPI void gpr_slice_buffer_trim_end(gpr_slice_buffer *src, size_t n,
+                                      gpr_slice_buffer *garbage);
+/* move the first n bytes of src into dst */
+GPRAPI void gpr_slice_buffer_move_first(gpr_slice_buffer *src, size_t n,
+                                        gpr_slice_buffer *dst);
+/* take the first slice in the slice buffer */
+GPRAPI gpr_slice gpr_slice_buffer_take_first(gpr_slice_buffer *src);
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* GRPC_SUPPORT_SLICE_BUFFER_H */
diff --git a/include/grpc/support/sync.h b/include/grpc/support/sync.h
index a0145803c2..a7bbb38c27 100644
--- a/include/grpc/support/sync.h
+++ b/include/grpc/support/sync.h
@@ -34,6 +34,258 @@
 #ifndef GRPC_SUPPORT_SYNC_H
 #define GRPC_SUPPORT_SYNC_H
 
+#include <grpc/impl/codegen/gpr_types.h> /* for gpr_timespec */
 #include <grpc/impl/codegen/sync.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* --- Mutex interface ---
+
+   At most one thread may hold an exclusive lock on a mutex at any given time.
+   Actions taken by a thread that holds a mutex exclusively happen after
+   actions taken by all previous holders of the mutex.  Variables of type
+   gpr_mu are uninitialized when first declared.  */
+
+/* Initialize *mu.  Requires:  *mu uninitialized.  */
+GPRAPI void gpr_mu_init(gpr_mu *mu);
+
+/* Cause *mu no longer to be initialized, freeing any memory in use.  Requires:
+   *mu initialized; no other concurrent operation on *mu.  */
+GPRAPI void gpr_mu_destroy(gpr_mu *mu);
+
+/* Wait until no thread has a lock on *mu, cause the calling thread to own an
+   exclusive lock on *mu, then return.  May block indefinitely or crash if the
+   calling thread has a lock on *mu.  Requires:  *mu initialized.  */
+GPRAPI void gpr_mu_lock(gpr_mu *mu);
+
+/* Release an exclusive lock on *mu held by the calling thread.  Requires:  *mu
+   initialized; the calling thread holds an exclusive lock on *mu.  */
+GPRAPI void gpr_mu_unlock(gpr_mu *mu);
+
+/* Without blocking, attempt to acquire an exclusive lock on *mu for the
+   calling thread, then return non-zero iff success.  Fail, if any thread holds
+   the lock; succeeds with high probability if no thread holds the lock.
+   Requires:  *mu initialized.  */
+GPRAPI int gpr_mu_trylock(gpr_mu *mu);
+
+/* --- Condition variable interface ---
+
+   A while-loop should be used with gpr_cv_wait() when waiting for conditions
+   to become true.  See the example below.  Variables of type gpr_cv are
+   uninitialized when first declared.  */
+
+/* Initialize *cv.  Requires:  *cv uninitialized.  */
+GPRAPI void gpr_cv_init(gpr_cv *cv);
+
+/* Cause *cv no longer to be initialized, freeing any memory in use.  Requires:
+   *cv initialized; no other concurrent operation on *cv.*/
+GPRAPI void gpr_cv_destroy(gpr_cv *cv);
+
+/* Atomically release *mu and wait on *cv.  When the calling thread is woken
+   from *cv or the deadline abs_deadline is exceeded, execute gpr_mu_lock(mu)
+   and return whether the deadline was exceeded.  Use
+   abs_deadline==gpr_inf_future for no deadline.  abs_deadline can be either
+   an absolute deadline, or a GPR_TIMESPAN.  May return even when not
+   woken explicitly.  Requires:  *mu and *cv initialized; the calling thread
+   holds an exclusive lock on *mu.  */
+GPRAPI int gpr_cv_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline);
+
+/* If any threads are waiting on *cv, wake at least one.
