Merge github.com:grpc/grpc into fuzz-me

183 files changed, 7253 insertions, 1843 deletions

diff --git a/src/compiler/config.h b/src/compiler/config.h
index d8b95818db..f2abb85186 100644
--- a/src/compiler/config.h
+++ b/src/compiler/config.h
@@ -34,8 +34,7 @@
 #ifndef SRC_COMPILER_CONFIG_H
 #define SRC_COMPILER_CONFIG_H
 
-#include <grpc++/support/config.h>
-#include <grpc++/support/config_protobuf.h>
+#include <grpc++/impl/codegen/config_protobuf.h>
 
 #ifndef GRPC_CUSTOM_DESCRIPTOR
 #include <google/protobuf/descriptor.h>
@@ -75,7 +74,15 @@
 #define GRPC_CUSTOM_PARSEGENERATORPARAMETER ::google::protobuf::compiler::ParseGeneratorParameter
 #endif
 
+#ifndef GRPC_CUSTOM_STRING
+#include <string>
+#define GRPC_CUSTOM_STRING std::string
+#endif
+
 namespace grpc {
+
+typedef GRPC_CUSTOM_STRING string;
+
 namespace protobuf {
 typedef GRPC_CUSTOM_DESCRIPTOR Descriptor;
 typedef GRPC_CUSTOM_FILEDESCRIPTOR FileDescriptor;
diff --git a/src/compiler/cpp_generator_helpers.h b/src/compiler/cpp_generator_helpers.h
index be68cbe695..87e278f1b9 100644
--- a/src/compiler/cpp_generator_helpers.h
+++ b/src/compiler/cpp_generator_helpers.h
@@ -65,6 +65,13 @@ inline grpc::string ClassName(const grpc::protobuf::Descriptor *descriptor,
   }
 }
 
+// Get leading or trailing comments in a string. Comment lines start with "// ".
+// Leading detached comments are put in in front of leading comments.
+template <typename DescriptorType>
+inline grpc::string GetCppComments(const DescriptorType *desc, bool leading) {
+  return grpc_generator::GetPrefixedComments(desc, leading, "//");
+}
+
 }  // namespace grpc_cpp_generator
 
 #endif  // GRPC_INTERNAL_COMPILER_CPP_GENERATOR_HELPERS_H
diff --git a/src/compiler/cpp_plugin.cc b/src/compiler/cpp_plugin.cc
index 0ec183e474..fc0296cd28 100644
--- a/src/compiler/cpp_plugin.cc
+++ b/src/compiler/cpp_plugin.cc
@@ -43,7 +43,7 @@
 #include "src/compiler/cpp_generator_helpers.h"
 #include "src/compiler/generator_helpers.h"
 
-using grpc_generator::GetCppComments;
+using grpc_cpp_generator::GetCppComments;
 
 class ProtoBufMethod : public grpc_cpp_generator::Method {
  public:
diff --git a/src/compiler/csharp_generator.cc b/src/compiler/csharp_generator.cc
index 29c359c539..fc8feaf0fc 100644
--- a/src/compiler/csharp_generator.cc
+++ b/src/compiler/csharp_generator.cc
@@ -52,7 +52,6 @@ using grpc::protobuf::MethodDescriptor;
 using grpc::protobuf::io::Printer;
 using grpc::protobuf::io::StringOutputStream;
 using grpc_generator::MethodType;
-using grpc_generator::GetCppComments;
 using grpc_generator::GetMethodType;
 using grpc_generator::METHODTYPE_NO_STREAMING;
 using grpc_generator::METHODTYPE_CLIENT_STREAMING;
@@ -120,18 +119,10 @@ std::string GetServiceClassName(const ServiceDescriptor* service) {
   return service->name();
 }
 
-std::string GetClientInterfaceName(const ServiceDescriptor* service) {
-  return "I" + service->name() + "Client";
-}
-
 std::string GetClientClassName(const ServiceDescriptor* service) {
   return service->name() + "Client";
 }
 
-std::string GetServerInterfaceName(const ServiceDescriptor* service) {
-  return "I" + service->name();
-}
-
 std::string GetServerClassName(const ServiceDescriptor* service) {
   return service->name() + "Base";
 }
@@ -303,86 +294,6 @@ void GenerateServiceDescriptorProperty(Printer* out, const ServiceDescriptor *se
   out->Print("\n");
 }
 
-void GenerateClientInterface(Printer* out, const ServiceDescriptor *service) {
-  out->Print("/// <summary>Client for $servicename$</summary>\n",
-             "servicename", GetServiceClassName(service));
-  out->Print("[System.Obsolete(\"Client side interfaced will be removed "
-             "in the next release. Use client class directly.\")]\n");
-  out->Print("public interface $name$\n", "name",
-             GetClientInterfaceName(service));
-  out->Print("{\n");
-  out->Indent();
-  for (int i = 0; i < service->method_count(); i++) {
-    const MethodDescriptor *method = service->method(i);
-    MethodType method_type = GetMethodType(method);
-
-    if (method_type == METHODTYPE_NO_STREAMING) {
-      // unary calls have an extra synchronous stub method
-      GenerateDocCommentBody(out, method);
-      out->Print(
-          "$response$ $methodname$($request$ request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));\n",
-          "methodname", method->name(), "request",
-          GetClassName(method->input_type()), "response",
-          GetClassName(method->output_type()));
-
-      // overload taking CallOptions as a param
-      GenerateDocCommentBody(out, method);
-      out->Print(
-          "$response$ $methodname$($request$ request, CallOptions options);\n",
-          "methodname", method->name(), "request",
-          GetClassName(method->input_type()), "response",
-          GetClassName(method->output_type()));
-    }
-
-    std::string method_name = method->name();
-    if (method_type == METHODTYPE_NO_STREAMING) {
-      method_name += "Async";  // prevent name clash with synchronous method.
-    }
-    GenerateDocCommentBody(out, method);
-    out->Print(
-        "$returntype$ $methodname$($request_maybe$Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));\n",
-        "methodname", method_name, "request_maybe",
-        GetMethodRequestParamMaybe(method), "returntype",
-        GetMethodReturnTypeClient(method));
-
-    // overload taking CallOptions as a param
-    GenerateDocCommentBody(out, method);
-    out->Print(
-        "$returntype$ $methodname$($request_maybe$CallOptions options);\n",
-        "methodname", method_name, "request_maybe",
-        GetMethodRequestParamMaybe(method), "returntype",
-        GetMethodReturnTypeClient(method));
-  }
-  out->Outdent();
-  out->Print("}\n");
-  out->Print("\n");
-}
-
-void GenerateServerInterface(Printer* out, const ServiceDescriptor *service) {
-  out->Print("/// <summary>Interface of server-side implementations of $servicename$</summary>\n",
-             "servicename", GetServiceClassName(service));
-  out->Print("[System.Obsolete(\"Service implementations should inherit"
-      " from the generated abstract base class instead.\")]\n");
-  out->Print("public interface $name$\n", "name",
-             GetServerInterfaceName(service));
-  out->Print("{\n");
-  out->Indent();
-  for (int i = 0; i < service->method_count(); i++) {
-    const MethodDescriptor *method = service->method(i);
-    GenerateDocCommentBody(out, method);
-    out->Print(
-        "$returntype$ $methodname$($request$$response_stream_maybe$, "
-        "ServerCallContext context);\n",
-        "methodname", method->name(), "returntype",
-        GetMethodReturnTypeServer(method), "request",
-        GetMethodRequestParamServer(method), "response_stream_maybe",
-        GetMethodResponseStreamMaybe(method));
-  }
-  out->Outdent();
-  out->Print("}\n");
-  out->Print("\n");
-}
-
 void GenerateServerClass(Printer* out, const ServiceDescriptor *service) {
   out->Print("/// <summary>Base class for server-side implementations of $servicename$</summary>\n",
              "servicename", GetServiceClassName(service));
@@ -415,12 +326,9 @@ void GenerateServerClass(Printer* out, const ServiceDescriptor *service) {
 void GenerateClientStub(Printer* out, const ServiceDescriptor *service) {
   out->Print("/// <summary>Client for $servicename$</summary>\n",
              "servicename", GetServiceClassName(service));
-  out->Print("#pragma warning disable 0618\n");
   out->Print(
-      "public class $name$ : ClientBase<$name$>, $interface$\n",
-      "name", GetClientClassName(service),
-      "interface", GetClientInterfaceName(service));
-  out->Print("#pragma warning restore 0618\n");
+      "public class $name$ : ClientBase<$name$>\n",
+      "name", GetClientClassName(service));
   out->Print("{\n");
   out->Indent();
 
@@ -547,22 +455,16 @@ void GenerateClientStub(Printer* out, const ServiceDescriptor *service) {
   out->Print("\n");
 }
 
-void GenerateBindServiceMethod(Printer* out, const ServiceDescriptor *service,
-                               bool use_server_class) {
+void GenerateBindServiceMethod(Printer* out, const ServiceDescriptor *service) {
   out->Print(
       "/// <summary>Creates service definition that can be registered with a server</summary>\n");
-  out->Print("#pragma warning disable 0618\n");
   out->Print(
-      "public static ServerServiceDefinition BindService($interface$ serviceImpl)\n",
-      "interface", use_server_class ? GetServerClassName(service) :
-          GetServerInterfaceName(service));
-  out->Print("#pragma warning restore 0618\n");
+      "public static ServerServiceDefinition BindService($implclass$ serviceImpl)\n",
+      "implclass", GetServerClassName(service));
   out->Print("{\n");
   out->Indent();
 
-  out->Print(
-      "return ServerServiceDefinition.CreateBuilder($servicenamefield$)\n",
-      "servicenamefield", GetServiceNameFieldName());
+  out->Print("return ServerServiceDefinition.CreateBuilder()\n");
   out->Indent();
   out->Indent();
   for (int i = 0; i < service->method_count(); i++) {
@@ -617,11 +519,7 @@ void GenerateService(Printer* out, const ServiceDescriptor *service,
   }
   GenerateServiceDescriptorProperty(out, service);
 
-  if (generate_client) {
-    GenerateClientInterface(out, service);
-  }
   if (generate_server) {
-    GenerateServerInterface(out, service);
     GenerateServerClass(out, service);
   }
   if (generate_client) {
@@ -629,8 +527,7 @@ void GenerateService(Printer* out, const ServiceDescriptor *service,
     GenerateNewStubMethods(out, service);
   }
   if (generate_server) {
-    GenerateBindServiceMethod(out, service, false);
-    GenerateBindServiceMethod(out, service, true);
+    GenerateBindServiceMethod(out, service);
   }
 
   out->Outdent();
@@ -659,7 +556,7 @@ grpc::string GetServices(const FileDescriptor *file, bool generate_client,
     out.Print("// source: $filename$\n", "filename", file->name());
 
     // use C++ style as there are no file-level XML comments in .NET
-    grpc::string leading_comments = GetCppComments(file, true);
+    grpc::string leading_comments = GetCsharpComments(file, true);
     if (!leading_comments.empty()) {
       out.Print("// Original file comments:\n");
       out.Print(leading_comments.c_str());
diff --git a/src/compiler/csharp_generator_helpers.h b/src/compiler/csharp_generator_helpers.h
index 5639ea058b..9bdf6fb535 100644
--- a/src/compiler/csharp_generator_helpers.h
+++ b/src/compiler/csharp_generator_helpers.h
@@ -45,6 +45,13 @@ inline bool ServicesFilename(const grpc::protobuf::FileDescriptor *file,
   return true;
 }
 
+// Get leading or trailing comments in a string. Comment lines start with "// ".
+// Leading detached comments are put in in front of leading comments.
+template <typename DescriptorType>
+inline grpc::string GetCsharpComments(const DescriptorType *desc, bool leading) {
+  return grpc_generator::GetPrefixedComments(desc, leading, "//");
+}
+
 }  // namespace grpc_csharp_generator
 
 #endif  // GRPC_INTERNAL_COMPILER_CSHARP_GENERATOR_HELPERS_H
diff --git a/src/compiler/generator_helpers.h b/src/compiler/generator_helpers.h
index bd077cf798..53391bc41a 100644
--- a/src/compiler/generator_helpers.h
+++ b/src/compiler/generator_helpers.h
@@ -265,10 +265,10 @@ inline grpc::string GenerateCommentsWithPrefix(
   return oss.str();
 }
 
-// Get leading or trailing comments in a string. Comment lines start with "// ".
-// Leading detached comments are put in in front of leading comments.
 template <typename DescriptorType>
-inline grpc::string GetCppComments(const DescriptorType *desc, bool leading) {
+inline grpc::string GetPrefixedComments(const DescriptorType *desc,
+                                        bool leading,
+                                        const grpc::string &prefix) {
   std::vector<grpc::string> out;
   if (leading) {
     grpc_generator::GetComment(
@@ -281,7 +281,7 @@ inline grpc::string GetCppComments(const DescriptorType *desc, bool leading) {
     grpc_generator::GetComment(desc, grpc_generator::COMMENTTYPE_TRAILING,
                                &out);
   }
-  return GenerateCommentsWithPrefix(out, "//");
+  return GenerateCommentsWithPrefix(out, prefix);
 }
 
 }  // namespace grpc_generator
diff --git a/src/compiler/node_generator.cc b/src/compiler/node_generator.cc
index 822622cccf..986b97c26e 100644
--- a/src/compiler/node_generator.cc
+++ b/src/compiler/node_generator.cc
@@ -181,62 +181,67 @@ void PrintMethod(const MethodDescriptor *method, Printer *out) {
 // Prints out the service descriptor object
 void PrintService(const ServiceDescriptor *service, Printer *out) {
   map<grpc::string, grpc::string> template_vars;
+  out->Print(GetNodeComments(service, true).c_str());
   template_vars["name"] = service->name();
   out->Print(template_vars, "var $name$Service = exports.$name$Service = {\n");
   out->Indent();
   for (int i = 0; i < service->method_count(); i++) {
     grpc::string method_name = grpc_generator::LowercaseFirstLetter(
         service->method(i)->name());
+    out->Print(GetNodeComments(service->method(i), true).c_str());
     out->Print("$method_name$: ",
                "method_name", method_name);
     PrintMethod(service->method(i), out);
     out->Print(",\n");
+    out->Print(GetNodeComments(service->method(i), false).c_str());
   }
   out->Outdent();
   out->Print("};\n\n");
   out->Print(template_vars, "exports.$name$Client = "
              "grpc.makeGenericClientConstructor($name$Service);\n");
+  out->Print(GetNodeComments(service, false).c_str());
 }
 
-}
-
-grpc::string GetImports(const FileDescriptor *file) {
-  grpc::string output;
-  {
-    StringOutputStream output_stream(&output);
-    Printer out(&output_stream, '$');
-
-    if (file->service_count() == 0) {
-      return output;
-    }
-
-    out.Print("// GENERATED CODE -- DO NOT EDIT!\n\n");
+void PrintImports(const FileDescriptor *file, Printer *out) {
+  out->Print("var grpc = require('grpc');\n");
+  if (file->message_type_count() > 0) {
+    grpc::string file_path = GetRelativePath(file->name(),
+                                             GetJSMessageFilename(
+                                                 file->name()));
+    out->Print("var $module_alias$ = require('$file_path$');\n",
+               "module_alias", ModuleAlias(file->name()),
+               "file_path", file_path);
+  }
 
-    out.Print("'use strict';\n");
+  for (int i = 0; i < file->dependency_count(); i++) {
+    grpc::string file_path = GetRelativePath(
+        file->name(), GetJSMessageFilename(file->dependency(i)->name()));
+    out->Print("var $module_alias$ = require('$file_path$');\n",
+               "module_alias", ModuleAlias(file->dependency(i)->name()),
+               "file_path", file_path);
+  }
+  out->Print("\n");
+}
 
-    out.Print("var grpc = require('grpc');\n");
-    if (file->message_type_count() > 0) {
-      grpc::string file_path = GetRelativePath(file->name(),
-                                               GetJSMessageFilename(
-                                                   file->name()));
-      out.Print("var $module_alias$ = require('$file_path$');\n",
-                "module_alias", ModuleAlias(file->name()),
-                "file_path", file_path);
-    }
+void PrintTransformers(const FileDescriptor *file, Printer *out) {
+  map<grpc::string, const Descriptor*> messages = GetAllMessages(file);
+  for (std::map<grpc::string, const Descriptor*>::iterator it =
+           messages.begin();
+       it != messages.end(); it++) {
+    PrintMessageTransformer(it->second, out);
+  }
+  out->Print("\n");
+}
 
-    for (int i = 0; i < file->dependency_count(); i++) {
-      grpc::string file_path = GetRelativePath(
-          file->name(), GetJSMessageFilename(file->dependency(i)->name()));
-      out.Print("var $module_alias$ = require('$file_path$');\n",
-                "module_alias", ModuleAlias(file->dependency(i)->name()),
-                "file_path", file_path);
-    }
-    out.Print("\n");
+void PrintServices(const FileDescriptor *file, Printer *out) {
+  for (int i = 0; i < file->service_count(); i++) {
+    PrintService(file->service(i), out);
   }
-  return output;
 }
 
-grpc::string GetTransformers(const FileDescriptor *file) {
+}
+
+grpc::string GenerateFile(const FileDescriptor *file) {
   grpc::string output;
   {
     StringOutputStream output_stream(&output);
@@ -245,31 +250,23 @@ grpc::string GetTransformers(const FileDescriptor *file) {
     if (file->service_count() == 0) {
       return output;
     }
+    out.Print("// GENERATED CODE -- DO NOT EDIT!\n\n");
 
-    map<grpc::string, const Descriptor*> messages = GetAllMessages(file);
-    for (std::map<grpc::string, const Descriptor*>::iterator it =
-             messages.begin();
-         it != messages.end(); it++) {
-      PrintMessageTransformer(it->second, &out);
+    grpc::string leading_comments = GetNodeComments(file, true);
+    if (!leading_comments.empty()) {
+      out.Print("// Original file comments:\n");
+      out.Print(leading_comments.c_str());
     }
-    out.Print("\n");
-  }
-  return output;
-}
 
-grpc::string GetServices(const FileDescriptor *file) {
-  grpc::string output;
-  {
-    StringOutputStream output_stream(&output);
-    Printer out(&output_stream, '$');
+    out.Print("'use strict';\n");
 
-    if (file->service_count() == 0) {
-      return output;
-    }
+    PrintImports(file, &out);
 
-    for (int i = 0; i < file->service_count(); i++) {
-      PrintService(file->service(i), &out);
-    }
+    PrintTransformers(file, &out);
+
+    PrintServices(file, &out);
+
+    out.Print(GetNodeComments(file, false).c_str());
   }
   return output;
 }
diff --git a/src/compiler/node_generator.h b/src/compiler/node_generator.h
index 249a0d011f..d7765e2d28 100644
--- a/src/compiler/node_generator.h
+++ b/src/compiler/node_generator.h
@@ -38,11 +38,7 @@
 
 namespace grpc_node_generator {
 
-grpc::string GetImports(const grpc::protobuf::FileDescriptor *file);
-
-grpc::string GetTransformers(const grpc::protobuf::FileDescriptor *file);
-
-grpc::string GetServices(const grpc::protobuf::FileDescriptor *file);
+grpc::string GenerateFile(const grpc::protobuf::FileDescriptor *file);
 
 }  // namespace grpc_node_generator
 
diff --git a/src/compiler/node_generator_helpers.h b/src/compiler/node_generator_helpers.h
index f41a2bcf59..5862772841 100644
--- a/src/compiler/node_generator_helpers.h
+++ b/src/compiler/node_generator_helpers.h
@@ -45,6 +45,13 @@ inline grpc::string GetJSServiceFilename(const grpc::string& filename) {
   return grpc_generator::StripProto(filename) + "_grpc_pb.js";
 }
 
+// Get leading or trailing comments in a string. Comment lines start with "// ".
+// Leading detached comments are put in in front of leading comments.
+template <typename DescriptorType>
+inline grpc::string GetNodeComments(const DescriptorType *desc, bool leading) {
+  return grpc_generator::GetPrefixedComments(desc, leading, "//");
+}
+
 }  // namespace grpc_node_generator
 
 #endif  // GRPC_INTERNAL_COMPILER_NODE_GENERATOR_HELPERS_H
diff --git a/src/compiler/node_plugin.cc b/src/compiler/node_plugin.cc
index ac5ced3558..39dfa77b8d 100644
--- a/src/compiler/node_plugin.cc
+++ b/src/compiler/node_plugin.cc
@@ -39,10 +39,8 @@
 #include "src/compiler/node_generator.h"
 #include "src/compiler/node_generator_helpers.h"
 
-using grpc_node_generator::GetImports;
+using grpc_node_generator::GenerateFile;
 using grpc_node_generator::GetJSServiceFilename;
-using grpc_node_generator::GetServices;
-using grpc_node_generator::GetTransformers;
 
 class NodeGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
  public:
@@ -53,9 +51,7 @@ class NodeGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
                 const grpc::string &parameter,
                 grpc::protobuf::compiler::GeneratorContext *context,
                 grpc::string *error) const {
-    grpc::string code = GetImports(file) +
-        GetTransformers(file) +
-        GetServices(file);
+    grpc::string code = GenerateFile(file);
     if (code.size() == 0) {
       return true;
     }
diff --git a/src/compiler/ruby_generator.cc b/src/compiler/ruby_generator.cc
index 936a186beb..1501c3f3e0 100644
--- a/src/compiler/ruby_generator.cc
+++ b/src/compiler/ruby_generator.cc
@@ -66,7 +66,9 @@ void PrintMethod(const MethodDescriptor *method, const grpc::string &package,
   std::map<grpc::string, grpc::string> method_vars =
       ListToDict({"mth.name", method->name(), "input.type", input_type,
                   "output.type", output_type, });
+  out->Print(GetRubyComments(method, true).c_str());
   out->Print(method_vars, "rpc :$mth.name$, $input.type$, $output.type$\n");
+  out->Print(GetRubyComments(method, false).c_str());
 }
 
 // Prints out the service using the ruby gRPC DSL.
@@ -82,12 +84,7 @@ void PrintService(const ServiceDescriptor *service, const grpc::string &package,
   out->Print(module_vars, "module $module.name$\n");
   out->Indent();
 
-  // TODO(temiola): add documentation
-  grpc::string doc = "TODO: add proto service documentation here";
-  std::map<grpc::string, grpc::string> template_vars =
-      ListToDict({"Documentation", doc, });
-  out->Print("\n");
-  out->Print(template_vars, "# $Documentation$\n");
+  out->Print(GetRubyComments(service, true).c_str());
   out->Print("class Service\n");
 
   // Write the indented class body.
@@ -113,6 +110,7 @@ void PrintService(const ServiceDescriptor *service, const grpc::string &package,
   // End the service module
   out->Outdent();
   out->Print("end\n");
+  out->Print(GetRubyComments(service, false).c_str());
 }
 
 }  // namespace
@@ -138,6 +136,12 @@ grpc::string GetServices(const FileDescriptor *file) {
     out.Print(header_comment_vars,
               "# Source: $file.name$ for package '$file.package$'\n");
 
+    grpc::string leading_comments = GetRubyComments(file, true);
+    if (!leading_comments.empty()) {
+      out.Print("# Original file comments:\n");
+      out.Print(leading_comments.c_str());
+    }
+
     out.Print("\n");
     out.Print("require 'grpc'\n");
     // Write out require statemment to import the separately generated file
@@ -164,6 +168,8 @@ grpc::string GetServices(const FileDescriptor *file) {
       out.Outdent();
       out.Print("end\n");
     }
+
+    out.Print(GetRubyComments(file, false).c_str());
   }
   return output;
 }
diff --git a/src/compiler/ruby_generator_helpers-inl.h b/src/compiler/ruby_generator_helpers-inl.h
index 9da7cab3c7..ff6939ed9f 100644
--- a/src/compiler/ruby_generator_helpers-inl.h
+++ b/src/compiler/ruby_generator_helpers-inl.h
@@ -35,6 +35,7 @@
 #define GRPC_INTERNAL_COMPILER_RUBY_GENERATOR_HELPERS_INL_H
 
 #include "src/compiler/config.h"
+#include "src/compiler/generator_helpers.h"
 #include "src/compiler/ruby_generator_string-inl.h"
 
 namespace grpc_ruby_generator {
@@ -60,6 +61,13 @@ inline grpc::string MessagesRequireName(
   return Replace(file->name(), ".proto", "");
 }
 
+// Get leading or trailing comments in a string. Comment lines start with "# ".
+// Leading detached comments are put in in front of leading comments.
+template <typename DescriptorType>
+inline grpc::string GetRubyComments(const DescriptorType *desc, bool leading) {
+  return grpc_generator::GetPrefixedComments(desc, leading, "#");
+}
+
 }  // namespace grpc_ruby_generator
 
 #endif  // GRPC_INTERNAL_COMPILER_RUBY_GENERATOR_HELPERS_INL_H
diff --git a/src/core/ext/census/grpc_filter.c b/src/core/ext/census/grpc_filter.c
index 5e278ef127..86ec2ae87a 100644
--- a/src/core/ext/census/grpc_filter.c
+++ b/src/core/ext/census/grpc_filter.c
@@ -134,7 +134,9 @@ static void client_init_call_elem(grpc_exec_ctx *exec_ctx,
 }
 
 static void client_destroy_call_elem(grpc_exec_ctx *exec_ctx,
-                                     grpc_call_element *elem, void *ignored) {
+                                     grpc_call_element *elem,
+                                     const grpc_call_stats *stats,
+                                     void *ignored) {
   call_data *d = elem->call_data;
   GPR_ASSERT(d != NULL);
   /* TODO(hongyu): record rpc client stats and census_rpc_end_op here */
@@ -152,7 +154,9 @@ static void server_init_call_elem(grpc_exec_ctx *exec_ctx,
 }
 
 static void server_destroy_call_elem(grpc_exec_ctx *exec_ctx,
-                                     grpc_call_element *elem, void *ignored) {
+                                     grpc_call_element *elem,
+                                     const grpc_call_stats *stats,
+                                     void *ignored) {
   call_data *d = elem->call_data;
   GPR_ASSERT(d != NULL);
   /* TODO(hongyu): record rpc server stats and census_tracing_end_op here */
@@ -176,7 +180,7 @@ const grpc_channel_filter grpc_client_census_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     client_init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     client_destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
@@ -189,7 +193,7 @@ const grpc_channel_filter grpc_server_census_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     server_init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     server_destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
diff --git a/src/core/ext/client_config/channel_connectivity.c b/src/core/ext/client_config/channel_connectivity.c
index 3ebc333608..cc60f2485a 100644
--- a/src/core/ext/client_config/channel_connectivity.c
+++ b/src/core/ext/client_config/channel_connectivity.c
@@ -62,7 +62,7 @@ grpc_connectivity_state grpc_channel_check_connectivity_state(
           "not a (u)client channel, but '%s'",
           client_channel_elem->filter->name);
   grpc_exec_ctx_finish(&exec_ctx);
-  return GRPC_CHANNEL_FATAL_FAILURE;
+  return GRPC_CHANNEL_SHUTDOWN;
 }
 
 typedef enum {
diff --git a/src/core/ext/client_config/client_channel.c b/src/core/ext/client_config/client_channel.c
index 9b5a078aec..e297dfa0ef 100644
--- a/src/core/ext/client_config/client_channel.c
+++ b/src/core/ext/client_config/client_channel.c
@@ -119,7 +119,7 @@ static void set_channel_connectivity_state_locked(grpc_exec_ctx *exec_ctx,
                                                   grpc_connectivity_state state,
                                                   const char *reason) {
   if ((state == GRPC_CHANNEL_TRANSIENT_FAILURE ||
-       state == GRPC_CHANNEL_FATAL_FAILURE) &&
+       state == GRPC_CHANNEL_SHUTDOWN) &&
       chand->lb_policy != NULL) {
     /* cancel fail-fast picks */
     grpc_lb_policy_cancel_picks(
@@ -136,8 +136,7 @@ static void on_lb_policy_state_changed_locked(
   /* check if the notification is for a stale policy */
   if (w->lb_policy != w->chand->lb_policy) return;
 
-  if (publish_state == GRPC_CHANNEL_FATAL_FAILURE &&
-      w->chand->resolver != NULL) {
+  if (publish_state == GRPC_CHANNEL_SHUTDOWN && w->chand->resolver != NULL) {
     publish_state = GRPC_CHANNEL_TRANSIENT_FAILURE;
     grpc_resolver_channel_saw_error(exec_ctx, w->chand->resolver);
     GRPC_LB_POLICY_UNREF(exec_ctx, w->chand->lb_policy, "channel");
@@ -145,7 +144,7 @@ static void on_lb_policy_state_changed_locked(
   }
   set_channel_connectivity_state_locked(exec_ctx, w->chand, publish_state,
                                         "lb_changed");
-  if (w->state != GRPC_CHANNEL_FATAL_FAILURE) {
+  if (w->state != GRPC_CHANNEL_SHUTDOWN) {
     watch_lb_policy(exec_ctx, w->chand, w->lb_policy, w->state);
   }
 }
@@ -237,7 +236,7 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
       chand->resolver = NULL;
     }
     set_channel_connectivity_state_locked(
-        exec_ctx, chand, GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone");
+        exec_ctx, chand, GRPC_CHANNEL_SHUTDOWN, "resolver_gone");
     gpr_mu_unlock(&chand->mu_config);
   }
 
@@ -292,8 +291,8 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
   }
 
   if (op->disconnect && chand->resolver != NULL) {
-    set_channel_connectivity_state_locked(
-        exec_ctx, chand, GRPC_CHANNEL_FATAL_FAILURE, "disconnect");
+    set_channel_connectivity_state_locked(exec_ctx, chand,
+                                          GRPC_CHANNEL_SHUTDOWN, "disconnect");
     grpc_resolver_shutdown(exec_ctx, chand->resolver);
     GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
     chand->resolver = NULL;
@@ -377,7 +376,7 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
     int r;
     GRPC_LB_POLICY_REF(lb_policy, "cc_pick_subchannel");
     gpr_mu_unlock(&chand->mu_config);
-    r = grpc_lb_policy_pick(exec_ctx, lb_policy, calld->pollset,
+    r = grpc_lb_policy_pick(exec_ctx, lb_policy, calld->pollent,
                             initial_metadata, initial_metadata_flags,
                             connected_subchannel, on_ready);
     GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "cc_pick_subchannel");
@@ -416,6 +415,7 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                              const grpc_call_stats *stats,
                               void *and_free_memory) {
   grpc_subchannel_call_holder_destroy(exec_ctx, elem->call_data);
   gpr_free(and_free_memory);
@@ -461,10 +461,11 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
   gpr_mu_destroy(&chand->mu_config);
 }
 
-static void cc_set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                           grpc_pollset *pollset) {
+static void cc_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                          grpc_call_element *elem,
+                                          grpc_polling_entity *pollent) {
   call_data *calld = elem->call_data;
-  calld->pollset = pollset;
+  calld->pollent = pollent;
 }
 
 const grpc_channel_filter grpc_client_channel_filter = {
@@ -472,7 +473,7 @@ const grpc_channel_filter grpc_client_channel_filter = {
     cc_start_transport_op,
     sizeof(call_data),
     init_call_elem,
-    cc_set_pollset,
+    cc_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
diff --git a/src/core/ext/client_config/lb_policy.c b/src/core/ext/client_config/lb_policy.c
index a7ad9842dc..20535398d6 100644
--- a/src/core/ext/client_config/lb_policy.c
+++ b/src/core/ext/client_config/lb_policy.c
@@ -99,12 +99,12 @@ void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx,
 }
 
