Merge github.com:grpc/grpc into an-update-on-c++

49 files changed, 1466 insertions, 1073 deletions

diff --git a/INSTALL b/INSTALL
index d2f08ec677..f1e7aa7bf4 100644
--- a/INSTALL
+++ b/INSTALL
@@ -95,6 +95,44 @@ will need clang and its instrumented libc++:
 
   # apt-get install clang libc++-dev
 
+Mac-specific notes:
+-------------------
+
+For a Mac system, git is not available by default. You will first need to
+install Xcode from the Mac AppStore and then run the following command from a
+terminal:
+
+  $ sudo xcode-select --install
+
+You should also install "port" following the instructions at
+https://www.macports.org . This will reside in /opt/local/bin/port for
+most Mac installations. Do the "git submodule" command listed above.
+
+Then execute the following for all the needed build dependencies
+
+  $ sudo /opt/local/bin/port install autoconf automake libtool gflags cmake
+  $ mkdir ~/gtest
+  $ svn checkout http://googletest.googlecode.com/svn/trunk/ gtest-svn
+  $ mkdir mybuild
+  $ cd mybuild
+  $ cmake ../gtest-svn
+  $ make
+  $ make gtest.a gtest_main.a
+  $ sudo cp libgtest.a libgtest_main.a /opt/local/lib
+  $ sudo mkdir /opt/local/include/gtest
+  $ sudo cp -pr ../gtest-svn/include/gtest /opt/local/include/gtest 
+
+We will also need to make openssl and install it appropriately
+
+  $ cd <git directory>
+  $ cd third_party/openssl
+  $ sudo make install
+  $ cd ../../
+
+If you are going to make changes and need to regenerate the projects file,
+you will need to install certain modules for python.
+
+  $ sudo easy_install simplejson mako
 
 A word on OpenSSL
 -----------------
diff --git a/Makefile b/Makefile
index e45b128dbe..f1fa9dba12 100644
--- a/Makefile
+++ b/Makefile
@@ -177,7 +177,9 @@ LDFLAGS += -g -fPIC
 
 INCLUDES = . include $(GENDIR)
 ifeq ($(SYSTEM),Darwin)
+INCLUDES += /usr/local/ssl/include /opt/local/include
 LIBS = m z
+LDFLAGS += -L/usr/local/ssl/lib -L/opt/local/lib
 else
 LIBS = rt m z pthread
 LDFLAGS += -pthread
@@ -890,16 +892,19 @@ $(LIBDIR)/$(CONFIG)/protobuf/libprotobuf.a: third_party/protobuf/configure
 
 static: static_c static_cxx
 
-static_c:  $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.a $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a
+static_c:  $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a
 
 static_cxx:  $(LIBDIR)/$(CONFIG)/libgrpc++.a
 
 shared: shared_c shared_cxx
 
-shared_c:  $(LIBDIR)/$(CONFIG)/libgpr.$(SHARED_EXT) $(LIBDIR)/$(CONFIG)/libgrpc.$(SHARED_EXT) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.$(SHARED_EXT) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.$(SHARED_EXT)
+shared_c:  $(LIBDIR)/$(CONFIG)/libgpr.$(SHARED_EXT) $(LIBDIR)/$(CONFIG)/libgrpc.$(SHARED_EXT) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.$(SHARED_EXT)
 
 shared_cxx:  $(LIBDIR)/$(CONFIG)/libgrpc++.$(SHARED_EXT)
 
+shared_csharp: shared_c  $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.$(SHARED_EXT)
+grpc_csharp_ext: shared_csharp
+
 privatelibs: privatelibs_c privatelibs_cxx
 
 privatelibs_c:  $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libend2end_fixture_chttp2_fake_security.a $(LIBDIR)/$(CONFIG)/libend2end_fixture_chttp2_fullstack.a $(LIBDIR)/$(CONFIG)/libend2end_fixture_chttp2_fullstack_uds.a $(LIBDIR)/$(CONFIG)/libend2end_fixture_chttp2_simple_ssl_fullstack.a $(LIBDIR)/$(CONFIG)/libend2end_fixture_chttp2_simple_ssl_with_oauth2_fullstack.a $(LIBDIR)/$(CONFIG)/libend2end_fixture_chttp2_socket_pair.a $(LIBDIR)/$(CONFIG)/libend2end_fixture_chttp2_socket_pair_one_byte_at_a_time.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_after_accept.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_after_accept_and_writes_closed.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_after_invoke.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_before_invoke.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_in_a_vacuum.a $(LIBDIR)/$(CONFIG)/libend2end_test_census_simple_request.a $(LIBDIR)/$(CONFIG)/libend2end_test_disappearing_server.a $(LIBDIR)/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_inflight_calls.a $(LIBDIR)/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_tags.a $(LIBDIR)/$(CONFIG)/libend2end_test_empty_batch.a $(LIBDIR)/$(CONFIG)/libend2end_test_graceful_server_shutdown.a $(LIBDIR)/$(CONFIG)/libend2end_test_invoke_large_request.a $(LIBDIR)/$(CONFIG)/libend2end_test_max_concurrent_streams.a $(LIBDIR)/$(CONFIG)/libend2end_test_no_op.a $(LIBDIR)/$(CONFIG)/libend2end_test_ping_pong_streaming.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_response_with_binary_metadata_and_payload.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_response_with_metadata_and_payload.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_response_with_payload.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_with_large_metadata.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_with_payload.a $(LIBDIR)/$(CONFIG)/libend2end_test_simple_delayed_request.a $(LIBDIR)/$(CONFIG)/libend2end_test_simple_request.a $(LIBDIR)/$(CONFIG)/libend2end_test_thread_stress.a $(LIBDIR)/$(CONFIG)/libend2end_test_writes_done_hangs_with_pending_read.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_after_accept_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_after_accept_and_writes_closed_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_after_invoke_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_before_invoke_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_cancel_in_a_vacuum_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_census_simple_request_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_disappearing_server_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_inflight_calls_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_tags_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_graceful_server_shutdown_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_invoke_large_request_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_max_concurrent_streams_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_no_op_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_ping_pong_streaming_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_response_with_binary_metadata_and_payload_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_response_with_metadata_and_payload_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_response_with_payload_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_response_with_trailing_metadata_and_payload_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_with_large_metadata_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_request_with_payload_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_simple_delayed_request_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_simple_request_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_thread_stress_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_test_writes_done_hangs_with_pending_read_legacy.a $(LIBDIR)/$(CONFIG)/libend2end_certs.a
@@ -1763,8 +1768,6 @@ ifeq ($(CONFIG),opt)
 	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgpr.a
 	$(E) "[STRIP]   Stripping libgrpc.a"
 	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgrpc.a
-	$(E) "[STRIP]   Stripping libgrpc_csharp_ext.a"
-	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.a
 	$(E) "[STRIP]   Stripping libgrpc_unsecure.a"
 	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a
 endif
@@ -1781,8 +1784,6 @@ ifeq ($(CONFIG),opt)
 	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgpr.$(SHARED_EXT)
 	$(E) "[STRIP]   Stripping libgrpc.so"
 	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgrpc.$(SHARED_EXT)
-	$(E) "[STRIP]   Stripping libgrpc_csharp_ext.so"
-	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.$(SHARED_EXT)
 	$(E) "[STRIP]   Stripping libgrpc_unsecure.so"
 	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.$(SHARED_EXT)
 endif
@@ -1793,6 +1794,12 @@ ifeq ($(CONFIG),opt)
 	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgrpc++.$(SHARED_EXT)
 endif
 
+strip-shared_csharp: shared_csharp
+ifeq ($(CONFIG),opt)
+	$(E) "[STRIP]   Stripping libgrpc_csharp_ext.so"
+	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.$(SHARED_EXT)
+endif
+
 ifeq ($(NO_PROTOC),true)
 $(GENDIR)/examples/pubsub/empty.pb.cc: protoc_dep_error
 else
@@ -1911,6 +1918,10 @@ install_c: install-headers_c install-static_c install-shared_c
 
 install_cxx: install-headers_cxx install-static_cxx install-shared_cxx
 
+install_csharp: install-shared_csharp install_c
+
+install_grpc_csharp_ext: install_csharp
+
 install-headers: install-headers_c install-headers_cxx
 
 install-headers_c:
@@ -1928,8 +1939,6 @@ install-static_c: static_c strip-static_c
 	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgpr.a $(prefix)/lib/libgpr.a
 	$(E) "[INSTALL] Installing libgrpc.a"
 	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgrpc.a $(prefix)/lib/libgrpc.a
-	$(E) "[INSTALL] Installing libgrpc_csharp_ext.a"
-	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.a $(prefix)/lib/libgrpc_csharp_ext.a
 	$(E) "[INSTALL] Installing libgrpc_unsecure.a"
 	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a $(prefix)/lib/libgrpc_unsecure.a
 
@@ -1961,17 +1970,6 @@ ifneq ($(SYSTEM),Darwin)
 endif
 endif
 ifeq ($(SYSTEM),MINGW32)
-	$(E) "[INSTALL] Installing grpc_csharp_ext.$(SHARED_EXT)"
-	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/grpc_csharp_ext.$(SHARED_EXT) $(prefix)/lib/grpc_csharp_ext.$(SHARED_EXT)
-	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext-imp.a $(prefix)/lib/libgrpc_csharp_ext-imp.a
-else
-	$(E) "[INSTALL] Installing libgrpc_csharp_ext.$(SHARED_EXT)"
-	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.$(SHARED_EXT) $(prefix)/lib/libgrpc_csharp_ext.$(SHARED_EXT)
-ifneq ($(SYSTEM),Darwin)
-	$(Q) ln -sf libgrpc_csharp_ext.$(SHARED_EXT) $(prefix)/lib/libgrpc_csharp_ext.so
-endif
-endif
-ifeq ($(SYSTEM),MINGW32)
 	$(E) "[INSTALL] Installing grpc_unsecure.$(SHARED_EXT)"
 	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/grpc_unsecure.$(SHARED_EXT) $(prefix)/lib/grpc_unsecure.$(SHARED_EXT)
 	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure-imp.a $(prefix)/lib/libgrpc_unsecure-imp.a
@@ -2006,6 +2004,24 @@ ifneq ($(SYSTEM),Darwin)
 endif
 endif
 
+install-shared_csharp: shared_csharp strip-shared_csharp
+ifeq ($(SYSTEM),MINGW32)
+	$(E) "[INSTALL] Installing grpc_csharp_ext.$(SHARED_EXT)"
+	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/grpc_csharp_ext.$(SHARED_EXT) $(prefix)/lib/grpc_csharp_ext.$(SHARED_EXT)
+	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext-imp.a $(prefix)/lib/libgrpc_csharp_ext-imp.a
+else
+	$(E) "[INSTALL] Installing libgrpc_csharp_ext.$(SHARED_EXT)"
+	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.$(SHARED_EXT) $(prefix)/lib/libgrpc_csharp_ext.$(SHARED_EXT)
+ifneq ($(SYSTEM),Darwin)
+	$(Q) ln -sf libgrpc_csharp_ext.$(SHARED_EXT) $(prefix)/lib/libgrpc_csharp_ext.so
+endif
+endif
+ifneq ($(SYSTEM),MINGW32)
+ifneq ($(SYSTEM),Darwin)
+	$(Q) ldconfig
+endif
+endif
+
 clean:
 	$(Q) $(RM) -rf $(OBJDIR) $(LIBDIR) $(BINDIR) $(GENDIR)
 
@@ -3007,6 +3023,7 @@ LIBGRPC++_SRC = \
     src/cpp/util/time.cc \
 
 PUBLIC_HEADERS_CXX += \
+    include/grpc++/async_unary_call.h \
     include/grpc++/channel_arguments.h \
     include/grpc++/channel_interface.h \
     include/grpc++/client_context.h \
diff --git a/build.json b/build.json
index 4bca52e302..c552228496 100644
--- a/build.json
+++ b/build.json
@@ -345,7 +345,7 @@
     {
       "name": "grpc_csharp_ext",
       "build": "all",
-      "language": "c",
+      "language": "csharp",
       "src": [
         "src/csharp/ext/grpc_csharp_ext.c"
       ],
@@ -398,6 +398,7 @@
       "build": "all",
       "language": "c++",
       "public_headers": [
+        "include/grpc++/async_unary_call.h",
         "include/grpc++/channel_arguments.h",
         "include/grpc++/channel_interface.h",
         "include/grpc++/client_context.h",
diff --git a/include/grpc++/async_unary_call.h b/include/grpc++/async_unary_call.h
new file mode 100644
index 0000000000..105250ce9d
--- /dev/null
+++ b/include/grpc++/async_unary_call.h
@@ -0,0 +1,144 @@
+/*
+ *
+ * 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 __GRPCPP_ASYNC_UNARY_CALL_H__
+#define __GRPCPP_ASYNC_UNARY_CALL_H__
+
+#include <grpc++/channel_interface.h>
+#include <grpc++/client_context.h>
+#include <grpc++/completion_queue.h>
+#include <grpc++/server_context.h>
+#include <grpc++/impl/call.h>
+#include <grpc++/impl/service_type.h>
+#include <grpc++/status.h>
+#include <grpc/support/log.h>
+
+namespace grpc {
+template <class R>
+class ClientAsyncResponseReader final {
+ public:
+  ClientAsyncResponseReader(ChannelInterface* channel, CompletionQueue* cq,
+                    const RpcMethod& method, ClientContext* context,
+                    const google::protobuf::Message& request, void* tag)
+      : context_(context),
+        call_(channel->CreateCall(method, context, cq)) {
+    init_buf_.Reset(tag);
+    init_buf_.AddSendInitialMetadata(&context->send_initial_metadata_);
+    init_buf_.AddSendMessage(request);
+    init_buf_.AddClientSendClose();
+    call_.PerformOps(&init_buf_);
+  }
+
+  void ReadInitialMetadata(void* tag) {
+    GPR_ASSERT(!context_->initial_metadata_received_);
+
+    meta_buf_.Reset(tag);
+    meta_buf_.AddRecvInitialMetadata(context_);
+    call_.PerformOps(&meta_buf_);
+  }
+
+  void Finish(R* msg, Status* status, void* tag) {
+    finish_buf_.Reset(tag);
+    if (!context_->initial_metadata_received_) {
+      finish_buf_.AddRecvInitialMetadata(context_);
+    }
+    finish_buf_.AddRecvMessage(msg);
+    finish_buf_.AddClientRecvStatus(context_, status);
+    call_.PerformOps(&finish_buf_);
+  }
+
+
+ private:
+  ClientContext* context_ = nullptr;
+  Call call_;
+  CallOpBuffer init_buf_;
+  CallOpBuffer meta_buf_;
+  CallOpBuffer finish_buf_;
+};
+
+template <class W>
+class ServerAsyncResponseWriter final : public ServerAsyncStreamingInterface {
+ public:
+  explicit ServerAsyncResponseWriter(ServerContext* ctx)
+      : call_(nullptr, nullptr, nullptr), ctx_(ctx) {}
+
+  void SendInitialMetadata(void* tag) {
+    GPR_ASSERT(!ctx_->sent_initial_metadata_);
+
+    meta_buf_.Reset(tag);
+    meta_buf_.AddSendInitialMetadata(&ctx_->initial_metadata_);
+    ctx_->sent_initial_metadata_ = true;
+    call_.PerformOps(&meta_buf_);
+  }
+
+  void Finish(const W& msg, const Status& status, void* tag) {
+    finish_buf_.Reset(tag);
+    if (!ctx_->sent_initial_metadata_) {
+      finish_buf_.AddSendInitialMetadata(&ctx_->initial_metadata_);
+      ctx_->sent_initial_metadata_ = true;
+    }
+    // The response is dropped if the status is not OK.
+    if (status.IsOk()) {
+      finish_buf_.AddSendMessage(msg);
+    }
+    bool cancelled = false;
+    finish_buf_.AddServerRecvClose(&cancelled);
+    finish_buf_.AddServerSendStatus(&ctx_->trailing_metadata_, status);
+    call_.PerformOps(&finish_buf_);
+  }
+
+  void FinishWithError(const Status& status, void* tag) {
+    GPR_ASSERT(!status.IsOk());
+    finish_buf_.Reset(tag);
+    if (!ctx_->sent_initial_metadata_) {
+      finish_buf_.AddSendInitialMetadata(&ctx_->initial_metadata_);
+      ctx_->sent_initial_metadata_ = true;
+    }
+    bool cancelled = false;
+    finish_buf_.AddServerRecvClose(&cancelled);
+    finish_buf_.AddServerSendStatus(&ctx_->trailing_metadata_, status);
+    call_.PerformOps(&finish_buf_);
+  }
+
+ private:
+  void BindCall(Call* call) override { call_ = *call; }
+
+  Call call_;
+  ServerContext* ctx_;
+  CallOpBuffer meta_buf_;
+  CallOpBuffer finish_buf_;
+};
+
+}  // namespace grpc
+
+#endif  // __GRPCPP_ASYNC_UNARY_CALL_H__
diff --git a/include/grpc++/client_context.h b/include/grpc++/client_context.h
index 52bedd4d38..1e7e6bfad7 100644
--- a/include/grpc++/client_context.h
+++ b/include/grpc++/client_context.h
@@ -72,6 +72,8 @@ template <class W>
 class ClientAsyncWriter;
 template <class R, class W>
 class ClientAsyncReaderWriter;
+template <class R>
+class ClientAsyncResponseReader;
 
 class ClientContext {
  public:
@@ -119,6 +121,8 @@ class ClientContext {
   friend class ::grpc::ClientAsyncWriter;
   template <class R, class W>
   friend class ::grpc::ClientAsyncReaderWriter;
+  template <class R>
+  friend class ::grpc::ClientAsyncResponseReader;
 
   grpc_call *call() { return call_; }
   void set_call(grpc_call *call) {
diff --git a/include/grpc++/impl/client_unary_call.h b/include/grpc++/impl/client_unary_call.h
index a29621edb3..f25ded7a24 100644
--- a/include/grpc++/impl/client_unary_call.h
+++ b/include/grpc++/impl/client_unary_call.h
@@ -48,13 +48,6 @@ class CompletionQueue;
 class RpcMethod;
 class Status;
 
-// Wrapper that begins an asynchronous unary call
-void AsyncUnaryCall(ChannelInterface *channel, const RpcMethod &method,
-                    ClientContext *context,
-                    const google::protobuf::Message &request,
-                    google::protobuf::Message *result, Status *status,
-                    CompletionQueue *cq, void *tag);
-
 // Wrapper that performs a blocking unary call
 Status BlockingUnaryCall(ChannelInterface *channel, const RpcMethod &method,
                          ClientContext *context,
diff --git a/include/grpc++/stream.h b/include/grpc++/stream.h
index bb2a84949a..cd95ff7c92 100644
--- a/include/grpc++/stream.h
+++ b/include/grpc++/stream.h
@@ -550,56 +550,6 @@ class ClientAsyncReaderWriter final : public ClientAsyncStreamingInterface,
   CallOpBuffer finish_buf_;
 };
 
-// TODO(yangg) Move out of stream.h
-template <class W>
-class ServerAsyncResponseWriter final : public ServerAsyncStreamingInterface {
- public:
-  explicit ServerAsyncResponseWriter(ServerContext* ctx)
-      : call_(nullptr, nullptr, nullptr), ctx_(ctx) {}
-
-  void SendInitialMetadata(void* tag) {
-    GPR_ASSERT(!ctx_->sent_initial_metadata_);
-
-    meta_buf_.Reset(tag);
-    meta_buf_.AddSendInitialMetadata(&ctx_->initial_metadata_);
-    ctx_->sent_initial_metadata_ = true;
-    call_.PerformOps(&meta_buf_);
-  }
-
-  void Finish(const W& msg, const Status& status, void* tag) {
-    finish_buf_.Reset(tag);
-    if (!ctx_->sent_initial_metadata_) {
-      finish_buf_.AddSendInitialMetadata(&ctx_->initial_metadata_);
-      ctx_->sent_initial_metadata_ = true;
-    }
-    // The response is dropped if the status is not OK.
-    if (status.IsOk()) {
-      finish_buf_.AddSendMessage(msg);
-    }
-    finish_buf_.AddServerSendStatus(&ctx_->trailing_metadata_, status);
-    call_.PerformOps(&finish_buf_);
-  }
-
-  void FinishWithError(const Status& status, void* tag) {
-    GPR_ASSERT(!status.IsOk());
-    finish_buf_.Reset(tag);
-    if (!ctx_->sent_initial_metadata_) {
-      finish_buf_.AddSendInitialMetadata(&ctx_->initial_metadata_);
-      ctx_->sent_initial_metadata_ = true;
-    }
-    finish_buf_.AddServerSendStatus(&ctx_->trailing_metadata_, status);
-    call_.PerformOps(&finish_buf_);
-  }
-
- private:
-  void BindCall(Call* call) override { call_ = *call; }
-
-  Call call_;
-  ServerContext* ctx_;
-  CallOpBuffer meta_buf_;
-  CallOpBuffer finish_buf_;
-};
-
 template <class W, class R>
 class ServerAsyncReader : public ServerAsyncStreamingInterface,
                           public AsyncReaderInterface<R> {
diff --git a/include/grpc/grpc.h b/include/grpc/grpc.h
index b33cc3da87..4a720d11f8 100644
--- a/include/grpc/grpc.h
+++ b/include/grpc/grpc.h
@@ -354,10 +354,18 @@ typedef struct grpc_op {
   } data;
 } grpc_op;
 