+   Clients may treat this as an optimization of gpr_cv_broadcast()
+   for use in the case where waking more than one waiter is not useful.
+   Requires:  *cv initialized.  */
+GPRAPI void gpr_cv_signal(gpr_cv *cv);
+
+/* Wake all threads waiting on *cv.  Requires:  *cv initialized.  */
+GPRAPI void gpr_cv_broadcast(gpr_cv *cv);
+
+/* --- One-time initialization ---
+
+   gpr_once must be declared with static storage class, and initialized with
+   GPR_ONCE_INIT.  e.g.,
+     static gpr_once once_var = GPR_ONCE_INIT;     */
+
+/* Ensure that (*init_routine)() has been called exactly once (for the
+   specified gpr_once instance) and then return.
+   If multiple threads call gpr_once() on the same gpr_once instance, one of
+   them will call (*init_routine)(), and the others will block until that call
+   finishes.*/
+GPRAPI void gpr_once_init(gpr_once *once, void (*init_routine)(void));
+
+/* --- One-time event notification ---
+
+  These operations act on a gpr_event, which should be initialized with
+  gpr_ev_init(), or with GPR_EVENT_INIT if static, e.g.,
+       static gpr_event event_var = GPR_EVENT_INIT;
+  It requires no destruction.  */
+
+/* Initialize *ev. */
+GPRAPI void gpr_event_init(gpr_event *ev);
+
+/* Set *ev so that gpr_event_get() and gpr_event_wait() will return value.
+   Requires:  *ev initialized; value != NULL; no prior or concurrent calls to
+   gpr_event_set(ev, ...) since initialization.  */
+GPRAPI void gpr_event_set(gpr_event *ev, void *value);
+
+/* Return the value set by gpr_event_set(ev, ...), or NULL if no such call has
+   completed.  If the result is non-NULL, all operations that occurred prior to
+   the gpr_event_set(ev, ...) set will be visible after this call returns.
+   Requires:  *ev initialized.  This operation is faster than acquiring a mutex
+   on most platforms.  */
+GPRAPI void *gpr_event_get(gpr_event *ev);
+
+/* Wait until *ev is set by gpr_event_set(ev, ...), or abs_deadline is
+   exceeded, then return gpr_event_get(ev).  Requires:  *ev initialized.  Use
+   abs_deadline==gpr_inf_future for no deadline.  When the event has been
+   signalled before the call, this operation is faster than acquiring a mutex
+   on most platforms.  */
+GPRAPI void *gpr_event_wait(gpr_event *ev, gpr_timespec abs_deadline);
+
+/* --- Reference counting ---
+
+   These calls act on the type gpr_refcount.  It requires no destruction.  */
+
+/* Initialize *r to value n.  */
+GPRAPI void gpr_ref_init(gpr_refcount *r, int n);
+
+/* Increment the reference count *r.  Requires *r initialized. */
+GPRAPI void gpr_ref(gpr_refcount *r);
+
+/* Increment the reference count *r.  Requires *r initialized.
+   Crashes if refcount is zero */
+GPRAPI void gpr_ref_non_zero(gpr_refcount *r);
+
+/* Increment the reference count *r by n.  Requires *r initialized, n > 0. */
+GPRAPI void gpr_refn(gpr_refcount *r, int n);
+
+/* Decrement the reference count *r and return non-zero iff it has reached
+   zero. .  Requires *r initialized. */
+GPRAPI int gpr_unref(gpr_refcount *r);
+
+/* --- Stats counters ---
+
+   These calls act on the integral type gpr_stats_counter.  It requires no
+   destruction.  Static instances may be initialized with
+       gpr_stats_counter c = GPR_STATS_INIT;
+   Beware:  These operations do not imply memory barriers.  Do not use them to
+   synchronize other events.  */
+
+/* Initialize *c to the value n. */
+GPRAPI void gpr_stats_init(gpr_stats_counter *c, intptr_t n);
+
+/* *c += inc.  Requires: *c initialized. */
+GPRAPI void gpr_stats_inc(gpr_stats_counter *c, intptr_t inc);
+
+/* Return *c.  Requires: *c initialized. */
+GPRAPI intptr_t gpr_stats_read(const gpr_stats_counter *c);
+
+/* ==================Example use of interface===================
+   A producer-consumer queue of up to N integers,
+   illustrating the use of the calls in this interface. */
+#if 0
+
+#define N 4
+
+   typedef struct queue {
+     gpr_cv non_empty;  /* Signalled when length becomes non-zero. */
+     gpr_cv non_full;   /* Signalled when length becomes non-N. */
+     gpr_mu mu;         /* Protects all fields below.