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                        grpc_pollset *pollset,
+                        grpc_polling_entity *pollent,
                         grpc_metadata_batch *initial_metadata,
                         uint32_t initial_metadata_flags,
                         grpc_connected_subchannel **target,
                         grpc_closure *on_complete) {
-  return policy->vtable->pick(exec_ctx, policy, pollset, initial_metadata,
+  return policy->vtable->pick(exec_ctx, policy, pollent, initial_metadata,
                               initial_metadata_flags, target, on_complete);
 }
 
diff --git a/src/core/ext/client_config/lb_policy.h b/src/core/ext/client_config/lb_policy.h
index 0384e0b2eb..56fa11198b 100644
--- a/src/core/ext/client_config/lb_policy.h
+++ b/src/core/ext/client_config/lb_policy.h
@@ -35,6 +35,7 @@
 #define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H
 
 #include "src/core/ext/client_config/subchannel.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /** A load balancing policy: specified by a vtable and a struct (which
@@ -59,7 +60,8 @@ struct grpc_lb_policy_vtable {
 
   /** implement grpc_lb_policy_pick */
   int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-              grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+              grpc_polling_entity *pollent,
+              grpc_metadata_batch *initial_metadata,
               uint32_t initial_metadata_flags,
               grpc_connected_subchannel **target, grpc_closure *on_complete);
   void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
@@ -124,7 +126,7 @@ void grpc_lb_policy_init(grpc_lb_policy *policy,
     \a target.
     Picking can be asynchronous. Any IO should be done under \a pollset. */
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                        grpc_pollset *pollset,
+                        grpc_polling_entity *pollent,
                         grpc_metadata_batch *initial_metadata,
                         uint32_t initial_metadata_flags,
                         grpc_connected_subchannel **target,
diff --git a/src/core/ext/client_config/subchannel.c b/src/core/ext/client_config/subchannel.c
index cfd39e7cfb..85183b0564 100644
--- a/src/core/ext/client_config/subchannel.c
+++ b/src/core/ext/client_config/subchannel.c
@@ -480,11 +480,11 @@ static void subchannel_on_child_state_changed(grpc_exec_ctx *exec_ctx, void *p,
   if (iomgr_success) {
     if (sw->connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
       /* any errors on a subchannel ==> we're done, create a new one */
-      sw->connectivity_state = GRPC_CHANNEL_FATAL_FAILURE;
+      sw->connectivity_state = GRPC_CHANNEL_SHUTDOWN;
     }
     grpc_connectivity_state_set(exec_ctx, &c->state_tracker,
                                 sw->connectivity_state, "reflect_child");
-    if (sw->connectivity_state != GRPC_CHANNEL_FATAL_FAILURE) {
+    if (sw->connectivity_state != GRPC_CHANNEL_SHUTDOWN) {
       grpc_connected_subchannel_notify_on_state_change(
           exec_ctx, GET_CONNECTED_SUBCHANNEL(c, no_barrier), NULL,
           &sw->connectivity_state, &sw->closure);
@@ -645,7 +645,7 @@ static void subchannel_call_destroy(grpc_exec_ctx *exec_ctx, void *call,
   grpc_subchannel_call *c = call;
   GPR_TIMER_BEGIN("grpc_subchannel_call_unref.destroy", 0);
   grpc_connected_subchannel *connection = c->connection;
-  grpc_call_stack_destroy(exec_ctx, SUBCHANNEL_CALL_TO_CALL_STACK(c), c);
+  grpc_call_stack_destroy(exec_ctx, SUBCHANNEL_CALL_TO_CALL_STACK(c), NULL, c);
   GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, connection, "subchannel_call");
   GPR_TIMER_END("grpc_subchannel_call_unref.destroy", 0);
 }
@@ -683,7 +683,7 @@ grpc_connected_subchannel *grpc_subchannel_get_connected_subchannel(
 
 grpc_subchannel_call *grpc_connected_subchannel_create_call(
     grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *con,
-    grpc_pollset *pollset) {
+    grpc_polling_entity *pollent) {
   grpc_channel_stack *chanstk = CHANNEL_STACK_FROM_CONNECTION(con);
   grpc_subchannel_call *call =
       gpr_malloc(sizeof(grpc_subchannel_call) + chanstk->call_stack_size);
@@ -692,7 +692,7 @@ grpc_subchannel_call *grpc_connected_subchannel_create_call(
   GRPC_CONNECTED_SUBCHANNEL_REF(con, "subchannel_call");
   grpc_call_stack_init(exec_ctx, chanstk, 1, subchannel_call_destroy, call,
                        NULL, NULL, callstk);
-  grpc_call_stack_set_pollset(exec_ctx, callstk, pollset);
+  grpc_call_stack_set_pollset_or_pollset_set(exec_ctx, callstk, pollent);
   return call;
 }
 
diff --git a/src/core/ext/client_config/subchannel.h b/src/core/ext/client_config/subchannel.h
index 0765a544e8..525f854a44 100644
--- a/src/core/ext/client_config/subchannel.h
+++ b/src/core/ext/client_config/subchannel.h
@@ -36,6 +36,7 @@
 
 #include "src/core/ext/client_config/connector.h"
 #include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /** A (sub-)channel that knows how to connect to exactly one target
@@ -109,7 +110,7 @@ void grpc_subchannel_call_unref(grpc_exec_ctx *exec_ctx,
 /** construct a subchannel call */
 grpc_subchannel_call *grpc_connected_subchannel_create_call(
     grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *connected_subchannel,
-    grpc_pollset *pollset);
+    grpc_polling_entity *pollent);
 
 /** process a transport level op */
 void grpc_connected_subchannel_process_transport_op(
diff --git a/src/core/ext/client_config/subchannel_call_holder.c b/src/core/ext/client_config/subchannel_call_holder.c
index 91fa917661..3df1f254d6 100644
--- a/src/core/ext/client_config/subchannel_call_holder.c
+++ b/src/core/ext/client_config/subchannel_call_holder.c
@@ -68,6 +68,7 @@ void grpc_subchannel_call_holder_init(
   holder->waiting_ops_capacity = 0;
   holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
   holder->owning_call = owning_call;
+  holder->pollent = NULL;
 }
 
 void grpc_subchannel_call_holder_destroy(grpc_exec_ctx *exec_ctx,
@@ -157,7 +158,7 @@ retry:
     gpr_atm_rel_store(
         &holder->subchannel_call,
         (gpr_atm)(uintptr_t)grpc_connected_subchannel_create_call(
-            exec_ctx, holder->connected_subchannel, holder->pollset));
+            exec_ctx, holder->connected_subchannel, holder->pollent));
     retry_waiting_locked(exec_ctx, holder);
     goto retry;
   }
@@ -183,7 +184,7 @@ static void subchannel_ready(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
     gpr_atm_rel_store(
         &holder->subchannel_call,
         (gpr_atm)(uintptr_t)grpc_connected_subchannel_create_call(
-            exec_ctx, holder->connected_subchannel, holder->pollset));
+            exec_ctx, holder->connected_subchannel, holder->pollent));
     retry_waiting_locked(exec_ctx, holder);
   }
   gpr_mu_unlock(&holder->mu);
diff --git a/src/core/ext/client_config/subchannel_call_holder.h b/src/core/ext/client_config/subchannel_call_holder.h
index 9299908788..8d2deb02f3 100644
--- a/src/core/ext/client_config/subchannel_call_holder.h
+++ b/src/core/ext/client_config/subchannel_call_holder.h
@@ -35,6 +35,7 @@
 #define GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_CALL_HOLDER_H
 
 #include "src/core/ext/client_config/subchannel.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 
 /** Pick a subchannel for grpc_subchannel_call_holder;
     Return 1 if subchannel is available immediately (in which case on_ready
@@ -71,7 +72,7 @@ typedef struct grpc_subchannel_call_holder {
 
   grpc_subchannel_call_holder_creation_phase creation_phase;
   grpc_connected_subchannel *connected_subchannel;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
 
   grpc_transport_stream_op *waiting_ops;
   size_t waiting_ops_count;
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index 0d215cd196..cc559eb2da 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -39,7 +39,7 @@
 
 typedef struct pending_pick {
   struct pending_pick *next;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
   uint32_t initial_metadata_flags;
   grpc_connected_subchannel **target;
   grpc_closure *on_complete;
@@ -104,7 +104,7 @@ static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   pp = p->pending_picks;
   p->pending_picks = NULL;
   grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                              GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
+                              GRPC_CHANNEL_SHUTDOWN, "shutdown");
   /* cancel subscription */
   if (selected != NULL) {
     grpc_connected_subchannel_notify_on_state_change(
@@ -118,8 +118,8 @@ static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   while (pp != NULL) {
     pending_pick *next = pp->next;
     *pp->target = NULL;
-    grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                 pp->pollset);
+    grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                             p->base.interested_parties);
     grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
     gpr_free(pp);
     pp = next;
@@ -136,8 +136,8 @@ static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   while (pp != NULL) {
     pending_pick *next = pp->next;
     if (pp->target == target) {
-      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                   pp->pollset);
+      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                               p->base.interested_parties);
       *target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
@@ -162,8 +162,8 @@ static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                   pp->pollset);
+      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                               p->base.interested_parties);
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
     } else {
@@ -196,7 +196,8 @@ static void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 }
 
 static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                   grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+                   grpc_polling_entity *pollent,
+                   grpc_metadata_batch *initial_metadata,
                    uint32_t initial_metadata_flags,
                    grpc_connected_subchannel **target,
                    grpc_closure *on_complete) {
@@ -221,10 +222,11 @@ static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
+    grpc_polling_entity_add_to_pollset_set(exec_ctx, pollent,
+                                           p->base.interested_parties);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
-    pp->pollset = pollset;
+    pp->pollent = pollent;
     pp->target = target;
     pp->initial_metadata_flags = initial_metadata_flags;
     pp->on_complete = on_complete;
@@ -273,11 +275,11 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
   } else if (selected != NULL) {
     if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
       /* if the selected channel goes bad, we're done */
-      p->checking_connectivity = GRPC_CHANNEL_FATAL_FAILURE;
+      p->checking_connectivity = GRPC_CHANNEL_SHUTDOWN;
     }
     grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                 p->checking_connectivity, "selected_changed");
-    if (p->checking_connectivity != GRPC_CHANNEL_FATAL_FAILURE) {
+    if (p->checking_connectivity != GRPC_CHANNEL_SHUTDOWN) {
       grpc_connected_subchannel_notify_on_state_change(
           exec_ctx, selected, p->base.interested_parties,
           &p->checking_connectivity, &p->connectivity_changed);
@@ -304,8 +306,8 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
           *pp->target = selected;
-          grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                       pp->pollset);
+          grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                                   p->base.interested_parties);
           grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
           gpr_free(pp);
         }
@@ -343,7 +345,7 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
             p->base.interested_parties, &p->checking_connectivity,
             &p->connectivity_changed);
         break;
-      case GRPC_CHANNEL_FATAL_FAILURE:
+      case GRPC_CHANNEL_SHUTDOWN:
         p->num_subchannels--;
         GPR_SWAP(grpc_subchannel *, p->subchannels[p->checking_subchannel],
                  p->subchannels[p->num_subchannels]);
@@ -351,7 +353,7 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                               "pick_first");
         if (p->num_subchannels == 0) {
           grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                      GRPC_CHANNEL_FATAL_FAILURE,
+                                      GRPC_CHANNEL_SHUTDOWN,
                                       "no_more_channels");
           while ((pp = p->pending_picks)) {
             p->pending_picks = pp->next;
diff --git a/src/core/ext/lb_policy/round_robin/round_robin.c b/src/core/ext/lb_policy/round_robin/round_robin.c
index dcdc0c6285..8645333c8e 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -48,7 +48,7 @@ int grpc_lb_round_robin_trace = 0;
  * Once a pick is available, \a target is updated and \a on_complete called. */
 typedef struct pending_pick {
   struct pending_pick *next;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
   uint32_t initial_metadata_flags;
   grpc_connected_subchannel **target;
   grpc_closure *on_complete;
@@ -243,7 +243,7 @@ static void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     gpr_free(pp);
   }
   grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                              GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
+                              GRPC_CHANNEL_SHUTDOWN, "shutdown");
   for (i = 0; i < p->num_subchannels; i++) {
     subchannel_data *sd = p->subchannels[i];
     grpc_subchannel_notify_on_state_change(exec_ctx, sd->subchannel, NULL, NULL,
@@ -262,8 +262,8 @@ static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   while (pp != NULL) {
     pending_pick *next = pp->next;
     if (pp->target == target) {
-      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                   pp->pollset);
+      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                               p->base.interested_parties);
       *target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
@@ -288,8 +288,8 @@ static void rr_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                   pp->pollset);
+      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                               p->base.interested_parties);
       *pp->target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
@@ -331,7 +331,8 @@ static void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 }
 
 static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                   grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+                   grpc_polling_entity *pollent,
+                   grpc_metadata_batch *initial_metadata,
                    uint32_t initial_metadata_flags,
                    grpc_connected_subchannel **target,
                    grpc_closure *on_complete) {
@@ -354,10 +355,11 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
+    grpc_polling_entity_add_to_pollset_set(exec_ctx, pollent,
+                                           p->base.interested_parties);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
-    pp->pollset = pollset;
+    pp->pollent = pollent;
     pp->target = target;
     pp->on_complete = on_complete;
     pp->initial_metadata_flags = initial_metadata_flags;
@@ -406,8 +408,8 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                     "[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
                     selected->subchannel, selected);
           }
-          grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                       pp->pollset);
+          grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                                   p->base.interested_parties);
           grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
           gpr_free(pp);
         }
@@ -439,7 +441,7 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                                     GRPC_CHANNEL_TRANSIENT_FAILURE,
                                     "connecting_transient_failure");
         break;
-      case GRPC_CHANNEL_FATAL_FAILURE:
+      case GRPC_CHANNEL_SHUTDOWN:
         if (sd->ready_list_node != NULL) {
           remove_disconnected_sc_locked(p, sd->ready_list_node);
           sd->ready_list_node = NULL;
@@ -455,7 +457,7 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         unref = 1;
         if (p->num_subchannels == 0) {
           grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                      GRPC_CHANNEL_FATAL_FAILURE,
+                                      GRPC_CHANNEL_SHUTDOWN,
                                       "no_more_channels");
           while ((pp = p->pending_picks)) {
             p->pending_picks = pp->next;
diff --git a/src/core/ext/load_reporting/load_reporting.c b/src/core/ext/load_reporting/load_reporting.c
new file mode 100644
index 0000000000..60082dbaaa
--- /dev/null
+++ b/src/core/ext/load_reporting/load_reporting.c
@@ -0,0 +1,132 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <limits.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/sync.h>
+
+#include "src/core/ext/load_reporting/load_reporting.h"
+#include "src/core/ext/load_reporting/load_reporting_filter.h"
+#include "src/core/lib/channel/channel_stack_builder.h"
+#include "src/core/lib/surface/channel_init.h"
+
+struct grpc_load_reporting_config {
+  grpc_load_reporting_fn fn;
+  void *user_data;
+};
+
+grpc_load_reporting_config *grpc_load_reporting_config_create(
+    grpc_load_reporting_fn fn, void *user_data) {
+  GPR_ASSERT(fn != NULL);
+  grpc_load_reporting_config *lrc =
+      gpr_malloc(sizeof(grpc_load_reporting_config));
+  lrc->fn = fn;
+  lrc->user_data = user_data;
+  return lrc;
+}
+
+grpc_load_reporting_config *grpc_load_reporting_config_copy(
+    grpc_load_reporting_config *src) {
+  return grpc_load_reporting_config_create(src->fn, src->user_data);
+}
+
+void grpc_load_reporting_config_destroy(grpc_load_reporting_config *lrc) {
+  gpr_free(lrc);
+}
+
+void grpc_load_reporting_config_call(
+    grpc_load_reporting_config *lrc,
+    const grpc_load_reporting_call_data *call_data) {
+  lrc->fn(call_data, lrc->user_data);
+}
+
+static bool is_load_reporting_enabled(const grpc_channel_args *a) {
+  if (a == NULL) return false;
+  for (size_t i = 0; i < a->num_args; i++) {
+    if (0 == strcmp(a->args[i].key, GRPC_ARG_ENABLE_LOAD_REPORTING)) {
+      return a->args[i].value.pointer.p != NULL;
+    }
+  }
+  return false;
+}
+
+static bool maybe_add_load_reporting_filter(grpc_channel_stack_builder *builder,
+                                            void *arg) {
+  const grpc_channel_args *args =
+      grpc_channel_stack_builder_get_channel_arguments(builder);
+  if (is_load_reporting_enabled(args)) {
+    return grpc_channel_stack_builder_prepend_filter(
+        builder, (const grpc_channel_filter *)arg, NULL, NULL);
+  }
+  return true;
+}
+
+static void lrd_arg_destroy(void *p) { grpc_load_reporting_config_destroy(p); }
+
+static void *lrd_arg_copy(void *p) {
+  return grpc_load_reporting_config_copy(p);
+}
+
+static int lrd_arg_cmp(void *a, void *b) {
+  grpc_load_reporting_config *lhs = a;
+  grpc_load_reporting_config *rhs = b;
+  return !(lhs->fn == rhs->fn && lhs->user_data == rhs->user_data);
+}
+
+static const grpc_arg_pointer_vtable lrd_ptr_vtable = {
+    lrd_arg_copy, lrd_arg_destroy, lrd_arg_cmp};
+
+grpc_arg grpc_load_reporting_config_create_arg(
+    grpc_load_reporting_config *lrc) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_POINTER;
+  arg.key = GRPC_ARG_ENABLE_LOAD_REPORTING;
+  arg.value.pointer.p = lrc;
+  arg.value.pointer.vtable = &lrd_ptr_vtable;
+  return arg;
+}
+
+/* Plugin registration */
+
+void grpc_load_reporting_plugin_init(void) {
+  grpc_channel_init_register_stage(GRPC_CLIENT_CHANNEL, INT_MAX,
+                                   maybe_add_load_reporting_filter,
+                                   (void *)&grpc_load_reporting_filter);
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
+                                   maybe_add_load_reporting_filter,
+                                   (void *)&grpc_load_reporting_filter);
+}
+
+void grpc_load_reporting_plugin_shutdown() {}
diff --git a/src/core/ext/load_reporting/load_reporting.h b/src/core/ext/load_reporting/load_reporting.h
new file mode 100644
index 0000000000..316cd89bd7
--- /dev/null
+++ b/src/core/ext/load_reporting/load_reporting.h
@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H
+#define GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H
+
+#include "src/core/lib/iomgr/closure.h"
+#include "src/core/lib/surface/call.h"
+
+typedef struct grpc_load_reporting_config grpc_load_reporting_config;
+
+/** Call information to be passed to the provided load reporting function upon
+ * completion of the call */
+typedef struct grpc_load_reporting_call_data {
+  const grpc_call_stats *stats;   /**< Stats for the call */
+  const char *trailing_md_string; /**< LR trailing metadata info */
+} grpc_load_reporting_call_data;
+
+/** Custom function to be called by the load reporting filter. */
+typedef void (*grpc_load_reporting_fn)(
+    const grpc_load_reporting_call_data *call_data, void *user_data);
+
+/** Register \a fn as the function to be invoked by the load reporting filter.
+ * \a fn will be invoked at the beginning and at the end of the call.
+ *
+ * For the first invocation, \a fn's first argument
+ * (grpc_load_reporting_call_data*) will be NULL. \a user_data is always passed
+ * as-is. */
+grpc_load_reporting_config *grpc_load_reporting_config_create(
+    grpc_load_reporting_fn fn, void *user_data);
+
+grpc_load_reporting_config *grpc_load_reporting_config_copy(
+    grpc_load_reporting_config *src);
+
+void grpc_load_reporting_config_destroy(grpc_load_reporting_config *lrc);
+
+/** Invoke the function registered by \a grpc_load_reporting_init. */
+void grpc_load_reporting_config_call(
+    grpc_load_reporting_config *lrc,
+    const grpc_load_reporting_call_data *call_data);
+
+/** Return a \a grpc_arg enabling load reporting */
+grpc_arg grpc_load_reporting_config_create_arg(grpc_load_reporting_config *lrc);
+
+#endif /* GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H */
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
new file mode 100644
index 0000000000..f372f88c3a
--- /dev/null
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -0,0 +1,151 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/sync.h>
+#include <string.h>
+
+#include "src/core/ext/load_reporting/load_reporting.h"
+#include "src/core/ext/load_reporting/load_reporting_filter.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/transport/static_metadata.h"
+
+typedef struct call_data { const char *trailing_md_string; } call_data;
+typedef struct channel_data {
+  gpr_mu mu;
+  grpc_load_reporting_config *lrc;
+} channel_data;
+
+static void invoke_lr_fn_locked(grpc_load_reporting_config *lrc,
+                                grpc_load_reporting_call_data *lr_call_data) {
+  GPR_TIMER_BEGIN("load_reporting_config_fn", 0);
+  grpc_load_reporting_config_call(lrc, lr_call_data);
+  GPR_TIMER_END("load_reporting_config_fn", 0);
+}
+
+/* Constructor for call_data */
+static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                           grpc_call_element_args *args) {
+  call_data *calld = elem->call_data;
+  memset(calld, 0, sizeof(call_data));
+}
+
+/* Destructor for call_data */
+static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                              const grpc_call_stats *stats, void *ignored) {
+  channel_data *chand = elem->channel_data;
+  call_data *calld = elem->call_data;
+
+  grpc_load_reporting_call_data lr_call_data = {stats,
+                                                calld->trailing_md_string};
+
+  gpr_mu_lock(&chand->mu);
+  invoke_lr_fn_locked(chand->lrc, &lr_call_data);
+  gpr_mu_unlock(&chand->mu);
+}
+
+/* Constructor for channel_data */
+static void init_channel_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_channel_element *elem,
+                              grpc_channel_element_args *args) {
+  GPR_ASSERT(!args->is_last);
+
+  channel_data *chand = elem->channel_data;
+  memset(chand, 0, sizeof(channel_data));
+
+  gpr_mu_init(&chand->mu);
+  for (size_t i = 0; i < args->channel_args->num_args; i++) {
+    if (0 == strcmp(args->channel_args->args[i].key,
+                    GRPC_ARG_ENABLE_LOAD_REPORTING)) {
+      grpc_load_reporting_config *arg_lrc =
+          args->channel_args->args[i].value.pointer.p;
+      chand->lrc = grpc_load_reporting_config_copy(arg_lrc);
+      GPR_ASSERT(chand->lrc != NULL);
+      break;
+    }
+  }
+  GPR_ASSERT(chand->lrc != NULL); /* arg actually found */
+
+  gpr_mu_lock(&chand->mu);
+  invoke_lr_fn_locked(chand->lrc, NULL);
+  gpr_mu_unlock(&chand->mu);
+}
+
+/* Destructor for channel data */
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {
+  channel_data *chand = elem->channel_data;
+  gpr_mu_destroy(&chand->mu);
+  grpc_load_reporting_config_destroy(chand->lrc);
+}
+
+static grpc_mdelem *lr_trailing_md_filter(void *user_data, grpc_mdelem *md) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+
+  if (md->key == GRPC_MDSTR_LOAD_REPORTING) {
+    calld->trailing_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
+    return NULL;
+  }
+
+  return md;
+}
+
+static void lr_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
+                                         grpc_call_element *elem,
+                                         grpc_transport_stream_op *op) {
+  GPR_TIMER_BEGIN("lr_start_transport_stream_op", 0);
+
+  if (op->send_trailing_metadata) {
+    grpc_metadata_batch_filter(op->send_trailing_metadata,
+                               lr_trailing_md_filter, elem);
+  }
+  grpc_call_next_op(exec_ctx, elem, op);
+
+  GPR_TIMER_END("lr_start_transport_stream_op", 0);
+}
+
+const grpc_channel_filter grpc_load_reporting_filter = {
+    lr_start_transport_stream_op,
+    grpc_channel_next_op,
+    sizeof(call_data),
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    "load_reporting"};
diff --git a/src/core/ext/load_reporting/load_reporting_filter.h b/src/core/ext/load_reporting/load_reporting_filter.h
new file mode 100644
index 0000000000..f69cd6fdc6
--- /dev/null
+++ b/src/core/ext/load_reporting/load_reporting_filter.h
@@ -0,0 +1,41 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_FILTER_H
+#define GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_FILTER_H
+
+#include "src/core/lib/channel/channel_stack.h"
+
+extern const grpc_channel_filter grpc_load_reporting_filter;
+
+#endif /* GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_FILTER_H */
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index d531d215e9..63fd8dbf1b 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -444,7 +444,7 @@ static void close_transport_locked(grpc_exec_ctx *exec_ctx,
                                    void *arg_ignored) {
   if (!t->closed) {
     t->closed = 1;
-    connectivity_state_set(exec_ctx, &t->global, GRPC_CHANNEL_FATAL_FAILURE,
+    connectivity_state_set(exec_ctx, &t->global, GRPC_CHANNEL_SHUTDOWN,
                            "close_transport");
     if (t->ep) {
       allow_endpoint_shutdown_locked(exec_ctx, t);
@@ -1428,93 +1428,95 @@ static void close_from_api(grpc_exec_ctx *exec_ctx,
 
   GPR_ASSERT(status >= 0 && (int)status < 100);
 
-  GPR_ASSERT(stream_global->id != 0);
-
-  /* Hand roll a header block.
-     This is unnecessarily ugly - at some point we should find a more elegant
-     solution.
-     It's complicated by the fact that our send machinery would be dead by the
-     time we got around to sending this, so instead we ignore HPACK compression
-     and just write the uncompressed bytes onto the wire. */
-  status_hdr = gpr_slice_malloc(15 + (status >= 10));
-  p = GPR_SLICE_START_PTR(status_hdr);
-  *p++ = 0x40; /* literal header */
-  *p++ = 11;   /* len(grpc-status) */
-  *p++ = 'g';
-  *p++ = 'r';
-  *p++ = 'p';
-  *p++ = 'c';
-  *p++ = '-';
-  *p++ = 's';
-  *p++ = 't';
-  *p++ = 'a';
-  *p++ = 't';
-  *p++ = 'u';
-  *p++ = 's';
-  if (status < 10) {
-    *p++ = 1;
-    *p++ = (uint8_t)('0' + status);
-  } else {
-    *p++ = 2;
-    *p++ = (uint8_t)('0' + (status / 10));
-    *p++ = (uint8_t)('0' + (status % 10));
-  }
-  GPR_ASSERT(p == GPR_SLICE_END_PTR(status_hdr));
-  len += (uint32_t)GPR_SLICE_LENGTH(status_hdr);
-
-  if (optional_message) {
-    GPR_ASSERT(GPR_SLICE_LENGTH(*optional_message) < 127);
-    message_pfx = gpr_slice_malloc(15);
-    p = GPR_SLICE_START_PTR(message_pfx);
-    *p++ = 0x40;
-    *p++ = 12; /* len(grpc-message) */
+  if (stream_global->id != 0 && !transport_global->is_client) {
+    /* Hand roll a header block.
+       This is unnecessarily ugly - at some point we should find a more elegant
+       solution.
+       It's complicated by the fact that our send machinery would be dead by the
+       time we got around to sending this, so instead we ignore HPACK
+       compression
+       and just write the uncompressed bytes onto the wire. */
+    status_hdr = gpr_slice_malloc(15 + (status >= 10));
+    p = GPR_SLICE_START_PTR(status_hdr);
+    *p++ = 0x40; /* literal header */
+    *p++ = 11;   /* len(grpc-status) */
     *p++ = 'g';
     *p++ = 'r';
     *p++ = 'p';
     *p++ = 'c';
     *p++ = '-';
-    *p++ = 'm';
-    *p++ = 'e';
-    *p++ = 's';
     *p++ = 's';
+    *p++ = 't';
     *p++ = 'a';
-    *p++ = 'g';
-    *p++ = 'e';
-    *p++ = (uint8_t)GPR_SLICE_LENGTH(*optional_message);
-    GPR_ASSERT(p == GPR_SLICE_END_PTR(message_pfx));
-    len += (uint32_t)GPR_SLICE_LENGTH(message_pfx);
-    len += (uint32_t)GPR_SLICE_LENGTH(*optional_message);
-  }
-
-  hdr = gpr_slice_malloc(9);
-  p = GPR_SLICE_START_PTR(hdr);
-  *p++ = (uint8_t)(len >> 16);
-  *p++ = (uint8_t)(len >> 8);
-  *p++ = (uint8_t)(len);
-  *p++ = GRPC_CHTTP2_FRAME_HEADER;
-  *p++ = GRPC_CHTTP2_DATA_FLAG_END_STREAM | GRPC_CHTTP2_DATA_FLAG_END_HEADERS;
-  *p++ = (uint8_t)(stream_global->id >> 24);
-  *p++ = (uint8_t)(stream_global->id >> 16);
-  *p++ = (uint8_t)(stream_global->id >> 8);
-  *p++ = (uint8_t)(stream_global->id);
-  GPR_ASSERT(p == GPR_SLICE_END_PTR(hdr));
-
-  gpr_slice_buffer_add(&transport_global->qbuf, hdr);
-  gpr_slice_buffer_add(&transport_global->qbuf, status_hdr);
-  if (optional_message) {
-    gpr_slice_buffer_add(&transport_global->qbuf, message_pfx);
-    gpr_slice_buffer_add(&transport_global->qbuf,
-                         gpr_slice_ref(*optional_message));
-  }
-
-  gpr_slice_buffer_add(
-      &transport_global->qbuf,
-      grpc_chttp2_rst_stream_create(stream_global->id, GRPC_CHTTP2_NO_ERROR,
-                                    &stream_global->stats.outgoing));
-
-  if (optional_message) {
-    gpr_slice_ref(*optional_message);
+    *p++ = 't';
+    *p++ = 'u';
+    *p++ = 's';
+    if (status < 10) {
+      *p++ = 1;
+      *p++ = (uint8_t)('0' + status);
+    } else {
+      *p++ = 2;
+      *p++ = (uint8_t)('0' + (status / 10));
+      *p++ = (uint8_t)('0' + (status % 10));
+    }
+    GPR_ASSERT(p == GPR_SLICE_END_PTR(status_hdr));
+    len += (uint32_t)GPR_SLICE_LENGTH(status_hdr);
+
+    if (optional_message) {
+      GPR_ASSERT(GPR_SLICE_LENGTH(*optional_message) < 127);
+      message_pfx = gpr_slice_malloc(15);
+      p = GPR_SLICE_START_PTR(message_pfx);
+      *p++ = 0x40;
+      *p++ = 12; /* len(grpc-message) */
+      *p++ = 'g';
+      *p++ = 'r';
+      *p++ = 'p';
+      *p++ = 'c';
+      *p++ = '-';
+      *p++ = 'm';
+      *p++ = 'e';
+      *p++ = 's';
+      *p++ = 's';
+      *p++ = 'a';
+      *p++ = 'g';
+      *p++ = 'e';
+      *p++ = (uint8_t)GPR_SLICE_LENGTH(*optional_message);
+      GPR_ASSERT(p == GPR_SLICE_END_PTR(message_pfx));
+      len += (uint32_t)GPR_SLICE_LENGTH(message_pfx);
+      len += (uint32_t)GPR_SLICE_LENGTH(*optional_message);
+    }
+
+    hdr = gpr_slice_malloc(9);
+    p = GPR_SLICE_START_PTR(hdr);
+    *p++ = (uint8_t)(len >> 16);
+    *p++ = (uint8_t)(len >> 8);
+    *p++ = (uint8_t)(len);
+    *p++ = GRPC_CHTTP2_FRAME_HEADER;
+    *p++ = GRPC_CHTTP2_DATA_FLAG_END_STREAM | GRPC_CHTTP2_DATA_FLAG_END_HEADERS;
+    *p++ = (uint8_t)(stream_global->id >> 24);
+    *p++ = (uint8_t)(stream_global->id >> 16);
+    *p++ = (uint8_t)(stream_global->id >> 8);
+    *p++ = (uint8_t)(stream_global->id);
+    GPR_ASSERT(p == GPR_SLICE_END_PTR(hdr));
+
+    gpr_slice_buffer_add(&transport_global->qbuf, hdr);
+    gpr_slice_buffer_add(&transport_global->qbuf, status_hdr);
+    if (optional_message) {
+      gpr_slice_buffer_add(&transport_global->qbuf, message_pfx);
+      gpr_slice_buffer_add(&transport_global->qbuf,
+                           gpr_slice_ref(*optional_message));
+    }
+
+    gpr_slice_buffer_add(
+        &transport_global->qbuf,
+        grpc_chttp2_rst_stream_create(stream_global->id, GRPC_CHTTP2_NO_ERROR,
+                                      &stream_global->stats.outgoing));
+
+    if (optional_message) {
+      gpr_slice_ref(*optional_message);
+    }
   }
+
   grpc_chttp2_fake_status(exec_ctx, transport_global, stream_global, status,
                           optional_message);
   grpc_chttp2_mark_stream_closed(exec_ctx, transport_global, stream_global, 1,
@@ -1734,6 +1736,13 @@ static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                                    add_to_pollset_locked, pollset, 0);
 }
 