-/* Initialize the grpc library */
+/* Initialize the grpc library.
+   It is not safe to call any other grpc functions before calling this.
+   (To avoid overhead, little checking is done, and some things may work. We
+   do not warrant that they will continue to do so in future revisions of this
+   library). */
 void grpc_init(void);
 
-/* Shut down the grpc library */
+/* Shut down the grpc library. 
+   No memory is used by grpc after this call returns, nor are any instructions
+   executing within the grpc library.
+   Prior to calling, all application owned grpc objects must have been
+   destroyed. */
 void grpc_shutdown(void);
 
 grpc_completion_queue *grpc_completion_queue_create(void);
@@ -386,7 +394,12 @@ grpc_event *grpc_completion_queue_pluck(grpc_completion_queue *cq, void *tag,
 void grpc_event_finish(grpc_event *event);
 
 /* Begin destruction of a completion queue. Once all possible events are
-   drained it's safe to call grpc_completion_queue_destroy. */
+   drained then grpc_completion_queue_next will start to produce
+   GRPC_QUEUE_SHUTDOWN events only. At that point it's safe to call 
+   grpc_completion_queue_destroy. 
+   
+   After calling this function applications should ensure that no
+   NEW work is added to be published on this completion queue. */
 void grpc_completion_queue_shutdown(grpc_completion_queue *cq);
 
 /* Destroy a completion queue. The caller must ensure that the queue is
diff --git a/src/compiler/cpp_generator.cc b/src/compiler/cpp_generator.cc
index aa764cbb33..b73b000a1c 100644
--- a/src/compiler/cpp_generator.cc
+++ b/src/compiler/cpp_generator.cc
@@ -127,6 +127,8 @@ std::string GetHeaderIncludes(const google::protobuf::FileDescriptor *file) {
       "class ServerContext;\n";
   if (HasUnaryCalls(file)) {
     temp.append(
+        "template <class OutMessage> class ClientAsyncResponseReader;\n");
+    temp.append(
         "template <class OutMessage> class ServerAsyncResponseWriter;\n");
   }
   if (HasClientOnlyStreaming(file)) {
@@ -160,7 +162,8 @@ std::string GetHeaderIncludes(const google::protobuf::FileDescriptor *file) {
 }
 
 std::string GetSourceIncludes() {
-  return "#include <grpc++/channel_interface.h>\n"
+  return "#include <grpc++/async_unary_call.h>\n"
+         "#include <grpc++/channel_interface.h>\n"
          "#include <grpc++/impl/client_unary_call.h>\n"
          "#include <grpc++/impl/rpc_method.h>\n"
          "#include <grpc++/impl/rpc_service_method.h>\n"
@@ -181,9 +184,9 @@ void PrintHeaderClientMethod(google::protobuf::io::Printer *printer,
                    "::grpc::Status $Method$(::grpc::ClientContext* context, "
                    "const $Request$& request, $Response$* response);\n");
     printer->Print(*vars,
-                   "void $Method$(::grpc::ClientContext* context, "
-                   "const $Request$& request, $Response$* response, "
-                   "::grpc::Status* status, "
+                   "::grpc::ClientAsyncResponseReader< $Response$>* "
+                   "$Method$(::grpc::ClientContext* context, "
+                   "const $Request$& request, "
                    "::grpc::CompletionQueue* cq, void* tag);\n");
   } else if (ClientOnlyStreaming(method)) {
     printer->Print(*vars,
@@ -378,14 +381,15 @@ void PrintSourceClientMethod(google::protobuf::io::Printer *printer,
                    "context, request, response);\n"
                    "}\n\n");
     printer->Print(*vars,
-                   "void $Service$::Stub::$Method$("
-                   "::grpc::ClientContext* context, "
-                   "const $Request$& request, $Response$* response, ::grpc::Status* status, "
+                   "::grpc::ClientAsyncResponseReader< $Response$>* "
+                   "$Service$::Stub::$Method$(::grpc::ClientContext* context, "
+                   "const $Request$& request, "
                    "::grpc::CompletionQueue* cq, void* tag) {\n");
     printer->Print(*vars,
-                   "  ::grpc::AsyncUnaryCall(channel(),"
+                   "  return new ClientAsyncResponseReader< $Response$>("
+                   "channel(), cq, "
                    "::grpc::RpcMethod($Service$_method_names[$Idx$]), "
-                   "context, request, response, status, cq, tag);\n"
+                   "context, request, tag);\n"
                    "}\n\n");
   } else if (ClientOnlyStreaming(method)) {
     printer->Print(
diff --git a/src/core/iomgr/pollset_multipoller_with_epoll.c b/src/core/iomgr/pollset_multipoller_with_epoll.c
index 9fb2819506..a1c3938a33 100644
--- a/src/core/iomgr/pollset_multipoller_with_epoll.c
+++ b/src/core/iomgr/pollset_multipoller_with_epoll.c
@@ -93,7 +93,7 @@ static int multipoll_with_epoll_pollset_maybe_work(
 
   /* If you want to ignore epoll's ability to sanely handle parallel pollers,
    * for a more apples-to-apples performance comparison with poll, add a
-   * if (pollset->counter == 0) { return 0 }
+   * if (pollset->counter != 0) { return 0; }
    * here.
    */
 
diff --git a/src/core/security/credentials.c b/src/core/security/credentials.c
index b2e0fd215a..60e82d9dfa 100644
--- a/src/core/security/credentials.c
+++ b/src/core/security/credentials.c
@@ -313,7 +313,7 @@ static void oauth2_token_fetcher_destroy(grpc_credentials *creds) {
     grpc_mdelem_unref(c->access_token_md);
   }
   gpr_mu_destroy(&c->mu);
-  grpc_mdctx_orphan(c->md_ctx);
+  grpc_mdctx_unref(c->md_ctx);
   gpr_free(c);
 }
 
@@ -587,7 +587,7 @@ static void fake_oauth2_destroy(grpc_credentials *creds) {
   if (c->access_token_md != NULL) {
     grpc_mdelem_unref(c->access_token_md);
   }
-  grpc_mdctx_orphan(c->md_ctx);
+  grpc_mdctx_unref(c->md_ctx);
   gpr_free(c);
 }
 
@@ -897,7 +897,7 @@ static void iam_destroy(grpc_credentials *creds) {
   grpc_iam_credentials *c = (grpc_iam_credentials *)creds;
   grpc_mdelem_unref(c->token_md);
   grpc_mdelem_unref(c->authority_selector_md);
-  grpc_mdctx_orphan(c->md_ctx);
+  grpc_mdctx_unref(c->md_ctx);
   gpr_free(c);
 }
 
diff --git a/src/core/surface/call.c b/src/core/surface/call.c
index 89a6ba63b2..40caa93868 100644
--- a/src/core/surface/call.c
+++ b/src/core/surface/call.c
@@ -313,7 +313,6 @@ static void set_status_code(grpc_call *call, status_source source,
   }
 
   if (flush && !grpc_bbq_empty(&call->incoming_queue)) {
-    gpr_log(GPR_ERROR, "Flushing unread messages due to error status %d", status);
     grpc_bbq_flush(&call->incoming_queue);
   }
 }
diff --git a/src/core/surface/channel.c b/src/core/surface/channel.c
index e308c60410..e38734c6a4 100644
--- a/src/core/surface/channel.c
+++ b/src/core/surface/channel.c
@@ -146,7 +146,7 @@ static void destroy_channel(void *p, int ok) {
   grpc_mdstr_unref(channel->grpc_message_string);
   grpc_mdstr_unref(channel->path_string);
   grpc_mdstr_unref(channel->authority_string);
-  grpc_mdctx_orphan(channel->metadata_context);
+  grpc_mdctx_unref(channel->metadata_context);
   gpr_free(channel);
 }
 
diff --git a/src/core/transport/chttp2_transport.c b/src/core/transport/chttp2_transport.c
index 551ae27e61..5b2d0a5e5b 100644
--- a/src/core/transport/chttp2_transport.c
+++ b/src/core/transport/chttp2_transport.c
@@ -336,11 +336,9 @@ static void recv_data(void *tp, gpr_slice *slices, size_t nslices,
  * CONSTRUCTION/DESTRUCTION/REFCOUNTING
  */
 
-static void unref_transport(transport *t) {
+static void destruct_transport(transport *t) {
   size_t i;
 
-  if (!gpr_unref(&t->refs)) return;
-
   gpr_mu_lock(&t->mu);
 
   GPR_ASSERT(t->ep == NULL);
@@ -380,9 +378,16 @@ static void unref_transport(transport *t) {
 
   grpc_sopb_destroy(&t->nuke_later_sopb);
 
+  grpc_mdctx_unref(t->metadata_context);
+
   gpr_free(t);
 }
 
+static void unref_transport(transport *t) {
+  if (!gpr_unref(&t->refs)) return;
+  destruct_transport(t);
+}
+
 static void ref_transport(transport *t) { gpr_ref(&t->refs); }
 
 static void init_transport(transport *t, grpc_transport_setup_callback setup,
@@ -401,6 +406,7 @@ static void init_transport(transport *t, grpc_transport_setup_callback setup,
   gpr_ref_init(&t->refs, 2);
   gpr_mu_init(&t->mu);
   gpr_cv_init(&t->cv);
+  grpc_mdctx_ref(mdctx);
   t->metadata_context = mdctx;
   t->str_grpc_timeout =
       grpc_mdstr_from_string(t->metadata_context, "grpc-timeout");
@@ -1025,8 +1031,6 @@ static void cancel_stream_inner(transport *t, stream *s, gpr_uint32 id,
   int had_outgoing;
   char buffer[GPR_LTOA_MIN_BUFSIZE];
 
-  gpr_log(GPR_DEBUG, "cancel %d", id);
-
   if (s) {
     /* clear out any unreported input & output: nobody cares anymore */
     had_outgoing = s->outgoing_sopb.nops != 0;
diff --git a/src/core/transport/metadata.c b/src/core/transport/metadata.c
index 3dc23e7de2..1c15716fad 100644
--- a/src/core/transport/metadata.c
+++ b/src/core/transport/metadata.c
@@ -79,7 +79,7 @@ typedef struct internal_metadata {
 
 struct grpc_mdctx {
   gpr_uint32 hash_seed;
-  int orphaned;
+  int refs;
 
   gpr_mu mu;
 
@@ -114,7 +114,7 @@ static void unlock(grpc_mdctx *ctx) {
      mdelems on every unlock (instead of the usual 'I'm too loaded' trigger
      case), since otherwise we can be stuck waiting for a garbage collection
      that will never happen. */
-  if (ctx->orphaned) {
+  if (ctx->refs == 0) {
     /* uncomment if you're having trouble diagnosing an mdelem leak to make
        things clearer (slows down destruction a lot, however) */
     /* gc_mdtab(ctx); */
@@ -139,7 +139,7 @@ static void ref_md(internal_metadata *md) {
 grpc_mdctx *grpc_mdctx_create_with_seed(gpr_uint32 seed) {
   grpc_mdctx *ctx = gpr_malloc(sizeof(grpc_mdctx));
 
-  ctx->orphaned = 0;
+  ctx->refs = 1;
   ctx->hash_seed = seed;
   gpr_mu_init(&ctx->mu);
   ctx->strtab = gpr_malloc(sizeof(internal_string *) * INITIAL_STRTAB_CAPACITY);
@@ -197,10 +197,17 @@ static void metadata_context_destroy(grpc_mdctx *ctx) {
   gpr_free(ctx);
 }
 
-void grpc_mdctx_orphan(grpc_mdctx *ctx) {
+void grpc_mdctx_ref(grpc_mdctx *ctx) {
   lock(ctx);
-  GPR_ASSERT(!ctx->orphaned);
-  ctx->orphaned = 1;
+  GPR_ASSERT(ctx->refs > 0);
+  ctx->refs++;
+  unlock(ctx);
+}
+
+void grpc_mdctx_unref(grpc_mdctx *ctx) {
+  lock(ctx);
+  GPR_ASSERT(ctx->refs > 0);
+  ctx->refs--;
   unlock(ctx);
 }
 
diff --git a/src/core/transport/metadata.h b/src/core/transport/metadata.h
index 430cae6847..7a56e34690 100644
--- a/src/core/transport/metadata.h
+++ b/src/core/transport/metadata.h
@@ -84,7 +84,8 @@ struct grpc_mdelem {
 /* Create/orphan a metadata context */
 grpc_mdctx *grpc_mdctx_create(void);
 grpc_mdctx *grpc_mdctx_create_with_seed(gpr_uint32 seed);
-void grpc_mdctx_orphan(grpc_mdctx *mdctx);
+void grpc_mdctx_ref(grpc_mdctx *mdctx);
+void grpc_mdctx_unref(grpc_mdctx *mdctx);
 
 /* Test only accessors to internal state - only for testing this code - do not
    rely on it outside of metadata_test.c */
diff --git a/src/cpp/client/client_unary_call.cc b/src/cpp/client/client_unary_call.cc
index a5ef989946..684b3cbadb 100644
--- a/src/cpp/client/client_unary_call.cc
+++ b/src/cpp/client/client_unary_call.cc
@@ -61,30 +61,4 @@ Status BlockingUnaryCall(ChannelInterface *channel, const RpcMethod &method,
   return status;
 }
 
-class ClientAsyncRequest final : public CallOpBuffer {
- public:
-  bool FinalizeResult(void **tag, bool *status) override {
-    bool r = CallOpBuffer::FinalizeResult(tag, status);
-    delete this;
-    return r;
-  }
-};
-
-void AsyncUnaryCall(ChannelInterface *channel, const RpcMethod &method,
-                    ClientContext *context,
-                    const google::protobuf::Message &request,
-                    google::protobuf::Message *result, Status *status,
-                    CompletionQueue *cq, void *tag) {
-  ClientAsyncRequest *buf = new ClientAsyncRequest;
-  buf->Reset(tag);
-  Call call(channel->CreateCall(method, context, cq));
-  buf->AddSendInitialMetadata(context);
-  buf->AddSendMessage(request);
-  buf->AddRecvInitialMetadata(context);
-  buf->AddRecvMessage(result);
-  buf->AddClientSendClose();
-  buf->AddClientRecvStatus(context, status);
-  call.PerformOps(buf);
-}
-
 }  // namespace grpc
diff --git a/src/csharp/GrpcApi/MathGrpc.cs b/src/csharp/GrpcApi/MathGrpc.cs
index caea1608ec..44e704e496 100644
--- a/src/csharp/GrpcApi/MathGrpc.cs
+++ b/src/csharp/GrpcApi/MathGrpc.cs
@@ -81,7 +81,7 @@ namespace math
 
             Task<DivReply> DivAsync(DivArgs request, CancellationToken token = default(CancellationToken));
 
-            Task Fib(FibArgs request, IObserver<Num> responseObserver, CancellationToken token = default(CancellationToken));
+            void Fib(FibArgs request, IObserver<Num> responseObserver, CancellationToken token = default(CancellationToken));
 
             ClientStreamingAsyncResult<Num, Num> Sum(CancellationToken token = default(CancellationToken));
 
@@ -109,10 +109,10 @@ namespace math
                 return Calls.AsyncUnaryCall(call, request, token);
             }
 
-            public Task Fib(FibArgs request, IObserver<Num> responseObserver, CancellationToken token = default(CancellationToken))
+            public void Fib(FibArgs request, IObserver<Num> responseObserver, CancellationToken token = default(CancellationToken))
             {
                 var call = new Google.GRPC.Core.Call<FibArgs, Num>(fibMethod, channel);
-                return Calls.AsyncServerStreamingCall(call, request, responseObserver, token);
+                Calls.AsyncServerStreamingCall(call, request, responseObserver, token);
             }
 
             public ClientStreamingAsyncResult<Num, Num> Sum(CancellationToken token = default(CancellationToken))
diff --git a/src/csharp/GrpcApi/TestServiceGrpc.cs b/src/csharp/GrpcApi/TestServiceGrpc.cs
index 6534a44ef4..64d5c09563 100644
--- a/src/csharp/GrpcApi/TestServiceGrpc.cs
+++ b/src/csharp/GrpcApi/TestServiceGrpc.cs
@@ -99,7 +99,7 @@ namespace grpc.testing
 
             Task<SimpleResponse> UnaryCallAsync(SimpleRequest request, CancellationToken token = default(CancellationToken));
 
-            Task StreamingOutputCall(StreamingOutputCallRequest request, IObserver<StreamingOutputCallResponse> responseObserver, CancellationToken token = default(CancellationToken));
+            void StreamingOutputCall(StreamingOutputCallRequest request, IObserver<StreamingOutputCallResponse> responseObserver, CancellationToken token = default(CancellationToken));
 
             ClientStreamingAsyncResult<StreamingInputCallRequest, StreamingInputCallResponse> StreamingInputCall(CancellationToken token = default(CancellationToken));
 
@@ -141,9 +141,9 @@ namespace grpc.testing
                 return Calls.AsyncUnaryCall(call, request, token);
             }
 
-            public Task StreamingOutputCall(StreamingOutputCallRequest request, IObserver<StreamingOutputCallResponse> responseObserver, CancellationToken token = default(CancellationToken)) {
+            public void StreamingOutputCall(StreamingOutputCallRequest request, IObserver<StreamingOutputCallResponse> responseObserver, CancellationToken token = default(CancellationToken)) {
                 var call = new Google.GRPC.Core.Call<StreamingOutputCallRequest, StreamingOutputCallResponse>(streamingOutputCallMethod, channel);
-                return Calls.AsyncServerStreamingCall(call, request, responseObserver, token);
+                Calls.AsyncServerStreamingCall(call, request, responseObserver, token);
             }
 
             public ClientStreamingAsyncResult<StreamingInputCallRequest, StreamingInputCallResponse> StreamingInputCall(CancellationToken token = default(CancellationToken))
diff --git a/src/csharp/GrpcApiTests/MathClientServerTests.cs b/src/csharp/GrpcApiTests/MathClientServerTests.cs
index bd298b0932..9056142097 100644
--- a/src/csharp/GrpcApiTests/MathClientServerTests.cs
+++ b/src/csharp/GrpcApiTests/MathClientServerTests.cs
@@ -64,6 +64,15 @@ namespace math.Tests
             client = MathGrpc.NewStub(channel);
         }
 
+        [TestFixtureTearDown]
+        public void Cleanup()
+        {
+            channel.Dispose();
+
+            server.ShutdownAsync().Wait();
+            GrpcEnvironment.Shutdown();
+        }
+
         [Test]
         public void Div1()
         {
@@ -136,15 +145,6 @@ namespace math.Tests
             CollectionAssert.AreEqual(new long[] {3, 4, 3}, result.ConvertAll((divReply) => divReply.Quotient));
             CollectionAssert.AreEqual(new long[] {1, 16, 1}, result.ConvertAll((divReply) => divReply.Remainder));
         }
-
-        [TestFixtureTearDown]
-        public void Cleanup()
-        {
-            channel.Dispose();
-
-            server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
-        }
     }
 }
 
diff --git a/src/csharp/GrpcCore/Calls.cs b/src/csharp/GrpcCore/Calls.cs
index d89d9a16f9..e5ddd879d6 100644
--- a/src/csharp/GrpcCore/Calls.cs
+++ b/src/csharp/GrpcCore/Calls.cs
@@ -47,50 +47,42 @@ namespace Google.GRPC.Core
     {
         public static TResponse BlockingUnaryCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, CancellationToken token)
         {
-            //TODO: implement this in real synchronous style once new GRPC C core API is available.
-            return AsyncUnaryCall(call, req, token).Result;
+            //TODO: implement this in real synchronous style.
+            try {
+                return AsyncUnaryCall(call, req, token).Result;
+            } catch(AggregateException ae) {
+                foreach (var e in ae.InnerExceptions)
+                {
+                    if (e is RpcException)
+                    {
+                        throw e;
+                    }
+                }
+                throw;
+            }
         }
 
         public static async Task<TResponse> AsyncUnaryCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, CancellationToken token)
         {
             var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);
-            asyncCall.Initialize(call.Channel, call.MethodName);
-            asyncCall.Start(false, GetCompletionQueue());
-
-            await asyncCall.WriteAsync(req);
-            await asyncCall.WritesCompletedAsync();
-
-            TResponse response = await asyncCall.ReadAsync();
-
-            Status status = await asyncCall.Finished;
-
-            if (status.StatusCode != StatusCode.GRPC_STATUS_OK)
-            {
-                throw new RpcException(status);
-            }
-            return response;
+            asyncCall.Initialize(call.Channel, GetCompletionQueue(), call.MethodName);
+            return await asyncCall.UnaryCallAsync(req);
         }
 