+                            (That is, except during initialization or
+                            destruction, the fields below should be accessed
+                            only by a thread that holds mu.) */
+     int head;           /* Index of head of queue 0..N-1. */
+     int length;         /* Number of valid elements in queue 0..N. */
+     int elem[N];        /* elem[head .. head+length-1] are queue elements. */
+   } queue;
+
+   /* Initialize *q. */
+   void queue_init(queue *q) {
+     gpr_mu_init(&q->mu);
+     gpr_cv_init(&q->non_empty);
+     gpr_cv_init(&q->non_full);
+     q->head = 0;
+     q->length = 0;
+   }
+
+   /* Free storage associated with *q. */
+   void queue_destroy(queue *q) {
+     gpr_mu_destroy(&q->mu);
+     gpr_cv_destroy(&q->non_empty);
+     gpr_cv_destroy(&q->non_full);
+   }
+
+   /* Wait until there is room in *q, then append x to *q. */
+   void queue_append(queue *q, int x) {
+     gpr_mu_lock(&q->mu);
+     /* To wait for a predicate without a deadline, loop on the negation of the
+        predicate, and use gpr_cv_wait(..., gpr_inf_future) inside the loop
+        to release the lock, wait, and reacquire on each iteration.  Code that
+        makes the condition true should use gpr_cv_broadcast() on the
+        corresponding condition variable.  The predicate must be on state
+        protected by the lock.  */
+     while (q->length == N) {
+       gpr_cv_wait(&q->non_full, &q->mu, gpr_inf_future);
+     }
+     if (q->length == 0) {  /* Wake threads blocked in queue_remove(). */
+       /* It's normal to use gpr_cv_broadcast() or gpr_signal() while
+          holding the lock. */
+       gpr_cv_broadcast(&q->non_empty);
+     }
+     q->elem[(q->head + q->length) % N] = x;
+     q->length++;
+     gpr_mu_unlock(&q->mu);
+   }
+
+   /* If it can be done without blocking, append x to *q and return non-zero.