+static void set_pollset_set(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
+                            grpc_stream *gs, grpc_pollset_set *pollset_set) {
+  grpc_chttp2_run_with_global_lock(exec_ctx, (grpc_chttp2_transport *)gt,
+                                   (grpc_chttp2_stream *)gs,
+                                   add_to_pollset_set_locked, pollset_set, 0);
+}
+
 /*******************************************************************************
  * BYTE STREAM
  */
@@ -2055,6 +2064,7 @@ static const grpc_transport_vtable vtable = {sizeof(grpc_chttp2_stream),
                                              "chttp2",
                                              init_stream,
                                              set_pollset,
+                                             set_pollset_set,
                                              perform_stream_op,
                                              perform_transport_op,
                                              destroy_stream,
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.c b/src/core/ext/transport/cronet/transport/cronet_transport.c
index df160aaaf6..1bb53b756c 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.c
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.c
@@ -152,6 +152,10 @@ static void next_recv_step(stream_obj *s, enum e_caller caller);
 static void set_pollset_do_nothing(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                                    grpc_stream *gs, grpc_pollset *pollset) {}
 
+static void set_pollset_set_do_nothing(grpc_exec_ctx *exec_ctx,
+                                       grpc_transport *gt, grpc_stream *gs,
+                                       grpc_pollset_set *pollset_set) {}
+
 static void enqueue_callbacks(grpc_closure *callback_list[]) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   if (callback_list[0]) {
@@ -646,7 +650,13 @@ static void destroy_transport(grpc_exec_ctx *exec_ctx, grpc_transport *gt) {
   }
 }
 
-const grpc_transport_vtable grpc_cronet_vtable = {
-    sizeof(stream_obj),     "cronet_http",     init_stream,
-    set_pollset_do_nothing, perform_stream_op, NULL,
-    destroy_stream,         destroy_transport, NULL};
+const grpc_transport_vtable grpc_cronet_vtable = {sizeof(stream_obj),
+                                                  "cronet_http",
+                                                  init_stream,
+                                                  set_pollset_do_nothing,
+                                                  set_pollset_set_do_nothing,
+                                                  perform_stream_op,
+                                                  NULL,
+                                                  destroy_stream,
+                                                  destroy_transport,
+                                                  NULL};
diff --git a/src/core/lib/channel/channel_stack.c b/src/core/lib/channel/channel_stack.c
index ad182d1f69..5c161652ac 100644
--- a/src/core/lib/channel/channel_stack.c
+++ b/src/core/lib/channel/channel_stack.c
@@ -189,9 +189,9 @@ void grpc_call_stack_init(grpc_exec_ctx *exec_ctx,
   }
 }
 
-void grpc_call_stack_set_pollset(grpc_exec_ctx *exec_ctx,
-                                 grpc_call_stack *call_stack,
-                                 grpc_pollset *pollset) {
+void grpc_call_stack_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                                grpc_call_stack *call_stack,
+                                                grpc_polling_entity *pollent) {
   size_t count = call_stack->count;
   grpc_call_element *call_elems;
   char *user_data;
@@ -203,17 +203,19 @@ void grpc_call_stack_set_pollset(grpc_exec_ctx *exec_ctx,
 
   /* init per-filter data */
   for (i = 0; i < count; i++) {
-    call_elems[i].filter->set_pollset(exec_ctx, &call_elems[i], pollset);
+    call_elems[i].filter->set_pollset_or_pollset_set(exec_ctx, &call_elems[i],
+                                                     pollent);
     user_data +=
         ROUND_UP_TO_ALIGNMENT_SIZE(call_elems[i].filter->sizeof_call_data);
   }
 }
 
-void grpc_call_stack_ignore_set_pollset(grpc_exec_ctx *exec_ctx,
-                                        grpc_call_element *elem,
-                                        grpc_pollset *pollset) {}
+void grpc_call_stack_ignore_set_pollset_or_pollset_set(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_polling_entity *pollent) {}
 
 void grpc_call_stack_destroy(grpc_exec_ctx *exec_ctx, grpc_call_stack *stack,
+                             const grpc_call_stats *call_stats,
                              void *and_free_memory) {
   grpc_call_element *elems = CALL_ELEMS_FROM_STACK(stack);
   size_t count = stack->count;
@@ -221,7 +223,7 @@ void grpc_call_stack_destroy(grpc_exec_ctx *exec_ctx, grpc_call_stack *stack,
 
   /* destroy per-filter data */
   for (i = 0; i < count; i++) {
-    elems[i].filter->destroy_call_elem(exec_ctx, &elems[i],
+    elems[i].filter->destroy_call_elem(exec_ctx, &elems[i], call_stats,
                                        i == count - 1 ? and_free_memory : NULL);
   }
 }
diff --git a/src/core/lib/channel/channel_stack.h b/src/core/lib/channel/channel_stack.h
index 36c17cb467..3ca643c893 100644
--- a/src/core/lib/channel/channel_stack.h
+++ b/src/core/lib/channel/channel_stack.h
@@ -45,7 +45,10 @@
 
 #include <grpc/grpc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/time.h>
+
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/transport.h"
 
 typedef struct grpc_channel_element grpc_channel_element;
@@ -67,6 +70,12 @@ typedef struct {
   grpc_call_context_element *context;
 } grpc_call_element_args;
 
+typedef struct {
+  grpc_transport_stream_stats transport_stream_stats;
+  gpr_timespec latency; /* From call creating to enqueing of received status */
+  grpc_status_code final_status;
+} grpc_call_stats;
+
 /* Channel filters specify:
    1. the amount of memory needed in the channel & call (via the sizeof_XXX
       members)
@@ -101,14 +110,16 @@ typedef struct {
      argument. */
   void (*init_call_elem)(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                          grpc_call_element_args *args);
-  void (*set_pollset)(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                      grpc_pollset *pollset);
+  void (*set_pollset_or_pollset_set)(grpc_exec_ctx *exec_ctx,
+                                     grpc_call_element *elem,
+                                     grpc_polling_entity *pollent);
   /* Destroy per call data.
      The filter does not need to do any chaining.
      The bottom filter of a stack will be passed a non-NULL pointer to
      \a and_free_memory that should be passed to gpr_free when destruction
      is complete. */
   void (*destroy_call_elem)(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                            const grpc_call_stats *stats,
                             void *and_free_memory);
 
   /* sizeof(per channel data) */
@@ -201,10 +212,11 @@ void grpc_call_stack_init(grpc_exec_ctx *exec_ctx,
                           grpc_call_context_element *context,
                           const void *transport_server_data,
                           grpc_call_stack *call_stack);
-/* Set a pollset for a call stack: must occur before the first op is started */
-void grpc_call_stack_set_pollset(grpc_exec_ctx *exec_ctx,
-                                 grpc_call_stack *call_stack,
-                                 grpc_pollset *pollset);
+/* Set a pollset or a pollset_set for a call stack: must occur before the first
+ * op is started */
+void grpc_call_stack_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                                grpc_call_stack *call_stack,
+                                                grpc_polling_entity *pollent);
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
 #define GRPC_CALL_STACK_REF(call_stack, reason) \
@@ -228,13 +240,14 @@ void grpc_call_stack_set_pollset(grpc_exec_ctx *exec_ctx,
 
 /* Destroy a call stack */
 void grpc_call_stack_destroy(grpc_exec_ctx *exec_ctx, grpc_call_stack *stack,
+                             const grpc_call_stats *call_stats,
                              void *and_free_memory);
 
-/* Ignore set pollset - used by filters to implement the set_pollset method
-   if they don't care about pollsets at all. Does nothing. */
-void grpc_call_stack_ignore_set_pollset(grpc_exec_ctx *exec_ctx,
-                                        grpc_call_element *elem,
-                                        grpc_pollset *pollset);
+/* Ignore set pollset{_set} - used by filters if they don't care about pollsets
+ * at all. Does nothing. */
+void grpc_call_stack_ignore_set_pollset_or_pollset_set(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_polling_entity *pollent);
 /* Call the next operation in a call stack */
 void grpc_call_next_op(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                        grpc_transport_stream_op *op);
diff --git a/src/core/lib/channel/compress_filter.c b/src/core/lib/channel/compress_filter.c
index 0e548c61b8..7c8c1d6f31 100644
--- a/src/core/lib/channel/compress_filter.c
+++ b/src/core/lib/channel/compress_filter.c
@@ -271,7 +271,7 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                              void *ignored) {
+                              const grpc_call_stats *stats, void *ignored) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   gpr_slice_buffer_destroy(&calld->slices);
@@ -325,7 +325,7 @@ const grpc_channel_filter grpc_compress_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
diff --git a/src/core/lib/channel/connected_channel.c b/src/core/lib/channel/connected_channel.c
index 68a3a7d6fd..0a7d27a1dc 100644
--- a/src/core/lib/channel/connected_channel.c
+++ b/src/core/lib/channel/connected_channel.c
@@ -93,16 +93,18 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   GPR_ASSERT(r == 0);
 }
 
-static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                        grpc_pollset *pollset) {
+static void set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                       grpc_call_element *elem,
+                                       grpc_polling_entity *pollent) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
-  grpc_transport_set_pollset(exec_ctx, chand->transport,
-                             TRANSPORT_STREAM_FROM_CALL_DATA(calld), pollset);
+  grpc_transport_set_pops(exec_ctx, chand->transport,
+                          TRANSPORT_STREAM_FROM_CALL_DATA(calld), pollent);
 }
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                              const grpc_call_stats *stats,
                               void *and_free_memory) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
@@ -137,7 +139,7 @@ static const grpc_channel_filter connected_channel_filter = {
     con_start_transport_op,
     sizeof(call_data),
     init_call_elem,
-    set_pollset,
+    set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
diff --git a/src/core/lib/channel/http_client_filter.c b/src/core/lib/channel/http_client_filter.c
index 516e708d1f..7cb66797eb 100644
--- a/src/core/lib/channel/http_client_filter.c
+++ b/src/core/lib/channel/http_client_filter.c
@@ -156,7 +156,7 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                              void *ignored) {}
+                              const grpc_call_stats *stats, void *ignored) {}
 
 static grpc_mdelem *scheme_from_args(const grpc_channel_args *args) {
   unsigned i;
@@ -250,7 +250,7 @@ const grpc_channel_filter grpc_http_client_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
diff --git a/src/core/lib/channel/http_server_filter.c b/src/core/lib/channel/http_server_filter.c
index ba865416de..aa8e377571 100644
--- a/src/core/lib/channel/http_server_filter.c
+++ b/src/core/lib/channel/http_server_filter.c
@@ -226,7 +226,7 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                              void *ignored) {}
+                              const grpc_call_stats *stats, void *ignored) {}
 
 /* Constructor for channel_data */
 static void init_channel_elem(grpc_exec_ctx *exec_ctx,
@@ -244,7 +244,7 @@ const grpc_channel_filter grpc_http_server_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
diff --git a/src/core/lib/http/httpcli.c b/src/core/lib/http/httpcli.c
index f22721ac8f..e8957bfe89 100644
--- a/src/core/lib/http/httpcli.c
+++ b/src/core/lib/http/httpcli.c
@@ -62,7 +62,7 @@ typedef struct {
   grpc_httpcli_response_cb on_response;
   void *user_data;
   grpc_httpcli_context *context;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
   grpc_iomgr_object iomgr_obj;
   gpr_slice_buffer incoming;
   gpr_slice_buffer outgoing;
@@ -97,8 +97,8 @@ static void next_address(grpc_exec_ctx *exec_ctx, internal_request *req);
 
 static void finish(grpc_exec_ctx *exec_ctx, internal_request *req,
                    int success) {
-  grpc_pollset_set_del_pollset(exec_ctx, req->context->pollset_set,
-                               req->pollset);
+  grpc_polling_entity_del_from_pollset_set(exec_ctx, req->pollent,
+                                           req->context->pollset_set);
   req->on_response(exec_ctx, req->user_data,
                    success ? &req->parser.http.response : NULL);
   grpc_http_parser_destroy(&req->parser);
@@ -222,7 +222,7 @@ static void on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
 
 static void internal_request_begin(
     grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-    grpc_pollset *pollset, const grpc_httpcli_request *request,
+    grpc_polling_entity *pollent, const grpc_httpcli_request *request,
     gpr_timespec deadline, grpc_httpcli_response_cb on_response,
     void *user_data, const char *name, gpr_slice request_text) {
   internal_request *req = gpr_malloc(sizeof(internal_request));
@@ -235,7 +235,7 @@ static void internal_request_begin(
   req->handshaker =
       request->handshaker ? request->handshaker : &grpc_httpcli_plaintext;
   req->context = context;
-  req->pollset = pollset;
+  req->pollent = pollent;
   grpc_closure_init(&req->on_read, on_read, req);
   grpc_closure_init(&req->done_write, done_write, req);
   gpr_slice_buffer_init(&req->incoming);
@@ -244,14 +244,15 @@ static void internal_request_begin(
   req->host = gpr_strdup(request->host);
   req->ssl_host_override = gpr_strdup(request->ssl_host_override);
 
-  grpc_pollset_set_add_pollset(exec_ctx, req->context->pollset_set,
-                               req->pollset);
+  GPR_ASSERT(pollent);
+  grpc_polling_entity_add_to_pollset_set(exec_ctx, req->pollent,
+                                         req->context->pollset_set);
   grpc_resolve_address(exec_ctx, request->host, req->handshaker->default_port,
                        on_resolved, req);
 }
 
 void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-                      grpc_pollset *pollset,
+                      grpc_polling_entity *pollent,
                       const grpc_httpcli_request *request,
                       gpr_timespec deadline,
                       grpc_httpcli_response_cb on_response, void *user_data) {
@@ -261,14 +262,14 @@ void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
     return;
   }
   gpr_asprintf(&name, "HTTP:GET:%s:%s", request->host, request->http.path);
-  internal_request_begin(exec_ctx, context, pollset, request, deadline,
+  internal_request_begin(exec_ctx, context, pollent, request, deadline,
                          on_response, user_data, name,
                          grpc_httpcli_format_get_request(request));
   gpr_free(name);
 }
 
 void grpc_httpcli_post(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-                       grpc_pollset *pollset,
+                       grpc_polling_entity *pollent,
                        const grpc_httpcli_request *request,
                        const char *body_bytes, size_t body_size,
                        gpr_timespec deadline,
@@ -281,7 +282,7 @@ void grpc_httpcli_post(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
   }
   gpr_asprintf(&name, "HTTP:POST:%s:%s", request->host, request->http.path);
   internal_request_begin(
-      exec_ctx, context, pollset, request, deadline, on_response, user_data,
+      exec_ctx, context, pollent, request, deadline, on_response, user_data,
       name, grpc_httpcli_format_post_request(request, body_bytes, body_size));
   gpr_free(name);
 }
diff --git a/src/core/lib/http/httpcli.h b/src/core/lib/http/httpcli.h
index 11a32a125c..7e7784f1ab 100644
--- a/src/core/lib/http/httpcli.h
+++ b/src/core/lib/http/httpcli.h
@@ -41,6 +41,7 @@
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 
 /* User agent this library reports */
@@ -100,7 +101,7 @@ void grpc_httpcli_context_destroy(grpc_httpcli_context *context);
    'on_response' is a callback to report results to (and 'user_data' is a user
      supplied pointer to pass to said call) */
 void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-                      grpc_pollset *pollset,
+                      grpc_polling_entity *pollent,
                       const grpc_httpcli_request *request,
                       gpr_timespec deadline,
                       grpc_httpcli_response_cb on_response, void *user_data);
@@ -121,7 +122,7 @@ void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
      supplied pointer to pass to said call)
    Does not support ?var1=val1&var2=val2 in the path. */
 void grpc_httpcli_post(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-                       grpc_pollset *pollset,
+                       grpc_polling_entity *pollent,
                        const grpc_httpcli_request *request,
                        const char *body_bytes, size_t body_size,
                        gpr_timespec deadline,
diff --git a/src/core/lib/iomgr/iocp_windows.c b/src/core/lib/iomgr/iocp_windows.c
index d46558ab1b..708232295e 100644
--- a/src/core/lib/iomgr/iocp_windows.c
+++ b/src/core/lib/iomgr/iocp_windows.c
@@ -39,7 +39,7 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/thd.h>
 
 #include "src/core/lib/iomgr/iocp_windows.h"
diff --git a/src/core/lib/iomgr/iomgr_windows.c b/src/core/lib/iomgr/iomgr_windows.c
index 398517fc75..7653f6e635 100644
--- a/src/core/lib/iomgr/iomgr_windows.c
+++ b/src/core/lib/iomgr/iomgr_windows.c
@@ -35,7 +35,7 @@
 
 #ifdef GPR_WINSOCK_SOCKET
 
-#include "src/core/lib/iomgr/sockaddr_win32.h"
+#include "src/core/lib/iomgr/sockaddr_windows.h"
 
 #include <grpc/support/log.h>
 
diff --git a/src/core/lib/iomgr/polling_entity.c b/src/core/lib/iomgr/polling_entity.c
new file mode 100644
index 0000000000..d1686aa12f
--- /dev/null
+++ b/src/core/lib/iomgr/polling_entity.c
@@ -0,0 +1,104 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/iomgr/polling_entity.h"
+
+grpc_polling_entity grpc_polling_entity_create_from_pollset_set(
+    grpc_pollset_set *pollset_set) {
+  grpc_polling_entity pollent;
+  pollent.pollent.pollset_set = pollset_set;
+  pollent.tag = POPS_POLLSET_SET;
+  return pollent;
+}
+
+grpc_polling_entity grpc_polling_entity_create_from_pollset(
+    grpc_pollset *pollset) {
+  grpc_polling_entity pollent;
+  pollent.pollent.pollset = pollset;
+  pollent.tag = POPS_POLLSET;
+  return pollent;
+}
+
+grpc_pollset *grpc_polling_entity_pollset(grpc_polling_entity *pollent) {
+  if (pollent->tag == POPS_POLLSET) {
+    return pollent->pollent.pollset;
+  }
+  return NULL;
+}
+
+grpc_pollset_set *grpc_polling_entity_pollset_set(
+    grpc_polling_entity *pollent) {
+  if (pollent->tag == POPS_POLLSET_SET) {
+    return pollent->pollent.pollset_set;
+  }
+  return NULL;
+}
+
+bool grpc_polling_entity_is_empty(const grpc_polling_entity *pollent) {
+  return pollent->tag == POPS_NONE;
+}
+
+void grpc_polling_entity_add_to_pollset_set(grpc_exec_ctx *exec_ctx,
+                                            grpc_polling_entity *pollent,
+                                            grpc_pollset_set *pss_dst) {
+  if (pollent->tag == POPS_POLLSET) {
+    GPR_ASSERT(pollent->pollent.pollset != NULL);
+    grpc_pollset_set_add_pollset(exec_ctx, pss_dst, pollent->pollent.pollset);
+  } else if (pollent->tag == POPS_POLLSET_SET) {
+    GPR_ASSERT(pollent->pollent.pollset_set != NULL);
+    grpc_pollset_set_add_pollset_set(exec_ctx, pss_dst,
+                                     pollent->pollent.pollset_set);
+  } else {
+    gpr_log(GPR_ERROR, "Invalid grpc_polling_entity tag '%d'", pollent->tag);
+    abort();
+  }
+}
+
+void grpc_polling_entity_del_from_pollset_set(grpc_exec_ctx *exec_ctx,
+                                              grpc_polling_entity *pollent,
+                                              grpc_pollset_set *pss_dst) {
+  if (pollent->tag == POPS_POLLSET) {
+    GPR_ASSERT(pollent->pollent.pollset != NULL);
+    grpc_pollset_set_del_pollset(exec_ctx, pss_dst, pollent->pollent.pollset);
+  } else if (pollent->tag == POPS_POLLSET_SET) {
+    GPR_ASSERT(pollent->pollent.pollset_set != NULL);
+    grpc_pollset_set_del_pollset_set(exec_ctx, pss_dst,
+                                     pollent->pollent.pollset_set);
+  } else {
+    gpr_log(GPR_ERROR, "Invalid grpc_polling_entity tag '%d'", pollent->tag);
+    abort();
+  }
+}
diff --git a/src/core/lib/iomgr/polling_entity.h b/src/core/lib/iomgr/polling_entity.h
new file mode 100644
index 0000000000..e81531053c
--- /dev/null
+++ b/src/core/lib/iomgr/polling_entity.h
@@ -0,0 +1,81 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_POLLING_ENTITY_H
+#define GRPC_CORE_LIB_IOMGR_POLLING_ENTITY_H
+
+#include "src/core/lib/iomgr/pollset.h"
+#include "src/core/lib/iomgr/pollset_set.h"
+
+/* A grpc_polling_entity is a pollset-or-pollset_set container. It allows
+ * functions that
+ * accept a pollset XOR a pollset_set to do so through an abstract interface.
+ * No ownership is taken. */
+
+typedef struct grpc_polling_entity {
+  union {
+    grpc_pollset *pollset;
+    grpc_pollset_set *pollset_set;
+  } pollent;
+  enum pops_tag { POPS_NONE, POPS_POLLSET, POPS_POLLSET_SET } tag;
+} grpc_polling_entity;
+
+grpc_polling_entity grpc_polling_entity_create_from_pollset_set(
+    grpc_pollset_set *pollset_set);
+grpc_polling_entity grpc_polling_entity_create_from_pollset(
+    grpc_pollset *pollset);
+
+/** If \a pollent contains a pollset, return it. Otherwise, return NULL */
+grpc_pollset *grpc_polling_entity_pollset(grpc_polling_entity *pollent);
+
+/** If \a pollent contains a pollset_set, return it. Otherwise, return NULL */
+grpc_pollset_set *grpc_polling_entity_pollset_set(grpc_polling_entity *pollent);
+
+bool grpc_polling_entity_is_empty(const grpc_polling_entity *pollent);
+
+/** Add the pollset or pollset_set in \a pollent to the destination pollset_set
+ * \a
+ * pss_dst */
+void grpc_polling_entity_add_to_pollset_set(grpc_exec_ctx *exec_ctx,
+                                            grpc_polling_entity *pollent,
+                                            grpc_pollset_set *pss_dst);
+
+/** Delete the pollset or pollset_set in \a pollent from the destination
+ * pollset_set \a
+ * pss_dst */
+void grpc_polling_entity_del_from_pollset_set(grpc_exec_ctx *exec_ctx,
+                                              grpc_polling_entity *pollent,
+                                              grpc_pollset_set *pss_dst);
+/* pollset_set specific */
+
+#endif /* GRPC_CORE_LIB_IOMGR_POLLING_ENTITY_H */
diff --git a/src/core/lib/iomgr/pollset_set_windows.c b/src/core/lib/iomgr/pollset_set_windows.c
index 89f60b92fb..a35a9766fc 100644
--- a/src/core/lib/iomgr/pollset_set_windows.c
+++ b/src/core/lib/iomgr/pollset_set_windows.c
@@ -32,12 +32,15 @@
  */
 
 #include <grpc/support/port_platform.h>
+#include <stdint.h>
 
 #ifdef GPR_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/pollset_set_windows.h"
 
-grpc_pollset_set* grpc_pollset_set_create(void) { return NULL; }
+grpc_pollset_set* grpc_pollset_set_create(void) {
+  return (grpc_pollset_set*)((intptr_t)0xdeafbeef);
+}
 
 void grpc_pollset_set_destroy(grpc_pollset_set* pollset_set) {}
 
diff --git a/src/core/lib/iomgr/resolve_address_windows.c b/src/core/lib/iomgr/resolve_address_windows.c
index 914736234d..c1bbb3db6b 100644
--- a/src/core/lib/iomgr/resolve_address_windows.c
+++ b/src/core/lib/iomgr/resolve_address_windows.c
@@ -43,7 +43,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/host_port.h>
 #include <grpc/support/log.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
diff --git a/src/core/lib/iomgr/sockaddr.h b/src/core/lib/iomgr/sockaddr.h
index 891a2f094f..5563d0b8a6 100644
--- a/src/core/lib/iomgr/sockaddr.h
+++ b/src/core/lib/iomgr/sockaddr.h
@@ -36,8 +36,8 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
-#include "src/core/lib/iomgr/sockaddr_win32.h"
+#ifdef GPR_WINDOWS
+#include "src/core/lib/iomgr/sockaddr_windows.h"
 #endif
 
 #ifdef GPR_POSIX_SOCKETADDR
diff --git a/src/core/lib/iomgr/sockaddr_win32.h b/src/core/lib/iomgr/sockaddr_windows.h
index 02aeae7619..971db5b32b 100644
--- a/src/core/lib/iomgr/sockaddr_win32.h
+++ b/src/core/lib/iomgr/sockaddr_windows.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_IOMGR_SOCKADDR_WIN32_H
-#define GRPC_CORE_LIB_IOMGR_SOCKADDR_WIN32_H
+#ifndef GRPC_CORE_LIB_IOMGR_SOCKADDR_WINDOWS_H
+#define GRPC_CORE_LIB_IOMGR_SOCKADDR_WINDOWS_H
 
 #include <winsock2.h>
 #include <ws2tcpip.h>
@@ -40,4 +40,4 @@
 // must be included after the above
 #include <mswsock.h>
 
-#endif /* GRPC_CORE_LIB_IOMGR_SOCKADDR_WIN32_H */
+#endif /* GRPC_CORE_LIB_IOMGR_SOCKADDR_WINDOWS_H */
diff --git a/src/core/lib/iomgr/socket_windows.c b/src/core/lib/iomgr/socket_windows.c
index ebd77e0372..7d8f9f761d 100644
--- a/src/core/lib/iomgr/socket_windows.c
+++ b/src/core/lib/iomgr/socket_windows.c
@@ -42,7 +42,7 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/iomgr/iocp_windows.h"
diff --git a/src/core/lib/iomgr/tcp_client_windows.c b/src/core/lib/iomgr/tcp_client_windows.c
index 66f9ff7a46..efa0140f54 100644
--- a/src/core/lib/iomgr/tcp_client_windows.c
+++ b/src/core/lib/iomgr/tcp_client_windows.c
@@ -35,11 +35,11 @@
 
 #ifdef GPR_WINSOCK_SOCKET
 
-#include "src/core/lib/iomgr/sockaddr_win32.h"
+#include "src/core/lib/iomgr/sockaddr_windows.h"
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/slice_buffer.h>
 #include <grpc/support/useful.h>
 
diff --git a/src/core/lib/iomgr/tcp_server_windows.c b/src/core/lib/iomgr/tcp_server_windows.c
index e15f8b0cdf..8a21d930c8 100644
--- a/src/core/lib/iomgr/tcp_server_windows.c
+++ b/src/core/lib/iomgr/tcp_server_windows.c
@@ -41,7 +41,7 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index 551149e1a6..f44bf5fda4 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -37,11 +37,11 @@
 
 #include <limits.h>
 
-#include "src/core/lib/iomgr/sockaddr_win32.h"
+#include "src/core/lib/iomgr/sockaddr_windows.h"
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/slice_buffer.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
diff --git a/src/core/lib/iomgr/timer.c b/src/core/lib/iomgr/timer.c
index acb5b26c87..69d3babfdb 100644
--- a/src/core/lib/iomgr/timer.c
+++ b/src/core/lib/iomgr/timer.c
@@ -278,8 +278,8 @@ static int refill_queue(shard_type *shard, gpr_timespec now) {
   return !grpc_timer_heap_is_empty(&shard->heap);
 }
 
-/* This pops the next non-cancelled timer with deadline <= now from the queue,
-   or returns NULL if there isn't one.
+/* This pops the next non-cancelled timer with deadline <= now from the
+   queue, or returns NULL if there isn't one.
    REQUIRES: shard->mu locked */
 static grpc_timer *pop_one(shard_type *shard, gpr_timespec now) {
   grpc_timer *timer;
diff --git a/src/core/lib/iomgr/workqueue.h b/src/core/lib/iomgr/workqueue.h
index 3e2b223670..eeca8c0bf2 100644
--- a/src/core/lib/iomgr/workqueue.h
+++ b/src/core/lib/iomgr/workqueue.h
@@ -43,7 +43,7 @@
 #include "src/core/lib/iomgr/workqueue_posix.h"
 #endif
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 #include "src/core/lib/iomgr/workqueue_windows.h"
 #endif
 
diff --git a/src/core/lib/iomgr/workqueue_windows.c b/src/core/lib/iomgr/workqueue_windows.c
index c3c0446a57..275f040b1c 100644
--- a/src/core/lib/iomgr/workqueue_windows.c
+++ b/src/core/lib/iomgr/workqueue_windows.c
@@ -33,8 +33,8 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 #include "src/core/lib/iomgr/workqueue.h"
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
diff --git a/src/core/lib/security/credentials/composite/composite_credentials.c b/src/core/lib/security/credentials/composite/composite_credentials.c
index 18189a8fb8..07db8bfd75 100644
--- a/src/core/lib/security/credentials/composite/composite_credentials.c
+++ b/src/core/lib/security/credentials/composite/composite_credentials.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -35,6 +35,7 @@
 