-        public static async Task AsyncServerStreamingCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, IObserver<TResponse> outputs, CancellationToken token)
+        public static void AsyncServerStreamingCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, IObserver<TResponse> outputs, CancellationToken token)
         {
             var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);
-            asyncCall.Initialize(call.Channel, call.MethodName);
-            asyncCall.Start(false, GetCompletionQueue());
 
-            asyncCall.StartReadingToStream(outputs);
-
-            await asyncCall.WriteAsync(req);
-            await asyncCall.WritesCompletedAsync();
+            asyncCall.Initialize(call.Channel, GetCompletionQueue(), call.MethodName);
+            asyncCall.StartServerStreamingCall(req, outputs);
         }
 
         public static ClientStreamingAsyncResult<TRequest, TResponse> AsyncClientStreamingCall<TRequest, TResponse>(Call<TRequest, TResponse> call, CancellationToken token)
         {
             var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);
-            asyncCall.Initialize(call.Channel, call.MethodName);
-            asyncCall.Start(false, GetCompletionQueue());
-
-            var task = asyncCall.ReadAsync();
-            var inputs = new StreamingInputObserver<TRequest, TResponse>(asyncCall);
+            asyncCall.Initialize(call.Channel, GetCompletionQueue(), call.MethodName);
+            var task = asyncCall.ClientStreamingCallAsync();
+            var inputs = new ClientStreamingInputObserver<TRequest, TResponse>(asyncCall);
             return new ClientStreamingAsyncResult<TRequest, TResponse>(task, inputs);
         }
 
@@ -102,12 +94,10 @@ namespace Google.GRPC.Core
         public static IObserver<TRequest> DuplexStreamingCall<TRequest, TResponse>(Call<TRequest, TResponse> call, IObserver<TResponse> outputs, CancellationToken token)
         {
             var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);
-            asyncCall.Initialize(call.Channel, call.MethodName);
-            asyncCall.Start(false, GetCompletionQueue());
+            asyncCall.Initialize(call.Channel, GetCompletionQueue(), call.MethodName);
 
-            asyncCall.StartReadingToStream(outputs);
-            var inputs = new StreamingInputObserver<TRequest, TResponse>(asyncCall);
-            return inputs;
+            asyncCall.StartDuplexStreamingCall(outputs);
+            return new ClientStreamingInputObserver<TRequest, TResponse>(asyncCall);
         }
 
         private static CompletionQueueSafeHandle GetCompletionQueue() {
diff --git a/src/csharp/GrpcCore/GrpcCore.csproj b/src/csharp/GrpcCore/GrpcCore.csproj
index 34b9f6dfb8..ee76b742ce 100644
--- a/src/csharp/GrpcCore/GrpcCore.csproj
+++ b/src/csharp/GrpcCore/GrpcCore.csproj
@@ -47,21 +47,21 @@
     <Compile Include="Internal\ChannelSafeHandle.cs" />
     <Compile Include="Internal\CompletionQueueSafeHandle.cs" />
     <Compile Include="Internal\Enums.cs" />
-    <Compile Include="Internal\Event.cs" />
     <Compile Include="Internal\SafeHandleZeroIsInvalid.cs" />
     <Compile Include="Internal\Timespec.cs" />
     <Compile Include="Internal\GrpcThreadPool.cs" />
     <Compile Include="Internal\AsyncCall.cs" />
     <Compile Include="Internal\ServerSafeHandle.cs" />
-    <Compile Include="Internal\StreamingInputObserver.cs" />
     <Compile Include="Method.cs" />
     <Compile Include="ServerCalls.cs" />
     <Compile Include="ServerCallHandler.cs" />
-    <Compile Include="Internal\ServerWritingObserver.cs" />
     <Compile Include="Marshaller.cs" />
     <Compile Include="ServerServiceDefinition.cs" />
     <Compile Include="Utils\RecordingObserver.cs" />
     <Compile Include="Utils\RecordingQueue.cs" />
+    <Compile Include="Internal\ClientStreamingInputObserver.cs" />
+    <Compile Include="Internal\ServerStreamingOutputObserver.cs" />
+    <Compile Include="Internal\BatchContextSafeHandleNotOwned.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>
diff --git a/src/csharp/GrpcCore/GrpcEnvironment.cs b/src/csharp/GrpcCore/GrpcEnvironment.cs
index c4f030267d..55a6cac8f6 100644
--- a/src/csharp/GrpcCore/GrpcEnvironment.cs
+++ b/src/csharp/GrpcCore/GrpcEnvironment.cs
@@ -42,7 +42,7 @@ namespace Google.GRPC.Core
     /// </summary>
     public class GrpcEnvironment
     {
-        const int THREAD_POOL_SIZE = 1;
+        const int THREAD_POOL_SIZE = 4;
 
         [DllImport("grpc_csharp_ext.dll")]
         static extern void grpcsharp_init();
diff --git a/src/csharp/GrpcCore/Internal/AsyncCall.cs b/src/csharp/GrpcCore/Internal/AsyncCall.cs
index d5f3239e1e..ce0ba30d53 100644
--- a/src/csharp/GrpcCore/Internal/AsyncCall.cs
+++ b/src/csharp/GrpcCore/Internal/AsyncCall.cs
@@ -2,11 +2,11 @@
 
 // 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
@@ -16,7 +16,7 @@
 //     * 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
@@ -42,171 +42,177 @@ using Google.GRPC.Core.Internal;
 namespace Google.GRPC.Core.Internal
 {
     /// <summary>
-    /// Listener for call events that can be delivered from a completion queue.
+    /// Handles native call lifecycle and provides convenience methods.
     /// </summary>
-    internal interface ICallEventListener {
-
-        void OnClientMetadata();
-
-        void OnRead(byte[] payload);
-
-        void OnWriteAccepted(GRPCOpError error);
-
-        void OnFinishAccepted(GRPCOpError error);
-
-        // ignore the status on server
-        void OnFinished(Status status);
-    }
-
-    /// <summary>
-    /// Handle native call lifecycle and provides convenience methods.
-    /// </summary>
-    internal class AsyncCall<TWrite, TRead>: ICallEventListener, IDisposable
+    internal class AsyncCall<TWrite, TRead>
     {
         readonly Func<TWrite, byte[]> serializer;
         readonly Func<byte[], TRead> deserializer;
 
-        // TODO: make sure the delegate doesn't get garbage collected while
-        // native callbacks are in the completion queue.
-        readonly EventCallbackDelegate callbackHandler;
+        readonly CompletionCallbackDelegate unaryResponseHandler;
+        readonly CompletionCallbackDelegate finishedHandler;
+        readonly CompletionCallbackDelegate writeFinishedHandler;
+        readonly CompletionCallbackDelegate readFinishedHandler;
+        readonly CompletionCallbackDelegate halfclosedHandler;
+        readonly CompletionCallbackDelegate finishedServersideHandler;
 
         object myLock = new object();
-        bool disposed;
+        GCHandle gchandle;
         CallSafeHandle call;
+        bool disposed;
+
+        bool server;
 
         bool started;
         bool errorOccured;
-
         bool cancelRequested;
+        bool readingDone;
         bool halfcloseRequested;
         bool halfclosed;
-        bool doneWithReading;
-        Nullable<Status> finishedStatus;
+        bool finished;
 
+        // Completion of a pending write if not null.
         TaskCompletionSource<object> writeTcs;
+
+        // Completion of a pending read if not null.
         TaskCompletionSource<TRead> readTcs;
-        TaskCompletionSource<object> halfcloseTcs = new TaskCompletionSource<object>();
-        TaskCompletionSource<Status> finishedTcs = new TaskCompletionSource<Status>();
 
+        // Completion of a pending halfclose if not null.
+        TaskCompletionSource<object> halfcloseTcs;
+
+        // Completion of a pending unary response if not null.
+        TaskCompletionSource<TRead> unaryResponseTcs;
+
+        // Set after status is received on client. Only used for server streaming and duplex streaming calls.
+        Nullable<Status> finishedStatus;
+        TaskCompletionSource<object> finishedServersideTcs = new TaskCompletionSource<object>();
+
+        // For streaming, the reads will be delivered to this observer.
         IObserver<TRead> readObserver;
 
         public AsyncCall(Func<TWrite, byte[]> serializer, Func<byte[], TRead> deserializer)
         {
             this.serializer = serializer;
             this.deserializer = deserializer;
-            this.callbackHandler = HandleEvent;
+            this.unaryResponseHandler = HandleUnaryResponse;
+            this.finishedHandler = HandleFinished;
+            this.writeFinishedHandler = HandleWriteFinished;
+            this.readFinishedHandler = HandleReadFinished;
+            this.halfclosedHandler = HandleHalfclosed;
+            this.finishedServersideHandler = HandleFinishedServerside;
         }
 
-        public Task WriteAsync(TWrite msg)
+        public void Initialize(Channel channel, CompletionQueueSafeHandle cq, String methodName)
         {
-            return StartWrite(msg, false).Task;
+            InitializeInternal(CallSafeHandle.Create(channel.Handle, cq, methodName, channel.Target, Timespec.InfFuture), false);
         }
 
-        public Task WritesCompletedAsync()
+        public void InitializeServer(CallSafeHandle call)
         {
-            WritesDone();
-            return halfcloseTcs.Task;
+            InitializeInternal(call, true);
         }
 
-        public Task WriteStatusAsync(Status status)
+        public Task<TRead> UnaryCallAsync(TWrite msg)
         {
-            WriteStatus(status);
-            return halfcloseTcs.Task;
-        }
+            lock (myLock)
+            {
+                started = true;
+                halfcloseRequested = true;
+                readingDone = true;
 
-        public Task<TRead> ReadAsync()
-        {
-            return StartRead().Task;
-        }
+                // TODO: handle serialization error...
+                byte[] payload = serializer(msg);
 
-        public Task Halfclosed
-        {
-            get
-            {
-                return halfcloseTcs.Task;
+                unaryResponseTcs = new TaskCompletionSource<TRead>();
+                call.StartUnary(payload, unaryResponseHandler);
+
+                return unaryResponseTcs.Task;
             }
         }
 
-        public Task<Status> Finished
+        public Task<TRead> ClientStreamingCallAsync()
         {
-            get
+            lock (myLock)
             {
-                return finishedTcs.Task;
+                started = true;
+                readingDone = true;
+
+                unaryResponseTcs = new TaskCompletionSource<TRead>();
+                call.StartClientStreaming(unaryResponseHandler);
+
+                return unaryResponseTcs.Task;
             }
         }
 
-        /// <summary>
-        /// Initiates reading to given observer.
-        /// </summary>
-        public void StartReadingToStream(IObserver<TRead> readObserver) {
+        public void StartServerStreamingCall(TWrite msg, IObserver<TRead> readObserver)
+        {
             lock (myLock)
             {
-                CheckStarted();
-                if (this.readObserver != null)
-                {
-                    throw new InvalidOperationException("Already registered an observer.");
-                }
+                started = true;
+                halfcloseRequested = true;
+        
                 this.readObserver = readObserver;
-                StartRead();
-            }
-        }
 
-        public void Initialize(Channel channel, String methodName) {
-            lock (myLock)
-            {
-               this.call = CallSafeHandle.Create(channel.Handle, methodName, channel.Target, Timespec.InfFuture);
+                // TODO: handle serialization error...
+                byte[] payload = serializer(msg);
+        
+                call.StartServerStreaming(payload, finishedHandler);
+
+                ReceiveMessageAsync();
             }
         }
 
-        public void InitializeServer(CallSafeHandle call)
+        public void StartDuplexStreamingCall(IObserver<TRead> readObserver)
         {
-            lock(myLock)
+            lock (myLock)
             {
-                this.call = call;
+                started = true;
+
+                this.readObserver = readObserver;
+
+                call.StartDuplexStreaming(finishedHandler);
+
+                ReceiveMessageAsync();
             }
         }
 
-        // Client only
-        public void Start(bool buffered, CompletionQueueSafeHandle cq)
+        public Task ServerSideUnaryRequestCallAsync()
         {
             lock (myLock)
             {
-                if (started)
-                {
-                    throw new InvalidOperationException("Already started.");
-                }
-
-                call.Invoke(cq, buffered, callbackHandler, callbackHandler);
                 started = true;
+                call.StartServerSide(finishedServersideHandler);
+                return finishedServersideTcs.Task;
             }
         }
 
-        // Server only
-        public void Accept(CompletionQueueSafeHandle cq)
+        public Task ServerSideStreamingRequestCallAsync(IObserver<TRead> readObserver)
         {
             lock (myLock)
             {
-                if (started)
+                started = true;
+                call.StartServerSide(finishedServersideHandler);
+               
+                if (this.readObserver != null)
                 {
-                    throw new InvalidOperationException("Already started.");
+                    throw new InvalidOperationException("Already registered an observer.");
                 }
+                this.readObserver = readObserver;
+                ReceiveMessageAsync();
 
-                call.ServerAccept(cq, callbackHandler);
-                call.ServerEndInitialMetadata(0);
-                started = true;
+                return finishedServersideTcs.Task;
             }
         }
 
-        public TaskCompletionSource<object> StartWrite(TWrite msg, bool buffered)
+        public Task SendMessageAsync(TWrite msg)
         {
             lock (myLock)
             {
+                CheckNotDisposed();
                 CheckStarted();
-                CheckNotFinished();
                 CheckNoError();
-                CheckCancelNotRequested();
 
-                if (halfcloseRequested || halfclosed)
+                if (halfcloseRequested)
                 {
                     throw new InvalidOperationException("Already halfclosed.");
                 }
@@ -219,63 +225,62 @@ namespace Google.GRPC.Core.Internal
                 // TODO: wrap serialization...
                 byte[] payload = serializer(msg);
 
-                call.StartWrite(payload, buffered, callbackHandler);
+                call.StartSendMessage(payload, writeFinishedHandler);
                 writeTcs = new TaskCompletionSource<object>();
-                return writeTcs;
+                return writeTcs.Task;
             }
         }
 
-        // client only
-        public void WritesDone()
+        public Task SendCloseFromClientAsync()
         {
             lock (myLock)
             {
+                CheckNotDisposed();
                 CheckStarted();
-                CheckNotFinished();
                 CheckNoError();
-                CheckCancelNotRequested();
 
-                if (halfcloseRequested || halfclosed)
+                if (halfcloseRequested)
                 {
                     throw new InvalidOperationException("Already halfclosed.");
                 }
 
-                call.WritesDone(callbackHandler);
+                call.StartSendCloseFromClient(halfclosedHandler);
+
                 halfcloseRequested = true;
+                halfcloseTcs = new TaskCompletionSource<object>();
+                return halfcloseTcs.Task;
             }
         }
 
-        // server only
-        public void WriteStatus(Status status)
+        public Task SendStatusFromServerAsync(Status status)
         {
             lock (myLock)
             {
+                CheckNotDisposed();
                 CheckStarted();
-                CheckNotFinished();
                 CheckNoError();
-                CheckCancelNotRequested();
 
-                if (halfcloseRequested || halfclosed)
+                if (halfcloseRequested)
                 {
                     throw new InvalidOperationException("Already halfclosed.");
                 }
 
-                call.StartWriteStatus(status, callbackHandler);
+                call.StartSendStatusFromServer(status, halfclosedHandler);
                 halfcloseRequested = true;
+                halfcloseTcs = new TaskCompletionSource<object>();
+                return halfcloseTcs.Task;
             }
         }
 
-        public TaskCompletionSource<TRead> StartRead()
+        public Task<TRead> ReceiveMessageAsync()
         {
             lock (myLock)
             {
+                CheckNotDisposed();
                 CheckStarted();
-                CheckNotFinished();
                 CheckNoError();
 
-                // TODO: add check for not cancelled?
-
-                if (doneWithReading)
+                if (readingDone)
                 {
                     throw new InvalidOperationException("Already read the last message.");
                 }
@@ -285,10 +290,10 @@ namespace Google.GRPC.Core.Internal
                     throw new InvalidOperationException("Only one read can be pending at a time");
                 }
 
-                call.StartRead(callbackHandler);
+                call.StartReceiveMessage(readFinishedHandler);
 
                 readTcs = new TaskCompletionSource<TRead>();
-                return readTcs;
+                return readTcs.Task;
             }
         }
 
@@ -296,9 +301,8 @@ namespace Google.GRPC.Core.Internal
         {
             lock (myLock)
             {
+                CheckNotDisposed();
                 CheckStarted();
-                CheckNotFinished();
-
                 cancelRequested = true;
             }
             // grpc_call_cancel is threadsafe
@@ -309,218 +313,304 @@ namespace Google.GRPC.Core.Internal
         {
             lock (myLock)
             {
+                CheckNotDisposed();
                 CheckStarted();
-                CheckNotFinished();
-
                 cancelRequested = true;
             }
             // grpc_call_cancel_with_status is threadsafe
             call.CancelWithStatus(status);
         }
 
-        public void OnClientMetadata()
+        private void InitializeInternal(CallSafeHandle call, bool server)
         {
-            // TODO: implement....
+            lock (myLock)
+            {
+                // Make sure this object and the delegated held by it will not be garbage collected
+                // before we release this handle.
+                gchandle = GCHandle.Alloc(this);
+                this.call = call;
+                this.server = server;
+            }
         }
 
-        public void OnRead(byte[] payload)
+        private void CheckStarted()
         {
-            TaskCompletionSource<TRead> oldTcs = null;
-            IObserver<TRead> observer = null;
-            lock (myLock)
+            if (!started)
             {
-                oldTcs = readTcs;
-                readTcs = null;
-                if (payload == null)
-                {
-                    doneWithReading = true;
-                }
-                observer = readObserver;
+                throw new InvalidOperationException("Call not started");
             }
+        }
 
-            // TODO: wrap deserialization...
-            TRead msg = payload != null ? deserializer(payload) : default(TRead);
-
-            oldTcs.SetResult(msg);
-
-            // TODO: make sure we deliver reads in the right order.
+        private void CheckNotDisposed()
+        {
+            if (disposed)
+            {
+                throw new InvalidOperationException("Call has already been disposed.");
+            }
+        }
 
-            if (observer != null)
+        private void CheckNoError()
+        {
+            if (errorOccured)
             {
-                if (payload != null)
-                {
-                    // TODO: wrap to handle exceptions
-                    observer.OnNext(msg);
+                throw new InvalidOperationException("Error occured when processing call.");
+            }
+        }
 
-                    // start a new read
-                    StartRead();
-                }
-                else
+        private bool ReleaseResourcesIfPossible()
+        {
+            if (!disposed && call != null)
+            {
+                if (halfclosed && readingDone && finished)
                 {
-                    // TODO: wrap to handle exceptions;
-                    observer.OnCompleted();
+                    ReleaseResources();
+                    return true;
                 }
+            }
+            return false;
+        }
 
+        private void ReleaseResources()
+        {
+            if (call != null) {
+                call.Dispose();
             }
+            gchandle.Free();
+            disposed = true;
         }
 
-        public void OnWriteAccepted(GRPCOpError error)
+        private void CompleteStreamObserver(Status status)
         {
-            TaskCompletionSource<object> oldTcs = null;
-            lock (myLock)
+            if (status.StatusCode != StatusCode.GRPC_STATUS_OK)
             {
-                UpdateErrorOccured(error);
-                oldTcs = writeTcs;
-                writeTcs = null;
+                // TODO: wrap to handle exceptions;
+                readObserver.OnError(new RpcException(status));
+            } else {
+                // TODO: wrap to handle exceptions;
+                readObserver.OnCompleted();
             }
+        }
 