+      Otherwise return 0. */
+   int queue_try_append(queue *q, int x) {
+     int result = 0;
+     if (gpr_mu_trylock(&q->mu)) {
+       if (q->length != N) {
+         if (q->length == 0) {  /* Wake threads blocked in queue_remove(). */
+           gpr_cv_broadcast(&q->non_empty);
+         }
+         q->elem[(q->head + q->length) % N] = x;
+         q->length++;
+         result = 1;
+       }
+       gpr_mu_unlock(&q->mu);
+     }
+     return result;
+   }
+
+   /* Wait until the *q is non-empty or deadline abs_deadline passes.  If the
+      queue is non-empty, remove its head entry, place it in *head, and return
+      non-zero.  Otherwise return 0.  */
+   int queue_remove(queue *q, int *head, gpr_timespec abs_deadline) {
+     int result = 0;
+     gpr_mu_lock(&q->mu);
+     /* To wait for a predicate with a deadline, loop on the negation of the
+        predicate or until gpr_cv_wait() returns true.  Code that makes
+        the condition true should use gpr_cv_broadcast() on the corresponding
+        condition variable.  The predicate must be on state protected by the
+        lock. */
+     while (q->length == 0 &&
+            !gpr_cv_wait(&q->non_empty, &q->mu, abs_deadline)) {
+     }
+     if (q->length != 0) {    /* Queue is non-empty. */
+       result = 1;
+       if (q->length == N) {  /* Wake threads blocked in queue_append(). */
+         gpr_cv_broadcast(&q->non_full);
+       }
+       *head = q->elem[q->head];
+       q->head = (q->head + 1) % N;
+       q->length--;
+     } /* else deadline exceeded */
+     gpr_mu_unlock(&q->mu);
+     return result;
+   }
+#endif /* 0 */
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_SUPPORT_SYNC_H */
diff --git a/include/grpc/support/time.h b/include/grpc/support/time.h
index b3f2f8cd44..66bcfca6ed 100644
--- a/include/grpc/support/time.h
+++ b/include/grpc/support/time.h
@@ -34,6 +34,72 @@
 #ifndef GRPC_SUPPORT_TIME_H
 #define GRPC_SUPPORT_TIME_H
 
-#include <grpc/impl/codegen/time.h>
+#include <grpc/impl/codegen/gpr_types.h>
+
+#include <stddef.h>
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Time constants. */
+GPRAPI gpr_timespec
+gpr_time_0(gpr_clock_type type); /* The zero time interval. */
+GPRAPI gpr_timespec gpr_inf_future(gpr_clock_type type); /* The far future */
+GPRAPI gpr_timespec gpr_inf_past(gpr_clock_type type);   /* The far past. */
+
+#define GPR_MS_PER_SEC 1000
+#define GPR_US_PER_SEC 1000000
+#define GPR_NS_PER_SEC 1000000000
+#define GPR_NS_PER_MS 1000000
+#define GPR_NS_PER_US 1000
+#define GPR_US_PER_MS 1000
+
+/* initialize time subsystem */
+GPRAPI void gpr_time_init(void);
+
+/* Return the current time measured from the given clocks epoch. */
+GPRAPI gpr_timespec gpr_now(gpr_clock_type clock);
+
+/* Convert a timespec from one clock to another */
+GPRAPI gpr_timespec gpr_convert_clock_type(gpr_timespec t,
+                                           gpr_clock_type target_clock);
+
+/* Return -ve, 0, or +ve according to whether a < b, a == b, or a > b
+   respectively.  */
+GPRAPI int gpr_time_cmp(gpr_timespec a, gpr_timespec b);
+
+GPRAPI gpr_timespec gpr_time_max(gpr_timespec a, gpr_timespec b);
+GPRAPI gpr_timespec gpr_time_min(gpr_timespec a, gpr_timespec b);
+
+/* Add and subtract times.  Calculations saturate at infinities. */
+GPRAPI gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b);
+GPRAPI gpr_timespec gpr_time_sub(gpr_timespec a, gpr_timespec b);
+
+/* Return a timespec representing a given number of time units. INT64_MIN is
+   interpreted as gpr_inf_past, and INT64_MAX as gpr_inf_future.  */
+GPRAPI gpr_timespec gpr_time_from_micros(int64_t x, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_nanos(int64_t x, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_millis(int64_t x, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_seconds(int64_t x, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_minutes(int64_t x, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_hours(int64_t x, gpr_clock_type clock_type);
+
+GPRAPI int32_t gpr_time_to_millis(gpr_timespec timespec);
+
+/* Return 1 if two times are equal or within threshold of each other,
+   0 otherwise */
+GPRAPI int gpr_time_similar(gpr_timespec a, gpr_timespec b,
+                            gpr_timespec threshold);
+
+/* Sleep until at least 'until' - an absolute timeout */
+GPRAPI void gpr_sleep_until(gpr_timespec until);
+
+GPRAPI double gpr_timespec_to_micros(gpr_timespec t);
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* GRPC_SUPPORT_TIME_H */