 #include <string.h>
 
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/surface/api_trace.h"
 
 #include <grpc/support/alloc.h>
@@ -49,7 +50,7 @@ typedef struct {
   grpc_credentials_md_store *md_elems;
   grpc_auth_metadata_context auth_md_context;
   void *user_data;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
   grpc_credentials_metadata_cb cb;
 } grpc_composite_call_credentials_metadata_context;
 
@@ -93,7 +94,7 @@ static void composite_call_metadata_cb(grpc_exec_ctx *exec_ctx, void *user_data,
     grpc_call_credentials *inner_creds =
         ctx->composite_creds->inner.creds_array[ctx->creds_index++];
     grpc_call_credentials_get_request_metadata(
-        exec_ctx, inner_creds, ctx->pollset, ctx->auth_md_context,
+        exec_ctx, inner_creds, ctx->pollent, ctx->auth_md_context,
         composite_call_metadata_cb, ctx);
     return;
   }
@@ -106,7 +107,7 @@ static void composite_call_metadata_cb(grpc_exec_ctx *exec_ctx, void *user_data,
 
 static void composite_call_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context auth_md_context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context auth_md_context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   grpc_composite_call_credentials *c = (grpc_composite_call_credentials *)creds;
   grpc_composite_call_credentials_metadata_context *ctx;
@@ -117,10 +118,10 @@ static void composite_call_get_request_metadata(
   ctx->user_data = user_data;
   ctx->cb = cb;
   ctx->composite_creds = c;
-  ctx->pollset = pollset;
+  ctx->pollent = pollent;
   ctx->md_elems = grpc_credentials_md_store_create(c->inner.num_creds);
   grpc_call_credentials_get_request_metadata(
-      exec_ctx, c->inner.creds_array[ctx->creds_index++], pollset,
+      exec_ctx, c->inner.creds_array[ctx->creds_index++], ctx->pollent,
       auth_md_context, composite_call_metadata_cb, ctx);
 }
 
diff --git a/src/core/lib/security/credentials/credentials.c b/src/core/lib/security/credentials/credentials.c
index 3dde6e587d..f45a8d8ff6 100644
--- a/src/core/lib/security/credentials/credentials.c
+++ b/src/core/lib/security/credentials/credentials.c
@@ -111,7 +111,7 @@ void grpc_call_credentials_release(grpc_call_credentials *creds) {
 
 void grpc_call_credentials_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   if (creds == NULL || creds->vtable->get_request_metadata == NULL) {
     if (cb != NULL) {
@@ -119,7 +119,7 @@ void grpc_call_credentials_get_request_metadata(
     }
     return;
   }
-  creds->vtable->get_request_metadata(exec_ctx, creds, pollset, context, cb,
+  creds->vtable->get_request_metadata(exec_ctx, creds, pollent, context, cb,
                                       user_data);
 }
 
diff --git a/src/core/lib/security/credentials/credentials.h b/src/core/lib/security/credentials/credentials.h
index 5f44c7c3e3..15dcfe473d 100644
--- a/src/core/lib/security/credentials/credentials.h
+++ b/src/core/lib/security/credentials/credentials.h
@@ -41,6 +41,7 @@
 
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/http/parser.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/security/transport/security_connector.h"
 
 struct grpc_http_response;
@@ -164,7 +165,8 @@ typedef void (*grpc_credentials_metadata_cb)(grpc_exec_ctx *exec_ctx,
 typedef struct {
   void (*destruct)(grpc_call_credentials *c);
   void (*get_request_metadata)(grpc_exec_ctx *exec_ctx,
-                               grpc_call_credentials *c, grpc_pollset *pollset,
+                               grpc_call_credentials *c,
+                               grpc_polling_entity *pollent,
                                grpc_auth_metadata_context context,
                                grpc_credentials_metadata_cb cb,
                                void *user_data);
@@ -180,7 +182,7 @@ grpc_call_credentials *grpc_call_credentials_ref(grpc_call_credentials *creds);
 void grpc_call_credentials_unref(grpc_call_credentials *creds);
 void grpc_call_credentials_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data);
 
 /* Metadata-only credentials with the specified key and value where
diff --git a/src/core/lib/security/credentials/fake/fake_credentials.c b/src/core/lib/security/credentials/fake/fake_credentials.c
index 54d7cf2581..005777d3c6 100644
--- a/src/core/lib/security/credentials/fake/fake_credentials.c
+++ b/src/core/lib/security/credentials/fake/fake_credentials.c
@@ -106,7 +106,7 @@ static void on_simulated_token_fetch_done(grpc_exec_ctx *exec_ctx,
 
 static void md_only_test_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   grpc_md_only_test_credentials *c = (grpc_md_only_test_credentials *)creds;
 
diff --git a/src/core/lib/security/credentials/google_default/credentials_win32.c b/src/core/lib/security/credentials/google_default/credentials_windows.c
index cd8b48080a..208b8fd9ad 100644
--- a/src/core/lib/security/credentials/google_default/credentials_win32.c
+++ b/src/core/lib/security/credentials/google_default/credentials_windows.c
@@ -33,7 +33,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 #include "src/core/lib/security/credentials/google_default/google_default_credentials.h"
 
@@ -58,4 +58,4 @@ char *grpc_get_well_known_google_credentials_file_path_impl(void) {
   return result;
 }
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.c b/src/core/lib/security/credentials/google_default/google_default_credentials.c
index a521d95abc..98df68e7b3 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.c
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.c
@@ -41,6 +41,7 @@
 
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/http/parser.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/security/credentials/jwt/jwt_credentials.h"
 #include "src/core/lib/security/credentials/oauth2/oauth2_credentials.h"
 #include "src/core/lib/support/env.h"
@@ -62,7 +63,7 @@ static gpr_once g_once = GPR_ONCE_INIT;
 static void init_default_credentials(void) { gpr_mu_init(&g_state_mu); }
 
 typedef struct {
-  grpc_pollset *pollset;
+  grpc_polling_entity pollent;
   int is_done;
   int success;
 } compute_engine_detector;
@@ -86,7 +87,7 @@ static void on_compute_engine_detection_http_response(
   }
   gpr_mu_lock(g_polling_mu);
   detector->is_done = 1;
-  grpc_pollset_kick(detector->pollset, NULL);
+  grpc_pollset_kick(grpc_polling_entity_pollset(&detector->pollent), NULL);
   gpr_mu_unlock(g_polling_mu);
 }
 
@@ -105,8 +106,9 @@ static int is_stack_running_on_compute_engine(void) {
      on compute engine. */
   gpr_timespec max_detection_delay = gpr_time_from_seconds(1, GPR_TIMESPAN);
 
-  detector.pollset = gpr_malloc(grpc_pollset_size());
-  grpc_pollset_init(detector.pollset, &g_polling_mu);
+  grpc_pollset *pollset = gpr_malloc(grpc_pollset_size());
+  grpc_pollset_init(pollset, &g_polling_mu);
+  detector.pollent = grpc_polling_entity_create_from_pollset(pollset);
   detector.is_done = 0;
   detector.success = 0;
 
@@ -117,7 +119,7 @@ static int is_stack_running_on_compute_engine(void) {
   grpc_httpcli_context_init(&context);
 
   grpc_httpcli_get(
-      &exec_ctx, &context, detector.pollset, &request,
+      &exec_ctx, &context, &detector.pollent, &request,
       gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), max_detection_delay),
       on_compute_engine_detection_http_response, &detector);
 
@@ -128,19 +130,22 @@ static int is_stack_running_on_compute_engine(void) {
   gpr_mu_lock(g_polling_mu);
   while (!detector.is_done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, detector.pollset, &worker,
-                      gpr_now(GPR_CLOCK_MONOTONIC),
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&detector.pollent),
+                      &worker, gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
   }
   gpr_mu_unlock(g_polling_mu);
 
   grpc_httpcli_context_destroy(&context);
-  grpc_closure_init(&destroy_closure, destroy_pollset, detector.pollset);
-  grpc_pollset_shutdown(&exec_ctx, detector.pollset, &destroy_closure);
+  grpc_closure_init(&destroy_closure, destroy_pollset,
+                    grpc_polling_entity_pollset(&detector.pollent));
+  grpc_pollset_shutdown(&exec_ctx,
+                        grpc_polling_entity_pollset(&detector.pollent),
+                        &destroy_closure);
   grpc_exec_ctx_finish(&exec_ctx);
   g_polling_mu = NULL;
 
-  gpr_free(detector.pollset);
+  gpr_free(grpc_polling_entity_pollset(&detector.pollent));
 
   return detector.success;
 }
diff --git a/src/core/lib/security/credentials/iam/iam_credentials.c b/src/core/lib/security/credentials/iam/iam_credentials.c
index 89defa7c60..64d5871844 100644
--- a/src/core/lib/security/credentials/iam/iam_credentials.c
+++ b/src/core/lib/security/credentials/iam/iam_credentials.c
@@ -49,7 +49,7 @@ static void iam_destruct(grpc_call_credentials *creds) {
 
 static void iam_get_request_metadata(grpc_exec_ctx *exec_ctx,
                                      grpc_call_credentials *creds,
-                                     grpc_pollset *pollset,
+                                     grpc_polling_entity *pollent,
                                      grpc_auth_metadata_context context,
                                      grpc_credentials_metadata_cb cb,
                                      void *user_data) {
diff --git a/src/core/lib/security/credentials/jwt/jwt_credentials.c b/src/core/lib/security/credentials/jwt/jwt_credentials.c
index 8755a96af4..973fb75eaa 100644
--- a/src/core/lib/security/credentials/jwt/jwt_credentials.c
+++ b/src/core/lib/security/credentials/jwt/jwt_credentials.c
@@ -64,7 +64,7 @@ static void jwt_destruct(grpc_call_credentials *creds) {
 
 static void jwt_get_request_metadata(grpc_exec_ctx *exec_ctx,
                                      grpc_call_credentials *creds,
-                                     grpc_pollset *pollset,
+                                     grpc_polling_entity *pollent,
                                      grpc_auth_metadata_context context,
                                      grpc_credentials_metadata_cb cb,
                                      void *user_data) {
diff --git a/src/core/lib/security/credentials/jwt/jwt_verifier.c b/src/core/lib/security/credentials/jwt/jwt_verifier.c
index cd6c7ce392..1f67db103c 100644
--- a/src/core/lib/security/credentials/jwt/jwt_verifier.c
+++ b/src/core/lib/security/credentials/jwt/jwt_verifier.c
@@ -37,6 +37,7 @@
 #include <string.h>
 
 #include "src/core/lib/http/httpcli.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/security/util/b64.h"
 #include "src/core/lib/tsi/ssl_types.h"
 
@@ -321,7 +322,7 @@ grpc_jwt_verifier_status grpc_jwt_claims_check(const grpc_jwt_claims *claims,
 
 typedef struct {
   grpc_jwt_verifier *verifier;
-  grpc_pollset *pollset;
+  grpc_polling_entity pollent;
   jose_header *header;
   grpc_jwt_claims *claims;
   char *audience;
@@ -337,10 +338,11 @@ static verifier_cb_ctx *verifier_cb_ctx_create(
     grpc_jwt_claims *claims, const char *audience, gpr_slice signature,
     const char *signed_jwt, size_t signed_jwt_len, void *user_data,
     grpc_jwt_verification_done_cb cb) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   verifier_cb_ctx *ctx = gpr_malloc(sizeof(verifier_cb_ctx));
   memset(ctx, 0, sizeof(verifier_cb_ctx));
   ctx->verifier = verifier;
-  ctx->pollset = pollset;
+  ctx->pollent = grpc_polling_entity_create_from_pollset(pollset);
   ctx->header = header;
   ctx->audience = gpr_strdup(audience);
   ctx->claims = claims;
@@ -348,6 +350,7 @@ static verifier_cb_ctx *verifier_cb_ctx_create(
   ctx->signed_data = gpr_slice_from_copied_buffer(signed_jwt, signed_jwt_len);
   ctx->user_data = user_data;
   ctx->user_cb = cb;
+  grpc_exec_ctx_finish(&exec_ctx);
   return ctx;
 }
 
@@ -642,7 +645,7 @@ static void on_openid_config_retrieved(grpc_exec_ctx *exec_ctx, void *user_data,
     *(req.host + (req.http.path - jwks_uri)) = '\0';
   }
   grpc_httpcli_get(
-      exec_ctx, &ctx->verifier->http_ctx, ctx->pollset, &req,
+      exec_ctx, &ctx->verifier->http_ctx, &ctx->pollent, &req,
       gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay),
       on_keys_retrieved, ctx);
   grpc_json_destroy(json);
@@ -745,7 +748,7 @@ static void retrieve_key_and_verify(grpc_exec_ctx *exec_ctx,
   }
 
   grpc_httpcli_get(
-      exec_ctx, &ctx->verifier->http_ctx, ctx->pollset, &req,
+      exec_ctx, &ctx->verifier->http_ctx, &ctx->pollent, &req,
       gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay),
       http_cb, ctx);
   gpr_free(req.host);
diff --git a/src/core/lib/security/credentials/oauth2/oauth2_credentials.c b/src/core/lib/security/credentials/oauth2/oauth2_credentials.c
index 973c6e1d17..268026b9f0 100644
--- a/src/core/lib/security/credentials/oauth2/oauth2_credentials.c
+++ b/src/core/lib/security/credentials/oauth2/oauth2_credentials.c
@@ -244,7 +244,7 @@ static void on_oauth2_token_fetcher_http_response(
 
 static void oauth2_token_fetcher_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   grpc_oauth2_token_fetcher_credentials *c =
       (grpc_oauth2_token_fetcher_credentials *)creds;
@@ -270,7 +270,7 @@ static void oauth2_token_fetcher_get_request_metadata(
     c->fetch_func(
         exec_ctx,
         grpc_credentials_metadata_request_create(creds, cb, user_data),
-        &c->httpcli_context, pollset, on_oauth2_token_fetcher_http_response,
+        &c->httpcli_context, pollent, on_oauth2_token_fetcher_http_response,
         gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), refresh_threshold));
   }
 }
@@ -295,7 +295,7 @@ static grpc_call_credentials_vtable compute_engine_vtable = {
 
 static void compute_engine_fetch_oauth2(
     grpc_exec_ctx *exec_ctx, grpc_credentials_metadata_request *metadata_req,
-    grpc_httpcli_context *httpcli_context, grpc_pollset *pollset,
+    grpc_httpcli_context *httpcli_context, grpc_polling_entity *pollent,
     grpc_httpcli_response_cb response_cb, gpr_timespec deadline) {
   grpc_http_header header = {"Metadata-Flavor", "Google"};
   grpc_httpcli_request request;
@@ -304,7 +304,7 @@ static void compute_engine_fetch_oauth2(
   request.http.path = GRPC_COMPUTE_ENGINE_METADATA_TOKEN_PATH;
   request.http.hdr_count = 1;
   request.http.hdrs = &header;
-  grpc_httpcli_get(exec_ctx, httpcli_context, pollset, &request, deadline,
+  grpc_httpcli_get(exec_ctx, httpcli_context, pollent, &request, deadline,
                    response_cb, metadata_req);
 }
 
@@ -336,7 +336,7 @@ static grpc_call_credentials_vtable refresh_token_vtable = {
 
 static void refresh_token_fetch_oauth2(
     grpc_exec_ctx *exec_ctx, grpc_credentials_metadata_request *metadata_req,
-    grpc_httpcli_context *httpcli_context, grpc_pollset *pollset,
+    grpc_httpcli_context *httpcli_context, grpc_polling_entity *pollent,
     grpc_httpcli_response_cb response_cb, gpr_timespec deadline) {
   grpc_google_refresh_token_credentials *c =
       (grpc_google_refresh_token_credentials *)metadata_req->creds;
@@ -353,7 +353,7 @@ static void refresh_token_fetch_oauth2(
   request.http.hdr_count = 1;
   request.http.hdrs = &header;
   request.handshaker = &grpc_httpcli_ssl;
-  grpc_httpcli_post(exec_ctx, httpcli_context, pollset, &request, body,
+  grpc_httpcli_post(exec_ctx, httpcli_context, pollent, &request, body,
                     strlen(body), deadline, response_cb, metadata_req);
   gpr_free(body);
 }
@@ -396,7 +396,7 @@ static void access_token_destruct(grpc_call_credentials *creds) {
 
 static void access_token_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   grpc_access_token_credentials *c = (grpc_access_token_credentials *)creds;
   cb(exec_ctx, user_data, c->access_token_md->entries, 1, GRPC_CREDENTIALS_OK);
diff --git a/src/core/lib/security/credentials/oauth2/oauth2_credentials.h b/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
index 04915b333f..3bc8360a41 100644
--- a/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
+++ b/src/core/lib/security/credentials/oauth2/oauth2_credentials.h
@@ -70,7 +70,7 @@ void grpc_auth_refresh_token_destruct(grpc_auth_refresh_token *refresh_token);
 typedef void (*grpc_fetch_oauth2_func)(grpc_exec_ctx *exec_ctx,
                                        grpc_credentials_metadata_request *req,
                                        grpc_httpcli_context *http_context,
-                                       grpc_pollset *pollset,
+                                       grpc_polling_entity *pollent,
                                        grpc_httpcli_response_cb response_cb,
                                        gpr_timespec deadline);
 typedef struct {
diff --git a/src/core/lib/security/credentials/plugin/plugin_credentials.c b/src/core/lib/security/credentials/plugin/plugin_credentials.c
index bae357321e..9fb55e8466 100644
--- a/src/core/lib/security/credentials/plugin/plugin_credentials.c
+++ b/src/core/lib/security/credentials/plugin/plugin_credentials.c
@@ -94,7 +94,7 @@ static void plugin_md_request_metadata_ready(void *request,
 
 static void plugin_get_request_metadata(grpc_exec_ctx *exec_ctx,
                                         grpc_call_credentials *creds,
-                                        grpc_pollset *pollset,
+                                        grpc_polling_entity *pollent,
                                         grpc_auth_metadata_context context,
                                         grpc_credentials_metadata_cb cb,
                                         void *user_data) {
diff --git a/src/core/lib/security/transport/client_auth_filter.c b/src/core/lib/security/transport/client_auth_filter.c
index e3cbcb4433..76be2acd72 100644
--- a/src/core/lib/security/transport/client_auth_filter.c
+++ b/src/core/lib/security/transport/client_auth_filter.c
@@ -54,11 +54,11 @@ typedef struct {
   grpc_call_credentials *creds;
   grpc_mdstr *host;
   grpc_mdstr *method;
-  /* pollset bound to this call; if we need to make external
-     network requests, they should be done under this pollset
-     so that work can progress when this call wants work to
-     progress */
-  grpc_pollset *pollset;
+  /* pollset{_set} bound to this call; if we need to make external
+     network requests, they should be done under a pollset added to this
+     pollset_set so that work can progress when this call wants work to progress
+  */
+  grpc_polling_entity *pollent;
   grpc_transport_stream_op op;
   uint8_t security_context_set;
   grpc_linked_mdelem md_links[MAX_CREDENTIALS_METADATA_COUNT];
@@ -184,9 +184,9 @@ static void send_security_metadata(grpc_exec_ctx *exec_ctx,
   build_auth_metadata_context(&chand->security_connector->base,
                               chand->auth_context, calld);
   calld->op = *op; /* Copy op (originates from the caller's stack). */
-  GPR_ASSERT(calld->pollset);
+  GPR_ASSERT(calld->pollent != NULL);
   grpc_call_credentials_get_request_metadata(
-      exec_ctx, calld->creds, calld->pollset, calld->auth_md_context,
+      exec_ctx, calld->creds, calld->pollent, calld->auth_md_context,
       on_credentials_metadata, elem);
 }
 
@@ -270,15 +270,16 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   memset(calld, 0, sizeof(*calld));
 }
 
-static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                        grpc_pollset *pollset) {
+static void set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                       grpc_call_element *elem,
+                                       grpc_polling_entity *pollent) {
   call_data *calld = elem->call_data;
-  calld->pollset = pollset;
+  calld->pollent = pollent;
 }
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                              void *ignored) {
+                              const grpc_call_stats *stats, void *ignored) {
   call_data *calld = elem->call_data;
   grpc_call_credentials_unref(calld->creds);
   if (calld->host != NULL) {
@@ -329,8 +330,14 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
   GRPC_AUTH_CONTEXT_UNREF(chand->auth_context, "client_auth_filter");
 }
 
-const grpc_channel_filter grpc_client_auth_filter = {
-    auth_start_transport_op, grpc_channel_next_op, sizeof(call_data),
-    init_call_elem,          set_pollset,          destroy_call_elem,
-    sizeof(channel_data),    init_channel_elem,    destroy_channel_elem,
-    grpc_call_next_get_peer, "client-auth"};
+const grpc_channel_filter grpc_client_auth_filter = {auth_start_transport_op,
+                                                     grpc_channel_next_op,
+                                                     sizeof(call_data),
+                                                     init_call_elem,
+                                                     set_pollset_or_pollset_set,
+                                                     destroy_call_elem,
+                                                     sizeof(channel_data),
+                                                     init_channel_elem,
+                                                     destroy_channel_elem,
+                                                     grpc_call_next_get_peer,
+                                                     "client-auth"};
diff --git a/src/core/lib/security/transport/server_auth_filter.c b/src/core/lib/security/transport/server_auth_filter.c
index 006a30f0c6..b36be127fd 100644
--- a/src/core/lib/security/transport/server_auth_filter.c
+++ b/src/core/lib/security/transport/server_auth_filter.c
@@ -220,12 +220,9 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
       grpc_server_security_context_destroy;
 }
 
-static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                        grpc_pollset *pollset) {}
-
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                              void *ignored) {}
+                              const grpc_call_stats *stats, void *ignored) {}
 
 /* Constructor for channel_data */
 static void init_channel_elem(grpc_exec_ctx *exec_ctx,
@@ -258,7 +255,14 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
 }
 
 const grpc_channel_filter grpc_server_auth_filter = {
-    auth_start_transport_op, grpc_channel_next_op, sizeof(call_data),
-    init_call_elem,          set_pollset,          destroy_call_elem,
-    sizeof(channel_data),    init_channel_elem,    destroy_channel_elem,
-    grpc_call_next_get_peer, "server-auth"};
+    auth_start_transport_op,
+    grpc_channel_next_op,
+    sizeof(call_data),
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    "server-auth"};
diff --git a/src/core/lib/support/cpu_windows.c b/src/core/lib/support/cpu_windows.c
index ce32eb0a9d..34d006bfc8 100644
--- a/src/core/lib/support/cpu_windows.c
+++ b/src/core/lib/support/cpu_windows.c
@@ -33,7 +33,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 #include <grpc/support/log.h>
 
 unsigned gpr_cpu_num_cores(void) {
@@ -44,4 +44,4 @@ unsigned gpr_cpu_num_cores(void) {
 
 unsigned gpr_cpu_current_cpu(void) { return GetCurrentProcessorNumber(); }
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
diff --git a/src/core/lib/support/env_win32.c b/src/core/lib/support/env_windows.c
index e670e1e8d0..9116959442 100644
--- a/src/core/lib/support/env_win32.c
+++ b/src/core/lib/support/env_windows.c
@@ -33,13 +33,13 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32_ENV
+#ifdef GPR_WINDOWS_ENV
 
 #include <windows.h>
 
 #include "src/core/lib/support/env.h"
 #include "src/core/lib/support/string.h"
-#include "src/core/lib/support/string_win32.h"
+#include "src/core/lib/support/string_windows.h"
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
@@ -76,4 +76,4 @@ void gpr_setenv(const char *name, const char *value) {
   GPR_ASSERT(res);
 }
 
-#endif /* GPR_WIN32_ENV */
+#endif /* GPR_WINDOWS_ENV */
diff --git a/src/core/lib/support/log_win32.c b/src/core/lib/support/log_windows.c
index 29735bd18c..ea898c359d 100644
--- a/src/core/lib/support/log_win32.c
+++ b/src/core/lib/support/log_windows.c
@@ -33,19 +33,19 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32_LOG
+#ifdef GPR_WINDOWS_LOG
 
 #include <stdarg.h>
 #include <stdio.h>
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
 #include "src/core/lib/support/string.h"
-#include "src/core/lib/support/string_win32.h"
+#include "src/core/lib/support/string_windows.h"
 
 void gpr_log(const char *file, int line, gpr_log_severity severity,
              const char *format, ...) {
@@ -109,4 +109,4 @@ void gpr_default_log(gpr_log_func_args *args) {
   fflush(stderr);
 }
 
-#endif /* GPR_WIN32_LOG */
+#endif /* GPR_WINDOWS_LOG */
diff --git a/src/core/lib/support/string_util_win32.c b/src/core/lib/support/string_util_windows.c
index 0d7bcdb5aa..049c9a8c04 100644
--- a/src/core/lib/support/string_util_win32.c
+++ b/src/core/lib/support/string_util_windows.c
@@ -35,7 +35,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 /* Some platforms (namely msys) need wchar to be included BEFORE
    anything else, especially strsafe.h. */
@@ -91,4 +91,4 @@ char *gpr_format_message(int messageid) {
   return message;
 }
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
diff --git a/src/core/lib/support/string_win32.c b/src/core/lib/support/string_windows.c
index 6b92f79253..ecc2a3a4e5 100644
--- a/src/core/lib/support/string_win32.c
+++ b/src/core/lib/support/string_windows.c
@@ -35,7 +35,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32_STRING
+#ifdef GPR_WINDOWS_STRING
 
 #include <stdarg.h>
 #include <stdio.h>
@@ -80,4 +80,4 @@ int gpr_asprintf(char **strp, const char *format, ...) {
   return -1;
 }
 
-#endif /* GPR_WIN32_STRING */
+#endif /* GPR_WINDOWS_STRING */
diff --git a/src/core/lib/support/string_win32.h b/src/core/lib/support/string_windows.h
index ff4a694ca9..899563b72d 100644
--- a/src/core/lib/support/string_win32.h
+++ b/src/core/lib/support/string_windows.h
@@ -31,17 +31,17 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_STRING_WIN32_H
-#define GRPC_CORE_LIB_SUPPORT_STRING_WIN32_H
+#ifndef GRPC_CORE_LIB_SUPPORT_STRING_WINDOWS_H
+#define GRPC_CORE_LIB_SUPPORT_STRING_WINDOWS_H
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 /* These allocate new strings using gpr_malloc to convert from and to utf-8. */
 LPTSTR gpr_char_to_tchar(LPCSTR input);
 LPSTR gpr_tchar_to_char(LPCTSTR input);
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
 
-#endif /* GRPC_CORE_LIB_SUPPORT_STRING_WIN32_H */
+#endif /* GRPC_CORE_LIB_SUPPORT_STRING_WINDOWS_H */
diff --git a/src/core/lib/support/subprocess_windows.c b/src/core/lib/support/subprocess_windows.c
index 264306f1bd..dee8c44ac1 100644
--- a/src/core/lib/support/subprocess_windows.c
+++ b/src/core/lib/support/subprocess_windows.c
@@ -43,7 +43,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/subprocess.h>
 #include "src/core/lib/support/string.h"
-#include "src/core/lib/support/string_win32.h"
+#include "src/core/lib/support/string_windows.h"
 
 struct gpr_subprocess {
   PROCESS_INFORMATION pi;
diff --git a/src/core/lib/support/sync_win32.c b/src/core/lib/support/sync_windows.c
index 470a9f9704..8f0e8ff69f 100644
--- a/src/core/lib/support/sync_win32.c
+++ b/src/core/lib/support/sync_windows.c
@@ -35,7 +35,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
@@ -130,4 +130,4 @@ void gpr_once_init(gpr_once *once, void (*init_function)(void)) {
   InitOnceExecuteOnce(once, run_once_func, &arg, &dummy);
 }
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
diff --git a/src/core/lib/support/thd_win32.c b/src/core/lib/support/thd_windows.c
index 6deb3140eb..74d2250df4 100644
--- a/src/core/lib/support/thd_win32.c
+++ b/src/core/lib/support/thd_windows.c
@@ -35,7 +35,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
@@ -114,4 +114,4 @@ void gpr_thd_join(gpr_thd_id t) {
   destroy_thread(info);
 }
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
diff --git a/src/core/lib/support/time_win32.c b/src/core/lib/support/time_windows.c
index 9e924ab3f4..6459732879 100644
--- a/src/core/lib/support/time_win32.c
+++ b/src/core/lib/support/time_windows.c
@@ -35,7 +35,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32_TIME
+#ifdef GPR_WINDOWS_TIME
 
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
@@ -107,4 +107,4 @@ void gpr_sleep_until(gpr_timespec until) {
   }
 }
 
-#endif /* GPR_WIN32_TIME */
+#endif /* GPR_WINDOWS_TIME */
diff --git a/src/core/lib/support/tmpfile_msys.c b/src/core/lib/support/tmpfile_msys.c
index 2fdc89a64f..4f566c4c28 100644
--- a/src/core/lib/support/tmpfile_msys.c
+++ b/src/core/lib/support/tmpfile_msys.c
@@ -44,7 +44,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/string_win32.h"
+#include "src/core/lib/support/string_windows.h"
 #include "src/core/lib/support/tmpfile.h"
 
 FILE *gpr_tmpfile(const char *prefix, char **tmp_filename_out) {
diff --git a/src/core/lib/support/tmpfile_win32.c b/src/core/lib/support/tmpfile_windows.c
index 9ac73128c3..542f53e589 100644
--- a/src/core/lib/support/tmpfile_win32.c
+++ b/src/core/lib/support/tmpfile_windows.c
@@ -33,7 +33,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32_TMPFILE
+#ifdef GPR_WINDOWS_TMPFILE
 
 #include <io.h>
 #include <stdio.h>
@@ -44,7 +44,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/string_win32.h"
+#include "src/core/lib/support/string_windows.h"
 #include "src/core/lib/support/tmpfile.h"
 
 FILE *gpr_tmpfile(const char *prefix, char **tmp_filename_out) {
@@ -81,4 +81,4 @@ end:
   return result;
 }
 
-#endif /* GPR_WIN32_TMPFILE */
+#endif /* GPR_WINDOWS_TMPFILE */
diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
index 34ddfa75ad..e899bc8098 100644
--- a/src/core/lib/surface/call.c
+++ b/src/core/lib/surface/call.c
@@ -110,6 +110,7 @@ typedef struct batch_control {
 
 struct grpc_call {
   grpc_completion_queue *cq;
+  grpc_polling_entity pollent;
   grpc_channel *channel;
   grpc_call *parent;
   grpc_call *first_child;
@@ -151,7 +152,7 @@ struct grpc_call {
   received_status status[STATUS_SOURCE_COUNT];
 
   /* Call stats: only valid after trailing metadata received */
-  grpc_transport_stream_stats stats;
+  grpc_call_stats stats;
 