-            if (errorOccured)
+        /// <summary>
+        /// Handler for unary response completion.
+        /// </summary>
+        private void HandleUnaryResponse(GRPCOpError error, IntPtr batchContextPtr)
+        {
+            try
             {
-                // TODO: use the right type of exception...
-                oldTcs.SetException(new Exception("Write failed"));
-            }
-            else
+                TaskCompletionSource<TRead> tcs;
+                lock(myLock)
+                {
+                    finished = true;
+                    halfclosed = true;
+                    tcs = unaryResponseTcs;
+
+                    ReleaseResourcesIfPossible();
+                }
+
+                var ctx = new BatchContextSafeHandleNotOwned(batchContextPtr);
+
+                if (error != GRPCOpError.GRPC_OP_OK)
+                {
+                    tcs.SetException(new RpcException(
+                        new Status(StatusCode.GRPC_STATUS_INTERNAL, "Internal error occured.")
+                    ));
+                    return;
+                }
+
+                var status = ctx.GetReceivedStatus();
+                if (status.StatusCode != StatusCode.GRPC_STATUS_OK)
+                {
+                    tcs.SetException(new RpcException(status));
+                    return;
+                }
+
+                // TODO: handle deserialize error...
+                var msg = deserializer(ctx.GetReceivedMessage());
+                tcs.SetResult(msg);
+            } 
+            catch(Exception e)
             {
-                // TODO: where does the continuation run?
-                oldTcs.SetResult(null);
+                Console.WriteLine("Caught exception in a native handler: " + e);
             }
         }
 
-        public void OnFinishAccepted(GRPCOpError error)
+        private void HandleWriteFinished(GRPCOpError error, IntPtr batchContextPtr)
         {
-            lock (myLock)
+            try
             {
-                UpdateErrorOccured(error);
-                halfclosed = true;
-            }
+                TaskCompletionSource<object> oldTcs = null;
+                lock (myLock)
+                {
+                    oldTcs = writeTcs;
+                    writeTcs = null;
+                }
 
-            if (errorOccured)
-            {
-                halfcloseTcs.SetException(new Exception("Halfclose failed"));
+                if (errorOccured)
+                {
+                    // TODO: use the right type of exception...
+                    oldTcs.SetException(new Exception("Write failed"));
+                }
+                else
+                {
+                    // TODO: where does the continuation run?
+                    oldTcs.SetResult(null);
+                }
 
             }
-            else
+            catch(Exception e)
             {
-                halfcloseTcs.SetResult(null);
+                Console.WriteLine("Caught exception in a native handler: " + e);
             }
-
         }
 
-        public void OnFinished(Status status)
+        private void HandleHalfclosed(GRPCOpError error, IntPtr batchContextPtr)
         {
-            lock (myLock)
+            try
             {
-                finishedStatus = status;
+                lock (myLock)
+                {
+                    halfclosed = true;
 
-                DisposeResourcesIfNeeded();
-            }
-            finishedTcs.SetResult(status);
+                    ReleaseResourcesIfPossible();
+                }
 
-        }
+                if (error != GRPCOpError.GRPC_OP_OK)
+                {
+                    halfcloseTcs.SetException(new Exception("Halfclose failed"));
 
-        public void Dispose()
-        {
-            Dispose(true);
-            GC.SuppressFinalize(this);
+                }
+                else
+                {
+                    halfcloseTcs.SetResult(null);
+                }
+            }
+            catch(Exception e)
+            {
+                Console.WriteLine("Caught exception in a native handler: " + e);
+            }
         }
 
-        protected virtual void Dispose(bool disposing)
+        private void HandleReadFinished(GRPCOpError error, IntPtr batchContextPtr)
         {
-            if (!disposed)
+            try
             {
-                if (disposing)
+                var ctx = new BatchContextSafeHandleNotOwned(batchContextPtr);
+                var payload = ctx.GetReceivedMessage();
+
+                TaskCompletionSource<TRead> oldTcs = null;
+                IObserver<TRead> observer = null;
+
+                Nullable<Status> status = null;
+
+                lock (myLock)
                 {
-                    if (call != null)
+                    oldTcs = readTcs;
+                    readTcs = null;
+                    if (payload == null)
                     {
-                        call.Dispose();
+                        readingDone = true;
                     }
+                    observer = readObserver;
+                    status = finishedStatus;
                 }
-                disposed = true;
-            }
-        }
 
-        private void UpdateErrorOccured(GRPCOpError error)
-        {
-            if (error == GRPCOpError.GRPC_OP_ERROR)
-            {
-                errorOccured = true;
-            }
-        }
+                // TODO: wrap deserialization...
+                TRead msg = payload != null ? deserializer(payload) : default(TRead);
 
-        private void CheckStarted()
-        {
-            if (!started)
-            {
-                throw new InvalidOperationException("Call not started");
-            }
-        }
+                oldTcs.SetResult(msg);
 
-        private void CheckNoError()
-        {
-            if (errorOccured)
+                // TODO: make sure we deliver reads in the right order.
+
+                if (observer != null)
+                {
+                    if (payload != null)
+                    {
+                        // TODO: wrap to handle exceptions
+                        observer.OnNext(msg);
+
+                        // start a new read
+                        ReceiveMessageAsync();
+                    }
+                    else
+                    {
+                        if (!server)
+                        {
+                            if (status.HasValue)
+                            {
+                                CompleteStreamObserver(status.Value);
+                            }
+                        } 
+                        else 
+                        {
+                            // TODO: wrap to handle exceptions..
+                            observer.OnCompleted();
+                        }
+                        // TODO: completeStreamObserver serverside...
+                    }
+               }
+            }
+            catch(Exception e)
             {
-                throw new InvalidOperationException("Error occured when processing call.");
+                Console.WriteLine("Caught exception in a native handler: " + e);
             }
         }
 
-        private void CheckNotFinished()
+        private void HandleFinished(GRPCOpError error, IntPtr batchContextPtr)
         {
-            if (finishedStatus.HasValue)
+            try
             {
-                throw new InvalidOperationException("Already finished.");
-            }
-        }
+                var ctx = new BatchContextSafeHandleNotOwned(batchContextPtr);
+                var status = ctx.GetReceivedStatus();
 
-        private void CheckCancelNotRequested()
-        {
-            if (cancelRequested)
+                bool wasReadingDone;
+
+                lock (myLock)
+                {
+                    finished = true;
+                    finishedStatus = status;
+
+                    wasReadingDone = readingDone;
+
+                    ReleaseResourcesIfPossible();
+                }
+
+                if (wasReadingDone) {
+                    CompleteStreamObserver(status);
+                }
+
+            }
+            catch(Exception e)
             {
-                throw new InvalidOperationException("Cancel has been requested.");
+                Console.WriteLine("Caught exception in a native handler: " + e);
             }
         }
 
-        private void DisposeResourcesIfNeeded()
+        private void HandleFinishedServerside(GRPCOpError error, IntPtr batchContextPtr)
         {
-            if (call != null && started && finishedStatus.HasValue)
+            try
             {
-                // TODO: should we also wait for all the pending events to finish?
-
-                call.Dispose();
-            }
-        }
+                var ctx = new BatchContextSafeHandleNotOwned(batchContextPtr);
 
-        private void HandleEvent(IntPtr eventPtr) {
-            try {
-                var ev = new EventSafeHandleNotOwned(eventPtr);
-                switch (ev.GetCompletionType())
+                lock(myLock)
                 {
-                case GRPCCompletionType.GRPC_CLIENT_METADATA_READ:
-                    OnClientMetadata();
-                    break;
-
-                case GRPCCompletionType.GRPC_READ:
-                    byte[] payload = ev.GetReadData();
-                    OnRead(payload);
-                    break;
+                    finished = true;
 
-                case GRPCCompletionType.GRPC_WRITE_ACCEPTED:
-                    OnWriteAccepted(ev.GetWriteAccepted());
-                    break;
+                    // TODO: because of the way server calls are implemented, we need to set
+                    // reading done to true here. Should be fixed in the future.
+                    readingDone = true;
 
-                case GRPCCompletionType.GRPC_FINISH_ACCEPTED:
-                    OnFinishAccepted(ev.GetFinishAccepted());
-                    break;
+                    ReleaseResourcesIfPossible();
+                }
+                // TODO: handle error ...
 
-                case GRPCCompletionType.GRPC_FINISHED:
-                    OnFinished(ev.GetFinished());
-                    break;
+                finishedServersideTcs.SetResult(null);
 
-                default:
-                    throw new ArgumentException("Unexpected completion type");
-                }
-            } catch(Exception e) {
+            }
+            catch(Exception e)
+            {
                 Console.WriteLine("Caught exception in a native handler: " + e);
             }
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/csharp/GrpcCore/Internal/BatchContextSafeHandleNotOwned.cs b/src/csharp/GrpcCore/Internal/BatchContextSafeHandleNotOwned.cs
new file mode 100644
index 0000000000..ddfd94a3b5
--- /dev/null
+++ b/src/csharp/GrpcCore/Internal/BatchContextSafeHandleNotOwned.cs
@@ -0,0 +1,96 @@
+#region Copyright notice and license
+
+// 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.
+
+#endregion
+
+using System;
+using System.Runtime.InteropServices;
+using Google.GRPC.Core;
+
+namespace Google.GRPC.Core.Internal
+{
+    /// <summary>
+    /// Not owned version of 
+    /// grpcsharp_batch_context
+    /// </summary>
+    internal class BatchContextSafeHandleNotOwned : SafeHandleZeroIsInvalid
+    {
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern IntPtr grpcsharp_batch_context_recv_message_length(BatchContextSafeHandleNotOwned ctx);
+
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern void grpcsharp_batch_context_recv_message_to_buffer(BatchContextSafeHandleNotOwned ctx, byte[] buffer, UIntPtr bufferLen);
+
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern StatusCode grpcsharp_batch_context_recv_status_on_client_status(BatchContextSafeHandleNotOwned ctx);
+
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern IntPtr grpcsharp_batch_context_recv_status_on_client_details(BatchContextSafeHandleNotOwned ctx);  // returns const char*
+
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern CallSafeHandle grpcsharp_batch_context_server_rpc_new_call(BatchContextSafeHandleNotOwned ctx);
+
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern IntPtr grpcsharp_batch_context_server_rpc_new_method(BatchContextSafeHandleNotOwned ctx);  // returns const char*
+
+        public BatchContextSafeHandleNotOwned(IntPtr handle) : base(false)
+        {
+            SetHandle(handle);
+        }
+
+        public Status GetReceivedStatus()
+        {
+            // TODO: can the native method return string directly?
+            string details = Marshal.PtrToStringAnsi(grpcsharp_batch_context_recv_status_on_client_details(this));
+            return new Status(grpcsharp_batch_context_recv_status_on_client_status(this), details);
+        }
+
+        public byte[] GetReceivedMessage()
+        {
+            IntPtr len = grpcsharp_batch_context_recv_message_length(this);
+            if (len == new IntPtr(-1))
+            {
+                return null;
+            }
+            byte[] data = new byte[(int) len];
+            grpcsharp_batch_context_recv_message_to_buffer(this, data, new UIntPtr((ulong)data.Length));
+            return data;
+        }
+
+        public CallSafeHandle GetServerRpcNewCall() {
+            return grpcsharp_batch_context_server_rpc_new_call(this);
+        }
+
+        public string GetServerRpcNewMethod() {
+            return Marshal.PtrToStringAnsi(grpcsharp_batch_context_server_rpc_new_method(this));
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/csharp/GrpcCore/Internal/CallSafeHandle.cs b/src/csharp/GrpcCore/Internal/CallSafeHandle.cs
index e9ccd8d5f9..55d66a62ca 100644
--- a/src/csharp/GrpcCore/Internal/CallSafeHandle.cs
+++ b/src/csharp/GrpcCore/Internal/CallSafeHandle.cs
@@ -2,11 +2,11 @@
 
 // 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
@@ -16,7 +16,7 @@
 //     * 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
@@ -38,8 +38,8 @@ using Google.GRPC.Core;
 
 namespace Google.GRPC.Core.Internal
 {
-    // TODO: we need to make sure that the delegates are not collected before invoked.
-    internal delegate void EventCallbackDelegate(IntPtr eventPtr);
+    //TODO: rename the delegate
+    internal delegate void CompletionCallbackDelegate(GRPCOpError error, IntPtr batchContextPtr);
 
     /// <summary>
     /// grpc_call from <grpc/grpc.h>
@@ -49,142 +49,108 @@ namespace Google.GRPC.Core.Internal
         const UInt32 GRPC_WRITE_BUFFER_HINT = 1;
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern CallSafeHandle grpcsharp_channel_create_call_old(ChannelSafeHandle channel, string method, string host, Timespec deadline);
+        static extern CallSafeHandle grpcsharp_channel_create_call(ChannelSafeHandle channel, CompletionQueueSafeHandle cq, string method, string host, Timespec deadline);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_add_metadata(CallSafeHandle call, IntPtr metadata, UInt32 flags);
+        static extern GRPCCallError grpcsharp_call_cancel(CallSafeHandle call);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_invoke_old(CallSafeHandle call, CompletionQueueSafeHandle cq, IntPtr metadataReadTag, IntPtr finishedTag, UInt32 flags);
-
-        [DllImport("grpc_csharp_ext.dll", EntryPoint = "grpcsharp_call_invoke_old")]
-        static extern GRPCCallError grpcsharp_call_invoke_old_CALLBACK(CallSafeHandle call, CompletionQueueSafeHandle cq,
-                                                              [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate metadataReadCallback,
-                                                              [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate finishedCallback,
-                                                              UInt32 flags);
+        static extern GRPCCallError grpcsharp_call_cancel_with_status(CallSafeHandle call, StatusCode status, string description);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_server_accept_old(CallSafeHandle call, CompletionQueueSafeHandle completionQueue, IntPtr finishedTag);
-
-        [DllImport("grpc_csharp_ext.dll", EntryPoint = "grpcsharp_call_server_accept_old")]
-        static extern GRPCCallError grpcsharp_call_server_accept_old_CALLBACK(CallSafeHandle call, CompletionQueueSafeHandle completionQueue, [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate finishedCallback);
+        static extern GRPCCallError grpcsharp_call_start_unary(CallSafeHandle call,
+                                                                        [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback,
+                                                                        byte[] send_buffer, UIntPtr send_buffer_len);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_server_end_initial_metadata_old(CallSafeHandle call, UInt32 flags);
+        static extern GRPCCallError grpcsharp_call_start_client_streaming(CallSafeHandle call,
+                                                                      [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_cancel(CallSafeHandle call);
+        static extern GRPCCallError grpcsharp_call_start_server_streaming(CallSafeHandle call,
+                                                                      [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback,
+                                                                      byte[] send_buffer, UIntPtr send_buffer_len);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_cancel_with_status(CallSafeHandle call, StatusCode status, string description);
+        static extern GRPCCallError grpcsharp_call_start_duplex_streaming(CallSafeHandle call,
+                                                                          [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_start_write_status_old(CallSafeHandle call, StatusCode statusCode, string statusMessage, IntPtr tag);
-
-        [DllImport("grpc_csharp_ext.dll", EntryPoint = "grpcsharp_call_start_write_status_old")]
-        static extern GRPCCallError grpcsharp_call_start_write_status_old_CALLBACK(CallSafeHandle call, StatusCode statusCode, string statusMessage, [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate callback);
+        static extern GRPCCallError grpcsharp_call_send_message(CallSafeHandle call,
+                                                                      [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback,
+                                                                      byte[] send_buffer, UIntPtr send_buffer_len);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_writes_done_old(CallSafeHandle call, IntPtr tag);
-
-        [DllImport("grpc_csharp_ext.dll", EntryPoint = "grpcsharp_call_writes_done_old")]
-        static extern GRPCCallError grpcsharp_call_writes_done_old_CALLBACK(CallSafeHandle call, [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate callback);
+        static extern GRPCCallError grpcsharp_call_send_close_from_client(CallSafeHandle call,
+                                                                             [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCallError grpcsharp_call_start_read_old(CallSafeHandle call, IntPtr tag);
-
-        [DllImport("grpc_csharp_ext.dll", EntryPoint = "grpcsharp_call_start_read_old")]
-        static extern GRPCCallError grpcsharp_call_start_read_old_CALLBACK(CallSafeHandle call, [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate callback);
+        static extern GRPCCallError grpcsharp_call_send_status_from_server(CallSafeHandle call, [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback, StatusCode statusCode, string statusMessage);
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern void grpcsharp_call_start_write_from_copied_buffer(CallSafeHandle call,
-                                                                    byte[] buffer, UIntPtr length,
-                                                                    IntPtr tag, UInt32 flags);
+        static extern GRPCCallError grpcsharp_call_recv_message(CallSafeHandle call,
+                                                               [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback);
 
-        [DllImport("grpc_csharp_ext.dll", EntryPoint = "grpcsharp_call_start_write_from_copied_buffer")]
-        static extern void grpcsharp_call_start_write_from_copied_buffer_CALLBACK(CallSafeHandle call,
-                                                                             byte[] buffer, UIntPtr length,
-                                                                             [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate callback,
-                                                                             UInt32 flags);
+        [DllImport("grpc_csharp_ext.dll")]
+        static extern GRPCCallError grpcsharp_call_start_serverside(CallSafeHandle call,
+                                                                [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback);
 
-		[DllImport("grpc_csharp_ext.dll")]
+        [DllImport("grpc_csharp_ext.dll")]
         static extern void grpcsharp_call_destroy(IntPtr call);
 
-        private CallSafeHandle()
-        {
-        }
-
-        /// <summary>
-        /// Creates a client call.
-        /// </summary>
-        public static CallSafeHandle Create(ChannelSafeHandle channel, string method, string host, Timespec deadline)
-        {
-            return grpcsharp_channel_create_call_old(channel, method, host, deadline);
-        }
-
-        public void Invoke(CompletionQueueSafeHandle cq, IntPtr metadataReadTag, IntPtr finishedTag, bool buffered)
-        {
-            AssertCallOk(grpcsharp_call_invoke_old(this, cq, metadataReadTag, finishedTag, GetFlags(buffered)));
-        }
-
-        public void Invoke(CompletionQueueSafeHandle cq, bool buffered, EventCallbackDelegate metadataReadCallback, EventCallbackDelegate finishedCallback)
-        {
-            AssertCallOk(grpcsharp_call_invoke_old_CALLBACK(this, cq, metadataReadCallback, finishedCallback, GetFlags(buffered)));
-        }
 
-        public void ServerAccept(CompletionQueueSafeHandle cq, IntPtr finishedTag)
+        private CallSafeHandle()
         {
-            AssertCallOk(grpcsharp_call_server_accept_old(this, cq, finishedTag));
         }
 
-        public void ServerAccept(CompletionQueueSafeHandle cq, EventCallbackDelegate callback)
+        public static CallSafeHandle Create(ChannelSafeHandle channel, CompletionQueueSafeHandle cq, string method, string host, Timespec deadline)
         {
-            AssertCallOk(grpcsharp_call_server_accept_old_CALLBACK(this, cq, callback));
+            return grpcsharp_channel_create_call(channel, cq, method, host, deadline);
         }
 
-        public void ServerEndInitialMetadata(UInt32 flags)
+        public void StartUnary(byte[] payload, CompletionCallbackDelegate callback)
         {
-            AssertCallOk(grpcsharp_call_server_end_initial_metadata_old(this, flags));
+            AssertCallOk(grpcsharp_call_start_unary(this, callback, payload, new UIntPtr((ulong) payload.Length)));
         }
 
-        public void StartWrite(byte[] payload, IntPtr tag, bool buffered)
+        public void StartClientStreaming(CompletionCallbackDelegate callback)
         {
-            grpcsharp_call_start_write_from_copied_buffer(this, payload, new UIntPtr((ulong) payload.Length), tag, GetFlags(buffered));
+            AssertCallOk(grpcsharp_call_start_client_streaming(this, callback));
         }
 
-        public void StartWrite(byte[] payload, bool buffered, EventCallbackDelegate callback)
+        public void StartServerStreaming(byte[] payload, CompletionCallbackDelegate callback)
         {
-            grpcsharp_call_start_write_from_copied_buffer_CALLBACK(this, payload, new UIntPtr((ulong) payload.Length), callback, GetFlags(buffered));
+            AssertCallOk(grpcsharp_call_start_server_streaming(this, callback, payload, new UIntPtr((ulong) payload.Length)));
         }
 
-        public void StartWriteStatus(Status status, IntPtr tag)
+        public void StartDuplexStreaming(CompletionCallbackDelegate callback)
         {
-            AssertCallOk(grpcsharp_call_start_write_status_old(this, status.StatusCode, status.Detail, tag));
+            AssertCallOk(grpcsharp_call_start_duplex_streaming(this, callback));
         }
 
-        public void StartWriteStatus(Status status, EventCallbackDelegate callback)
+        public void StartSendMessage(byte[] payload, CompletionCallbackDelegate callback)
         {
-            AssertCallOk(grpcsharp_call_start_write_status_old_CALLBACK(this, status.StatusCode, status.Detail, callback));
+            AssertCallOk(grpcsharp_call_send_message(this, callback, payload, new UIntPtr((ulong) payload.Length)));
         }
 
-        public void WritesDone(IntPtr tag)
+        public void StartSendCloseFromClient(CompletionCallbackDelegate callback)
         {
-            AssertCallOk(grpcsharp_call_writes_done_old(this, tag));
+            AssertCallOk(grpcsharp_call_send_close_from_client(this, callback));
         }
 