   /* Compression algorithm for the call */
   grpc_compression_algorithm compression_algorithm;
@@ -218,13 +219,11 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call_stack,
 static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
                                   bool success);
 
-grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
-                            uint32_t propagation_mask,
-                            grpc_completion_queue *cq,
-                            const void *server_transport_data,
-                            grpc_mdelem **add_initial_metadata,
-                            size_t add_initial_metadata_count,
-                            gpr_timespec send_deadline) {
+grpc_call *grpc_call_create(
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_completion_queue *cq, grpc_pollset_set *pollset_set_alternative,
+    const void *server_transport_data, grpc_mdelem **add_initial_metadata,
+    size_t add_initial_metadata_count, gpr_timespec send_deadline) {
   size_t i, j;
   grpc_channel_stack *channel_stack = grpc_channel_get_channel_stack(channel);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
@@ -261,9 +260,20 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
                        call->context, server_transport_data,
                        CALL_STACK_FROM_CALL(call));
   if (cq != NULL) {
+    GPR_ASSERT(
+        pollset_set_alternative == NULL &&
+        "Only one of 'cq' and 'pollset_set_alternative' should be non-NULL.");
     GRPC_CQ_INTERNAL_REF(cq, "bind");
-    grpc_call_stack_set_pollset(&exec_ctx, CALL_STACK_FROM_CALL(call),
-                                grpc_cq_pollset(cq));
+    call->pollent =
+        grpc_polling_entity_create_from_pollset(grpc_cq_pollset(cq));
+  }
+  if (pollset_set_alternative != NULL) {
+    call->pollent =
+        grpc_polling_entity_create_from_pollset_set(pollset_set_alternative);
+  }
+  if (!grpc_polling_entity_is_empty(&call->pollent)) {
+    grpc_call_stack_set_pollset_or_pollset_set(
+        &exec_ctx, CALL_STACK_FROM_CALL(call), &call->pollent);
   }
   if (parent_call != NULL) {
     GRPC_CALL_INTERNAL_REF(parent_call, "child");
@@ -318,10 +328,16 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
 void grpc_call_set_completion_queue(grpc_exec_ctx *exec_ctx, grpc_call *call,
                                     grpc_completion_queue *cq) {
   GPR_ASSERT(cq);
+
+  if (grpc_polling_entity_pollset_set(&call->pollent) != NULL) {
+    gpr_log(GPR_ERROR, "A pollset_set is already registered for this call.");
+    abort();
+  }
   call->cq = cq;
   GRPC_CQ_INTERNAL_REF(cq, "bind");
-  grpc_call_stack_set_pollset(exec_ctx, CALL_STACK_FROM_CALL(call),
-                              grpc_cq_pollset(cq));
+  call->pollent = grpc_polling_entity_create_from_pollset(grpc_cq_pollset(cq));
+  grpc_call_stack_set_pollset_or_pollset_set(
+      exec_ctx, CALL_STACK_FROM_CALL(call), &call->pollent);
 }
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
@@ -368,7 +384,7 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call, bool success) {
     GRPC_CQ_INTERNAL_UNREF(c->cq, "bind");
   }
   grpc_channel *channel = c->channel;
-  grpc_call_stack_destroy(exec_ctx, CALL_STACK_FROM_CALL(c), c);
+  grpc_call_stack_destroy(exec_ctx, CALL_STACK_FROM_CALL(c), &c->stats, c);
   GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel, "call");
   GPR_TIMER_END("destroy_call", 0);
 }
@@ -1397,7 +1413,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         bctl->recv_final_op = 1;
         stream_op.recv_trailing_metadata =
             &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
-        stream_op.collect_stats = &call->stats;
+        stream_op.collect_stats = &call->stats.transport_stream_stats;
         break;
       case GRPC_OP_RECV_CLOSE_ON_SERVER:
         /* Flag validation: currently allow no flags */
@@ -1419,7 +1435,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         bctl->recv_final_op = 1;
         stream_op.recv_trailing_metadata =
             &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
-        stream_op.collect_stats = &call->stats;
+        stream_op.collect_stats = &call->stats.transport_stream_stats;
         break;
     }
   }
diff --git a/src/core/lib/surface/call.h b/src/core/lib/surface/call.h
index 2725e060b8..b640345c21 100644
--- a/src/core/lib/surface/call.h
+++ b/src/core/lib/surface/call.h
@@ -53,6 +53,8 @@ typedef void (*grpc_ioreq_completion_func)(grpc_exec_ctx *exec_ctx,
 grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
                             uint32_t propagation_mask,
                             grpc_completion_queue *cq,
+                            /* if not NULL, it'll be used in lieu of \a cq */
+                            grpc_pollset_set *pollset_set_alternative,
                             const void *server_transport_data,
                             grpc_mdelem **add_initial_metadata,
                             size_t add_initial_metadata_count,
diff --git a/src/core/lib/surface/channel.c b/src/core/lib/surface/channel.c
index b6b760b5d8..a7ea6fa1f0 100644
--- a/src/core/lib/surface/channel.c
+++ b/src/core/lib/surface/channel.c
@@ -166,12 +166,14 @@ char *grpc_channel_get_target(grpc_channel *channel) {
 
 static grpc_call *grpc_channel_create_call_internal(
     grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
-    grpc_completion_queue *cq, grpc_mdelem *path_mdelem,
-    grpc_mdelem *authority_mdelem, gpr_timespec deadline) {
+    grpc_completion_queue *cq, grpc_pollset_set *pollset_set_alternative,
+    grpc_mdelem *path_mdelem, grpc_mdelem *authority_mdelem,
+    gpr_timespec deadline) {
   grpc_mdelem *send_metadata[2];
   size_t num_metadata = 0;
 
   GPR_ASSERT(channel->is_client);
+  GPR_ASSERT(!(cq != NULL && pollset_set_alternative != NULL));
 
   send_metadata[num_metadata++] = path_mdelem;
   if (authority_mdelem != NULL) {
@@ -180,8 +182,9 @@ static grpc_call *grpc_channel_create_call_internal(
     send_metadata[num_metadata++] = GRPC_MDELEM_REF(channel->default_authority);
   }
 
-  return grpc_call_create(channel, parent_call, propagation_mask, cq, NULL,
-                          send_metadata, num_metadata, deadline);
+  return grpc_call_create(channel, parent_call, propagation_mask, cq,
+                          pollset_set_alternative, NULL, send_metadata,
+                          num_metadata, deadline);
 }
 
 grpc_call *grpc_channel_create_call(grpc_channel *channel,
@@ -201,7 +204,22 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
            (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
-      channel, parent_call, propagation_mask, cq,
+      channel, parent_call, propagation_mask, cq, NULL,
+      grpc_mdelem_from_metadata_strings(GRPC_MDSTR_PATH,
+                                        grpc_mdstr_from_string(method)),
+      host ? grpc_mdelem_from_metadata_strings(GRPC_MDSTR_AUTHORITY,
+                                               grpc_mdstr_from_string(host))
+           : NULL,
+      deadline);
+}
+
+grpc_call *grpc_channel_create_pollset_set_call(
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_pollset_set *pollset_set, const char *method, const char *host,
+    gpr_timespec deadline, void *reserved) {
+  GPR_ASSERT(!reserved);
+  return grpc_channel_create_call_internal(
+      channel, parent_call, propagation_mask, NULL, pollset_set,
       grpc_mdelem_from_metadata_strings(GRPC_MDSTR_PATH,
                                         grpc_mdstr_from_string(method)),
       host ? grpc_mdelem_from_metadata_strings(GRPC_MDSTR_AUTHORITY,
@@ -245,7 +263,7 @@ grpc_call *grpc_channel_create_registered_call(
           (int)deadline.tv_nsec, (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
-      channel, parent_call, propagation_mask, completion_queue,
+      channel, parent_call, propagation_mask, completion_queue, NULL,
       GRPC_MDELEM_REF(rc->path),
       rc->authority ? GRPC_MDELEM_REF(rc->authority) : NULL, deadline);
 }
diff --git a/src/core/lib/surface/channel.h b/src/core/lib/surface/channel.h
index 22dae930e4..ff3debc31f 100644
--- a/src/core/lib/surface/channel.h
+++ b/src/core/lib/surface/channel.h
@@ -42,6 +42,11 @@ grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
                                   grpc_channel_stack_type channel_stack_type,
                                   grpc_transport *optional_transport);
 
+grpc_call *grpc_channel_create_pollset_set_call(
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_pollset_set *pollset_set, const char *method, const char *host,
+    gpr_timespec deadline, void *reserved);
+
 /** Get a (borrowed) pointer to this channels underlying channel stack */
 grpc_channel_stack *grpc_channel_get_channel_stack(grpc_channel *channel);
 
diff --git a/src/core/lib/surface/lame_client.c b/src/core/lib/surface/lame_client.c
index f50ec54cea..8223555382 100644
--- a/src/core/lib/surface/lame_client.c
+++ b/src/core/lib/surface/lame_client.c
@@ -91,8 +91,8 @@ static void lame_start_transport_op(grpc_exec_ctx *exec_ctx,
                                     grpc_channel_element *elem,
                                     grpc_transport_op *op) {
   if (op->on_connectivity_state_change) {
-    GPR_ASSERT(*op->connectivity_state != GRPC_CHANNEL_FATAL_FAILURE);
-    *op->connectivity_state = GRPC_CHANNEL_FATAL_FAILURE;
+    GPR_ASSERT(*op->connectivity_state != GRPC_CHANNEL_SHUTDOWN);
+    *op->connectivity_state = GRPC_CHANNEL_SHUTDOWN;
     op->on_connectivity_state_change->cb(
         exec_ctx, op->on_connectivity_state_change->cb_arg, 1);
   }
@@ -108,6 +108,7 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                            grpc_call_element_args *args) {}
 
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                              const grpc_call_stats *stats,
                               void *and_free_memory) {
   gpr_free(and_free_memory);
 }
@@ -127,7 +128,7 @@ const grpc_channel_filter grpc_lame_filter = {
     lame_start_transport_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
diff --git a/src/core/lib/surface/server.c b/src/core/lib/surface/server.c
index 505b501968..88d898bc1c 100644
--- a/src/core/lib/surface/server.c
+++ b/src/core/lib/surface/server.c
@@ -793,9 +793,9 @@ static void accept_stream(grpc_exec_ctx *exec_ctx, void *cd,
                           const void *transport_server_data) {
   channel_data *chand = cd;
   /* create a call */
-  grpc_call *call =
-      grpc_call_create(chand->channel, NULL, 0, NULL, transport_server_data,
-                       NULL, 0, gpr_inf_future(GPR_CLOCK_MONOTONIC));
+  grpc_call *call = grpc_call_create(chand->channel, NULL, 0, NULL, NULL,
+                                     transport_server_data, NULL, 0,
+                                     gpr_inf_future(GPR_CLOCK_MONOTONIC));
   grpc_call_element *elem =
       grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
   call_data *calld = elem->call_data;
@@ -812,7 +812,7 @@ static void channel_connectivity_changed(grpc_exec_ctx *exec_ctx, void *cd,
                                          bool iomgr_status_ignored) {
   channel_data *chand = cd;
   grpc_server *server = chand->server;
-  if (chand->connectivity_state != GRPC_CHANNEL_FATAL_FAILURE) {
+  if (chand->connectivity_state != GRPC_CHANNEL_SHUTDOWN) {
     grpc_transport_op op;
     memset(&op, 0, sizeof(op));
     op.on_connectivity_state_change = &chand->channel_connectivity_changed,
@@ -845,7 +845,7 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 }
 
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                              void *ignored) {
+                              const grpc_call_stats *stats, void *ignored) {
   channel_data *chand = elem->channel_data;
   call_data *calld = elem->call_data;
 
@@ -910,7 +910,7 @@ const grpc_channel_filter grpc_server_top_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
diff --git a/src/core/lib/transport/connectivity_state.c b/src/core/lib/transport/connectivity_state.c
index e24ee638fd..74a5ef5c13 100644
--- a/src/core/lib/transport/connectivity_state.c
+++ b/src/core/lib/transport/connectivity_state.c
@@ -51,7 +51,7 @@ const char *grpc_connectivity_state_name(grpc_connectivity_state state) {
       return "READY";
     case GRPC_CHANNEL_TRANSIENT_FAILURE:
       return "TRANSIENT_FAILURE";
-    case GRPC_CHANNEL_FATAL_FAILURE:
+    case GRPC_CHANNEL_SHUTDOWN:
       return "FATAL_FAILURE";
   }
   GPR_UNREACHABLE_CODE(return "UNKNOWN");
@@ -72,8 +72,8 @@ void grpc_connectivity_state_destroy(grpc_exec_ctx *exec_ctx,
   while ((w = tracker->watchers)) {
     tracker->watchers = w->next;
 
-    if (GRPC_CHANNEL_FATAL_FAILURE != *w->current) {
-      *w->current = GRPC_CHANNEL_FATAL_FAILURE;
+    if (GRPC_CHANNEL_SHUTDOWN != *w->current) {
+      *w->current = GRPC_CHANNEL_SHUTDOWN;
       success = 1;
     } else {
       success = 0;
@@ -153,7 +153,7 @@ void grpc_connectivity_state_set(grpc_exec_ctx *exec_ctx,
   if (tracker->current_state == state) {
     return;
   }
-  GPR_ASSERT(tracker->current_state != GRPC_CHANNEL_FATAL_FAILURE);
+  GPR_ASSERT(tracker->current_state != GRPC_CHANNEL_SHUTDOWN);
   tracker->current_state = state;
   while ((w = tracker->watchers) != NULL) {
     *w->current = tracker->current_state;
diff --git a/src/core/lib/transport/static_metadata.c b/src/core/lib/transport/static_metadata.c
index 73b0041fd4..c5f16e530d 100644
--- a/src/core/lib/transport/static_metadata.c
+++ b/src/core/lib/transport/static_metadata.c
@@ -48,7 +48,7 @@ uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT] = {
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 4, 8, 6, 2, 4, 8, 6, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 
 const uint8_t grpc_static_metadata_elem_indices[GRPC_STATIC_MDELEM_COUNT * 2] =
     {11, 35, 10, 35, 12, 35, 12, 49, 13, 35, 14, 35, 15, 35, 16, 35, 17, 35,
@@ -56,10 +56,10 @@ const uint8_t grpc_static_metadata_elem_indices[GRPC_STATIC_MDELEM_COUNT * 2] =
      30, 18, 30, 35, 31, 35, 32, 35, 36, 35, 37, 35, 38, 35, 39, 35, 42, 33,
      42, 34, 42, 48, 42, 53, 42, 54, 42, 55, 42, 56, 43, 33, 43, 48, 43, 53,
      46, 0,  46, 1,  46, 2,  50, 35, 57, 35, 58, 35, 59, 35, 60, 35, 61, 35,
-     62, 35, 63, 35, 64, 35, 65, 35, 66, 40, 66, 68, 66, 71, 67, 79, 67, 80,
-     69, 35, 70, 35, 72, 35, 73, 35, 74, 35, 75, 35, 76, 41, 76, 51, 76, 52,
-     77, 35, 78, 35, 81, 3,  81, 4,  81, 5,  81, 6,  81, 7,  81, 8,  81, 9,
-     82, 35, 83, 84, 85, 35, 86, 35, 87, 35, 88, 35, 89, 35};
+     62, 35, 63, 35, 64, 35, 65, 35, 66, 35, 67, 40, 67, 69, 67, 72, 68, 80,
+     68, 81, 70, 35, 71, 35, 73, 35, 74, 35, 75, 35, 76, 35, 77, 41, 77, 51,
+     77, 52, 78, 35, 79, 35, 82, 3,  82, 4,  82, 5,  82, 6,  82, 7,  82, 8,
+     82, 9,  83, 35, 84, 85, 86, 35, 87, 35, 88, 35, 89, 35, 90, 35};
 
 const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT] = {
     "0",
@@ -126,6 +126,7 @@ const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT] = {
     "if-unmodified-since",
     "last-modified",
     "link",
+    "load-reporting",
     "location",
     "max-forwards",
     ":method",
diff --git a/src/core/lib/transport/static_metadata.h b/src/core/lib/transport/static_metadata.h
index f9d8bcdc8f..5ff0d2f3bc 100644
--- a/src/core/lib/transport/static_metadata.h
+++ b/src/core/lib/transport/static_metadata.h
@@ -44,7 +44,7 @@
 
 #include "src/core/lib/transport/metadata.h"
 
-#define GRPC_STATIC_MDSTR_COUNT 90
+#define GRPC_STATIC_MDSTR_COUNT 91
 extern grpc_mdstr grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
 /* "0" */
 #define GRPC_MDSTR_0 (&grpc_static_mdstr_table[0])
@@ -175,60 +175,62 @@ extern grpc_mdstr grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
 #define GRPC_MDSTR_LAST_MODIFIED (&grpc_static_mdstr_table[62])
 /* "link" */
 #define GRPC_MDSTR_LINK (&grpc_static_mdstr_table[63])
+/* "load-reporting" */
+#define GRPC_MDSTR_LOAD_REPORTING (&grpc_static_mdstr_table[64])
 /* "location" */
-#define GRPC_MDSTR_LOCATION (&grpc_static_mdstr_table[64])
+#define GRPC_MDSTR_LOCATION (&grpc_static_mdstr_table[65])
 /* "max-forwards" */
-#define GRPC_MDSTR_MAX_FORWARDS (&grpc_static_mdstr_table[65])
+#define GRPC_MDSTR_MAX_FORWARDS (&grpc_static_mdstr_table[66])
 /* ":method" */
-#define GRPC_MDSTR_METHOD (&grpc_static_mdstr_table[66])
+#define GRPC_MDSTR_METHOD (&grpc_static_mdstr_table[67])
 /* ":path" */
-#define GRPC_MDSTR_PATH (&grpc_static_mdstr_table[67])
+#define GRPC_MDSTR_PATH (&grpc_static_mdstr_table[68])
 /* "POST" */
-#define GRPC_MDSTR_POST (&grpc_static_mdstr_table[68])
+#define GRPC_MDSTR_POST (&grpc_static_mdstr_table[69])
 /* "proxy-authenticate" */
-#define GRPC_MDSTR_PROXY_AUTHENTICATE (&grpc_static_mdstr_table[69])
+#define GRPC_MDSTR_PROXY_AUTHENTICATE (&grpc_static_mdstr_table[70])
 /* "proxy-authorization" */
-#define GRPC_MDSTR_PROXY_AUTHORIZATION (&grpc_static_mdstr_table[70])
+#define GRPC_MDSTR_PROXY_AUTHORIZATION (&grpc_static_mdstr_table[71])
 /* "PUT" */
-#define GRPC_MDSTR_PUT (&grpc_static_mdstr_table[71])
+#define GRPC_MDSTR_PUT (&grpc_static_mdstr_table[72])
 /* "range" */
-#define GRPC_MDSTR_RANGE (&grpc_static_mdstr_table[72])
+#define GRPC_MDSTR_RANGE (&grpc_static_mdstr_table[73])
 /* "referer" */
-#define GRPC_MDSTR_REFERER (&grpc_static_mdstr_table[73])
+#define GRPC_MDSTR_REFERER (&grpc_static_mdstr_table[74])
 /* "refresh" */
-#define GRPC_MDSTR_REFRESH (&grpc_static_mdstr_table[74])
+#define GRPC_MDSTR_REFRESH (&grpc_static_mdstr_table[75])
 /* "retry-after" */
-#define GRPC_MDSTR_RETRY_AFTER (&grpc_static_mdstr_table[75])
+#define GRPC_MDSTR_RETRY_AFTER (&grpc_static_mdstr_table[76])
 /* ":scheme" */
-#define GRPC_MDSTR_SCHEME (&grpc_static_mdstr_table[76])
+#define GRPC_MDSTR_SCHEME (&grpc_static_mdstr_table[77])
 /* "server" */
-#define GRPC_MDSTR_SERVER (&grpc_static_mdstr_table[77])
+#define GRPC_MDSTR_SERVER (&grpc_static_mdstr_table[78])
 /* "set-cookie" */
-#define GRPC_MDSTR_SET_COOKIE (&grpc_static_mdstr_table[78])
+#define GRPC_MDSTR_SET_COOKIE (&grpc_static_mdstr_table[79])
 /* "/" */
-#define GRPC_MDSTR_SLASH (&grpc_static_mdstr_table[79])
+#define GRPC_MDSTR_SLASH (&grpc_static_mdstr_table[80])
 /* "/index.html" */
-#define GRPC_MDSTR_SLASH_INDEX_DOT_HTML (&grpc_static_mdstr_table[80])
+#define GRPC_MDSTR_SLASH_INDEX_DOT_HTML (&grpc_static_mdstr_table[81])
 /* ":status" */
-#define GRPC_MDSTR_STATUS (&grpc_static_mdstr_table[81])
+#define GRPC_MDSTR_STATUS (&grpc_static_mdstr_table[82])
 /* "strict-transport-security" */
-#define GRPC_MDSTR_STRICT_TRANSPORT_SECURITY (&grpc_static_mdstr_table[82])
+#define GRPC_MDSTR_STRICT_TRANSPORT_SECURITY (&grpc_static_mdstr_table[83])
 /* "te" */
-#define GRPC_MDSTR_TE (&grpc_static_mdstr_table[83])
+#define GRPC_MDSTR_TE (&grpc_static_mdstr_table[84])
 /* "trailers" */
-#define GRPC_MDSTR_TRAILERS (&grpc_static_mdstr_table[84])
+#define GRPC_MDSTR_TRAILERS (&grpc_static_mdstr_table[85])
 /* "transfer-encoding" */
-#define GRPC_MDSTR_TRANSFER_ENCODING (&grpc_static_mdstr_table[85])
+#define GRPC_MDSTR_TRANSFER_ENCODING (&grpc_static_mdstr_table[86])
 /* "user-agent" */
-#define GRPC_MDSTR_USER_AGENT (&grpc_static_mdstr_table[86])
+#define GRPC_MDSTR_USER_AGENT (&grpc_static_mdstr_table[87])
 /* "vary" */
-#define GRPC_MDSTR_VARY (&grpc_static_mdstr_table[87])
+#define GRPC_MDSTR_VARY (&grpc_static_mdstr_table[88])
 /* "via" */
-#define GRPC_MDSTR_VIA (&grpc_static_mdstr_table[88])
+#define GRPC_MDSTR_VIA (&grpc_static_mdstr_table[89])
 /* "www-authenticate" */
-#define GRPC_MDSTR_WWW_AUTHENTICATE (&grpc_static_mdstr_table[89])
+#define GRPC_MDSTR_WWW_AUTHENTICATE (&grpc_static_mdstr_table[90])
 
-#define GRPC_STATIC_MDELEM_COUNT 79
+#define GRPC_STATIC_MDELEM_COUNT 80
 extern grpc_mdelem grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT];
 extern uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT];
 /* "accept-charset": "" */
@@ -333,71 +335,73 @@ extern uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT];
 #define GRPC_MDELEM_LAST_MODIFIED_EMPTY (&grpc_static_mdelem_table[45])
 /* "link": "" */
 #define GRPC_MDELEM_LINK_EMPTY (&grpc_static_mdelem_table[46])
+/* "load-reporting": "" */
+#define GRPC_MDELEM_LOAD_REPORTING_EMPTY (&grpc_static_mdelem_table[47])
 /* "location": "" */
-#define GRPC_MDELEM_LOCATION_EMPTY (&grpc_static_mdelem_table[47])
+#define GRPC_MDELEM_LOCATION_EMPTY (&grpc_static_mdelem_table[48])
 /* "max-forwards": "" */
-#define GRPC_MDELEM_MAX_FORWARDS_EMPTY (&grpc_static_mdelem_table[48])
+#define GRPC_MDELEM_MAX_FORWARDS_EMPTY (&grpc_static_mdelem_table[49])
 /* ":method": "GET" */
-#define GRPC_MDELEM_METHOD_GET (&grpc_static_mdelem_table[49])
+#define GRPC_MDELEM_METHOD_GET (&grpc_static_mdelem_table[50])
 /* ":method": "POST" */
-#define GRPC_MDELEM_METHOD_POST (&grpc_static_mdelem_table[50])
+#define GRPC_MDELEM_METHOD_POST (&grpc_static_mdelem_table[51])
 /* ":method": "PUT" */
-#define GRPC_MDELEM_METHOD_PUT (&grpc_static_mdelem_table[51])
+#define GRPC_MDELEM_METHOD_PUT (&grpc_static_mdelem_table[52])
 /* ":path": "/" */
-#define GRPC_MDELEM_PATH_SLASH (&grpc_static_mdelem_table[52])
+#define GRPC_MDELEM_PATH_SLASH (&grpc_static_mdelem_table[53])
 /* ":path": "/index.html" */
-#define GRPC_MDELEM_PATH_SLASH_INDEX_DOT_HTML (&grpc_static_mdelem_table[53])
+#define GRPC_MDELEM_PATH_SLASH_INDEX_DOT_HTML (&grpc_static_mdelem_table[54])
 /* "proxy-authenticate": "" */
-#define GRPC_MDELEM_PROXY_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[54])
+#define GRPC_MDELEM_PROXY_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[55])
 /* "proxy-authorization": "" */
-#define GRPC_MDELEM_PROXY_AUTHORIZATION_EMPTY (&grpc_static_mdelem_table[55])
+#define GRPC_MDELEM_PROXY_AUTHORIZATION_EMPTY (&grpc_static_mdelem_table[56])
 /* "range": "" */
-#define GRPC_MDELEM_RANGE_EMPTY (&grpc_static_mdelem_table[56])
+#define GRPC_MDELEM_RANGE_EMPTY (&grpc_static_mdelem_table[57])
 /* "referer": "" */
-#define GRPC_MDELEM_REFERER_EMPTY (&grpc_static_mdelem_table[57])
+#define GRPC_MDELEM_REFERER_EMPTY (&grpc_static_mdelem_table[58])
 /* "refresh": "" */
-#define GRPC_MDELEM_REFRESH_EMPTY (&grpc_static_mdelem_table[58])
+#define GRPC_MDELEM_REFRESH_EMPTY (&grpc_static_mdelem_table[59])
 /* "retry-after": "" */
-#define GRPC_MDELEM_RETRY_AFTER_EMPTY (&grpc_static_mdelem_table[59])
+#define GRPC_MDELEM_RETRY_AFTER_EMPTY (&grpc_static_mdelem_table[60])
 /* ":scheme": "grpc" */
-#define GRPC_MDELEM_SCHEME_GRPC (&grpc_static_mdelem_table[60])
+#define GRPC_MDELEM_SCHEME_GRPC (&grpc_static_mdelem_table[61])
 /* ":scheme": "http" */
-#define GRPC_MDELEM_SCHEME_HTTP (&grpc_static_mdelem_table[61])
+#define GRPC_MDELEM_SCHEME_HTTP (&grpc_static_mdelem_table[62])
 /* ":scheme": "https" */
-#define GRPC_MDELEM_SCHEME_HTTPS (&grpc_static_mdelem_table[62])
+#define GRPC_MDELEM_SCHEME_HTTPS (&grpc_static_mdelem_table[63])
 /* "server": "" */
-#define GRPC_MDELEM_SERVER_EMPTY (&grpc_static_mdelem_table[63])
+#define GRPC_MDELEM_SERVER_EMPTY (&grpc_static_mdelem_table[64])
 /* "set-cookie": "" */
-#define GRPC_MDELEM_SET_COOKIE_EMPTY (&grpc_static_mdelem_table[64])
+#define GRPC_MDELEM_SET_COOKIE_EMPTY (&grpc_static_mdelem_table[65])
 /* ":status": "200" */
-#define GRPC_MDELEM_STATUS_200 (&grpc_static_mdelem_table[65])
+#define GRPC_MDELEM_STATUS_200 (&grpc_static_mdelem_table[66])
 /* ":status": "204" */
-#define GRPC_MDELEM_STATUS_204 (&grpc_static_mdelem_table[66])
+#define GRPC_MDELEM_STATUS_204 (&grpc_static_mdelem_table[67])
 /* ":status": "206" */
-#define GRPC_MDELEM_STATUS_206 (&grpc_static_mdelem_table[67])
+#define GRPC_MDELEM_STATUS_206 (&grpc_static_mdelem_table[68])
 /* ":status": "304" */
-#define GRPC_MDELEM_STATUS_304 (&grpc_static_mdelem_table[68])
+#define GRPC_MDELEM_STATUS_304 (&grpc_static_mdelem_table[69])
 /* ":status": "400" */
-#define GRPC_MDELEM_STATUS_400 (&grpc_static_mdelem_table[69])
+#define GRPC_MDELEM_STATUS_400 (&grpc_static_mdelem_table[70])
 /* ":status": "404" */
-#define GRPC_MDELEM_STATUS_404 (&grpc_static_mdelem_table[70])
+#define GRPC_MDELEM_STATUS_404 (&grpc_static_mdelem_table[71])
 /* ":status": "500" */
-#define GRPC_MDELEM_STATUS_500 (&grpc_static_mdelem_table[71])
+#define GRPC_MDELEM_STATUS_500 (&grpc_static_mdelem_table[72])
 /* "strict-transport-security": "" */
 #define GRPC_MDELEM_STRICT_TRANSPORT_SECURITY_EMPTY \
-  (&grpc_static_mdelem_table[72])
+  (&grpc_static_mdelem_table[73])
 /* "te": "trailers" */
-#define GRPC_MDELEM_TE_TRAILERS (&grpc_static_mdelem_table[73])
+#define GRPC_MDELEM_TE_TRAILERS (&grpc_static_mdelem_table[74])
 /* "transfer-encoding": "" */
-#define GRPC_MDELEM_TRANSFER_ENCODING_EMPTY (&grpc_static_mdelem_table[74])
+#define GRPC_MDELEM_TRANSFER_ENCODING_EMPTY (&grpc_static_mdelem_table[75])
 /* "user-agent": "" */
-#define GRPC_MDELEM_USER_AGENT_EMPTY (&grpc_static_mdelem_table[75])
+#define GRPC_MDELEM_USER_AGENT_EMPTY (&grpc_static_mdelem_table[76])
 /* "vary": "" */
-#define GRPC_MDELEM_VARY_EMPTY (&grpc_static_mdelem_table[76])
+#define GRPC_MDELEM_VARY_EMPTY (&grpc_static_mdelem_table[77])
 /* "via": "" */
-#define GRPC_MDELEM_VIA_EMPTY (&grpc_static_mdelem_table[77])
+#define GRPC_MDELEM_VIA_EMPTY (&grpc_static_mdelem_table[78])
 /* "www-authenticate": "" */
-#define GRPC_MDELEM_WWW_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[78])
+#define GRPC_MDELEM_WWW_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[79])
 
 extern const uint8_t
     grpc_static_metadata_elem_indices[GRPC_STATIC_MDELEM_COUNT * 2];
diff --git a/src/core/lib/transport/transport.c b/src/core/lib/transport/transport.c
index e6d524abe6..b65e157a02 100644
--- a/src/core/lib/transport/transport.c
+++ b/src/core/lib/transport/transport.c
@@ -125,10 +125,19 @@ void grpc_transport_perform_op(grpc_exec_ctx *exec_ctx,
   transport->vtable->perform_op(exec_ctx, transport, op);
 }
 
-void grpc_transport_set_pollset(grpc_exec_ctx *exec_ctx,
-                                grpc_transport *transport, grpc_stream *stream,
-                                grpc_pollset *pollset) {
-  transport->vtable->set_pollset(exec_ctx, transport, stream, pollset);
+void grpc_transport_set_pops(grpc_exec_ctx *exec_ctx, grpc_transport *transport,
+                             grpc_stream *stream,
+                             grpc_polling_entity *pollent) {
+  grpc_pollset *pollset;
+  grpc_pollset_set *pollset_set;
+  if ((pollset = grpc_polling_entity_pollset(pollent)) != NULL) {
+    transport->vtable->set_pollset(exec_ctx, transport, stream, pollset);
+  } else if ((pollset_set = grpc_polling_entity_pollset_set(pollent)) != NULL) {
+    transport->vtable->set_pollset_set(exec_ctx, transport, stream,
+                                       pollset_set);
+  } else {
+    abort();
+  }
 }
 
 void grpc_transport_destroy_stream(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/lib/transport/transport.h b/src/core/lib/transport/transport.h
index 482a9d1791..ed06fc3ed2 100644
--- a/src/core/lib/transport/transport.h
+++ b/src/core/lib/transport/transport.h
@@ -37,6 +37,7 @@
 #include <stddef.h>
 
 #include "src/core/lib/channel/context.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 #include "src/core/lib/transport/byte_stream.h"
@@ -197,9 +198,8 @@ int grpc_transport_init_stream(grpc_exec_ctx *exec_ctx,
                                grpc_stream_refcount *refcount,
                                const void *server_data);
 
-void grpc_transport_set_pollset(grpc_exec_ctx *exec_ctx,
-                                grpc_transport *transport, grpc_stream *stream,
-                                grpc_pollset *pollset);
+void grpc_transport_set_pops(grpc_exec_ctx *exec_ctx, grpc_transport *transport,
+                             grpc_stream *stream, grpc_polling_entity *pollent);
 
 /* Destroy transport data for a stream.
 
diff --git a/src/core/lib/transport/transport_impl.h b/src/core/lib/transport/transport_impl.h
index 956155eec8..fc7140671b 100644
--- a/src/core/lib/transport/transport_impl.h
+++ b/src/core/lib/transport/transport_impl.h
@@ -53,6 +53,10 @@ typedef struct grpc_transport_vtable {
   void (*set_pollset)(grpc_exec_ctx *exec_ctx, grpc_transport *self,
                       grpc_stream *stream, grpc_pollset *pollset);
 
+  /* implementation of grpc_transport_set_pollset */
+  void (*set_pollset_set)(grpc_exec_ctx *exec_ctx, grpc_transport *self,
+                          grpc_stream *stream, grpc_pollset_set *pollset_set);
+
   /* implementation of grpc_transport_perform_stream_op */
   void (*perform_stream_op)(grpc_exec_ctx *exec_ctx, grpc_transport *self,
                             grpc_stream *stream, grpc_transport_stream_op *op);
diff --git a/src/core/plugin_registry/grpc_cronet_plugin_registry.c b/src/core/plugin_registry/grpc_cronet_plugin_registry.c
new file mode 100644
index 0000000000..d0b5f5c702
--- /dev/null
+++ b/src/core/plugin_registry/grpc_cronet_plugin_registry.c
@@ -0,0 +1,46 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/grpc.h>
+
+extern void grpc_chttp2_plugin_init(void);
+extern void grpc_chttp2_plugin_shutdown(void);
+extern void grpc_client_config_init(void);
+extern void grpc_client_config_shutdown(void);
+
+void grpc_register_built_in_plugins(void) {
+  grpc_register_plugin(grpc_chttp2_plugin_init,
+                       grpc_chttp2_plugin_shutdown);
+  grpc_register_plugin(grpc_client_config_init,
+                       grpc_client_config_shutdown);
+}
diff --git a/src/core/plugin_registry/grpc_plugin_registry.c b/src/core/plugin_registry/grpc_plugin_registry.c
index 822aa6d8b7..905cd59e23 100644
--- a/src/core/plugin_registry/grpc_plugin_registry.c
+++ b/src/core/plugin_registry/grpc_plugin_registry.c
@@ -45,6 +45,8 @@ extern void grpc_resolver_dns_native_init(void);
 extern void grpc_resolver_dns_native_shutdown(void);
 extern void grpc_resolver_sockaddr_init(void);
 extern void grpc_resolver_sockaddr_shutdown(void);
+extern void grpc_load_reporting_plugin_init(void);
+extern void grpc_load_reporting_plugin_shutdown(void);
 extern void census_grpc_plugin_init(void);
 extern void census_grpc_plugin_shutdown(void);
 
@@ -61,6 +63,8 @@ void grpc_register_built_in_plugins(void) {
                        grpc_resolver_dns_native_shutdown);
   grpc_register_plugin(grpc_resolver_sockaddr_init,
                        grpc_resolver_sockaddr_shutdown);
+  grpc_register_plugin(grpc_load_reporting_plugin_init,
+                       grpc_load_reporting_plugin_shutdown);
   grpc_register_plugin(census_grpc_plugin_init,
                        census_grpc_plugin_shutdown);
 }
diff --git a/src/core/plugin_registry/grpc_unsecure_plugin_registry.c b/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
index a6108ae7a9..7995078725 100644
--- a/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
+++ b/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
@@ -41,6 +41,8 @@ extern void grpc_resolver_dns_native_init(void);
 extern void grpc_resolver_dns_native_shutdown(void);
 extern void grpc_resolver_sockaddr_init(void);
 extern void grpc_resolver_sockaddr_shutdown(void);
+extern void grpc_load_reporting_plugin_init(void);
+extern void grpc_load_reporting_plugin_shutdown(void);
 extern void grpc_lb_policy_pick_first_init(void);
 extern void grpc_lb_policy_pick_first_shutdown(void);
 extern void grpc_lb_policy_round_robin_init(void);
@@ -57,6 +59,8 @@ void grpc_register_built_in_plugins(void) {
                        grpc_resolver_dns_native_shutdown);
   grpc_register_plugin(grpc_resolver_sockaddr_init,
                        grpc_resolver_sockaddr_shutdown);
+  grpc_register_plugin(grpc_load_reporting_plugin_init,
+                       grpc_load_reporting_plugin_shutdown);
   grpc_register_plugin(grpc_lb_policy_pick_first_init,
                        grpc_lb_policy_pick_first_shutdown);
   grpc_register_plugin(grpc_lb_policy_round_robin_init,
diff --git a/src/csharp/Grpc.Core.Tests/AppDomainUnloadTest.cs b/src/csharp/Grpc.Core.Tests/AppDomainUnloadTest.cs
new file mode 100644
index 0000000000..e605a310f9
--- /dev/null
+++ b/src/csharp/Grpc.Core.Tests/AppDomainUnloadTest.cs
@@ -0,0 +1,90 @@
+#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.Diagnostics;
+using System.Linq;
+using System.Reflection;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+
+namespace Grpc.Core.Tests
+{
+    public class AppDomainUnloadTest
+    {
+        [Test]
+        public void AppDomainUnloadHookCanCleanupAbandonedCall()
+        {
+            var setup = new AppDomainSetup
+            {
+                ApplicationBase = AppDomain.CurrentDomain.BaseDirectory
+            };
+            var childDomain = AppDomain.CreateDomain("test", null, setup);
+            var remoteObj = childDomain.CreateInstance(typeof(AppDomainTestClass).Assembly.GetName().Name, typeof(AppDomainTestClass).FullName);
+
+            // Try to unload the appdomain once we've created a server and a channel inside the appdomain.
+            AppDomain.Unload(childDomain);
+        }
+
+        public class AppDomainTestClass
+        {
+            const string Host = "127.0.0.1";
+
+            /// <summary>
+            /// Creates a server and a channel and initiates a call. The code is invoked from inside of an AppDomain
+            /// to test if AppDomain.Unload() work if Grpc is being used.
+            /// </summary>
+            public AppDomainTestClass()
+            {
+                var helper = new MockServiceHelper(Host);
+                var server = helper.GetServer();
+                server.Start();
+                var channel = helper.GetChannel();
+
+                var readyToShutdown = new TaskCompletionSource<object>();
+                helper.DuplexStreamingHandler = new DuplexStreamingServerMethod<string, string>(async (requestStream, responseStream, context) =>
+                {
+                    readyToShutdown.SetResult(null);
+                    await requestStream.ToListAsync();
+                });
+
+                var call = Calls.AsyncDuplexStreamingCall(helper.CreateDuplexStreamingCall());
+                readyToShutdown.Task.Wait();  // make sure handler is running
+            }
+        }
+    }
+}
diff --git a/src/csharp/Grpc.Core.Tests/ChannelTest.cs b/src/csharp/Grpc.Core.Tests/ChannelTest.cs
index 850d70ce92..db0ef3a4cd 100644
--- a/src/csharp/Grpc.Core.Tests/ChannelTest.cs
+++ b/src/csharp/Grpc.Core.Tests/ChannelTest.cs
@@ -71,7 +71,7 @@ namespace Grpc.Core.Tests
         public void WaitForStateChangedAsync_InvalidArgument()
         {
             var channel = new Channel("localhost", ChannelCredentials.Insecure);
-            Assert.ThrowsAsync(typeof(ArgumentException), async () => await channel.WaitForStateChangedAsync(ChannelState.FatalFailure));
+            Assert.ThrowsAsync(typeof(ArgumentException), async () => await channel.WaitForStateChangedAsync(ChannelState.Shutdown));
             channel.ShutdownAsync().Wait();
         }
 
@@ -102,11 +102,11 @@ namespace Grpc.Core.Tests
         }
 
         [Test]
-        public async Task StateIsFatalFailureAfterShutdown()
+        public async Task StateIsShutdownAfterShutdown()
         {
             var channel = new Channel("localhost", ChannelCredentials.Insecure);
             await channel.ShutdownAsync();
-            Assert.AreEqual(ChannelState.FatalFailure, channel.State);
+            Assert.AreEqual(ChannelState.Shutdown, channel.State);
         }
 
         [Test]
diff --git a/src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj b/src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj
index 47131fc454..074c9603dc 100644
--- a/src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj
+++ b/src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj
@@ -86,6 +86,10 @@
     <Compile Include="NUnitMain.cs" />
     <Compile Include="Internal\FakeNativeCall.cs" />
     <Compile Include="Internal\AsyncCallServerTest.cs" />
+    <Compile Include="ShutdownHookServerTest.cs" />
+    <Compile Include="ShutdownHookPendingCallTest.cs" />
+    <Compile Include="ShutdownHookClientTest.cs" />
+    <Compile Include="AppDomainUnloadTest.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>
diff --git a/src/csharp/Grpc.Core.Tests/GrpcEnvironmentTest.cs b/src/csharp/Grpc.Core.Tests/GrpcEnvironmentTest.cs
index 6fe382751a..3ec2cf48cd 100644
--- a/src/csharp/Grpc.Core.Tests/GrpcEnvironmentTest.cs
+++ b/src/csharp/Grpc.Core.Tests/GrpcEnvironmentTest.cs
@@ -49,7 +49,7 @@ namespace Grpc.Core.Tests
             {
                 Assert.IsNotNull(env.CompletionQueues.ElementAt(i));
             }
-            GrpcEnvironment.Release();
+            GrpcEnvironment.ReleaseAsync().Wait();
         }
 
         [Test]
@@ -58,8 +58,8 @@ namespace Grpc.Core.Tests
             var env1 = GrpcEnvironment.AddRef();
             var env2 = GrpcEnvironment.AddRef();
             Assert.AreSame(env1, env2);
-            GrpcEnvironment.Release();
-            GrpcEnvironment.Release();
+            GrpcEnvironment.ReleaseAsync().Wait();
+            GrpcEnvironment.ReleaseAsync().Wait();
         }
 
         [Test]
@@ -68,10 +68,10 @@ namespace Grpc.Core.Tests
             Assert.AreEqual(0, GrpcEnvironment.GetRefCount());
 
             var env1 = GrpcEnvironment.AddRef();
-            GrpcEnvironment.Release();
+            GrpcEnvironment.ReleaseAsync().Wait();
 
             var env2 = GrpcEnvironment.AddRef();
-            GrpcEnvironment.Release();
+            GrpcEnvironment.ReleaseAsync().Wait();
 
             Assert.AreNotSame(env1, env2);
         }
@@ -80,7 +80,7 @@ namespace Grpc.Core.Tests
         public void ReleaseWithoutAddRef()
         {
             Assert.AreEqual(0, GrpcEnvironment.GetRefCount());
-            Assert.Throws(typeof(InvalidOperationException), () => GrpcEnvironment.Release());
+            Assert.ThrowsAsync(typeof(InvalidOperationException), async () => await GrpcEnvironment.ReleaseAsync());
         }
 
         [Test]
diff --git a/src/csharp/Grpc.Core.Tests/Internal/CompletionQueueSafeHandleTest.cs b/src/csharp/Grpc.Core.Tests/Internal/CompletionQueueSafeHandleTest.cs
index 195119f920..e9ec59eb3d 100644
--- a/src/csharp/Grpc.Core.Tests/Internal/CompletionQueueSafeHandleTest.cs
+++ b/src/csharp/Grpc.Core.Tests/Internal/CompletionQueueSafeHandleTest.cs
@@ -48,7 +48,7 @@ namespace Grpc.Core.Internal.Tests
             GrpcEnvironment.AddRef();
             var cq = CompletionQueueSafeHandle.Create();
             cq.Dispose();
-            GrpcEnvironment.Release();
+            GrpcEnvironment.ReleaseAsync().Wait();
         }
 
         [Test]
@@ -59,7 +59,7 @@ namespace Grpc.Core.Internal.Tests
             cq.Shutdown();
             var ev = cq.Next();
             cq.Dispose();
-            GrpcEnvironment.Release();
+            GrpcEnvironment.ReleaseAsync().Wait();
             Assert.AreEqual(CompletionQueueEvent.CompletionType.Shutdown, ev.type);
             Assert.AreNotEqual(IntPtr.Zero, ev.success);
             Assert.AreEqual(IntPtr.Zero, ev.tag);
diff --git a/src/csharp/Grpc.Core.Tests/MockServiceHelper.cs b/src/csharp/Grpc.Core.Tests/MockServiceHelper.cs
index 3047314345..4d90470056 100644
--- a/src/csharp/Grpc.Core.Tests/MockServiceHelper.cs
+++ b/src/csharp/Grpc.Core.Tests/MockServiceHelper.cs
@@ -102,7 +102,7 @@ namespace Grpc.Core.Tests
                 marshaller,
                 marshaller);
 
-            serviceDefinition = ServerServiceDefinition.CreateBuilder(ServiceName)
+            serviceDefinition = ServerServiceDefinition.CreateBuilder()
                 .AddMethod(unaryMethod, (request, context) => unaryHandler(request, context))
                 .AddMethod(clientStreamingMethod, (requestStream, context) => clientStreamingHandler(requestStream, context))
                 .AddMethod(serverStreamingMethod, (request, responseStream, context) => serverStreamingHandler(request, responseStream, context))
diff --git a/src/csharp/Grpc.Core.Tests/PInvokeTest.cs b/src/csharp/Grpc.Core.Tests/PInvokeTest.cs
index d2b2fc6a66..d3735c7880 100644
--- a/src/csharp/Grpc.Core.Tests/PInvokeTest.cs
+++ b/src/csharp/Grpc.Core.Tests/PInvokeTest.cs
@@ -65,7 +65,7 @@ namespace Grpc.Core.Tests
                     cq.Dispose();
                 });
 
-            GrpcEnvironment.Release();
+            GrpcEnvironment.ReleaseAsync().Wait();
         }
 
         /// <summary>
diff --git a/src/csharp/Grpc.Core.Tests/ServerTest.cs b/src/csharp/Grpc.Core.Tests/ServerTest.cs
index b40508accc..fa693162ad 100644
--- a/src/csharp/Grpc.Core.Tests/ServerTest.cs
+++ b/src/csharp/Grpc.Core.Tests/ServerTest.cs
@@ -89,7 +89,7 @@ namespace Grpc.Core.Tests
             };
             server.Start();
             Assert.Throws(typeof(InvalidOperationException), () => server.Ports.Add("localhost", 9999, ServerCredentials.Insecure));
-            Assert.Throws(typeof(InvalidOperationException), () => server.Services.Add(ServerServiceDefinition.CreateBuilder("serviceName").Build()));
+            Assert.Throws(typeof(InvalidOperationException), () => server.Services.Add(ServerServiceDefinition.CreateBuilder().Build()));
 
             server.ShutdownAsync().Wait();
         }
diff --git a/src/proto/grpc/testing/perf_db.proto b/src/csharp/Grpc.Core.Tests/ShutdownHookClientTest.cs
index 0ba8596fe9..12b8452f64 100644
--- a/src/proto/grpc/testing/perf_db.proto
+++ b/src/csharp/Grpc.Core.Tests/ShutdownHookClientTest.cs
@@ -1,3 +1,5 @@
+#region Copyright notice and license
+
 // Copyright 2015, Google Inc.
 // All rights reserved.
 //
@@ -27,43 +29,29 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-syntax = "proto3";
-
-import "src/proto/grpc/testing/control.proto";
-
-package grpc.testing;
+#endregion
 
-service PerfDbTransfer {
-  // Sends client info
-  rpc RecordSingleClientData(SingleUserRecordRequest)
-      returns (SingleUserRecordReply) {}
-}
+using System;
+using System.Diagnostics;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+using NUnit.Framework;
 
-// Metrics to be stored
-message Metrics {
-  double qps = 1;
-  double qps_per_core = 2;
-  double perc_lat_50 = 3;
-  double perc_lat_90 = 4;
-  double perc_lat_95 = 5;
-  double perc_lat_99 = 6;
-  double perc_lat_99_point_9 = 7;
-  double server_system_time = 8;
-  double server_user_time = 9;
-  double client_system_time = 10;
-  double client_user_time = 11;
-}
+namespace Grpc.Core.Tests
+{
+    public class ShutdownHookClientTest
+    {
+        const string Host = "127.0.0.1";
 
-// Request for storing a single user's data
-message SingleUserRecordRequest {
-  string hashed_id = 1;
-  string test_name = 2;
-  string sys_info = 3;
-  string tag = 4;
-  Metrics metrics = 5;
-  ClientConfig client_config = 6;
-  ServerConfig server_config = 7;
+        [Test]
+        public void ProcessExitHookCanCleanupAbandonedChannels()
+        {
+            var channel = new Channel(Host, 1000, ChannelCredentials.Insecure);
+            var channel2 = new Channel(Host, 1001, ChannelCredentials.Insecure);
+        }
+    }
 }
-
-// Reply to request for storing single user's data
-message SingleUserRecordReply {}
diff --git a/src/csharp/Grpc.Core.Tests/ShutdownHookPendingCallTest.cs b/src/csharp/Grpc.Core.Tests/ShutdownHookPendingCallTest.cs
new file mode 100644
index 0000000000..175233840d
--- /dev/null
+++ b/src/csharp/Grpc.Core.Tests/ShutdownHookPendingCallTest.cs
@@ -0,0 +1,69 @@
+#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.Diagnostics;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+
+namespace Grpc.Core.Tests
+{
+    public class ShutdownHookPendingCallTest
+    {
+        const string Host = "127.0.0.1";
+
+        [Test]
+        public void ProcessExitHookCanCleanupAbandonedCall()
+        {
+            var helper = new MockServiceHelper(Host);
+            var server = helper.GetServer();
+            server.Start();
+            var channel = helper.GetChannel();
+
+            var readyToShutdown = new TaskCompletionSource<object>();
+            helper.DuplexStreamingHandler = new DuplexStreamingServerMethod<string, string>(async (requestStream, responseStream, context) =>
+            {
+                readyToShutdown.SetResult(null);
+                await requestStream.ToListAsync();
+            });
+
+            var call = Calls.AsyncDuplexStreamingCall(helper.CreateDuplexStreamingCall());
+            readyToShutdown.Task.Wait();  // make sure handler is running
+        }
+    }
+}
diff --git a/src/csharp/Grpc.Core.Tests/ShutdownHookServerTest.cs b/src/csharp/Grpc.Core.Tests/ShutdownHookServerTest.cs
new file mode 100644
index 0000000000..e7ea7a0bf5
--- /dev/null
+++ b/src/csharp/Grpc.Core.Tests/ShutdownHookServerTest.cs
@@ -0,0 +1,58 @@
+#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.Diagnostics;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+
+namespace Grpc.Core.Tests
+{
+    public class ShutdownHookServerTest
+    {
+        const string Host = "127.0.0.1";
+
+        [Test]
+        public void ProcessExitHookCanCleanupAbandonedServers()
+        {
+            var helper = new MockServiceHelper(Host);
+            var server = helper.GetServer();
+            server.Start();
+        }
+    }
+}
diff --git a/src/csharp/Grpc.Core/AsyncClientStreamingCall.cs b/src/csharp/Grpc.Core/AsyncClientStreamingCall.cs
index 5646fed3d9..02b08d2a10 100644
--- a/src/csharp/Grpc.Core/AsyncClientStreamingCall.cs
+++ b/src/csharp/Grpc.Core/AsyncClientStreamingCall.cs
@@ -127,6 +127,10 @@ namespace Grpc.Core
         /// Otherwise, requests cancellation of the call which should terminate all pending async operations associated with the call.
         /// As a result, all resources being used by the call should be released eventually.
         /// </summary>
+        /// <remarks>
+        /// Normally, there is no need for you to dispose the call unless you want to utilize the
+        /// "Cancel" semantics of invoking <c>Dispose</c>.
+        /// </remarks>
         public void Dispose()
         {
             disposeAction.Invoke();
diff --git a/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs b/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
index e75108c7e5..68fd6d0b05 100644
--- a/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
+++ b/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
@@ -117,6 +117,10 @@ namespace Grpc.Core
         /// Otherwise, requests cancellation of the call which should terminate all pending async operations associated with the call.
         /// As a result, all resources being used by the call should be released eventually.
         /// </summary>
+        /// <remarks>
+        /// Normally, there is no need for you to dispose the call unless you want to utilize the
+        /// "Cancel" semantics of invoking <c>Dispose</c>.
+        /// </remarks>
         public void Dispose()
         {
             disposeAction.Invoke();
diff --git a/src/csharp/Grpc.Core/AsyncServerStreamingCall.cs b/src/csharp/Grpc.Core/AsyncServerStreamingCall.cs
index f953091984..5777c72615 100644
--- a/src/csharp/Grpc.Core/AsyncServerStreamingCall.cs
+++ b/src/csharp/Grpc.Core/AsyncServerStreamingCall.cs
@@ -103,6 +103,10 @@ namespace Grpc.Core
         /// Otherwise, requests cancellation of the call which should terminate all pending async operations associated with the call.
         /// As a result, all resources being used by the call should be released eventually.
         /// </summary>
+        /// <remarks>
+        /// Normally, there is no need for you to dispose the call unless you want to utilize the
+        /// "Cancel" semantics of invoking <c>Dispose</c>.
+        /// </remarks>
         public void Dispose()
         {
             disposeAction.Invoke();
diff --git a/src/csharp/Grpc.Core/AsyncUnaryCall.cs b/src/csharp/Grpc.Core/AsyncUnaryCall.cs
index 97df8f5e91..d180c27922 100644
--- a/src/csharp/Grpc.Core/AsyncUnaryCall.cs
+++ b/src/csharp/Grpc.Core/AsyncUnaryCall.cs
@@ -112,6 +112,10 @@ namespace Grpc.Core
         /// Otherwise, requests cancellation of the call which should terminate all pending async operations associated with the call.
         /// As a result, all resources being used by the call should be released eventually.
         /// </summary>
+        /// <remarks>
+        /// Normally, there is no need for you to dispose the call unless you want to utilize the
+        /// "Cancel" semantics of invoking <c>Dispose</c>.
+        /// </remarks>
         public void Dispose()
         {
             disposeAction.Invoke();
diff --git a/src/csharp/Grpc.Core/CallOptions.cs b/src/csharp/Grpc.Core/CallOptions.cs
index 9ca88849ee..35548cfc96 100644
--- a/src/csharp/Grpc.Core/CallOptions.cs
+++ b/src/csharp/Grpc.Core/CallOptions.cs
@@ -88,7 +88,13 @@ namespace Grpc.Core
         }
 
         /// <summary>
-        /// Token that can be used for cancelling the call.
+        /// Token that can be used for cancelling the call on the client side.
+        /// Cancelling the token will request cancellation
+        /// of the remote call. Best effort will be made to deliver the cancellation
+        /// notification to the server and interaction of the call with the server side
+        /// will be terminated. Unless the call finishes before the cancellation could
+        /// happen (there is an inherent race),
+        /// the call will finish with <c>StatusCode.Cancelled</c> status.
         /// </summary>
         public CancellationToken CancellationToken
         {
diff --git a/src/csharp/Grpc.Core/Channel.cs b/src/csharp/Grpc.Core/Channel.cs
index 886adfec33..4f29c35b32 100644
--- a/src/csharp/Grpc.Core/Channel.cs
+++ b/src/csharp/Grpc.Core/Channel.cs
@@ -67,8 +67,19 @@ namespace Grpc.Core
         /// </summary>
         /// <param name="target">Target of the channel.</param>
         /// <param name="credentials">Credentials to secure the channel.</param>
+        public Channel(string target, ChannelCredentials credentials) :
+            this(target, credentials, null)
+        {
+        }
+
+        /// <summary>
+        /// Creates a channel that connects to a specific host.
+        /// Port will default to 80 for an unsecure channel and to 443 for a secure channel.
+        /// </summary>
+        /// <param name="target">Target of the channel.</param>
+        /// <param name="credentials">Credentials to secure the channel.</param>
         /// <param name="options">Channel options.</param>
-        public Channel(string target, ChannelCredentials credentials, IEnumerable<ChannelOption> options = null)
+        public Channel(string target, ChannelCredentials credentials, IEnumerable<ChannelOption> options)
         {
             this.target = GrpcPreconditions.CheckNotNull(target, "target");
             this.options = CreateOptionsDictionary(options);
@@ -88,6 +99,18 @@ namespace Grpc.Core
                     this.handle = ChannelSafeHandle.CreateInsecure(target, nativeChannelArgs);
                 }
             }
+            GrpcEnvironment.RegisterChannel(this);
+        }
+
+        /// <summary>
+        /// Creates a channel that connects to a specific host and port.
+        /// </summary>
+        /// <param name="host">The name or IP address of the host.</param>
+        /// <param name="port">The port.</param>
+        /// <param name="credentials">Credentials to secure the channel.</param>
+        public Channel(string host, int port, ChannelCredentials credentials) :
+            this(host, port, credentials, null)
+        {
         }
 
         /// <summary>
@@ -97,14 +120,14 @@ namespace Grpc.Core
         /// <param name="port">The port.</param>
         /// <param name="credentials">Credentials to secure the channel.</param>
         /// <param name="options">Channel options.</param>
-        public Channel(string host, int port, ChannelCredentials credentials, IEnumerable<ChannelOption> options = null) :
+        public Channel(string host, int port, ChannelCredentials credentials, IEnumerable<ChannelOption> options) :
             this(string.Format("{0}:{1}", host, port), credentials, options)
         {
         }
 
         /// <summary>
         /// Gets current connectivity state of this channel.
-        /// After channel is has been shutdown, <c>ChannelState.FatalFailure</c> will be returned.
+        /// After channel is has been shutdown, <c>ChannelState.Shutdown</c> will be returned.
         /// </summary>
         public ChannelState State
         {
@@ -121,8 +144,8 @@ namespace Grpc.Core
         /// </summary>
         public Task WaitForStateChangedAsync(ChannelState lastObservedState, DateTime? deadline = null)
         {
-            GrpcPreconditions.CheckArgument(lastObservedState != ChannelState.FatalFailure,
-                "FatalFailure is a terminal state. No further state changes can occur.");
+            GrpcPreconditions.CheckArgument(lastObservedState != ChannelState.Shutdown,
+                "Shutdown is a terminal state. No further state changes can occur.");
             var tcs = new TaskCompletionSource<object>();
             var deadlineTimespec = deadline.HasValue ? Timespec.FromDateTime(deadline.Value) : Timespec.InfFuture;
             var handler = new BatchCompletionDelegate((success, ctx) =>
@@ -172,7 +195,7 @@ namespace Grpc.Core
         /// <summary>
         /// Allows explicitly requesting channel to connect without starting an RPC.
         /// Returned task completes once state Ready was seen. If the deadline is reached,
-        /// or channel enters the FatalFailure state, the task is cancelled.
+        /// or channel enters the Shutdown state, the task is cancelled.
         /// There is no need to call this explicitly unless your use case requires that.
         /// Starting an RPC on a new channel will request connection implicitly.
         /// </summary>
@@ -182,9 +205,9 @@ namespace Grpc.Core
             var currentState = GetConnectivityState(true);
             while (currentState != ChannelState.Ready)
             {
-                if (currentState == ChannelState.FatalFailure)
+                if (currentState == ChannelState.Shutdown)
                 {
-                    throw new OperationCanceledException("Channel has reached FatalFailure state.");
+                    throw new OperationCanceledException("Channel has reached Shutdown state.");
                 }
                 await WaitForStateChangedAsync(currentState, deadline).ConfigureAwait(false);
                 currentState = GetConnectivityState(false);
@@ -192,9 +215,16 @@ namespace Grpc.Core
         }
 
         /// <summary>
-        /// Waits until there are no more active calls for this channel and then cleans up
-        /// resources used by this channel.
+        /// Shuts down the channel cleanly. It is strongly recommended to shutdown
+        /// all previously created channels before exiting from the process.
         /// </summary>
+        /// <remarks>
+        /// This method doesn't wait for all calls on this channel to finish (nor does
+        /// it explicitly cancel all outstanding calls). It is user's responsibility to make sure
+        /// all the calls on this channel have finished (successfully or with an error)
+        /// before shutting down the channel to ensure channel shutdown won't impact
+        /// the outcome of those remote calls.
+        /// </remarks>
         public async Task ShutdownAsync()
         {
             lock (myLock)
@@ -202,6 +232,7 @@ namespace Grpc.Core
                 GrpcPreconditions.CheckState(!shutdownRequested);
                 shutdownRequested = true;
             }
+            GrpcEnvironment.UnregisterChannel(this);
 
             shutdownTokenSource.Cancel();
 
@@ -213,7 +244,7 @@ namespace Grpc.Core
 
             handle.Dispose();
 