-        public void WritesDone(EventCallbackDelegate callback)
+        public void StartSendStatusFromServer(Status status, CompletionCallbackDelegate callback)
         {
-            AssertCallOk(grpcsharp_call_writes_done_old_CALLBACK(this, callback));
+            AssertCallOk(grpcsharp_call_send_status_from_server(this, callback, status.StatusCode, status.Detail));
         }
 
-        public void StartRead(IntPtr tag)
+        public void StartReceiveMessage(CompletionCallbackDelegate callback)
         {
-            AssertCallOk(grpcsharp_call_start_read_old(this, tag));
+            AssertCallOk(grpcsharp_call_recv_message(this, callback));
         }
 
-        public void StartRead(EventCallbackDelegate callback)
+        public void StartServerSide(CompletionCallbackDelegate callback)
         {
-            AssertCallOk(grpcsharp_call_start_read_old_CALLBACK(this, callback));
+            AssertCallOk(grpcsharp_call_start_serverside(this, callback));
         }
 
         public void Cancel()
@@ -212,4 +178,4 @@ namespace Google.GRPC.Core.Internal
             return buffered ? 0 : GRPC_WRITE_BUFFER_HINT;
         }
 	}
-}
+}
\ No newline at end of file
diff --git a/src/csharp/GrpcCore/Internal/StreamingInputObserver.cs b/src/csharp/GrpcCore/Internal/ClientStreamingInputObserver.cs
index 60837de5e6..4d10a9bdf9 100644
--- a/src/csharp/GrpcCore/Internal/StreamingInputObserver.cs
+++ b/src/csharp/GrpcCore/Internal/ClientStreamingInputObserver.cs
@@ -2,11 +2,11 @@
 
 // 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
@@ -16,7 +16,7 @@
 //     * 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
@@ -36,19 +36,20 @@ using Google.GRPC.Core.Internal;
 
 namespace Google.GRPC.Core.Internal
 {
-    internal class StreamingInputObserver<TWrite, TRead> : IObserver<TWrite>
+    internal class ClientStreamingInputObserver<TWrite, TRead> : IObserver<TWrite>
 	{
         readonly AsyncCall<TWrite, TRead> call;
 
-        public StreamingInputObserver(AsyncCall<TWrite, TRead> call)
+        public ClientStreamingInputObserver(AsyncCall<TWrite, TRead> call)
 		{
             this.call = call;
 		}
 
 		public void OnCompleted()
 		{
+
             // TODO: how bad is the Wait here?
-            call.WritesCompletedAsync().Wait();
+            call.SendCloseFromClientAsync().Wait();
 		}
 
 		public void OnError(Exception error)
@@ -59,7 +60,7 @@ namespace Google.GRPC.Core.Internal
 		public void OnNext(TWrite value)
 		{
             // TODO: how bad is the Wait here?
-            call.WriteAsync(value).Wait();
+            call.SendMessageAsync(value).Wait();
 		}
 	}
 }
diff --git a/src/csharp/GrpcCore/Internal/CompletionQueueSafeHandle.cs b/src/csharp/GrpcCore/Internal/CompletionQueueSafeHandle.cs
index 666f220b8c..5ea436df19 100644
--- a/src/csharp/GrpcCore/Internal/CompletionQueueSafeHandle.cs
+++ b/src/csharp/GrpcCore/Internal/CompletionQueueSafeHandle.cs
@@ -46,12 +46,6 @@ namespace Google.GRPC.Core.Internal
         static extern CompletionQueueSafeHandle grpcsharp_completion_queue_create();
 
         [DllImport("grpc_csharp_ext.dll")]
-        static extern EventSafeHandle grpcsharp_completion_queue_pluck(CompletionQueueSafeHandle cq, IntPtr tag, Timespec deadline);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern EventSafeHandle grpcsharp_completion_queue_next(CompletionQueueSafeHandle cq, Timespec deadline);
-
-        [DllImport("grpc_csharp_ext.dll")]
         static extern void grpcsharp_completion_queue_shutdown(CompletionQueueSafeHandle cq);
 
         [DllImport("grpc_csharp_ext.dll")]
@@ -69,21 +63,11 @@ namespace Google.GRPC.Core.Internal
             return grpcsharp_completion_queue_create();
         }
 
-        public EventSafeHandle Next(Timespec deadline)
-        {
-            return grpcsharp_completion_queue_next(this, deadline);
-        }
-
         public GRPCCompletionType NextWithCallback()
         {
             return grpcsharp_completion_queue_next_with_callback(this);
         }
 
-        public EventSafeHandle Pluck(IntPtr tag, Timespec deadline)
-        {
-            return grpcsharp_completion_queue_pluck(this, tag, deadline);
-        }
-
         public void Shutdown()
         {
             grpcsharp_completion_queue_shutdown(this);
diff --git a/src/csharp/GrpcCore/Internal/Event.cs b/src/csharp/GrpcCore/Internal/Event.cs
deleted file mode 100644
index 6116e0975a..0000000000
--- a/src/csharp/GrpcCore/Internal/Event.cs
+++ /dev/null
@@ -1,224 +0,0 @@
-#region Copyright notice and license
-
-// 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.
-
-#endregion
-
-using System;
-using System.Runtime.InteropServices;
-using Google.GRPC.Core;
-
-namespace Google.GRPC.Core.Internal
-{
-    /// <summary>
-    /// grpc_event from grpc/grpc.h
-    /// </summary>
-    internal class EventSafeHandle : SafeHandleZeroIsInvalid
-    {
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern void grpcsharp_event_finish(IntPtr ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCompletionType grpcsharp_event_type(EventSafeHandle ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern CallSafeHandle grpcsharp_event_call(EventSafeHandle ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCOpError grpcsharp_event_write_accepted(EventSafeHandle ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCOpError grpcsharp_event_finish_accepted(EventSafeHandle ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern StatusCode grpcsharp_event_finished_status(EventSafeHandle ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern IntPtr grpcsharp_event_finished_details(EventSafeHandle ev);  // returns const char*
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern IntPtr grpcsharp_event_read_length(EventSafeHandle ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern void grpcsharp_event_read_copy_to_buffer(EventSafeHandle ev, byte[] buffer, UIntPtr bufferLen);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern IntPtr grpcsharp_event_server_rpc_new_method(EventSafeHandle ev); // returns const char*
-
-        public GRPCCompletionType GetCompletionType()
-        {
-            return grpcsharp_event_type(this);
-        }
-
-        public GRPCOpError GetWriteAccepted()
-        {
-            return grpcsharp_event_write_accepted(this);
-        }
-
-        public GRPCOpError GetFinishAccepted()
-        {
-            return grpcsharp_event_finish_accepted(this);
-        }
-
-        public Status GetFinished()
-        {
-            // TODO: can the native method return string directly?
-            string details = Marshal.PtrToStringAnsi(grpcsharp_event_finished_details(this));
-            return new Status(grpcsharp_event_finished_status(this), details);
-        }
-
-        public byte[] GetReadData()
-        {
-            IntPtr len = grpcsharp_event_read_length(this);
-            if (len == new IntPtr(-1))
-            {
-                return null;
-            }
-            byte[] data = new byte[(int) len];
-            grpcsharp_event_read_copy_to_buffer(this, data, new UIntPtr((ulong)data.Length));
-            return data;
-        }
-
-        public CallSafeHandle GetCall() {
-            return grpcsharp_event_call(this);
-        }
-
-        public string GetServerRpcNewMethod() {
-            // TODO: can the native method return string directly?
-            return Marshal.PtrToStringAnsi(grpcsharp_event_server_rpc_new_method(this));
-        }
-
-        //TODO: client_metadata_read event type
-
-        protected override bool ReleaseHandle()
-        {
-            grpcsharp_event_finish(handle);
-            return true;
-        }
-    }
-
-    // TODO: this is basically c&p of EventSafeHandle. Unify!
-    /// <summary>
-    /// Not owned version of
-    /// grpc_event from grpc/grpc.h
-    /// </summary>
-    internal class EventSafeHandleNotOwned : SafeHandleZeroIsInvalid
-    {
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern void grpcsharp_event_finish(IntPtr ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCCompletionType grpcsharp_event_type(EventSafeHandleNotOwned ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern CallSafeHandle grpcsharp_event_call(EventSafeHandleNotOwned ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCOpError grpcsharp_event_write_accepted(EventSafeHandleNotOwned ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern GRPCOpError grpcsharp_event_finish_accepted(EventSafeHandleNotOwned ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern StatusCode grpcsharp_event_finished_status(EventSafeHandleNotOwned ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern IntPtr grpcsharp_event_finished_details(EventSafeHandleNotOwned ev);  // returns const char*
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern IntPtr grpcsharp_event_read_length(EventSafeHandleNotOwned ev);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern void grpcsharp_event_read_copy_to_buffer(EventSafeHandleNotOwned ev, byte[] buffer, UIntPtr bufferLen);
-
-        [DllImport("grpc_csharp_ext.dll")]
-        static extern IntPtr grpcsharp_event_server_rpc_new_method(EventSafeHandleNotOwned ev); // returns const char*
-
-        public EventSafeHandleNotOwned() : base(false)
-        {
-        }
-
-        public EventSafeHandleNotOwned(IntPtr handle) : base(false)
-        {
-            SetHandle(handle);
-        }
-
-        public GRPCCompletionType GetCompletionType()
-        {
-            return grpcsharp_event_type(this);
-        }
-
-        public GRPCOpError GetWriteAccepted()
-        {
-            return grpcsharp_event_write_accepted(this);
-        }
-
-        public GRPCOpError GetFinishAccepted()
-        {
-            return grpcsharp_event_finish_accepted(this);
-        }
-
-        public Status GetFinished()
-        {
-            // TODO: can the native method return string directly?
-            string details = Marshal.PtrToStringAnsi(grpcsharp_event_finished_details(this));
-            return new Status(grpcsharp_event_finished_status(this), details);
-        }
-
-        public byte[] GetReadData()
-        {
-            IntPtr len = grpcsharp_event_read_length(this);
-            if (len == new IntPtr(-1))
-            {
-                return null;
-            }
-            byte[] data = new byte[(int) len];
-            grpcsharp_event_read_copy_to_buffer(this, data, new UIntPtr((ulong)data.Length));
-            return data;
-        }
-
-        public CallSafeHandle GetCall() {
-            return grpcsharp_event_call(this);
-        }
-
-        public string GetServerRpcNewMethod() {
-            // TODO: can the native method return string directly?
-            return Marshal.PtrToStringAnsi(grpcsharp_event_server_rpc_new_method(this));
-        }
-
-        //TODO: client_metadata_read event type
-
-        protected override bool ReleaseHandle()
-        {
-            grpcsharp_event_finish(handle);
-            return true;
-        }
-    }
-}
diff --git a/src/csharp/GrpcCore/Internal/GrpcThreadPool.cs b/src/csharp/GrpcCore/Internal/GrpcThreadPool.cs
index f8154fa250..634a0b2d72 100644
--- a/src/csharp/GrpcCore/Internal/GrpcThreadPool.cs
+++ b/src/csharp/GrpcCore/Internal/GrpcThreadPool.cs
@@ -48,7 +48,6 @@ namespace Google.GRPC.Core.Internal
         readonly object myLock = new object();
         readonly List<Thread> threads = new List<Thread>();
         readonly int poolSize;
-        readonly Action<EventSafeHandle> eventHandler;
 
         CompletionQueueSafeHandle cq;
 
@@ -56,11 +55,6 @@ namespace Google.GRPC.Core.Internal
             this.poolSize = poolSize;
         }
 
-        internal GrpcThreadPool(int poolSize, Action<EventSafeHandle> eventHandler) {
-            this.poolSize = poolSize;
-            this.eventHandler = eventHandler;
-        }
-
         public void Start() {
 
             lock (myLock)
@@ -104,34 +98,19 @@ namespace Google.GRPC.Core.Internal
             }
         }
 
-        private Thread CreateAndStartThread(int i) {
-            Action body;
-            if (eventHandler != null)
-            {
-                body = ThreadBodyWithHandler;
-            }
-            else
-            {
-                body = ThreadBodyNoHandler;
-            }
-            var thread = new Thread(new ThreadStart(body));
+        private Thread CreateAndStartThread(int i)
+        {
+            var thread = new Thread(new ThreadStart(RunHandlerLoop));
             thread.IsBackground = false;
             thread.Start();
-            if (eventHandler != null)
-            {
-                thread.Name = "grpc_server_newrpc " + i;
-            }
-            else
-            {
-                thread.Name = "grpc " + i;
-            }
+            thread.Name = "grpc " + i;
             return thread;
         }
 
         /// <summary>
         /// Body of the polling thread.
         /// </summary>
-        private void ThreadBodyNoHandler()
+        private void RunHandlerLoop()
         {
             GRPCCompletionType completionType;
             do
@@ -140,22 +119,6 @@ namespace Google.GRPC.Core.Internal
             } while(completionType != GRPCCompletionType.GRPC_QUEUE_SHUTDOWN);
             Console.WriteLine("Completion queue has shutdown successfully, thread " + Thread.CurrentThread.Name + " exiting.");
         }
-
-        /// <summary>
-        /// Body of the polling thread.
-        /// </summary>
-        private void ThreadBodyWithHandler()
-        {
-            GRPCCompletionType completionType;
-            do
-            {
-                using (EventSafeHandle ev = cq.Next(Timespec.InfFuture)) {
-                    completionType = ev.GetCompletionType();
-                    eventHandler(ev);
-                }
-            } while(completionType != GRPCCompletionType.GRPC_QUEUE_SHUTDOWN);
-            Console.WriteLine("Completion queue has shutdown successfully, thread " + Thread.CurrentThread.Name + " exiting.");
-        }
     }
 
 }
diff --git a/src/csharp/GrpcCore/Internal/SafeHandleZeroIsInvalid.cs b/src/csharp/GrpcCore/Internal/SafeHandleZeroIsInvalid.cs
index 74a8ef7b6e..59f08d4ca8 100644
--- a/src/csharp/GrpcCore/Internal/SafeHandleZeroIsInvalid.cs
+++ b/src/csharp/GrpcCore/Internal/SafeHandleZeroIsInvalid.cs
@@ -56,6 +56,12 @@ namespace Google.GRPC.Core.Internal
                 return handle == IntPtr.Zero;
             }
         }
+
+        protected override bool ReleaseHandle()
+        {
+            // handle is not owned.
+            return true;
+        }
     }
 }
 
diff --git a/src/csharp/GrpcCore/Internal/ServerSafeHandle.cs b/src/csharp/GrpcCore/Internal/ServerSafeHandle.cs
index c91de97ce3..047bde1add 100644
--- a/src/csharp/GrpcCore/Internal/ServerSafeHandle.cs
+++ b/src/csharp/GrpcCore/Internal/ServerSafeHandle.cs
@@ -38,24 +38,22 @@ using System.Collections.Concurrent;
 
 namespace Google.GRPC.Core.Internal
 {
+    // TODO: we need to make sure that the delegates are not collected before invoked.
+    internal delegate void ServerShutdownCallbackDelegate(IntPtr eventPtr);
+
     /// <summary>
     /// grpc_server from grpc/grpc.h
     /// </summary>
     internal sealed class ServerSafeHandle : SafeHandleZeroIsInvalid
     {
-        [DllImport("grpc_csharp_ext.dll", EntryPoint = "grpcsharp_server_request_call_old")]
-        static extern GRPCCallError grpcsharp_server_request_call_old_CALLBACK(ServerSafeHandle server, [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate callback);
-
         [DllImport("grpc_csharp_ext.dll")]
-        static extern ServerSafeHandle grpcsharp_server_create(CompletionQueueSafeHandle cq, IntPtr args);
+        static extern GRPCCallError grpcsharp_server_request_call(ServerSafeHandle server, CompletionQueueSafeHandle cq, [MarshalAs(UnmanagedType.FunctionPtr)] CompletionCallbackDelegate callback);
 
-        // TODO: check int representation size
         [DllImport("grpc_csharp_ext.dll")]
-        static extern int grpcsharp_server_add_http2_port(ServerSafeHandle server, string addr);
+        static extern ServerSafeHandle grpcsharp_server_create(CompletionQueueSafeHandle cq, IntPtr args);
 
-        // TODO: check int representation size
         [DllImport("grpc_csharp_ext.dll")]
-        static extern int grpcsharp_server_add_secure_http2_port(ServerSafeHandle server, string addr);
+        static extern Int32 grpcsharp_server_add_http2_port(ServerSafeHandle server, string addr);
 
         [DllImport("grpc_csharp_ext.dll")]
         static extern void grpcsharp_server_start(ServerSafeHandle server);
@@ -63,8 +61,9 @@ namespace Google.GRPC.Core.Internal
         [DllImport("grpc_csharp_ext.dll")]
         static extern void grpcsharp_server_shutdown(ServerSafeHandle server);
 
+        // TODO: get rid of the old callback style
         [DllImport("grpc_csharp_ext.dll", EntryPoint = "grpcsharp_server_shutdown_and_notify")]
-        static extern void grpcsharp_server_shutdown_and_notify_CALLBACK(ServerSafeHandle server, [MarshalAs(UnmanagedType.FunctionPtr)] EventCallbackDelegate callback);
+        static extern void grpcsharp_server_shutdown_and_notify_CALLBACK(ServerSafeHandle server, [MarshalAs(UnmanagedType.FunctionPtr)] ServerShutdownCallbackDelegate callback);
 
         [DllImport("grpc_csharp_ext.dll")]
         static extern void grpcsharp_server_destroy(IntPtr server);
@@ -81,7 +80,6 @@ namespace Google.GRPC.Core.Internal
 
         public int AddPort(string addr)
         {
-            // TODO: also grpc_server_add_secure_http2_port...
             return grpcsharp_server_add_http2_port(this, addr);
         }
 
@@ -95,14 +93,14 @@ namespace Google.GRPC.Core.Internal
             grpcsharp_server_shutdown(this);
         }
 
-        public void ShutdownAndNotify(EventCallbackDelegate callback)
+        public void ShutdownAndNotify(ServerShutdownCallbackDelegate callback)
         {
             grpcsharp_server_shutdown_and_notify_CALLBACK(this, callback);
         }
 
-        public GRPCCallError RequestCall(EventCallbackDelegate callback)
+        public GRPCCallError RequestCall(CompletionQueueSafeHandle cq, CompletionCallbackDelegate callback)
         {
-            return grpcsharp_server_request_call_old_CALLBACK(this, callback);
+            return grpcsharp_server_request_call(this, cq, callback);
         }
 
         protected override bool ReleaseHandle()
diff --git a/src/csharp/GrpcCore/Internal/ServerWritingObserver.cs b/src/csharp/GrpcCore/Internal/ServerStreamingOutputObserver.cs
index 1d29864b9f..e9cb65cb3b 100644
--- a/src/csharp/GrpcCore/Internal/ServerWritingObserver.cs
+++ b/src/csharp/GrpcCore/Internal/ServerStreamingOutputObserver.cs
@@ -40,11 +40,11 @@ namespace Google.GRPC.Core.Internal
     /// Observer that writes all arriving messages to a call abstraction (in blocking fashion)
     /// and then halfcloses the call. Used for server-side call handling.
     /// </summary>
-    internal class ServerWritingObserver<TWrite, TRead> : IObserver<TWrite>
+    internal class ServerStreamingOutputObserver<TWrite, TRead> : IObserver<TWrite>
 	{
         readonly AsyncCall<TWrite, TRead> call;
 
-        public ServerWritingObserver(AsyncCall<TWrite, TRead> call)
+        public ServerStreamingOutputObserver(AsyncCall<TWrite, TRead> call)
 		{
             this.call = call;
 		}
@@ -52,19 +52,19 @@ namespace Google.GRPC.Core.Internal
 		public void OnCompleted()
 		{
             // TODO: how bad is the Wait here?
-            call.WriteStatusAsync(new Status(StatusCode.GRPC_STATUS_OK, "")).Wait();
+            call.SendStatusFromServerAsync(new Status(StatusCode.GRPC_STATUS_OK, "")).Wait();
 		}
 
 		public void OnError(Exception error)
 		{
-            // TODO: handle this...
+            // TODO: implement this...
 			throw new InvalidOperationException("This should never be called.");
 		}
 
 		public void OnNext(TWrite value)
 		{
             // TODO: how bad is the Wait here?
-            call.WriteAsync(value).Wait();
+            call.SendMessageAsync(value).Wait();
 		}
 	}
 }
diff --git a/src/csharp/GrpcCore/Server.cs b/src/csharp/GrpcCore/Server.cs
index 0882a61299..91842d8182 100644
--- a/src/csharp/GrpcCore/Server.cs
+++ b/src/csharp/GrpcCore/Server.cs
@@ -49,8 +49,8 @@ namespace Google.GRPC.Core
     {
         // TODO: make sure the delegate doesn't get garbage collected while
         // native callbacks are in the completion queue.
-        readonly EventCallbackDelegate newRpcHandler;
-        readonly EventCallbackDelegate serverShutdownHandler;
+        readonly ServerShutdownCallbackDelegate serverShutdownHandler;
+        readonly CompletionCallbackDelegate newServerRpcHandler;
 
         readonly BlockingCollection<NewRpcInfo> newRpcQueue = new BlockingCollection<NewRpcInfo>();
         readonly ServerSafeHandle handle;
@@ -61,9 +61,8 @@ namespace Google.GRPC.Core
 
         public Server()
         {
-            // TODO: what is the tag for server shutdown?
             this.handle = ServerSafeHandle.NewServer(GetCompletionQueue(), IntPtr.Zero);
-            this.newRpcHandler = HandleNewRpc;
+            this.newServerRpcHandler = HandleNewServerRpc;
             this.serverShutdownHandler = HandleServerShutdown;
         }
 