-            await Task.Run(() => GrpcEnvironment.Release()).ConfigureAwait(false);
+            await GrpcEnvironment.ReleaseAsync().ConfigureAwait(false);
         }
 
         internal ChannelSafeHandle Handle
@@ -264,7 +295,7 @@ namespace Grpc.Core
             }
             catch (ObjectDisposedException)
             {
-                return ChannelState.FatalFailure;
+                return ChannelState.Shutdown;
             }
         }
 
diff --git a/src/csharp/Grpc.Core/ChannelState.cs b/src/csharp/Grpc.Core/ChannelState.cs
index d293b98f75..a6c3b2a488 100644
--- a/src/csharp/Grpc.Core/ChannelState.cs
+++ b/src/csharp/Grpc.Core/ChannelState.cs
@@ -64,6 +64,6 @@ namespace Grpc.Core
         /// <summary>
         /// Channel has seen a failure that it cannot recover from
         /// </summary>
-        FatalFailure
+        Shutdown
     }
 }
diff --git a/src/csharp/Grpc.Core/GrpcEnvironment.cs b/src/csharp/Grpc.Core/GrpcEnvironment.cs
index 18af1099f1..0359d9092a 100644
--- a/src/csharp/Grpc.Core/GrpcEnvironment.cs
+++ b/src/csharp/Grpc.Core/GrpcEnvironment.cs
@@ -35,6 +35,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.InteropServices;
+using System.Threading.Tasks;
 using Grpc.Core.Internal;
 using Grpc.Core.Logging;
 using Grpc.Core.Utils;
@@ -53,12 +54,16 @@ namespace Grpc.Core
         static int refCount;
         static int? customThreadPoolSize;
         static int? customCompletionQueueCount;
+        static readonly HashSet<Channel> registeredChannels = new HashSet<Channel>();
+        static readonly HashSet<Server> registeredServers = new HashSet<Server>();
 
         static ILogger logger = new ConsoleLogger();
 
+        readonly object myLock = new object();
         readonly GrpcThreadPool threadPool;
         readonly DebugStats debugStats = new DebugStats();
         readonly AtomicCounter cqPickerCounter = new AtomicCounter();
+
         bool isClosed;
 
         /// <summary>
@@ -67,6 +72,8 @@ namespace Grpc.Core
         /// </summary>
         internal static GrpcEnvironment AddRef()
         {
+            ShutdownHooks.Register();
+
             lock (staticLock)
             {
                 refCount++;
@@ -79,21 +86,26 @@ namespace Grpc.Core
         }
 
         /// <summary>
-        /// Decrements the reference count for currently active environment and shuts down the gRPC environment if reference count drops to zero.
-        /// (and blocks until the environment has been fully shutdown).
+        /// Decrements the reference count for currently active environment and asynchronously shuts down the gRPC environment if reference count drops to zero.
         /// </summary>
-        internal static void Release()
+        internal static async Task ReleaseAsync()
         {
+            GrpcEnvironment instanceToShutdown = null;
             lock (staticLock)
             {
                 GrpcPreconditions.CheckState(refCount > 0);
                 refCount--;
                 if (refCount == 0)
                 {
-                    instance.Close();
+                    instanceToShutdown = instance;
                     instance = null;
                 }
             }
+
+            if (instanceToShutdown != null)
+            {
+                await instanceToShutdown.ShutdownAsync();
+            }
         }
 
         internal static int GetRefCount()
@@ -104,6 +116,68 @@ namespace Grpc.Core
             }
         }
 
+        internal static void RegisterChannel(Channel channel)
+        {
+            lock (staticLock)
+            {
+                GrpcPreconditions.CheckNotNull(channel);
+                registeredChannels.Add(channel);
+            }
+        }
+
+        internal static void UnregisterChannel(Channel channel)
+        {
+            lock (staticLock)
+            {
+                GrpcPreconditions.CheckNotNull(channel);
+                GrpcPreconditions.CheckArgument(registeredChannels.Remove(channel), "Channel not found in the registered channels set.");
+            }
+        }
+
+        internal static void RegisterServer(Server server)
+        {
+            lock (staticLock)
+            {
+                GrpcPreconditions.CheckNotNull(server);
+                registeredServers.Add(server);
+            }
+        }
+
+        internal static void UnregisterServer(Server server)
+        {
+            lock (staticLock)
+            {
+                GrpcPreconditions.CheckNotNull(server);
+                GrpcPreconditions.CheckArgument(registeredServers.Remove(server), "Server not found in the registered servers set.");
+            }
+        }
+
+        /// <summary>
+        /// Requests shutdown of all channels created by the current process.
+        /// </summary>
+        public static Task ShutdownChannelsAsync()
+        {
+            HashSet<Channel> snapshot = null;
+            lock (staticLock)
+            {
+                snapshot = new HashSet<Channel>(registeredChannels);
+            }
+            return Task.WhenAll(snapshot.Select((channel) => channel.ShutdownAsync()));
+        }
+
+        /// <summary>
+        /// Requests immediate shutdown of all servers created by the current process.
+        /// </summary>
+        public static Task KillServersAsync()
+        {
+            HashSet<Server> snapshot = null;
+            lock (staticLock)
+            {
+                snapshot = new HashSet<Server>(registeredServers);
+            }
+            return Task.WhenAll(snapshot.Select((server) => server.KillAsync()));
+        }
+
         /// <summary>
         /// Gets application-wide logger used by gRPC.
         /// </summary>
@@ -180,6 +254,14 @@ namespace Grpc.Core
             }
         }
 
+        internal bool IsAlive
+        {
+            get
+            {
+                return this.threadPool.IsAlive;
+            }
+        }
+
         /// <summary>
         /// Picks a completion queue in a round-robin fashion.
         /// Shouldn't be invoked on a per-call basis (used at per-channel basis).
@@ -223,13 +305,13 @@ namespace Grpc.Core
         /// <summary>
         /// Shuts down this environment.
         /// </summary>
-        private void Close()
+        private async Task ShutdownAsync()
         {
             if (isClosed)
             {
                 throw new InvalidOperationException("Close has already been called");
             }
-            threadPool.Stop();
+            await threadPool.StopAsync().ConfigureAwait(false);
             GrpcNativeShutdown();
             isClosed = true;
 
@@ -257,5 +339,32 @@ namespace Grpc.Core
             // by default, create a completion queue for each thread
             return GetThreadPoolSizeOrDefault();
         }
+
+        private static class ShutdownHooks
+        {
+            static object staticLock = new object();
+            static bool hooksRegistered;
+
+            public static void Register()
+            {
+                lock (staticLock)
+                {
+                    if (!hooksRegistered)
+                    {
+                        AppDomain.CurrentDomain.ProcessExit += ShutdownHookHandler;
+                        AppDomain.CurrentDomain.DomainUnload += ShutdownHookHandler;
+                    }
+                    hooksRegistered = true;
+                }
+            }
+
+            /// <summary>
+            /// Handler for AppDomain.DomainUnload and AppDomain.ProcessExit hooks.
+            /// </summary>
+            private static void ShutdownHookHandler(object sender, EventArgs e)
+            {
+                Task.WaitAll(GrpcEnvironment.ShutdownChannelsAsync(), GrpcEnvironment.KillServersAsync());
+            }
+        }
     }
 }
diff --git a/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs b/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
index 4de543bef7..a446c1f99f 100644
--- a/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
+++ b/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
@@ -35,6 +35,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
+using System.Threading.Tasks;
 using Grpc.Core.Logging;
 using Grpc.Core.Utils;
 
@@ -53,6 +54,8 @@ namespace Grpc.Core.Internal
         readonly int poolSize;
         readonly int completionQueueCount;
 
+        bool stopRequested;
+
         IReadOnlyCollection<CompletionQueueSafeHandle> completionQueues;
 
         /// <summary>
@@ -84,15 +87,21 @@ namespace Grpc.Core.Internal
             }
         }
 
-        public void Stop()
+        public Task StopAsync()
         {
             lock (myLock)
             {
+                GrpcPreconditions.CheckState(!stopRequested, "Stop already requested.");
+                stopRequested = true;
+
                 foreach (var cq in completionQueues)
                 {
                     cq.Shutdown();
                 }
+            }
 
+            return Task.Run(() =>
+            {
                 foreach (var thread in threads)
                 {
                     thread.Join();
@@ -102,6 +111,21 @@ namespace Grpc.Core.Internal
                 {
                     cq.Dispose();
                 }
+            });
+        }
+
+        /// <summary>
+        /// Returns true if there is at least one thread pool thread that hasn't
+        /// already stopped.
+        /// Threads can either stop because all completion queues shut down or
+        /// because all foreground threads have already shutdown and process is
+        /// going to exit.
+        /// </summary>
+        internal bool IsAlive
+        {
+            get
+            {
+                return threads.Any(t => t.ThreadState != ThreadState.Stopped);
             }
         }
 
@@ -119,7 +143,7 @@ namespace Grpc.Core.Internal
             var cq = completionQueues.ElementAt(cqIndex);
 
             var thread = new Thread(new ThreadStart(() => RunHandlerLoop(cq)));
-            thread.IsBackground = false;
+            thread.IsBackground = true;
             thread.Name = string.Format("grpc {0} (cq {1})", threadIndex, cqIndex);
             thread.Start();
 
diff --git a/src/csharp/Grpc.Core/Server.cs b/src/csharp/Grpc.Core/Server.cs
index 069185e13a..ae7a8c9a9a 100644
--- a/src/csharp/Grpc.Core/Server.cs
+++ b/src/csharp/Grpc.Core/Server.cs
@@ -67,11 +67,19 @@ namespace Grpc.Core
         bool startRequested;
         volatile bool shutdownRequested;
 
+
+        /// <summary>
+        /// Creates a new server.
+        /// </summary>
+        public Server() : this(null)
+        {
+        }
+
         /// <summary>
-        /// Create a new server.
+        /// Creates a new server.
         /// </summary>
         /// <param name="options">Channel options.</param>
-        public Server(IEnumerable<ChannelOption> options = null)
+        public Server(IEnumerable<ChannelOption> options)
         {
             this.serviceDefinitions = new ServiceDefinitionCollection(this);
             this.ports = new ServerPortCollection(this);
@@ -86,6 +94,7 @@ namespace Grpc.Core
             {
                 this.handle.RegisterCompletionQueue(cq);
             }
+            GrpcEnvironment.RegisterServer(this);
         }
 
         /// <summary>
@@ -152,43 +161,24 @@ namespace Grpc.Core
         /// cleans up used resources. The returned task finishes when shutdown procedure
         /// is complete.
         /// </summary>
-        public async Task ShutdownAsync()
+        /// <remarks>
+        /// It is strongly recommended to shutdown all previously created servers before exiting from the process.
+        /// </remarks>
+        public Task ShutdownAsync()
         {
-            lock (myLock)
-            {
-                GrpcPreconditions.CheckState(startRequested);
-                GrpcPreconditions.CheckState(!shutdownRequested);
-                shutdownRequested = true;
-            }
-
-            var cq = environment.CompletionQueues.First();  // any cq will do
-            handle.ShutdownAndNotify(HandleServerShutdown, cq);
-            await shutdownTcs.Task.ConfigureAwait(false);
-            DisposeHandle();
-
-            await Task.Run(() => GrpcEnvironment.Release()).ConfigureAwait(false);
+            return ShutdownInternalAsync(false);
         }
 
         /// <summary>
         /// Requests server shutdown while cancelling all the in-progress calls.
         /// The returned task finishes when shutdown procedure is complete.
         /// </summary>
-        public async Task KillAsync()
+        /// <remarks>
+        /// It is strongly recommended to shutdown all previously created servers before exiting from the process.
+        /// </remarks>
+        public Task KillAsync()
         {
-            lock (myLock)
-            {
-                GrpcPreconditions.CheckState(startRequested);
-                GrpcPreconditions.CheckState(!shutdownRequested);
-                shutdownRequested = true;
-            }
-
-            var cq = environment.CompletionQueues.First();  // any cq will do
-            handle.ShutdownAndNotify(HandleServerShutdown, cq);
-            handle.CancelAllCalls();
-            await shutdownTcs.Task.ConfigureAwait(false);
-            DisposeHandle();
-
-            await Task.Run(() => GrpcEnvironment.Release()).ConfigureAwait(false);
+            return ShutdownInternalAsync(true);
         }
 
         internal void AddCallReference(object call)
@@ -207,6 +197,53 @@ namespace Grpc.Core
         }
 
         /// <summary>
+        /// Shuts down the server.
+        /// </summary>
+        private async Task ShutdownInternalAsync(bool kill)
+        {
+            lock (myLock)
+            {
+                GrpcPreconditions.CheckState(startRequested);
+                GrpcPreconditions.CheckState(!shutdownRequested);
+                shutdownRequested = true;
+            }
+            GrpcEnvironment.UnregisterServer(this);
+
+            var cq = environment.CompletionQueues.First();  // any cq will do
+            handle.ShutdownAndNotify(HandleServerShutdown, cq);
+            if (kill)
+            {
+                handle.CancelAllCalls();
+            }
+
+            await ShutdownCompleteOrEnvironmentDeadAsync().ConfigureAwait(false);
+
+            DisposeHandle();
+
+            await GrpcEnvironment.ReleaseAsync().ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// In case the environment's threadpool becomes dead, the shutdown completion will
+        /// never be delivered, but we need to release the environment's handle anyway.
+        /// </summary>
+        private async Task ShutdownCompleteOrEnvironmentDeadAsync()
+        {
+            while (true)
+            {
+                var task = await Task.WhenAny(shutdownTcs.Task, Task.Delay(20)).ConfigureAwait(false);
+                if (shutdownTcs.Task == task)
+                {
+                    return;
+                }
+                if (!environment.IsAlive)
+                {
+                    return;
+                }
+            }
+        }
+
+        /// <summary>
         /// Adds a service definition.
         /// </summary>
         private void AddServiceDefinitionInternal(ServerServiceDefinition serviceDefinition)
diff --git a/src/csharp/Grpc.Core/ServerServiceDefinition.cs b/src/csharp/Grpc.Core/ServerServiceDefinition.cs
index deb1431ca3..ac08c04bf6 100644
--- a/src/csharp/Grpc.Core/ServerServiceDefinition.cs
+++ b/src/csharp/Grpc.Core/ServerServiceDefinition.cs
@@ -63,11 +63,10 @@ namespace Grpc.Core
         /// <summary>
         /// Creates a new builder object for <c>ServerServiceDefinition</c>.
         /// </summary>
-        /// <param name="serviceName">The service name.</param>
         /// <returns>The builder object.</returns>
-        public static Builder CreateBuilder(string serviceName)
+        public static Builder CreateBuilder()
         {
-            return new Builder(serviceName);
+            return new Builder();
         }
 
         /// <summary>
@@ -75,16 +74,13 @@ namespace Grpc.Core
         /// </summary>
         public class Builder
         {
-            readonly string serviceName;
             readonly Dictionary<string, IServerCallHandler> callHandlers = new Dictionary<string, IServerCallHandler>();
 
             /// <summary>
             /// Creates a new instance of builder.
             /// </summary>
-            /// <param name="serviceName">The service name.</param>
-            public Builder(string serviceName)
+            public Builder()
             {
-                this.serviceName = serviceName;
             }
 
             /// <summary>
diff --git a/src/csharp/Grpc.Examples/MathGrpc.cs b/src/csharp/Grpc.Examples/MathGrpc.cs
index d700a18778..4bbefcbe01 100644
--- a/src/csharp/Grpc.Examples/MathGrpc.cs
+++ b/src/csharp/Grpc.Examples/MathGrpc.cs
@@ -81,103 +81,12 @@ namespace Math {
       get { return global::Math.MathReflection.Descriptor.Services[0]; }
     }
 
-    /// <summary>Client for Math</summary>
-    [System.Obsolete("Client side interfaced will be removed in the next release. Use client class directly.")]
-    public interface IMathClient
-    {
-      /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
-      /// </summary>
-      global::Math.DivReply Div(global::Math.DivArgs request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
-      /// </summary>
-      global::Math.DivReply Div(global::Math.DivArgs request, CallOptions options);
-      /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
-      /// </summary>
-      AsyncUnaryCall<global::Math.DivReply> DivAsync(global::Math.DivArgs request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
-      /// </summary>
-      AsyncUnaryCall<global::Math.DivReply> DivAsync(global::Math.DivArgs request, CallOptions options);
-      /// <summary>
-      ///  DivMany accepts an arbitrary number of division args from the client stream
-      ///  and sends back the results in the reply stream.  The stream continues until
-      ///  the client closes its end; the server does the same after sending all the
-      ///  replies.  The stream ends immediately if either end aborts.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Math.DivArgs, global::Math.DivReply> DivMany(Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  DivMany accepts an arbitrary number of division args from the client stream
-      ///  and sends back the results in the reply stream.  The stream continues until
-      ///  the client closes its end; the server does the same after sending all the
-      ///  replies.  The stream ends immediately if either end aborts.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Math.DivArgs, global::Math.DivReply> DivMany(CallOptions options);
-      /// <summary>
-      ///  Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
-      ///  generates up to limit numbers; otherwise it continues until the call is
-      ///  canceled.  Unlike Fib above, Fib has no final FibReply.
-      /// </summary>
-      AsyncServerStreamingCall<global::Math.Num> Fib(global::Math.FibArgs request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
-      ///  generates up to limit numbers; otherwise it continues until the call is
-      ///  canceled.  Unlike Fib above, Fib has no final FibReply.
-      /// </summary>
-      AsyncServerStreamingCall<global::Math.Num> Fib(global::Math.FibArgs request, CallOptions options);
-      /// <summary>
-      ///  Sum sums a stream of numbers, returning the final result once the stream
-      ///  is closed.
-      /// </summary>
-      AsyncClientStreamingCall<global::Math.Num, global::Math.Num> Sum(Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Sum sums a stream of numbers, returning the final result once the stream
-      ///  is closed.
-      /// </summary>
-      AsyncClientStreamingCall<global::Math.Num, global::Math.Num> Sum(CallOptions options);
-    }
-
-    /// <summary>Interface of server-side implementations of Math</summary>
-    [System.Obsolete("Service implementations should inherit from the generated abstract base class instead.")]
-    public interface IMath
-    {
-      /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Math.DivReply> Div(global::Math.DivArgs request, ServerCallContext context);
-      /// <summary>
-      ///  DivMany accepts an arbitrary number of division args from the client stream
-      ///  and sends back the results in the reply stream.  The stream continues until
-      ///  the client closes its end; the server does the same after sending all the
-      ///  replies.  The stream ends immediately if either end aborts.
-      /// </summary>
-      global::System.Threading.Tasks.Task DivMany(IAsyncStreamReader<global::Math.DivArgs> requestStream, IServerStreamWriter<global::Math.DivReply> responseStream, ServerCallContext context);
-      /// <summary>
-      ///  Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
-      ///  generates up to limit numbers; otherwise it continues until the call is
-      ///  canceled.  Unlike Fib above, Fib has no final FibReply.
-      /// </summary>
-      global::System.Threading.Tasks.Task Fib(global::Math.FibArgs request, IServerStreamWriter<global::Math.Num> responseStream, ServerCallContext context);
-      /// <summary>
-      ///  Sum sums a stream of numbers, returning the final result once the stream
-      ///  is closed.
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Math.Num> Sum(IAsyncStreamReader<global::Math.Num> requestStream, ServerCallContext context);
-    }
-
     /// <summary>Base class for server-side implementations of Math</summary>
     public abstract class MathBase
     {
       /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
+      ///  Div divides DivArgs.dividend by DivArgs.divisor and returns the quotient
+      ///  and remainder.
       /// </summary>
       public virtual global::System.Threading.Tasks.Task<global::Math.DivReply> Div(global::Math.DivArgs request, ServerCallContext context)
       {
@@ -196,7 +105,7 @@ namespace Math {
       }
 
       /// <summary>
-      ///  Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
+      ///  Fib generates numbers in the Fibonacci sequence.  If FibArgs.limit > 0, Fib
       ///  generates up to limit numbers; otherwise it continues until the call is
       ///  canceled.  Unlike Fib above, Fib has no final FibReply.
       /// </summary>
@@ -217,9 +126,7 @@ namespace Math {
     }
 
     /// <summary>Client for Math</summary>
-    #pragma warning disable 0618
-    public class MathClient : ClientBase<MathClient>, IMathClient
-    #pragma warning restore 0618
+    public class MathClient : ClientBase<MathClient>
     {
       public MathClient(Channel channel) : base(channel)
       {
@@ -237,32 +144,32 @@ namespace Math {
       }
 
       /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
+      ///  Div divides DivArgs.dividend by DivArgs.divisor and returns the quotient
+      ///  and remainder.
       /// </summary>
       public virtual global::Math.DivReply Div(global::Math.DivArgs request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
       {
         return Div(request, new CallOptions(headers, deadline, cancellationToken));
       }
       /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
+      ///  Div divides DivArgs.dividend by DivArgs.divisor and returns the quotient
+      ///  and remainder.
       /// </summary>
       public virtual global::Math.DivReply Div(global::Math.DivArgs request, CallOptions options)
       {
         return CallInvoker.BlockingUnaryCall(__Method_Div, null, options, request);
       }
       /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
+      ///  Div divides DivArgs.dividend by DivArgs.divisor and returns the quotient
+      ///  and remainder.
       /// </summary>
       public virtual AsyncUnaryCall<global::Math.DivReply> DivAsync(global::Math.DivArgs request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken))
       {
         return DivAsync(request, new CallOptions(headers, deadline, cancellationToken));
       }
       /// <summary>
-      ///  Div divides args.dividend by args.divisor and returns the quotient and
-      ///  remainder.
+      ///  Div divides DivArgs.dividend by DivArgs.divisor and returns the quotient
+      ///  and remainder.
       /// </summary>
       public virtual AsyncUnaryCall<global::Math.DivReply> DivAsync(global::Math.DivArgs request, CallOptions options)
       {
@@ -289,7 +196,7 @@ namespace Math {
         return CallInvoker.AsyncDuplexStreamingCall(__Method_DivMany, null, options);
       }
       /// <summary>
-      ///  Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
+      ///  Fib generates numbers in the Fibonacci sequence.  If FibArgs.limit > 0, Fib
       ///  generates up to limit numbers; otherwise it continues until the call is
       ///  canceled.  Unlike Fib above, Fib has no final FibReply.
       /// </summary>
@@ -298,7 +205,7 @@ namespace Math {
         return Fib(request, new CallOptions(headers, deadline, cancellationToken));
       }
       /// <summary>
-      ///  Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
+      ///  Fib generates numbers in the Fibonacci sequence.  If FibArgs.limit > 0, Fib
       ///  generates up to limit numbers; otherwise it continues until the call is
       ///  canceled.  Unlike Fib above, Fib has no final FibReply.
       /// </summary>
@@ -335,23 +242,9 @@ namespace Math {
     }
 
     /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
-    public static ServerServiceDefinition BindService(IMath serviceImpl)
-    #pragma warning restore 0618
-    {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
-          .AddMethod(__Method_Div, serviceImpl.Div)
-          .AddMethod(__Method_DivMany, serviceImpl.DivMany)
-          .AddMethod(__Method_Fib, serviceImpl.Fib)
-          .AddMethod(__Method_Sum, serviceImpl.Sum).Build();
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
     public static ServerServiceDefinition BindService(MathBase serviceImpl)
-    #pragma warning restore 0618
     {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
+      return ServerServiceDefinition.CreateBuilder()
           .AddMethod(__Method_Div, serviceImpl.Div)
           .AddMethod(__Method_DivMany, serviceImpl.DivMany)
           .AddMethod(__Method_Fib, serviceImpl.Fib)
diff --git a/src/csharp/Grpc.HealthCheck/HealthGrpc.cs b/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
index 51c6a39b1d..d0ade7d02b 100644
--- a/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
+++ b/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
@@ -58,23 +58,6 @@ namespace Grpc.Health.V1 {
       get { return global::Grpc.Health.V1.HealthReflection.Descriptor.Services[0]; }
     }
 
-    /// <summary>Client for Health</summary>
-    [System.Obsolete("Client side interfaced will be removed in the next release. Use client class directly.")]
-    public interface IHealthClient
-    {
-      global::Grpc.Health.V1.HealthCheckResponse Check(global::Grpc.Health.V1.HealthCheckRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      global::Grpc.Health.V1.HealthCheckResponse Check(global::Grpc.Health.V1.HealthCheckRequest request, CallOptions options);
-      AsyncUnaryCall<global::Grpc.Health.V1.HealthCheckResponse> CheckAsync(global::Grpc.Health.V1.HealthCheckRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      AsyncUnaryCall<global::Grpc.Health.V1.HealthCheckResponse> CheckAsync(global::Grpc.Health.V1.HealthCheckRequest request, CallOptions options);
-    }
-
-    /// <summary>Interface of server-side implementations of Health</summary>
-    [System.Obsolete("Service implementations should inherit from the generated abstract base class instead.")]
-    public interface IHealth
-    {
-      global::System.Threading.Tasks.Task<global::Grpc.Health.V1.HealthCheckResponse> Check(global::Grpc.Health.V1.HealthCheckRequest request, ServerCallContext context);
-    }
-
     /// <summary>Base class for server-side implementations of Health</summary>
     public abstract class HealthBase
     {
@@ -86,9 +69,7 @@ namespace Grpc.Health.V1 {
     }
 
     /// <summary>Client for Health</summary>
-    #pragma warning disable 0618
-    public class HealthClient : ClientBase<HealthClient>, IHealthClient
-    #pragma warning restore 0618
+    public class HealthClient : ClientBase<HealthClient>
     {
       public HealthClient(Channel channel) : base(channel)
       {
@@ -134,20 +115,9 @@ namespace Grpc.Health.V1 {
     }
 
     /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
-    public static ServerServiceDefinition BindService(IHealth serviceImpl)
-    #pragma warning restore 0618
-    {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
-          .AddMethod(__Method_Check, serviceImpl.Check).Build();
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
     public static ServerServiceDefinition BindService(HealthBase serviceImpl)
-    #pragma warning restore 0618
     {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
+      return ServerServiceDefinition.CreateBuilder()
           .AddMethod(__Method_Check, serviceImpl.Check).Build();
     }
 
diff --git a/src/csharp/Grpc.IntegrationTesting/GenericService.cs b/src/csharp/Grpc.IntegrationTesting/GenericService.cs
index c6128264ac..53fa1ee5f6 100644
--- a/src/csharp/Grpc.IntegrationTesting/GenericService.cs
+++ b/src/csharp/Grpc.IntegrationTesting/GenericService.cs
@@ -64,7 +64,7 @@ namespace Grpc.IntegrationTesting
 
         public static ServerServiceDefinition BindHandler(DuplexStreamingServerMethod<byte[], byte[]> handler)
         {
-            return ServerServiceDefinition.CreateBuilder(StreamingCallMethod.ServiceName)
+            return ServerServiceDefinition.CreateBuilder()
                 .AddMethod(StreamingCallMethod, handler).Build();
         }
     }
diff --git a/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs b/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
index 9d31d1c514..22bd27ec0a 100644
--- a/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
@@ -72,53 +72,6 @@ namespace Grpc.Testing {
       get { return global::Grpc.Testing.MetricsReflection.Descriptor.Services[0]; }
     }
 
-    /// <summary>Client for MetricsService</summary>
-    [System.Obsolete("Client side interfaced will be removed in the next release. Use client class directly.")]
-    public interface IMetricsServiceClient
-    {
-      /// <summary>
-      ///  Returns the values of all the gauges that are currently being maintained by
-      ///  the service
-      /// </summary>
-      AsyncServerStreamingCall<global::Grpc.Testing.GaugeResponse> GetAllGauges(global::Grpc.Testing.EmptyMessage request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Returns the values of all the gauges that are currently being maintained by
-      ///  the service
-      /// </summary>
-      AsyncServerStreamingCall<global::Grpc.Testing.GaugeResponse> GetAllGauges(global::Grpc.Testing.EmptyMessage request, CallOptions options);
-      /// <summary>
-      ///  Returns the value of one gauge
-      /// </summary>
-      global::Grpc.Testing.GaugeResponse GetGauge(global::Grpc.Testing.GaugeRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Returns the value of one gauge
-      /// </summary>
-      global::Grpc.Testing.GaugeResponse GetGauge(global::Grpc.Testing.GaugeRequest request, CallOptions options);
-      /// <summary>
-      ///  Returns the value of one gauge
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.GaugeResponse> GetGaugeAsync(global::Grpc.Testing.GaugeRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Returns the value of one gauge
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.GaugeResponse> GetGaugeAsync(global::Grpc.Testing.GaugeRequest request, CallOptions options);
-    }
-
-    /// <summary>Interface of server-side implementations of MetricsService</summary>
-    [System.Obsolete("Service implementations should inherit from the generated abstract base class instead.")]
-    public interface IMetricsService
-    {
-      /// <summary>
-      ///  Returns the values of all the gauges that are currently being maintained by
-      ///  the service
-      /// </summary>
-      global::System.Threading.Tasks.Task GetAllGauges(global::Grpc.Testing.EmptyMessage request, IServerStreamWriter<global::Grpc.Testing.GaugeResponse> responseStream, ServerCallContext context);
-      /// <summary>
-      ///  Returns the value of one gauge
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.GaugeResponse> GetGauge(global::Grpc.Testing.GaugeRequest request, ServerCallContext context);
-    }
-
     /// <summary>Base class for server-side implementations of MetricsService</summary>
     public abstract class MetricsServiceBase
     {
@@ -142,9 +95,7 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Client for MetricsService</summary>
-    #pragma warning disable 0618
-    public class MetricsServiceClient : ClientBase<MetricsServiceClient>, IMetricsServiceClient
-    #pragma warning restore 0618
+    public class MetricsServiceClient : ClientBase<MetricsServiceClient>
     {
       public MetricsServiceClient(Channel channel) : base(channel)
       {
@@ -218,21 +169,9 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
-    public static ServerServiceDefinition BindService(IMetricsService serviceImpl)
-    #pragma warning restore 0618
-    {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
-          .AddMethod(__Method_GetAllGauges, serviceImpl.GetAllGauges)
-          .AddMethod(__Method_GetGauge, serviceImpl.GetGauge).Build();
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
     public static ServerServiceDefinition BindService(MetricsServiceBase serviceImpl)
-    #pragma warning restore 0618
     {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
+      return ServerServiceDefinition.CreateBuilder()
           .AddMethod(__Method_GetAllGauges, serviceImpl.GetAllGauges)
           .AddMethod(__Method_GetGauge, serviceImpl.GetGauge).Build();
     }
diff --git a/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs b/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
index f7071ebf6b..9c99296115 100644
--- a/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
@@ -67,58 +67,6 @@ namespace Grpc.Testing {
       get { return global::Grpc.Testing.ServicesReflection.Descriptor.Services[0]; }
     }
 