@@ -99,7 +98,7 @@ namespace Google.GRPC.Core
             {
                 var rpcInfo = newRpcQueue.Take();
 
-                Console.WriteLine("Server received RPC " + rpcInfo.Method);
+                //Console.WriteLine("Server received RPC " + rpcInfo.Method);
 
                 IServerCallHandler callHandler;
                 if (!callHandlers.TryGetValue(rpcInfo.Method, out callHandler))
@@ -138,23 +137,25 @@ namespace Google.GRPC.Core
 
         private void AllowOneRpc()
         {
-            AssertCallOk(handle.RequestCall(newRpcHandler));
+            AssertCallOk(handle.RequestCall(GetCompletionQueue(), newServerRpcHandler));
         }
 
-        private void HandleNewRpc(IntPtr eventPtr)
-        {
-            try
-            {
-                var ev = new EventSafeHandleNotOwned(eventPtr);
-                var rpcInfo = new NewRpcInfo(ev.GetCall(), ev.GetServerRpcNewMethod());
+        private void HandleNewServerRpc(GRPCOpError error, IntPtr batchContextPtr) {
+            try {
+                var ctx = new BatchContextSafeHandleNotOwned(batchContextPtr);
+
+                if (error != GRPCOpError.GRPC_OP_OK) {
+                    // TODO: handle error
+                }
+
+                var rpcInfo = new NewRpcInfo(ctx.GetServerRpcNewCall(), ctx.GetServerRpcNewMethod());
 
                 // after server shutdown, the callback returns with null call
                 if (!rpcInfo.Call.IsInvalid) {
                     newRpcQueue.Add(rpcInfo);
                 }
-            }
-            catch (Exception e)
-            {
+
+            } catch(Exception e) {
                 Console.WriteLine("Caught exception in a native handler: " + e);
             }
         }
diff --git a/src/csharp/GrpcCore/ServerCallHandler.cs b/src/csharp/GrpcCore/ServerCallHandler.cs
index bcce4a091f..48d1eaa335 100644
--- a/src/csharp/GrpcCore/ServerCallHandler.cs
+++ b/src/csharp/GrpcCore/ServerCallHandler.cs
@@ -59,15 +59,16 @@ namespace Google.GRPC.Core
                 method.RequestMarshaller.Deserializer);
 
             asyncCall.InitializeServer(call);
-            asyncCall.Accept(cq);
+           
+            var finishedTask = asyncCall.ServerSideUnaryRequestCallAsync();
 
-            var request = asyncCall.ReadAsync().Result;
+            var request = asyncCall.ReceiveMessageAsync().Result;
 
-            var responseObserver = new ServerWritingObserver<TResponse, TRequest>(asyncCall);
+            var responseObserver = new ServerStreamingOutputObserver<TResponse, TRequest>(asyncCall);
             handler(request, responseObserver);
 
-            asyncCall.Halfclosed.Wait();
-            asyncCall.Finished.Wait();
+            finishedTask.Wait();
+
         }
     }
 
@@ -89,16 +90,11 @@ namespace Google.GRPC.Core
                 method.RequestMarshaller.Deserializer);
 
             asyncCall.InitializeServer(call);
-            asyncCall.Accept(cq);
 
-            var responseObserver = new ServerWritingObserver<TResponse, TRequest>(asyncCall);
+            var responseObserver = new ServerStreamingOutputObserver<TResponse, TRequest>(asyncCall);
             var requestObserver = handler(responseObserver);
-
-            // feed the requests
-            asyncCall.StartReadingToStream(requestObserver);
-
-            asyncCall.Halfclosed.Wait();
-            asyncCall.Finished.Wait();
+            var finishedTask = asyncCall.ServerSideStreamingRequestCallAsync(requestObserver);
+            finishedTask.Wait();
         }
     }
 
@@ -110,12 +106,31 @@ namespace Google.GRPC.Core
             AsyncCall<byte[], byte[]> asyncCall = new AsyncCall<byte[], byte[]>(
                 (payload) => payload, (payload) => payload);
 
+
             asyncCall.InitializeServer(call);
-            asyncCall.Accept(cq);
-            asyncCall.WriteStatusAsync(new Status(StatusCode.GRPC_STATUS_UNIMPLEMENTED, "No such method.")).Wait();
 
-            asyncCall.Finished.Wait();
+            var finishedTask = asyncCall.ServerSideStreamingRequestCallAsync(new NullObserver<byte[]>());
+
+            asyncCall.SendStatusFromServerAsync(new Status(StatusCode.GRPC_STATUS_UNIMPLEMENTED, "No such method.")).Wait();
+
+            finishedTask.Wait();
+        }
+    }
+
+    internal class NullObserver<T> : IObserver<T>
+    {
+        public void OnCompleted()
+        {
+        }
+
+        public void OnError(Exception error)
+        {
         }
+
+        public void OnNext(T value)
+        {
+        }
+
     }
 }
 
diff --git a/src/csharp/GrpcCoreTests/ClientServerTest.cs b/src/csharp/GrpcCoreTests/ClientServerTest.cs
index 4401156520..ba43e4f6a0 100644
--- a/src/csharp/GrpcCoreTests/ClientServerTest.cs
+++ b/src/csharp/GrpcCoreTests/ClientServerTest.cs
@@ -36,6 +36,7 @@ using NUnit.Framework;
 using Google.GRPC.Core;
 using Google.GRPC.Core.Internal;
 using System.Threading;
+using System.Diagnostics;
 using System.Threading.Tasks;
 using Google.GRPC.Core.Utils;
 
@@ -51,11 +52,21 @@ namespace Google.GRPC.Core.Tests
             Marshallers.StringMarshaller,
             Marshallers.StringMarshaller);
 
-        [Test]
-        public void EmptyCall()
+        [TestFixtureSetUp]
+        public void Init()
         {
             GrpcEnvironment.Initialize();
+        }
+
+        [TestFixtureTearDown]
+        public void Cleanup()
+        {
+            GrpcEnvironment.Shutdown();
+        }
 
+        [Test]
+        public void UnaryCall()
+        {
             Server server = new Server();
             server.AddServiceDefinition(
                 ServerServiceDefinition.CreateBuilder("someService")
@@ -69,19 +80,71 @@ namespace Google.GRPC.Core.Tests
                 var call = new Call<string, string>(unaryEchoStringMethod, channel);
 
                 Assert.AreEqual("ABC", Calls.BlockingUnaryCall(call, "ABC", default(CancellationToken)));
+
                 Assert.AreEqual("abcdef", Calls.BlockingUnaryCall(call, "abcdef", default(CancellationToken)));
             }
 
             server.ShutdownAsync().Wait();
+        }
 
-            GrpcEnvironment.Shutdown();
+        [Test]
+        public void UnaryCallPerformance()
+        {
+            Server server = new Server();
+            server.AddServiceDefinition(
+                ServerServiceDefinition.CreateBuilder("someService")
+                .AddMethod(unaryEchoStringMethod, HandleUnaryEchoString).Build());
+
+            int port = server.AddPort(host + ":0");
+            server.Start();
+
+            using (Channel channel = new Channel(host + ":" + port))
+            {
+                var call = new Call<string, string>(unaryEchoStringMethod, channel);
+
+                var stopwatch = new Stopwatch();
+                stopwatch.Start();
+                for (int i = 0; i < 1000; i++)
+                {
+                    Calls.BlockingUnaryCall(call, "ABC", default(CancellationToken));
+                }
+                stopwatch.Stop();
+                Console.WriteLine("Elapsed time: " + stopwatch.ElapsedMilliseconds + "ms");
+            }
+
+            server.ShutdownAsync().Wait();
         }
 
-        private void HandleUnaryEchoString(string request, IObserver<string> responseObserver) {
+        [Test]
+        public void UnknownMethodHandler()
+        {
+            Server server = new Server();
+            server.AddServiceDefinition(
+                ServerServiceDefinition.CreateBuilder("someService").Build());
+
+            int port = server.AddPort(host + ":0");
+            server.Start();
+
+            using (Channel channel = new Channel(host + ":" + port))
+            {
+                var call = new Call<string, string>(unaryEchoStringMethod, channel);
+
+                try {
+                    Calls.BlockingUnaryCall(call, "ABC", default(CancellationToken));
+                    Assert.Fail();
+                } catch(RpcException e) {
+                    Assert.AreEqual(StatusCode.GRPC_STATUS_UNIMPLEMENTED, e.Status.StatusCode);
+                }
+            }
+
+            server.ShutdownAsync().Wait();
+        }
+
+        private void HandleUnaryEchoString(string request, IObserver<string> responseObserver)
+        {
             responseObserver.OnNext(request);
             responseObserver.OnCompleted();
         }
-
     }
 }
 
diff --git a/src/csharp/README.md b/src/csharp/README.md
index a16f1e719e..f56ddabda5 100755
--- a/src/csharp/README.md
+++ b/src/csharp/README.md
@@ -25,10 +25,11 @@ INSTALLATION AND USAGE: WINDOWS
 INSTALLATION AND USAGE: LINUX & MONO
 ------------------------------------
 
-- Compile and install the gRPC C Core library
+- Compile and install the gRPC C# extension library (that will be used via
+  P/Invoke from C#).
 ```
-make shared_c
-sudo make install
+make grpc_csharp_ext
+sudo make install_grpc_csharp_ext
 ```
 
 - Prerequisites for development: Mono framework, MonoDevelop (IDE)
diff --git a/src/csharp/ext/grpc_csharp_ext.c b/src/csharp/ext/grpc_csharp_ext.c
index c7949af44e..304ee9cf34 100644
--- a/src/csharp/ext/grpc_csharp_ext.c
+++ b/src/csharp/ext/grpc_csharp_ext.c
@@ -32,9 +32,11 @@
  */
 
 #include <grpc/support/port_platform.h>
+#include <grpc/support/alloc.h>
 #include <grpc/grpc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/slice.h>
+#include <grpc/support/string.h>
 
 #include <string.h>
 
@@ -58,6 +60,139 @@ grpc_byte_buffer *string_to_byte_buffer(const char *buffer, size_t len) {
   return bb;
 }
 
+typedef void(GPR_CALLTYPE *callback_funcptr)(grpc_op_error op_error,
+                                             void *batch_context);
+
+/*
+ * Helper to maintain lifetime of batch op inputs and store batch op outputs.
+ */
+typedef struct gprcsharp_batch_context {
+  grpc_metadata_array send_initial_metadata;
+  grpc_byte_buffer *send_message;
+  struct {
+    grpc_metadata_array trailing_metadata;
+    char *status_details;
+  } send_status_from_server;
+  grpc_metadata_array recv_initial_metadata;
+  grpc_byte_buffer *recv_message;
+  struct {
+    grpc_metadata_array trailing_metadata;
+    grpc_status_code status;
+    char *status_details;
+    size_t status_details_capacity;
+  } recv_status_on_client;
+  int recv_close_on_server_cancelled;
+  struct {
+    grpc_call *call;
+    grpc_call_details call_details;
+    grpc_metadata_array request_metadata;
+  } server_rpc_new;
+
+  /* callback will be called upon completion */
+  callback_funcptr callback;
+
+} grpcsharp_batch_context;
+
+grpcsharp_batch_context *grpcsharp_batch_context_create() {
+  grpcsharp_batch_context *ctx = gpr_malloc(sizeof(grpcsharp_batch_context));
+  memset(ctx, 0, sizeof(grpcsharp_batch_context));
+  return ctx;
+}
+
+/**
+ * Destroys metadata array including keys and values.
+ */
+void grpcsharp_metadata_array_destroy_recursive(grpc_metadata_array *array) {
+  if (!array->metadata) {
+    return;
+  }
+  /* TODO: destroy also keys and values */
+  grpc_metadata_array_destroy(array);
+}
+
+void grpcsharp_batch_context_destroy(grpcsharp_batch_context *ctx) {
+  if (!ctx) {
+    return;
+  }
+  grpcsharp_metadata_array_destroy_recursive(&(ctx->send_initial_metadata));
+
+  grpc_byte_buffer_destroy(ctx->send_message);
+
+  grpcsharp_metadata_array_destroy_recursive(
+      &(ctx->send_status_from_server.trailing_metadata));
+  gpr_free(ctx->send_status_from_server.status_details);
+
+  grpc_metadata_array_destroy(&(ctx->recv_initial_metadata));
+
+  grpc_byte_buffer_destroy(ctx->recv_message);
+
+  grpc_metadata_array_destroy(&(ctx->recv_status_on_client.trailing_metadata));
+  gpr_free((void *)ctx->recv_status_on_client.status_details);
+
+  /* NOTE: ctx->server_rpc_new.call is not destroyed because callback handler is
+     supposed
+     to take its ownership. */
+
+  grpc_call_details_destroy(&(ctx->server_rpc_new.call_details));
+  grpc_metadata_array_destroy(&(ctx->server_rpc_new.request_metadata));
+
+  gpr_free(ctx);
+}
+
+GPR_EXPORT gpr_intptr GPR_CALLTYPE grpcsharp_batch_context_recv_message_length(
+    const grpcsharp_batch_context *ctx) {
+  if (!ctx->recv_message) {
+    return -1;
+  }
+  return grpc_byte_buffer_length(ctx->recv_message);
+}
+
+/*
+ * Copies data from recv_message to a buffer. Fatal error occurs if
+ * buffer is too small.
+ */
+GPR_EXPORT void GPR_CALLTYPE grpcsharp_batch_context_recv_message_to_buffer(
+    const grpcsharp_batch_context *ctx, char *buffer, size_t buffer_len) {
+  grpc_byte_buffer_reader *reader;
+  gpr_slice slice;
+  size_t offset = 0;
+
+  reader = grpc_byte_buffer_reader_create(ctx->recv_message);
+
+  while (grpc_byte_buffer_reader_next(reader, &slice)) {
+    size_t len = GPR_SLICE_LENGTH(slice);
+    GPR_ASSERT(offset + len <= buffer_len);
+    memcpy(buffer + offset, GPR_SLICE_START_PTR(slice),
+           GPR_SLICE_LENGTH(slice));
+    offset += len;
+    gpr_slice_unref(slice);
+  }
+  grpc_byte_buffer_reader_destroy(reader);
+}
+
+GPR_EXPORT grpc_status_code GPR_CALLTYPE
+grpcsharp_batch_context_recv_status_on_client_status(
+    const grpcsharp_batch_context *ctx) {
+  return ctx->recv_status_on_client.status;
+}
+
+GPR_EXPORT const char *GPR_CALLTYPE
+grpcsharp_batch_context_recv_status_on_client_details(
+    const grpcsharp_batch_context *ctx) {
+  return ctx->recv_status_on_client.status_details;
+}
+
+GPR_EXPORT grpc_call *GPR_CALLTYPE grpcsharp_batch_context_server_rpc_new_call(
+    const grpcsharp_batch_context *ctx) {
+  return ctx->server_rpc_new.call;
+}
+
+GPR_EXPORT const char *GPR_CALLTYPE
+grpcsharp_batch_context_server_rpc_new_method(
+    const grpcsharp_batch_context *ctx) {
+  return ctx->server_rpc_new.call_details.method;
+}
+
 /* Init & shutdown */
 
 GPR_EXPORT void GPR_CALLTYPE grpcsharp_init(void) { grpc_init(); }
@@ -71,18 +206,6 @@ grpcsharp_completion_queue_create(void) {
   return grpc_completion_queue_create();
 }
 
-GPR_EXPORT grpc_event *GPR_CALLTYPE
-grpcsharp_completion_queue_next(grpc_completion_queue *cq,
-                                gpr_timespec deadline) {
-  return grpc_completion_queue_next(cq, deadline);
-}
-
-GPR_EXPORT grpc_event *GPR_CALLTYPE
-grpcsharp_completion_queue_pluck(grpc_completion_queue *cq, void *tag,
-                                 gpr_timespec deadline) {
-  return grpc_completion_queue_pluck(cq, tag, deadline);
-}
-
 GPR_EXPORT void GPR_CALLTYPE
 grpcsharp_completion_queue_shutdown(grpc_completion_queue *cq) {
   grpc_completion_queue_shutdown(cq);
@@ -96,12 +219,18 @@ grpcsharp_completion_queue_destroy(grpc_completion_queue *cq) {
 GPR_EXPORT grpc_completion_type GPR_CALLTYPE
 grpcsharp_completion_queue_next_with_callback(grpc_completion_queue *cq) {
   grpc_event *ev;
+  grpcsharp_batch_context *batch_context;
   grpc_completion_type t;
   void(GPR_CALLTYPE * callback)(grpc_event *);
 
   ev = grpc_completion_queue_next(cq, gpr_inf_future);
   t = ev->type;
-  if (ev->tag) {
+  if (t == GRPC_OP_COMPLETE && ev->tag) {
+    /* NEW API handler */
+    batch_context = (grpcsharp_batch_context *)ev->tag;
+    batch_context->callback(ev->data.op_complete, batch_context);
+    grpcsharp_batch_context_destroy(batch_context);
+  } else if (ev->tag) {
     /* call the callback in ev->tag */
     /* C forbids to cast object pointers to function pointers, so
      * we cast to intptr first.
@@ -129,204 +258,286 @@ GPR_EXPORT void GPR_CALLTYPE grpcsharp_channel_destroy(grpc_channel *channel) {
 }
 
 GPR_EXPORT grpc_call *GPR_CALLTYPE
-grpcsharp_channel_create_call_old(grpc_channel *channel, const char *method,
-                                  const char *host, gpr_timespec deadline) {
-  return grpc_channel_create_call_old(channel, method, host, deadline);
+grpcsharp_channel_create_call(grpc_channel *channel, grpc_completion_queue *cq,
+                              const char *method, const char *host,
+                              gpr_timespec deadline) {
+  return grpc_channel_create_call(channel, cq, method, host, deadline);
 }
 
-/* Event */
+/* Timespec */
 
-GPR_EXPORT void GPR_CALLTYPE grpcsharp_event_finish(grpc_event *event) {
-  grpc_event_finish(event);
-}
+GPR_EXPORT gpr_timespec GPR_CALLTYPE gprsharp_now(void) { return gpr_now(); }
 
-GPR_EXPORT grpc_completion_type GPR_CALLTYPE
-grpcsharp_event_type(const grpc_event *event) {
-  return event->type;
+GPR_EXPORT gpr_timespec GPR_CALLTYPE gprsharp_inf_future(void) {
+  return gpr_inf_future;
 }
 
-GPR_EXPORT grpc_op_error GPR_CALLTYPE
-grpcsharp_event_write_accepted(const grpc_event *event) {
-  GPR_ASSERT(event->type == GRPC_WRITE_ACCEPTED);
-  return event->data.invoke_accepted;
+GPR_EXPORT gpr_int32 GPR_CALLTYPE gprsharp_sizeof_timespec(void) {
+  return sizeof(gpr_timespec);
 }
 
-GPR_EXPORT grpc_op_error GPR_CALLTYPE
-grpcsharp_event_finish_accepted(const grpc_event *event) {
-  GPR_ASSERT(event->type == GRPC_FINISH_ACCEPTED);
-  return event->data.finish_accepted;
-}
+/* Call */
 
-GPR_EXPORT grpc_status_code GPR_CALLTYPE
-grpcsharp_event_finished_status(const grpc_event *event) {
-  GPR_ASSERT(event->type == GRPC_FINISHED);
-  return event->data.finished.status;
+GPR_EXPORT grpc_call_error GPR_CALLTYPE grpcsharp_call_cancel(grpc_call *call) {
+  return grpc_call_cancel(call);
 }
 
-GPR_EXPORT const char *GPR_CALLTYPE
-grpcsharp_event_finished_details(const grpc_event *event) {
-  GPR_ASSERT(event->type == GRPC_FINISHED);
-  return event->data.finished.details;
+GPR_EXPORT grpc_call_error GPR_CALLTYPE
+grpcsharp_call_cancel_with_status(grpc_call *call, grpc_status_code status,
+                                  const char *description) {
+  return grpc_call_cancel_with_status(call, status, description);
 }
 
-GPR_EXPORT gpr_intptr GPR_CALLTYPE
-grpcsharp_event_read_length(const grpc_event *event) {
-  GPR_ASSERT(event->type == GRPC_READ);
-  if (!event->data.read) {
-    return -1;
-  }
-  return grpc_byte_buffer_length(event->data.read);
+GPR_EXPORT void GPR_CALLTYPE grpcsharp_call_destroy(grpc_call *call) {
+  grpc_call_destroy(call);
 }
 
-/*
- * Copies data from read event to a buffer. Fatal error occurs if
- * buffer is too small.
- */
 GPR_EXPORT void GPR_CALLTYPE
-grpcsharp_event_read_copy_to_buffer(const grpc_event *event, char *buffer,
-                                    size_t buffer_len) {
-  grpc_byte_buffer_reader *reader;
-  gpr_slice slice;
-  size_t offset = 0;
+grpcsharp_call_start_write_from_copied_buffer(grpc_call *call,
+                                              const char *buffer, size_t len,
+                                              void *tag, gpr_uint32 flags) {
+  grpc_byte_buffer *byte_buffer = string_to_byte_buffer(buffer, len);
+  GPR_ASSERT(grpc_call_start_write_old(call, byte_buffer, tag, flags) ==
+             GRPC_CALL_OK);
+  grpc_byte_buffer_destroy(byte_buffer);
+}
 
-  GPR_ASSERT(event->type == GRPC_READ);
-  reader = grpc_byte_buffer_reader_create(event->data.read);
+GPR_EXPORT grpc_call_error GPR_CALLTYPE
+grpcsharp_call_start_unary(grpc_call *call, callback_funcptr callback,
+                           const char *send_buffer, size_t send_buffer_len) {
+  /* TODO: don't use magic number */
+  grpc_op ops[6];
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
 
-  GPR_ASSERT(event->data.read);
-  while (grpc_byte_buffer_reader_next(reader, &slice)) {
-    size_t len = GPR_SLICE_LENGTH(slice);
-    GPR_ASSERT(offset + len <= buffer_len);
-    memcpy(buffer + offset, GPR_SLICE_START_PTR(slice),
-           GPR_SLICE_LENGTH(slice));
-    offset += len;
-    gpr_slice_unref(slice);
-  }
-  grpc_byte_buffer_reader_destroy(reader);
-}
+  /* TODO: implement sending the metadata... */
+  ops[0].op = GRPC_OP_SEND_INITIAL_METADATA;
+  /* ctx->send_initial_metadata is already zeroed out. */
+  ops[0].data.send_initial_metadata.count = 0;
+  ops[0].data.send_initial_metadata.metadata = NULL;
 
-GPR_EXPORT grpc_call *GPR_CALLTYPE
-grpcsharp_event_call(const grpc_event *event) {
-  /* we only allow this for newly incoming server calls. */
-  GPR_ASSERT(event->type == GRPC_SERVER_RPC_NEW);
-  return event->call;
-}
+  ops[1].op = GRPC_OP_SEND_MESSAGE;
+  ctx->send_message = string_to_byte_buffer(send_buffer, send_buffer_len);
+  ops[1].data.send_message = ctx->send_message;
 
-GPR_EXPORT const char *GPR_CALLTYPE
-grpcsharp_event_server_rpc_new_method(const grpc_event *event) {
-  GPR_ASSERT(event->type == GRPC_SERVER_RPC_NEW);
-  return event->data.server_rpc_new.method;
-}
+  ops[2].op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
 
-/* Timespec */
+  ops[3].op = GRPC_OP_RECV_INITIAL_METADATA;
+  ops[3].data.recv_initial_metadata = &(ctx->recv_initial_metadata);
 
-GPR_EXPORT gpr_timespec GPR_CALLTYPE gprsharp_now(void) { return gpr_now(); }
+  ops[4].op = GRPC_OP_RECV_MESSAGE;
+  ops[4].data.recv_message = &(ctx->recv_message);
 
-GPR_EXPORT gpr_timespec GPR_CALLTYPE gprsharp_inf_future(void) {
-  return gpr_inf_future;
-}
+  ops[5].op = GRPC_OP_RECV_STATUS_ON_CLIENT;
+  ops[5].data.recv_status_on_client.trailing_metadata =
+      &(ctx->recv_status_on_client.trailing_metadata);
+  ops[5].data.recv_status_on_client.status =
+      &(ctx->recv_status_on_client.status);
+  /* not using preallocation for status_details */
+  ops[5].data.recv_status_on_client.status_details =
+      &(ctx->recv_status_on_client.status_details);
+  ops[5].data.recv_status_on_client.status_details_capacity =
+      &(ctx->recv_status_on_client.status_details_capacity);
 
-GPR_EXPORT gpr_int32 GPR_CALLTYPE gprsharp_sizeof_timespec(void) {
-  return sizeof(gpr_timespec);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
-/* Call */
-
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_add_metadata_old(grpc_call *call, grpc_metadata *metadata,
-                                gpr_uint32 flags) {
-  return grpc_call_add_metadata_old(call, metadata, flags);
+grpcsharp_call_start_client_streaming(grpc_call *call,
+                                      callback_funcptr callback) {
+  /* TODO: don't use magic number */
+  grpc_op ops[4];
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
+
+  /* TODO: implement sending the metadata... */
+  ops[0].op = GRPC_OP_SEND_INITIAL_METADATA;
+  /* ctx->send_initial_metadata is already zeroed out. */
+  ops[0].data.send_initial_metadata.count = 0;
+  ops[0].data.send_initial_metadata.metadata = NULL;
+
+  ops[1].op = GRPC_OP_RECV_INITIAL_METADATA;
+  ops[1].data.recv_initial_metadata = &(ctx->recv_initial_metadata);
+
+  ops[2].op = GRPC_OP_RECV_MESSAGE;
+  ops[2].data.recv_message = &(ctx->recv_message);
+
+  ops[3].op = GRPC_OP_RECV_STATUS_ON_CLIENT;
+  ops[3].data.recv_status_on_client.trailing_metadata =
+      &(ctx->recv_status_on_client.trailing_metadata);
+  ops[3].data.recv_status_on_client.status =
+      &(ctx->recv_status_on_client.status);
+  /* not using preallocation for status_details */
+  ops[3].data.recv_status_on_client.status_details =
+      &(ctx->recv_status_on_client.status_details);
+  ops[3].data.recv_status_on_client.status_details_capacity =
+      &(ctx->recv_status_on_client.status_details_capacity);
+
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_invoke_old(grpc_call *call, grpc_completion_queue *cq,
-                          void *metadata_read_tag, void *finished_tag,
-                          gpr_uint32 flags) {
-  return grpc_call_invoke_old(call, cq, metadata_read_tag, finished_tag, flags);
+grpcsharp_call_start_server_streaming(grpc_call *call,
+                                      callback_funcptr callback,
+                                      const char *send_buffer,
+                                      size_t send_buffer_len) {
+  /* TODO: don't use magic number */
+  grpc_op ops[5];
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
+
+  /* TODO: implement sending the metadata... */
+  ops[0].op = GRPC_OP_SEND_INITIAL_METADATA;
+  /* ctx->send_initial_metadata is already zeroed out. */
+  ops[0].data.send_initial_metadata.count = 0;
+  ops[0].data.send_initial_metadata.metadata = NULL;
+
+  ops[1].op = GRPC_OP_SEND_MESSAGE;
+  ctx->send_message = string_to_byte_buffer(send_buffer, send_buffer_len);
+  ops[1].data.send_message = ctx->send_message;
+
+  ops[2].op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
+
+  ops[3].op = GRPC_OP_RECV_INITIAL_METADATA;
+  ops[3].data.recv_initial_metadata = &(ctx->recv_initial_metadata);
+
+  ops[4].op = GRPC_OP_RECV_STATUS_ON_CLIENT;
+  ops[4].data.recv_status_on_client.trailing_metadata =
+      &(ctx->recv_status_on_client.trailing_metadata);
+  ops[4].data.recv_status_on_client.status =
+      &(ctx->recv_status_on_client.status);
+  /* not using preallocation for status_details */
+  ops[4].data.recv_status_on_client.status_details =
+      &(ctx->recv_status_on_client.status_details);
+  ops[4].data.recv_status_on_client.status_details_capacity =
+      &(ctx->recv_status_on_client.status_details_capacity);
+
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_server_accept_old(grpc_call *call, grpc_completion_queue *cq,
-                                 void *finished_tag) {
-  return grpc_call_server_accept_old(call, cq, finished_tag);
+grpcsharp_call_start_duplex_streaming(grpc_call *call,
+                                      callback_funcptr callback) {
+  /* TODO: don't use magic number */
+  grpc_op ops[3];
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
+
+  /* TODO: implement sending the metadata... */
+  ops[0].op = GRPC_OP_SEND_INITIAL_METADATA;
+  /* ctx->send_initial_metadata is already zeroed out. */
+  ops[0].data.send_initial_metadata.count = 0;
+  ops[0].data.send_initial_metadata.metadata = NULL;
+
+  ops[1].op = GRPC_OP_RECV_INITIAL_METADATA;
+  ops[1].data.recv_initial_metadata = &(ctx->recv_initial_metadata);
+
+  ops[2].op = GRPC_OP_RECV_STATUS_ON_CLIENT;
+  ops[2].data.recv_status_on_client.trailing_metadata =
+      &(ctx->recv_status_on_client.trailing_metadata);
+  ops[2].data.recv_status_on_client.status =
+      &(ctx->recv_status_on_client.status);
+  /* not using preallocation for status_details */
+  ops[2].data.recv_status_on_client.status_details =
+      &(ctx->recv_status_on_client.status_details);
+  ops[2].data.recv_status_on_client.status_details_capacity =
+      &(ctx->recv_status_on_client.status_details_capacity);
+
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_server_end_initial_metadata_old(grpc_call *call,
-                                               gpr_uint32 flags) {
-  return grpc_call_server_end_initial_metadata_old(call, flags);
-}
+grpcsharp_call_send_message(grpc_call *call, callback_funcptr callback,
+                            const char *send_buffer, size_t send_buffer_len) {
+  /* TODO: don't use magic number */
+  grpc_op ops[1];
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
 
-GPR_EXPORT grpc_call_error GPR_CALLTYPE grpcsharp_call_cancel(grpc_call *call) {
-  return grpc_call_cancel(call);
-}
+  ops[0].op = GRPC_OP_SEND_MESSAGE;
+  ctx->send_message = string_to_byte_buffer(send_buffer, send_buffer_len);
+  ops[0].data.send_message = ctx->send_message;
 
-GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_cancel_with_status(grpc_call *call, grpc_status_code status,
-                                  const char *description) {
-  return grpc_call_cancel_with_status(call, status, description);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_start_write_old(grpc_call *call, grpc_byte_buffer *byte_buffer,
-                               void *tag, gpr_uint32 flags) {
-  return grpc_call_start_write_old(call, byte_buffer, tag, flags);
+grpcsharp_call_send_close_from_client(grpc_call *call,
+                                      callback_funcptr callback) {
+  /* TODO: don't use magic number */
+  grpc_op ops[1];
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
+
+  ops[0].op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
+
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_start_write_status_old(grpc_call *call,
-                                      grpc_status_code status_code,
-                                      const char *status_message, void *tag) {
-  return grpc_call_start_write_status_old(call, status_code, status_message,
-                                          tag);
+grpcsharp_call_send_status_from_server(grpc_call *call,
+                                       callback_funcptr callback,
+                                       grpc_status_code status_code,
+                                       const char *status_details) {
+  /* TODO: don't use magic number */
+  grpc_op ops[1];
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
+
+  ops[0].op = GRPC_OP_SEND_STATUS_FROM_SERVER;
+  ops[0].data.send_status_from_server.status = status_code;
+  ops[0].data.send_status_from_server.status_details =
+      gpr_strdup(status_details);
+  ops[0].data.send_status_from_server.trailing_metadata = NULL;
+  ops[0].data.send_status_from_server.trailing_metadata_count = 0;
+
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_writes_done_old(grpc_call *call, void *tag) {
-  return grpc_call_writes_done_old(call, tag);
+grpcsharp_call_recv_message(grpc_call *call, callback_funcptr callback) {
+  /* TODO: don't use magic number */
+  grpc_op ops[1];
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
+
+  ops[0].op = GRPC_OP_RECV_MESSAGE;
+  ops[0].data.recv_message = &(ctx->recv_message);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_call_start_read_old(grpc_call *call, void *tag) {
-  return grpc_call_start_read_old(call, tag);
-}
+grpcsharp_call_start_serverside(grpc_call *call, callback_funcptr callback) {
+  /* TODO: don't use magic number */
+  grpc_op ops[2];
 
-GPR_EXPORT void GPR_CALLTYPE grpcsharp_call_destroy(grpc_call *call) {
-  grpc_call_destroy(call);
-}
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
 
-GPR_EXPORT void GPR_CALLTYPE
-grpcsharp_call_start_write_from_copied_buffer(grpc_call *call,
-                                              const char *buffer, size_t len,
-                                              void *tag, gpr_uint32 flags) {
-  grpc_byte_buffer *byte_buffer = string_to_byte_buffer(buffer, len);
-  GPR_ASSERT(grpc_call_start_write_old(call, byte_buffer, tag, flags) ==
-             GRPC_CALL_OK);
-  grpc_byte_buffer_destroy(byte_buffer);
-}
+  ops[0].op = GRPC_OP_SEND_INITIAL_METADATA;
+  ops[0].data.send_initial_metadata.count = 0;
+  ops[0].data.send_initial_metadata.metadata = NULL;
 
-/* Server */
+  ops[1].op = GRPC_OP_RECV_CLOSE_ON_SERVER;
+  ops[1].data.recv_close_on_server.cancelled =
+      (&ctx->recv_close_on_server_cancelled);
 
-GPR_EXPORT grpc_call_error GPR_CALLTYPE
-grpcsharp_server_request_call_old(grpc_server *server, void *tag_new) {
-  return grpc_server_request_call_old(server, tag_new);
+  return grpc_call_start_batch(call, ops, sizeof(ops) / sizeof(ops[0]), ctx);
 }
 
+/* Server */
+
 GPR_EXPORT grpc_server *GPR_CALLTYPE
 grpcsharp_server_create(grpc_completion_queue *cq,
                         const grpc_channel_args *args) {
   return grpc_server_create(cq, args);
 }
 
-GPR_EXPORT int GPR_CALLTYPE
+GPR_EXPORT gpr_int32 GPR_CALLTYPE
 grpcsharp_server_add_http2_port(grpc_server *server, const char *addr) {
   return grpc_server_add_http2_port(server, addr);
 }
 
-GPR_EXPORT int GPR_CALLTYPE
-grpcsharp_server_add_secure_http2_port(grpc_server *server, const char *addr) {
-  return grpc_server_add_secure_http2_port(server, addr);
-}
-
 GPR_EXPORT void GPR_CALLTYPE grpcsharp_server_start(grpc_server *server) {
   grpc_server_start(server);
 }
@@ -343,3 +554,14 @@ grpcsharp_server_shutdown_and_notify(grpc_server *server, void *tag) {
 GPR_EXPORT void GPR_CALLTYPE grpcsharp_server_destroy(grpc_server *server) {
   grpc_server_destroy(server);
 }
+
+GPR_EXPORT grpc_call_error GPR_CALLTYPE
+grpcsharp_server_request_call(grpc_server *server, grpc_completion_queue *cq,
+                              callback_funcptr callback) {
+  grpcsharp_batch_context *ctx = grpcsharp_batch_context_create();
+  ctx->callback = callback;
+
+  return grpc_server_request_call(
+      server, &(ctx->server_rpc_new.call), &(ctx->server_rpc_new.call_details),
+      &(ctx->server_rpc_new.request_metadata), cq, ctx);
+}
diff --git a/templates/Makefile.template b/templates/Makefile.template
index 3e0f77c014..178ace6bcf 100644
--- a/templates/Makefile.template
+++ b/templates/Makefile.template
@@ -194,7 +194,9 @@ LDFLAGS += -g -fPIC
 
 INCLUDES = . include $(GENDIR)
 ifeq ($(SYSTEM),Darwin)
+INCLUDES += /usr/local/ssl/include /opt/local/include
 LIBS = m z
+LDFLAGS += -L/usr/local/ssl/lib -L/opt/local/lib
 else
 LIBS = rt m z pthread
 LDFLAGS += -pthread
@@ -527,6 +529,15 @@ shared_cxx: \
 % endfor
 
 
+shared_csharp: shared_c \
+% for lib in libs:
+% if lib.build == 'all' and lib.language == 'csharp':
+ $(LIBDIR)/$(CONFIG)/lib${lib.name}.$(SHARED_EXT)\
+% endif
+% endfor
+
+grpc_csharp_ext: shared_csharp
+
 privatelibs: privatelibs_c privatelibs_cxx
 
 privatelibs_c: \
@@ -660,6 +671,18 @@ ifeq ($(CONFIG),opt)
 % endfor
 endif
 
+strip-shared_csharp: shared_csharp
+ifeq ($(CONFIG),opt)
+% for lib in libs:
+% if lib.language == "csharp":
+% if lib.build == "all":
+	$(E) "[STRIP]   Stripping lib${lib.name}.so"
+	$(Q) $(STRIP) $(LIBDIR)/$(CONFIG)/lib${lib.name}.$(SHARED_EXT)
+% endif
+% endif
+% endfor
+endif
+
 % for p in protos:
 ifeq ($(NO_PROTOC),true)
 $(GENDIR)/${p}.pb.cc: protoc_dep_error
@@ -699,6 +722,10 @@ install_c: install-headers_c install-static_c install-shared_c
 
 install_cxx: install-headers_cxx install-static_cxx install-shared_cxx
 
+install_csharp: install-shared_csharp install_c
+
+install_grpc_csharp_ext: install_csharp
+
 install-headers: install-headers_c install-headers_cxx
 
 install-headers_c:
@@ -779,6 +806,30 @@ ifneq ($(SYSTEM),Darwin)
 endif
 endif
 
+install-shared_csharp: shared_csharp strip-shared_csharp
+% for lib in libs:
+% if lib.language == "csharp":
+% if lib.build == "all":
+ifeq ($(SYSTEM),MINGW32)
+	$(E) "[INSTALL] Installing ${lib.name}.$(SHARED_EXT)"
+	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/${lib.name}.$(SHARED_EXT) $(prefix)/lib/${lib.name}.$(SHARED_EXT)
+	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/lib${lib.name}-imp.a $(prefix)/lib/lib${lib.name}-imp.a
+else
+	$(E) "[INSTALL] Installing lib${lib.name}.$(SHARED_EXT)"
+	$(Q) $(INSTALL) $(LIBDIR)/$(CONFIG)/lib${lib.name}.$(SHARED_EXT) $(prefix)/lib/lib${lib.name}.$(SHARED_EXT)
+ifneq ($(SYSTEM),Darwin)
+	$(Q) ln -sf lib${lib.name}.$(SHARED_EXT) $(prefix)/lib/lib${lib.name}.so
+endif
+endif
+% endif
+% endif
+% endfor
+ifneq ($(SYSTEM),MINGW32)
+ifneq ($(SYSTEM),Darwin)
+	$(Q) ldconfig
+endif
+endif
+
 clean:
 	$(Q) $(RM) -rf $(OBJDIR) $(LIBDIR) $(BINDIR) $(GENDIR)
 
diff --git a/test/core/channel/channel_stack_test.c b/test/core/channel/channel_stack_test.c
index 0345f99bde..59a4564220 100644
--- a/test/core/channel/channel_stack_test.c
+++ b/test/core/channel/channel_stack_test.c
@@ -128,7 +128,7 @@ static void test_create_channel_stack(void) {
   grpc_channel_stack_destroy(channel_stack);
   gpr_free(channel_stack);
 
-  grpc_mdctx_orphan(metadata_context);
+  grpc_mdctx_unref(metadata_context);
 }
 
 int main(int argc, char **argv) {
diff --git a/test/core/channel/metadata_buffer_test.c b/test/core/channel/metadata_buffer_test.c
index 22776f8ca1..ba8100b7d2 100644
--- a/test/core/channel/metadata_buffer_test.c
+++ b/test/core/channel/metadata_buffer_test.c
@@ -182,7 +182,7 @@ static void test_case(size_t key_prefix_len, size_t value_prefix_len,
   gpr_free(stk);
 
   grpc_metadata_buffer_destroy(&buffer, GRPC_OP_OK);
-  grpc_mdctx_orphan(mdctx);
+  grpc_mdctx_unref(mdctx);
 }
 
 int main(int argc, char **argv) {
diff --git a/test/core/security/credentials_test.c b/test/core/security/credentials_test.c
index 302869d70e..f911db6de1 100644
--- a/test/core/security/credentials_test.c
+++ b/test/core/security/credentials_test.c
@@ -138,7 +138,7 @@ static void test_oauth2_token_fetcher_creds_parsing_ok(void) {
   GPR_ASSERT(!strcmp(grpc_mdstr_as_c_string(token_elem->value),
                      "Bearer ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_"));
   grpc_mdelem_unref(token_elem);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_bad_http_status(void) {
@@ -150,7 +150,7 @@ static void test_oauth2_token_fetcher_creds_parsing_bad_http_status(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, ctx, &token_elem, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_empty_http_body(void) {
@@ -161,7 +161,7 @@ static void test_oauth2_token_fetcher_creds_parsing_empty_http_body(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, ctx, &token_elem, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_invalid_json(void) {
@@ -176,7 +176,7 @@ static void test_oauth2_token_fetcher_creds_parsing_invalid_json(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, ctx, &token_elem, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_missing_token(void) {
@@ -190,7 +190,7 @@ static void test_oauth2_token_fetcher_creds_parsing_missing_token(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, ctx, &token_elem, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_missing_token_type(void) {
@@ -205,7 +205,7 @@ static void test_oauth2_token_fetcher_creds_parsing_missing_token_type(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, ctx, &token_elem, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_missing_token_lifetime(
@@ -220,7 +220,7 @@ static void test_oauth2_token_fetcher_creds_parsing_missing_token_lifetime(
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, ctx, &token_elem, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void check_metadata(expected_md *expected, grpc_mdelem **md_elems,
diff --git a/test/core/transport/chttp2/hpack_parser_test.c b/test/core/transport/chttp2/hpack_parser_test.c
index edab37b687..86c6bb1f56 100644
--- a/test/core/transport/chttp2/hpack_parser_test.c
+++ b/test/core/transport/chttp2/hpack_parser_test.c
@@ -214,7 +214,7 @@ static void test_vectors(grpc_slice_split_mode mode) {
               "set-cookie",
               "foo=ASDJKHQKBZXOQWEOPIUAXQWEOIU; max-age=3600; version=1", NULL);
   grpc_chttp2_hpack_parser_destroy(&parser);
-  grpc_mdctx_orphan(mdctx);
+  grpc_mdctx_unref(mdctx);
 }
 
 int main(int argc, char **argv) {
diff --git a/test/core/transport/chttp2/hpack_table_test.c b/test/core/transport/chttp2/hpack_table_test.c
index f3da9f0d49..d1e5f0829a 100644
--- a/test/core/transport/chttp2/hpack_table_test.c
+++ b/test/core/transport/chttp2/hpack_table_test.c
@@ -126,7 +126,7 @@ static void test_static_lookup(void) {
   assert_index(&tbl, 61, "www-authenticate", "");
 
   grpc_chttp2_hptbl_destroy(&tbl);
-  grpc_mdctx_orphan(mdctx);
+  grpc_mdctx_unref(mdctx);
 }
 
 static void test_many_additions(void) {
@@ -158,7 +158,7 @@ static void test_many_additions(void) {
   }
 
   grpc_chttp2_hptbl_destroy(&tbl);
-  grpc_mdctx_orphan(mdctx);
+  grpc_mdctx_unref(mdctx);
 }
 
 static grpc_chttp2_hptbl_find_result find_simple(grpc_chttp2_hptbl *tbl,
@@ -262,7 +262,7 @@ static void test_find(void) {
   GPR_ASSERT(r.has_value == 0);
 
   grpc_chttp2_hptbl_destroy(&tbl);
-  grpc_mdctx_orphan(mdctx);
+  grpc_mdctx_unref(mdctx);
 }
 
 int main(int argc, char **argv) {
diff --git a/test/core/transport/chttp2/stream_encoder_test.c b/test/core/transport/chttp2/stream_encoder_test.c
index 3013533f9b..5c7801079f 100644
--- a/test/core/transport/chttp2/stream_encoder_test.c
+++ b/test/core/transport/chttp2/stream_encoder_test.c
@@ -309,7 +309,7 @@ static void run_test(void (*test)(), const char *name) {
   grpc_sopb_init(&g_sopb);
   test();
   grpc_chttp2_hpack_compressor_destroy(&g_compressor);
-  grpc_mdctx_orphan(g_mdctx);
+  grpc_mdctx_unref(g_mdctx);
   grpc_sopb_destroy(&g_sopb);
 }
 
diff --git a/test/core/transport/metadata_test.c b/test/core/transport/metadata_test.c
index 07867c6b24..f345cebdb6 100644
--- a/test/core/transport/metadata_test.c
+++ b/test/core/transport/metadata_test.c
@@ -44,7 +44,7 @@
 #define LOG_TEST() gpr_log(GPR_INFO, "%s", __FUNCTION__)
 
 /* a large number */
-#define MANY 100000
+#define MANY 10000
 
 static void test_no_op(void) {
   grpc_mdctx *ctx;
@@ -52,7 +52,7 @@ static void test_no_op(void) {
   LOG_TEST();
 
   ctx = grpc_mdctx_create();
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_create_string(void) {
@@ -71,7 +71,7 @@ static void test_create_string(void) {
   GPR_ASSERT(gpr_slice_str_cmp(s3->slice, "very much not hello") == 0);
   grpc_mdstr_unref(s1);
   grpc_mdstr_unref(s2);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
   grpc_mdstr_unref(s3);
 }
 
@@ -95,7 +95,7 @@ static void test_create_metadata(void) {
   grpc_mdelem_unref(m1);
   grpc_mdelem_unref(m2);
   grpc_mdelem_unref(m3);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_create_many_ephemeral_metadata(void) {
@@ -116,7 +116,7 @@ static void test_create_many_ephemeral_metadata(void) {
   /* capacity should not grow */
   GPR_ASSERT(mdtab_capacity_before ==
              grpc_mdctx_get_mdtab_capacity_test_only(ctx));
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_create_many_persistant_metadata(void) {
@@ -145,7 +145,7 @@ static void test_create_many_persistant_metadata(void) {
   for (i = 0; i < MANY; i++) {
     grpc_mdelem_unref(created[i]);
   }
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 
   gpr_free(created);
 }
@@ -171,7 +171,7 @@ static void test_spin_creating_the_same_thing(void) {
   GPR_ASSERT(grpc_mdctx_get_mdtab_count_test_only(ctx) == 1);
   GPR_ASSERT(grpc_mdctx_get_mdtab_free_test_only(ctx) == 1);
 
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_things_stick_around(void) {
@@ -218,7 +218,7 @@ static void test_things_stick_around(void) {
     }
   }
 
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
   gpr_free(strs);
   gpr_free(shuf);
 }
@@ -245,7 +245,7 @@ static void test_slices_work(void) {
   gpr_slice_unref(slice);
   grpc_mdstr_unref(str);
 
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 static void test_base64_and_huffman_works(void) {
@@ -264,7 +264,7 @@ static void test_base64_and_huffman_works(void) {
 
   gpr_slice_unref(slice2);
   grpc_mdstr_unref(str);
-  grpc_mdctx_orphan(ctx);
+  grpc_mdctx_unref(ctx);
 }
 
 int main(int argc, char **argv) {
diff --git a/test/core/transport/transport_end2end_tests.c b/test/core/transport/transport_end2end_tests.c
index 6a0848fa97..6d13bf1f8c 100644
--- a/test/core/transport/transport_end2end_tests.c
+++ b/test/core/transport/transport_end2end_tests.c
@@ -927,7 +927,7 @@ void grpc_transport_end2end_tests(grpc_transport_test_config *config) {
     test_request_with_flow_ctl_cb(config, interesting_message_lengths[i]);
   }
 
-  grpc_mdctx_orphan(g_metadata_context);
+  grpc_mdctx_unref(g_metadata_context);
 
   gpr_log(GPR_INFO, "tests completed ok");
 }
diff --git a/test/cpp/end2end/async_end2end_test.cc b/test/cpp/end2end/async_end2end_test.cc
index 49990692e3..79160bfaa5 100644
--- a/test/cpp/end2end/async_end2end_test.cc
+++ b/test/cpp/end2end/async_end2end_test.cc
@@ -38,6 +38,7 @@
 #include "test/cpp/util/echo_duplicate.pb.h"
 #include "test/cpp/util/echo.pb.h"
 #include "src/cpp/util/time.h"
+#include <grpc++/async_unary_call.h>
 #include <grpc++/channel_arguments.h>
 #include <grpc++/channel_interface.h>
 #include <grpc++/client_context.h>
@@ -134,21 +135,23 @@ class AsyncEnd2endTest : public ::testing::Test {
       grpc::ServerAsyncResponseWriter<EchoResponse> response_writer(&srv_ctx);
 
       send_request.set_message("Hello");
-      stub_->Echo(
-          &cli_ctx, send_request, &recv_response, &recv_status, &cli_cq_, tag(1));
+      std::unique_ptr<ClientAsyncResponseReader<EchoResponse> >
+          response_reader(stub_->Echo(
+              &cli_ctx, send_request, &cli_cq_, tag(1)));
 
       service_.RequestEcho(
           &srv_ctx, &recv_request, &response_writer, &srv_cq_, tag(2));
 
       server_ok(2);
       EXPECT_EQ(send_request.message(), recv_request.message());
+      client_ok(1);
 
       send_response.set_message(recv_request.message());
       response_writer.Finish(send_response, Status::OK, tag(3));
-
       server_ok(3);
 
-      client_ok(1);
+      response_reader->Finish(&recv_response, &recv_status, tag(4));
+      client_ok(4);
 
       EXPECT_EQ(send_response.message(), recv_response.message());
       EXPECT_TRUE(recv_status.IsOk());
@@ -351,8 +354,8 @@ TEST_F(AsyncEnd2endTest, ClientInitialMetadataRpc) {
   cli_ctx.AddMetadata(meta1.first, meta1.second);
   cli_ctx.AddMetadata(meta2.first, meta2.second);
 
-  stub_->Echo(
-      &cli_ctx, send_request, &recv_response, &recv_status, &cli_cq_, tag(1));
+  std::unique_ptr<ClientAsyncResponseReader<EchoResponse> > response_reader(
+      stub_->Echo(&cli_ctx, send_request, &cli_cq_, tag(1)));
 
   service_.RequestEcho(
       &srv_ctx, &recv_request, &response_writer, &srv_cq_, tag(2));
@@ -362,13 +365,15 @@ TEST_F(AsyncEnd2endTest, ClientInitialMetadataRpc) {
   EXPECT_EQ(meta1.second, client_initial_metadata.find(meta1.first)->second);
   EXPECT_EQ(meta2.second, client_initial_metadata.find(meta2.first)->second);
   EXPECT_EQ(2, client_initial_metadata.size());
+  client_ok(1);
 
   send_response.set_message(recv_request.message());
   response_writer.Finish(send_response, Status::OK, tag(3));
 
   server_ok(3);
 
-  client_ok(1);
+  response_reader->Finish(&recv_response, &recv_status, tag(4));
+  client_ok(4);
 
   EXPECT_EQ(send_response.message(), recv_response.message());
   EXPECT_TRUE(recv_status.IsOk());
@@ -391,8 +396,8 @@ TEST_F(AsyncEnd2endTest, ServerInitialMetadataRpc) {
   std::pair<grpc::string, grpc::string> meta1("key1", "val1");
   std::pair<grpc::string, grpc::string> meta2("key2", "val2");
 
-  stub_->Echo(
-      &cli_ctx, send_request, &recv_response, &recv_status, &cli_cq_, tag(1));
+  std::unique_ptr<ClientAsyncResponseReader<EchoResponse> > response_reader(
+      stub_->Echo(&cli_ctx, send_request, &cli_cq_, tag(1)));
 
   service_.RequestEcho(
       &srv_ctx, &recv_request, &response_writer, &srv_cq_, tag(2));
@@ -400,22 +405,26 @@ TEST_F(AsyncEnd2endTest, ServerInitialMetadataRpc) {
   EXPECT_EQ(send_request.message(), recv_request.message());
   srv_ctx.AddInitialMetadata(meta1.first, meta1.second);
   srv_ctx.AddInitialMetadata(meta2.first, meta2.second);
+  client_ok(1);
   response_writer.SendInitialMetadata(tag(3));
   server_ok(3);
 
-  send_response.set_message(recv_request.message());
-  response_writer.Finish(send_response, Status::OK, tag(4));
+  response_reader->ReadInitialMetadata(tag(4));
+  client_ok(4);
+  auto server_initial_metadata = cli_ctx.GetServerInitialMetadata();
+  EXPECT_EQ(meta1.second, server_initial_metadata.find(meta1.first)->second);
+  EXPECT_EQ(meta2.second, server_initial_metadata.find(meta2.first)->second);
+  EXPECT_EQ(2, server_initial_metadata.size());
 
-  server_ok(4);
+  send_response.set_message(recv_request.message());
+  response_writer.Finish(send_response, Status::OK, tag(5));
+  server_ok(5);
 
-  client_ok(1);
+  response_reader->Finish(&recv_response, &recv_status, tag(6));
+  client_ok(6);
 
   EXPECT_EQ(send_response.message(), recv_response.message());
   EXPECT_TRUE(recv_status.IsOk());
-  auto server_initial_metadata = cli_ctx.GetServerInitialMetadata();
-  EXPECT_EQ(meta1.second, server_initial_metadata.find(meta1.first)->second);
-  EXPECT_EQ(meta2.second, server_initial_metadata.find(meta2.first)->second);
-  EXPECT_EQ(2, server_initial_metadata.size());
 }
 
 TEST_F(AsyncEnd2endTest, ServerTrailingMetadataRpc) {
@@ -435,8 +444,8 @@ TEST_F(AsyncEnd2endTest, ServerTrailingMetadataRpc) {
   std::pair<grpc::string, grpc::string> meta1("key1", "val1");
   std::pair<grpc::string, grpc::string> meta2("key2", "val2");
 
-  stub_->Echo(
-      &cli_ctx, send_request, &recv_response, &recv_status, &cli_cq_, tag(1));
+  std::unique_ptr<ClientAsyncResponseReader<EchoResponse> > response_reader(
+      stub_->Echo(&cli_ctx, send_request, &cli_cq_, tag(1)));
 
   service_.RequestEcho(
       &srv_ctx, &recv_request, &response_writer, &srv_cq_, tag(2));
@@ -444,6 +453,7 @@ TEST_F(AsyncEnd2endTest, ServerTrailingMetadataRpc) {
   EXPECT_EQ(send_request.message(), recv_request.message());
   response_writer.SendInitialMetadata(tag(3));
   server_ok(3);
+  client_ok(1);
 
   send_response.set_message(recv_request.message());
   srv_ctx.AddTrailingMetadata(meta1.first, meta1.second);
@@ -452,8 +462,9 @@ TEST_F(AsyncEnd2endTest, ServerTrailingMetadataRpc) {
 
   server_ok(4);
 
-  client_ok(1);
 
+  response_reader->Finish(&recv_response, &recv_status, tag(5));
+  client_ok(5);
   EXPECT_EQ(send_response.message(), recv_response.message());
   EXPECT_TRUE(recv_status.IsOk());
   auto server_trailing_metadata = cli_ctx.GetServerTrailingMetadata();
@@ -477,17 +488,20 @@ TEST_F(AsyncEnd2endTest, MetadataRpc) {
 
   send_request.set_message("Hello");
   std::pair<grpc::string, grpc::string> meta1("key1", "val1");
-  std::pair<grpc::string, grpc::string> meta2("key2-bin", {"\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc", 13});
+  std::pair<grpc::string, grpc::string> meta2(
+      "key2-bin", {"\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc", 13});
   std::pair<grpc::string, grpc::string> meta3("key3", "val3");
-  std::pair<grpc::string, grpc::string> meta6("key4-bin", {"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d", 14});
+  std::pair<grpc::string, grpc::string> meta6("key4-bin",
+      {"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d", 14});
   std::pair<grpc::string, grpc::string> meta5("key5", "val5");
-  std::pair<grpc::string, grpc::string> meta4("key6-bin", {"\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee", 15});
+  std::pair<grpc::string, grpc::string> meta4("key6-bin",
+      {"\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee", 15});
 
   cli_ctx.AddMetadata(meta1.first, meta1.second);
   cli_ctx.AddMetadata(meta2.first, meta2.second);
 
-  stub_->Echo(
-      &cli_ctx, send_request, &recv_response, &recv_status, &cli_cq_, tag(1));
+  std::unique_ptr<ClientAsyncResponseReader<EchoResponse> > response_reader(
+      stub_->Echo(&cli_ctx, send_request, &cli_cq_, tag(1)));
 
   service_.RequestEcho(
       &srv_ctx, &recv_request, &response_writer, &srv_cq_, tag(2));
@@ -497,27 +511,31 @@ TEST_F(AsyncEnd2endTest, MetadataRpc) {
   EXPECT_EQ(meta1.second, client_initial_metadata.find(meta1.first)->second);
   EXPECT_EQ(meta2.second, client_initial_metadata.find(meta2.first)->second);
   EXPECT_EQ(2, client_initial_metadata.size());
+  client_ok(1);
 
   srv_ctx.AddInitialMetadata(meta3.first, meta3.second);
   srv_ctx.AddInitialMetadata(meta4.first, meta4.second);
   response_writer.SendInitialMetadata(tag(3));
   server_ok(3);
+  response_reader->ReadInitialMetadata(tag(4));
+  client_ok(4);
+  auto server_initial_metadata = cli_ctx.GetServerInitialMetadata();
+  EXPECT_EQ(meta3.second, server_initial_metadata.find(meta3.first)->second);
+  EXPECT_EQ(meta4.second, server_initial_metadata.find(meta4.first)->second);
+  EXPECT_EQ(2, server_initial_metadata.size());
 
   send_response.set_message(recv_request.message());
   srv_ctx.AddTrailingMetadata(meta5.first, meta5.second);
   srv_ctx.AddTrailingMetadata(meta6.first, meta6.second);
-  response_writer.Finish(send_response, Status::OK, tag(4));
+  response_writer.Finish(send_response, Status::OK, tag(5));
 
-  server_ok(4);
+  server_ok(5);
 
-  client_ok(1);
 
+  response_reader->Finish(&recv_response, &recv_status, tag(6));
+  client_ok(6);
   EXPECT_EQ(send_response.message(), recv_response.message());
   EXPECT_TRUE(recv_status.IsOk());
-  auto server_initial_metadata = cli_ctx.GetServerInitialMetadata();
-  EXPECT_EQ(meta3.second, server_initial_metadata.find(meta3.first)->second);
-  EXPECT_EQ(meta4.second, server_initial_metadata.find(meta4.first)->second);
-  EXPECT_EQ(2, server_initial_metadata.size());
   auto server_trailing_metadata = cli_ctx.GetServerTrailingMetadata();
   EXPECT_EQ(meta5.second, server_trailing_metadata.find(meta5.first)->second);
   EXPECT_EQ(meta6.second, server_trailing_metadata.find(meta6.first)->second);
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 72a4b0cd12..64478b3753 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -62,15 +62,18 @@ class SimpleConfig(object):
 # ValgrindConfig: compile with some CONFIG=config, but use valgrind to run
 class ValgrindConfig(object):
 
-  def __init__(self, config, tool):
+  def __init__(self, config, tool, args=[]):
     self.build_config = config
     self.tool = tool
+    self.args = args
     self.maxjobs = 2 * multiprocessing.cpu_count()
     self.allow_hashing = False
 
   def job_spec(self, binary, hash_targets):
-    return jobset.JobSpec(cmdline=['valgrind', '--tool=%s' % self.tool, binary],
-                   hash_targets=None)
+    return jobset.JobSpec(cmdline=['valgrind', '--tool=%s' % self.tool] +
+                          self.args + [binary],
+                          shortname='valgrind %s' % binary,
+                          hash_targets=None)
 
 
 class CLanguage(object):
@@ -144,7 +147,7 @@ _CONFIGS = {
     'asan': SimpleConfig('asan', environ={
         'ASAN_OPTIONS': 'detect_leaks=1:color=always:suppressions=tools/tsan_suppressions.txt'}),
     'gcov': SimpleConfig('gcov'),
-    'memcheck': ValgrindConfig('valgrind', 'memcheck'),
+    'memcheck': ValgrindConfig('valgrind', 'memcheck', ['--leak-check=full']),
     'helgrind': ValgrindConfig('dbg', 'helgrind')
     }