-    /// <summary>Client for BenchmarkService</summary>
-    [System.Obsolete("Client side interfaced will be removed in the next release. Use client class directly.")]
-    public interface IBenchmarkServiceClient
-    {
-      /// <summary>
-      ///  One request followed by one response.
-      ///  The server returns the client payload as-is.
-      /// </summary>
-      global::Grpc.Testing.SimpleResponse UnaryCall(global::Grpc.Testing.SimpleRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  One request followed by one response.
-      ///  The server returns the client payload as-is.
-      /// </summary>
-      global::Grpc.Testing.SimpleResponse UnaryCall(global::Grpc.Testing.SimpleRequest request, CallOptions options);
-      /// <summary>
-      ///  One request followed by one response.
-      ///  The server returns the client payload as-is.
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.SimpleResponse> UnaryCallAsync(global::Grpc.Testing.SimpleRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  One request followed by one response.
-      ///  The server returns the client payload as-is.
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.SimpleResponse> UnaryCallAsync(global::Grpc.Testing.SimpleRequest request, CallOptions options);
-      /// <summary>
-      ///  One request followed by one response.
-      ///  The server returns the client payload as-is.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingCall(Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  One request followed by one response.
-      ///  The server returns the client payload as-is.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingCall(CallOptions options);
-    }
-
-    /// <summary>Interface of server-side implementations of BenchmarkService</summary>
-    [System.Obsolete("Service implementations should inherit from the generated abstract base class instead.")]
-    public interface IBenchmarkService
-    {
-      /// <summary>
-      ///  One request followed by one response.
-      ///  The server returns the client payload as-is.
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.SimpleResponse> UnaryCall(global::Grpc.Testing.SimpleRequest request, ServerCallContext context);
-      /// <summary>
-      ///  One request followed by one response.
-      ///  The server returns the client payload as-is.
-      /// </summary>
-      global::System.Threading.Tasks.Task StreamingCall(IAsyncStreamReader<global::Grpc.Testing.SimpleRequest> requestStream, IServerStreamWriter<global::Grpc.Testing.SimpleResponse> responseStream, ServerCallContext context);
-    }
-
     /// <summary>Base class for server-side implementations of BenchmarkService</summary>
     public abstract class BenchmarkServiceBase
     {
@@ -143,9 +91,7 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Client for BenchmarkService</summary>
-    #pragma warning disable 0618
-    public class BenchmarkServiceClient : ClientBase<BenchmarkServiceClient>, IBenchmarkServiceClient
-    #pragma warning restore 0618
+    public class BenchmarkServiceClient : ClientBase<BenchmarkServiceClient>
     {
       public BenchmarkServiceClient(Channel channel) : base(channel)
       {
@@ -223,21 +169,9 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
-    public static ServerServiceDefinition BindService(IBenchmarkService serviceImpl)
-    #pragma warning restore 0618
-    {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
-          .AddMethod(__Method_UnaryCall, serviceImpl.UnaryCall)
-          .AddMethod(__Method_StreamingCall, serviceImpl.StreamingCall).Build();
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
     public static ServerServiceDefinition BindService(BenchmarkServiceBase serviceImpl)
-    #pragma warning restore 0618
     {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
+      return ServerServiceDefinition.CreateBuilder()
           .AddMethod(__Method_UnaryCall, serviceImpl.UnaryCall)
           .AddMethod(__Method_StreamingCall, serviceImpl.StreamingCall).Build();
     }
@@ -289,112 +223,6 @@ namespace Grpc.Testing {
       get { return global::Grpc.Testing.ServicesReflection.Descriptor.Services[1]; }
     }
 
-    /// <summary>Client for WorkerService</summary>
-    [System.Obsolete("Client side interfaced will be removed in the next release. Use client class directly.")]
-    public interface IWorkerServiceClient
-    {
-      /// <summary>
-      ///  Start server with specified workload.
-      ///  First request sent specifies the ServerConfig followed by ServerStatus
-      ///  response. After that, a "Mark" can be sent anytime to request the latest
-      ///  stats. Closing the stream will initiate shutdown of the test server
-      ///  and once the shutdown has finished, the OK status is sent to terminate
-      ///  this RPC.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus> RunServer(Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Start server with specified workload.
-      ///  First request sent specifies the ServerConfig followed by ServerStatus
-      ///  response. After that, a "Mark" can be sent anytime to request the latest
-      ///  stats. Closing the stream will initiate shutdown of the test server
-      ///  and once the shutdown has finished, the OK status is sent to terminate
-      ///  this RPC.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus> RunServer(CallOptions options);
-      /// <summary>
-      ///  Start client with specified workload.
-      ///  First request sent specifies the ClientConfig followed by ClientStatus
-      ///  response. After that, a "Mark" can be sent anytime to request the latest
-      ///  stats. Closing the stream will initiate shutdown of the test client
-      ///  and once the shutdown has finished, the OK status is sent to terminate
-      ///  this RPC.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus> RunClient(Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Start client with specified workload.
-      ///  First request sent specifies the ClientConfig followed by ClientStatus
-      ///  response. After that, a "Mark" can be sent anytime to request the latest
-      ///  stats. Closing the stream will initiate shutdown of the test client
-      ///  and once the shutdown has finished, the OK status is sent to terminate
-      ///  this RPC.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus> RunClient(CallOptions options);
-      /// <summary>
-      ///  Just return the core count - unary call
-      /// </summary>
-      global::Grpc.Testing.CoreResponse CoreCount(global::Grpc.Testing.CoreRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Just return the core count - unary call
-      /// </summary>
-      global::Grpc.Testing.CoreResponse CoreCount(global::Grpc.Testing.CoreRequest request, CallOptions options);
-      /// <summary>
-      ///  Just return the core count - unary call
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.CoreResponse> CoreCountAsync(global::Grpc.Testing.CoreRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Just return the core count - unary call
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.CoreResponse> CoreCountAsync(global::Grpc.Testing.CoreRequest request, CallOptions options);
-      /// <summary>
-      ///  Quit this worker
-      /// </summary>
-      global::Grpc.Testing.Void QuitWorker(global::Grpc.Testing.Void request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Quit this worker
-      /// </summary>
-      global::Grpc.Testing.Void QuitWorker(global::Grpc.Testing.Void request, CallOptions options);
-      /// <summary>
-      ///  Quit this worker
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.Void> QuitWorkerAsync(global::Grpc.Testing.Void request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  Quit this worker
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.Void> QuitWorkerAsync(global::Grpc.Testing.Void request, CallOptions options);
-    }
-
-    /// <summary>Interface of server-side implementations of WorkerService</summary>
-    [System.Obsolete("Service implementations should inherit from the generated abstract base class instead.")]
-    public interface IWorkerService
-    {
-      /// <summary>
-      ///  Start server with specified workload.
-      ///  First request sent specifies the ServerConfig followed by ServerStatus
-      ///  response. After that, a "Mark" can be sent anytime to request the latest
-      ///  stats. Closing the stream will initiate shutdown of the test server
-      ///  and once the shutdown has finished, the OK status is sent to terminate
-      ///  this RPC.
-      /// </summary>
-      global::System.Threading.Tasks.Task RunServer(IAsyncStreamReader<global::Grpc.Testing.ServerArgs> requestStream, IServerStreamWriter<global::Grpc.Testing.ServerStatus> responseStream, ServerCallContext context);
-      /// <summary>
-      ///  Start client with specified workload.
-      ///  First request sent specifies the ClientConfig followed by ClientStatus
-      ///  response. After that, a "Mark" can be sent anytime to request the latest
-      ///  stats. Closing the stream will initiate shutdown of the test client
-      ///  and once the shutdown has finished, the OK status is sent to terminate
-      ///  this RPC.
-      /// </summary>
-      global::System.Threading.Tasks.Task RunClient(IAsyncStreamReader<global::Grpc.Testing.ClientArgs> requestStream, IServerStreamWriter<global::Grpc.Testing.ClientStatus> responseStream, ServerCallContext context);
-      /// <summary>
-      ///  Just return the core count - unary call
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.CoreResponse> CoreCount(global::Grpc.Testing.CoreRequest request, ServerCallContext context);
-      /// <summary>
-      ///  Quit this worker
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.Void> QuitWorker(global::Grpc.Testing.Void request, ServerCallContext context);
-    }
-
     /// <summary>Base class for server-side implementations of WorkerService</summary>
     public abstract class WorkerServiceBase
     {
@@ -443,9 +271,7 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Client for WorkerService</summary>
-    #pragma warning disable 0618
-    public class WorkerServiceClient : ClientBase<WorkerServiceClient>, IWorkerServiceClient
-    #pragma warning restore 0618
+    public class WorkerServiceClient : ClientBase<WorkerServiceClient>
     {
       public WorkerServiceClient(Channel channel) : base(channel)
       {
@@ -579,23 +405,9 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
-    public static ServerServiceDefinition BindService(IWorkerService serviceImpl)
-    #pragma warning restore 0618
-    {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
-          .AddMethod(__Method_RunServer, serviceImpl.RunServer)
-          .AddMethod(__Method_RunClient, serviceImpl.RunClient)
-          .AddMethod(__Method_CoreCount, serviceImpl.CoreCount)
-          .AddMethod(__Method_QuitWorker, serviceImpl.QuitWorker).Build();
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
     public static ServerServiceDefinition BindService(WorkerServiceBase serviceImpl)
-    #pragma warning restore 0618
     {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
+      return ServerServiceDefinition.CreateBuilder()
           .AddMethod(__Method_RunServer, serviceImpl.RunServer)
           .AddMethod(__Method_RunClient, serviceImpl.RunClient)
           .AddMethod(__Method_CoreCount, serviceImpl.CoreCount)
diff --git a/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs b/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
index cf43a77118..6c252013f8 100644
--- a/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
@@ -105,127 +105,6 @@ namespace Grpc.Testing {
       get { return global::Grpc.Testing.TestReflection.Descriptor.Services[0]; }
     }
 
-    /// <summary>Client for TestService</summary>
-    [System.Obsolete("Client side interfaced will be removed in the next release. Use client class directly.")]
-    public interface ITestServiceClient
-    {
-      /// <summary>
-      ///  One empty request followed by one empty response.
-      /// </summary>
-      global::Grpc.Testing.Empty EmptyCall(global::Grpc.Testing.Empty request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  One empty request followed by one empty response.
-      /// </summary>
-      global::Grpc.Testing.Empty EmptyCall(global::Grpc.Testing.Empty request, CallOptions options);
-      /// <summary>
-      ///  One empty request followed by one empty response.
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.Empty> EmptyCallAsync(global::Grpc.Testing.Empty request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  One empty request followed by one empty response.
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.Empty> EmptyCallAsync(global::Grpc.Testing.Empty request, CallOptions options);
-      /// <summary>
-      ///  One request followed by one response.
-      /// </summary>
-      global::Grpc.Testing.SimpleResponse UnaryCall(global::Grpc.Testing.SimpleRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  One request followed by one response.
-      /// </summary>
-      global::Grpc.Testing.SimpleResponse UnaryCall(global::Grpc.Testing.SimpleRequest request, CallOptions options);
-      /// <summary>
-      ///  One request followed by one response.
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.SimpleResponse> UnaryCallAsync(global::Grpc.Testing.SimpleRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  One request followed by one response.
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.SimpleResponse> UnaryCallAsync(global::Grpc.Testing.SimpleRequest request, CallOptions options);
-      /// <summary>
-      ///  One request followed by a sequence of responses (streamed download).
-      ///  The server returns the payload with client desired type and sizes.
-      /// </summary>
-      AsyncServerStreamingCall<global::Grpc.Testing.StreamingOutputCallResponse> StreamingOutputCall(global::Grpc.Testing.StreamingOutputCallRequest request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  One request followed by a sequence of responses (streamed download).
-      ///  The server returns the payload with client desired type and sizes.
-      /// </summary>
-      AsyncServerStreamingCall<global::Grpc.Testing.StreamingOutputCallResponse> StreamingOutputCall(global::Grpc.Testing.StreamingOutputCallRequest request, CallOptions options);
-      /// <summary>
-      ///  A sequence of requests followed by one response (streamed upload).
-      ///  The server returns the aggregated size of client payload as the result.
-      /// </summary>
-      AsyncClientStreamingCall<global::Grpc.Testing.StreamingInputCallRequest, global::Grpc.Testing.StreamingInputCallResponse> StreamingInputCall(Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  A sequence of requests followed by one response (streamed upload).
-      ///  The server returns the aggregated size of client payload as the result.
-      /// </summary>
-      AsyncClientStreamingCall<global::Grpc.Testing.StreamingInputCallRequest, global::Grpc.Testing.StreamingInputCallResponse> StreamingInputCall(CallOptions options);
-      /// <summary>
-      ///  A sequence of requests with each request served by the server immediately.
-      ///  As one request could lead to multiple responses, this interface
-      ///  demonstrates the idea of full duplexing.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.StreamingOutputCallRequest, global::Grpc.Testing.StreamingOutputCallResponse> FullDuplexCall(Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  A sequence of requests with each request served by the server immediately.
-      ///  As one request could lead to multiple responses, this interface
-      ///  demonstrates the idea of full duplexing.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.StreamingOutputCallRequest, global::Grpc.Testing.StreamingOutputCallResponse> FullDuplexCall(CallOptions options);
-      /// <summary>
-      ///  A sequence of requests followed by a sequence of responses.
-      ///  The server buffers all the client requests and then serves them in order. A
-      ///  stream of responses are returned to the client when the server starts with
-      ///  first request.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.StreamingOutputCallRequest, global::Grpc.Testing.StreamingOutputCallResponse> HalfDuplexCall(Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  A sequence of requests followed by a sequence of responses.
-      ///  The server buffers all the client requests and then serves them in order. A
-      ///  stream of responses are returned to the client when the server starts with
-      ///  first request.
-      /// </summary>
-      AsyncDuplexStreamingCall<global::Grpc.Testing.StreamingOutputCallRequest, global::Grpc.Testing.StreamingOutputCallResponse> HalfDuplexCall(CallOptions options);
-    }
-
-    /// <summary>Interface of server-side implementations of TestService</summary>
-    [System.Obsolete("Service implementations should inherit from the generated abstract base class instead.")]
-    public interface ITestService
-    {
-      /// <summary>
-      ///  One empty request followed by one empty response.
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.Empty> EmptyCall(global::Grpc.Testing.Empty request, ServerCallContext context);
-      /// <summary>
-      ///  One request followed by one response.
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.SimpleResponse> UnaryCall(global::Grpc.Testing.SimpleRequest request, ServerCallContext context);
-      /// <summary>
-      ///  One request followed by a sequence of responses (streamed download).
-      ///  The server returns the payload with client desired type and sizes.
-      /// </summary>
-      global::System.Threading.Tasks.Task StreamingOutputCall(global::Grpc.Testing.StreamingOutputCallRequest request, IServerStreamWriter<global::Grpc.Testing.StreamingOutputCallResponse> responseStream, ServerCallContext context);
-      /// <summary>
-      ///  A sequence of requests followed by one response (streamed upload).
-      ///  The server returns the aggregated size of client payload as the result.
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.StreamingInputCallResponse> StreamingInputCall(IAsyncStreamReader<global::Grpc.Testing.StreamingInputCallRequest> requestStream, ServerCallContext context);
-      /// <summary>
-      ///  A sequence of requests with each request served by the server immediately.
-      ///  As one request could lead to multiple responses, this interface
-      ///  demonstrates the idea of full duplexing.
-      /// </summary>
-      global::System.Threading.Tasks.Task FullDuplexCall(IAsyncStreamReader<global::Grpc.Testing.StreamingOutputCallRequest> requestStream, IServerStreamWriter<global::Grpc.Testing.StreamingOutputCallResponse> responseStream, ServerCallContext context);
-      /// <summary>
-      ///  A sequence of requests followed by a sequence of responses.
-      ///  The server buffers all the client requests and then serves them in order. A
-      ///  stream of responses are returned to the client when the server starts with
-      ///  first request.
-      /// </summary>
-      global::System.Threading.Tasks.Task HalfDuplexCall(IAsyncStreamReader<global::Grpc.Testing.StreamingOutputCallRequest> requestStream, IServerStreamWriter<global::Grpc.Testing.StreamingOutputCallResponse> responseStream, ServerCallContext context);
-    }
-
     /// <summary>Base class for server-side implementations of TestService</summary>
     public abstract class TestServiceBase
     {
@@ -287,9 +166,7 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Client for TestService</summary>
-    #pragma warning disable 0618
-    public class TestServiceClient : ClientBase<TestServiceClient>, ITestServiceClient
-    #pragma warning restore 0618
+    public class TestServiceClient : ClientBase<TestServiceClient>
     {
       public TestServiceClient(Channel channel) : base(channel)
       {
@@ -445,25 +322,9 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
-    public static ServerServiceDefinition BindService(ITestService serviceImpl)
-    #pragma warning restore 0618
-    {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
-          .AddMethod(__Method_EmptyCall, serviceImpl.EmptyCall)
-          .AddMethod(__Method_UnaryCall, serviceImpl.UnaryCall)
-          .AddMethod(__Method_StreamingOutputCall, serviceImpl.StreamingOutputCall)
-          .AddMethod(__Method_StreamingInputCall, serviceImpl.StreamingInputCall)
-          .AddMethod(__Method_FullDuplexCall, serviceImpl.FullDuplexCall)
-          .AddMethod(__Method_HalfDuplexCall, serviceImpl.HalfDuplexCall).Build();
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
     public static ServerServiceDefinition BindService(TestServiceBase serviceImpl)
-    #pragma warning restore 0618
     {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
+      return ServerServiceDefinition.CreateBuilder()
           .AddMethod(__Method_EmptyCall, serviceImpl.EmptyCall)
           .AddMethod(__Method_UnaryCall, serviceImpl.UnaryCall)
           .AddMethod(__Method_StreamingOutputCall, serviceImpl.StreamingOutputCall)
@@ -496,38 +357,6 @@ namespace Grpc.Testing {
       get { return global::Grpc.Testing.TestReflection.Descriptor.Services[1]; }
     }
 
-    /// <summary>Client for UnimplementedService</summary>
-    [System.Obsolete("Client side interfaced will be removed in the next release. Use client class directly.")]
-    public interface IUnimplementedServiceClient
-    {
-      /// <summary>
-      ///  A call that no server should implement
-      /// </summary>
-      global::Grpc.Testing.Empty UnimplementedCall(global::Grpc.Testing.Empty request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  A call that no server should implement
-      /// </summary>
-      global::Grpc.Testing.Empty UnimplementedCall(global::Grpc.Testing.Empty request, CallOptions options);
-      /// <summary>
-      ///  A call that no server should implement
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.Empty> UnimplementedCallAsync(global::Grpc.Testing.Empty request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      /// <summary>
-      ///  A call that no server should implement
-      /// </summary>
-      AsyncUnaryCall<global::Grpc.Testing.Empty> UnimplementedCallAsync(global::Grpc.Testing.Empty request, CallOptions options);
-    }
-
-    /// <summary>Interface of server-side implementations of UnimplementedService</summary>
-    [System.Obsolete("Service implementations should inherit from the generated abstract base class instead.")]
-    public interface IUnimplementedService
-    {
-      /// <summary>
-      ///  A call that no server should implement
-      /// </summary>
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.Empty> UnimplementedCall(global::Grpc.Testing.Empty request, ServerCallContext context);
-    }
-
     /// <summary>Base class for server-side implementations of UnimplementedService</summary>
     public abstract class UnimplementedServiceBase
     {
@@ -542,9 +371,7 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Client for UnimplementedService</summary>
-    #pragma warning disable 0618
-    public class UnimplementedServiceClient : ClientBase<UnimplementedServiceClient>, IUnimplementedServiceClient
-    #pragma warning restore 0618
+    public class UnimplementedServiceClient : ClientBase<UnimplementedServiceClient>
     {
       public UnimplementedServiceClient(Channel channel) : base(channel)
       {
@@ -602,20 +429,9 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
-    public static ServerServiceDefinition BindService(IUnimplementedService serviceImpl)
-    #pragma warning restore 0618
-    {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
-          .AddMethod(__Method_UnimplementedCall, serviceImpl.UnimplementedCall).Build();
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
     public static ServerServiceDefinition BindService(UnimplementedServiceBase serviceImpl)
-    #pragma warning restore 0618
     {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
+      return ServerServiceDefinition.CreateBuilder()
           .AddMethod(__Method_UnimplementedCall, serviceImpl.UnimplementedCall).Build();
     }
 
@@ -651,28 +467,6 @@ namespace Grpc.Testing {
       get { return global::Grpc.Testing.TestReflection.Descriptor.Services[2]; }
     }
 
-    /// <summary>Client for ReconnectService</summary>
-    [System.Obsolete("Client side interfaced will be removed in the next release. Use client class directly.")]
-    public interface IReconnectServiceClient
-    {
-      global::Grpc.Testing.Empty Start(global::Grpc.Testing.ReconnectParams request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      global::Grpc.Testing.Empty Start(global::Grpc.Testing.ReconnectParams request, CallOptions options);
-      AsyncUnaryCall<global::Grpc.Testing.Empty> StartAsync(global::Grpc.Testing.ReconnectParams request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      AsyncUnaryCall<global::Grpc.Testing.Empty> StartAsync(global::Grpc.Testing.ReconnectParams request, CallOptions options);
-      global::Grpc.Testing.ReconnectInfo Stop(global::Grpc.Testing.Empty request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      global::Grpc.Testing.ReconnectInfo Stop(global::Grpc.Testing.Empty request, CallOptions options);
-      AsyncUnaryCall<global::Grpc.Testing.ReconnectInfo> StopAsync(global::Grpc.Testing.Empty request, Metadata headers = null, DateTime? deadline = null, CancellationToken cancellationToken = default(CancellationToken));
-      AsyncUnaryCall<global::Grpc.Testing.ReconnectInfo> StopAsync(global::Grpc.Testing.Empty request, CallOptions options);
-    }
-
-    /// <summary>Interface of server-side implementations of ReconnectService</summary>
-    [System.Obsolete("Service implementations should inherit from the generated abstract base class instead.")]
-    public interface IReconnectService
-    {
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.Empty> Start(global::Grpc.Testing.ReconnectParams request, ServerCallContext context);
-      global::System.Threading.Tasks.Task<global::Grpc.Testing.ReconnectInfo> Stop(global::Grpc.Testing.Empty request, ServerCallContext context);
-    }
-
     /// <summary>Base class for server-side implementations of ReconnectService</summary>
     public abstract class ReconnectServiceBase
     {
@@ -689,9 +483,7 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Client for ReconnectService</summary>
-    #pragma warning disable 0618
-    public class ReconnectServiceClient : ClientBase<ReconnectServiceClient>, IReconnectServiceClient
-    #pragma warning restore 0618
+    public class ReconnectServiceClient : ClientBase<ReconnectServiceClient>
     {
       public ReconnectServiceClient(Channel channel) : base(channel)
       {
@@ -753,21 +545,9 @@ namespace Grpc.Testing {
     }
 
     /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
-    public static ServerServiceDefinition BindService(IReconnectService serviceImpl)
-    #pragma warning restore 0618
-    {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
-          .AddMethod(__Method_Start, serviceImpl.Start)
-          .AddMethod(__Method_Stop, serviceImpl.Stop).Build();
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    #pragma warning disable 0618
     public static ServerServiceDefinition BindService(ReconnectServiceBase serviceImpl)
-    #pragma warning restore 0618
     {
-      return ServerServiceDefinition.CreateBuilder(__ServiceName)
+      return ServerServiceDefinition.CreateBuilder()
           .AddMethod(__Method_Start, serviceImpl.Start)
           .AddMethod(__Method_Stop, serviceImpl.Stop).Build();
     }
diff --git a/src/csharp/ext/grpc_csharp_ext.c b/src/csharp/ext/grpc_csharp_ext.c
index 4beef9ded8..2a243b94cb 100644
--- a/src/csharp/ext/grpc_csharp_ext.c
+++ b/src/csharp/ext/grpc_csharp_ext.c
@@ -45,7 +45,7 @@
 
 #include <string.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 #define GPR_EXPORT __declspec(dllexport)
 #define GPR_CALLTYPE __stdcall
 #endif
diff --git a/src/csharp/tests.json b/src/csharp/tests.json
index f6af3408d5..7e7aee1093 100644
--- a/src/csharp/tests.json
+++ b/src/csharp/tests.json
@@ -7,6 +7,7 @@
     "Grpc.Core.Internal.Tests.CompletionQueueSafeHandleTest",
     "Grpc.Core.Internal.Tests.MetadataArraySafeHandleTest",
     "Grpc.Core.Internal.Tests.TimespecTest",
+    "Grpc.Core.Tests.AppDomainUnloadTest",
     "Grpc.Core.Tests.CallCredentialsTest",
     "Grpc.Core.Tests.CallOptionsTest",
     "Grpc.Core.Tests.ChannelCredentialsTest",
@@ -25,6 +26,9 @@
     "Grpc.Core.Tests.ResponseHeadersTest",
     "Grpc.Core.Tests.SanityTest",
     "Grpc.Core.Tests.ServerTest",
+    "Grpc.Core.Tests.ShutdownHookClientTest",
+    "Grpc.Core.Tests.ShutdownHookPendingCallTest",
+    "Grpc.Core.Tests.ShutdownHookServerTest",
     "Grpc.Core.Tests.ShutdownTest",
     "Grpc.Core.Tests.TimeoutsTest",
     "Grpc.Core.Tests.UserAgentStringTest"
diff --git a/src/node/ext/node_grpc.cc b/src/node/ext/node_grpc.cc
index 6b6e42737b..f18ce01c6f 100644
--- a/src/node/ext/node_grpc.cc
+++ b/src/node/ext/node_grpc.cc
@@ -220,7 +220,7 @@ void InitConnectivityStateConstants(Local<Object> exports) {
   Nan::Set(channel_state, Nan::New("TRANSIENT_FAILURE").ToLocalChecked(),
            TRANSIENT_FAILURE);
   Local<Value> FATAL_FAILURE(
-      Nan::New<Uint32, uint32_t>(GRPC_CHANNEL_FATAL_FAILURE));
+      Nan::New<Uint32, uint32_t>(GRPC_CHANNEL_SHUTDOWN));
   Nan::Set(channel_state, Nan::New("FATAL_FAILURE").ToLocalChecked(),
            FATAL_FAILURE);
 }
diff --git a/src/node/test/math/math_grpc_pb.js b/src/node/test/math/math_grpc_pb.js
index 083ed66913..17a4bf7243 100644
--- a/src/node/test/math/math_grpc_pb.js
+++ b/src/node/test/math/math_grpc_pb.js
@@ -1,94 +1,135 @@
 // GENERATED CODE -- DO NOT EDIT!
 
+// Original file comments:
+// 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.
+//
 'use strict';
 var grpc = require('grpc');
-var math_pb = require('./math_pb.js');
+var math_math_pb = require('../math/math_pb.js');
 
 function serialize_DivArgs(arg) {
-  if (!(arg instanceof math_pb.DivArgs)) {
+  if (!(arg instanceof math_math_pb.DivArgs)) {
     throw new Error('Expected argument of type DivArgs');
   }
   return new Buffer(arg.serializeBinary());
 }
 
 function deserialize_DivArgs(buffer_arg) {
-  return math_pb.DivArgs.deserializeBinary(new Uint8Array(buffer_arg));
+  return math_math_pb.DivArgs.deserializeBinary(new Uint8Array(buffer_arg));
 }
 
 function serialize_DivReply(arg) {
-  if (!(arg instanceof math_pb.DivReply)) {
+  if (!(arg instanceof math_math_pb.DivReply)) {
     throw new Error('Expected argument of type DivReply');
   }
   return new Buffer(arg.serializeBinary());
 }
 
 function deserialize_DivReply(buffer_arg) {
-  return math_pb.DivReply.deserializeBinary(new Uint8Array(buffer_arg));
+  return math_math_pb.DivReply.deserializeBinary(new Uint8Array(buffer_arg));
 }
 
 function serialize_FibArgs(arg) {
-  if (!(arg instanceof math_pb.FibArgs)) {
+  if (!(arg instanceof math_math_pb.FibArgs)) {
     throw new Error('Expected argument of type FibArgs');
   }
   return new Buffer(arg.serializeBinary());
 }
 
 function deserialize_FibArgs(buffer_arg) {
-  return math_pb.FibArgs.deserializeBinary(new Uint8Array(buffer_arg));
+  return math_math_pb.FibArgs.deserializeBinary(new Uint8Array(buffer_arg));
 }
 
 function serialize_Num(arg) {
-  if (!(arg instanceof math_pb.Num)) {
+  if (!(arg instanceof math_math_pb.Num)) {
     throw new Error('Expected argument of type Num');
   }
   return new Buffer(arg.serializeBinary());
 }
 
 function deserialize_Num(buffer_arg) {
-  return math_pb.Num.deserializeBinary(new Uint8Array(buffer_arg));
+  return math_math_pb.Num.deserializeBinary(new Uint8Array(buffer_arg));
 }
 
 
 var MathService = exports.MathService = {
+  // Div divides args.dividend by args.divisor and returns the quotient and
+  // remainder.
   div: {
     path: '/math.Math/Div',
     requestStream: false,
     responseStream: false,
-    requestType: math_pb.DivArgs,
-    responseType: math_pb.DivReply,
+    requestType: math_math_pb.DivArgs,
+    responseType: math_math_pb.DivReply,
     requestSerialize: serialize_DivArgs,
     requestDeserialize: deserialize_DivArgs,
     responseSerialize: serialize_DivReply,
     responseDeserialize: deserialize_DivReply,
   },
+  // DivMany accepts an arbitrary number of division args from the client stream
+  // and sends back the results in the reply stream.  The stream continues until
+  // the client closes its end; the server does the same after sending all the
+  // replies.  The stream ends immediately if either end aborts.
   divMany: {
     path: '/math.Math/DivMany',
     requestStream: true,
     responseStream: true,
-    requestType: math_pb.DivArgs,
-    responseType: math_pb.DivReply,
+    requestType: math_math_pb.DivArgs,
+    responseType: math_math_pb.DivReply,
     requestSerialize: serialize_DivArgs,
     requestDeserialize: deserialize_DivArgs,
     responseSerialize: serialize_DivReply,
     responseDeserialize: deserialize_DivReply,
   },
+  // Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
+  // generates up to limit numbers; otherwise it continues until the call is
+  // canceled.  Unlike Fib above, Fib has no final FibReply.
   fib: {
     path: '/math.Math/Fib',
     requestStream: false,
     responseStream: true,
-    requestType: math_pb.FibArgs,
-    responseType: math_pb.Num,
+    requestType: math_math_pb.FibArgs,
+    responseType: math_math_pb.Num,
     requestSerialize: serialize_FibArgs,
     requestDeserialize: deserialize_FibArgs,
     responseSerialize: serialize_Num,
     responseDeserialize: deserialize_Num,
   },
+  // Sum sums a stream of numbers, returning the final result once the stream
+  // is closed.
   sum: {
     path: '/math.Math/Sum',
     requestStream: true,
     responseStream: false,
-    requestType: math_pb.Num,
-    responseType: math_pb.Num,
+    requestType: math_math_pb.Num,
+    responseType: math_math_pb.Num,
     requestSerialize: serialize_Num,
     requestDeserialize: deserialize_Num,
     responseSerialize: serialize_Num,
diff --git a/src/node/test/math/math_pb.js b/src/node/test/math/math_pb.js
index 3489143bec..ccc05c6e06 100644
--- a/src/node/test/math/math_pb.js
+++ b/src/node/test/math/math_pb.js
@@ -65,7 +65,7 @@ proto.math.DivArgs.toObject = function(includeInstance, msg) {
   };
 
   if (includeInstance) {
-    obj.$jspbMessageInstance = msg
+    obj.$jspbMessageInstance = msg;
   }
   return obj;
 };
@@ -251,7 +251,7 @@ proto.math.DivReply.toObject = function(includeInstance, msg) {
   };
 
   if (includeInstance) {
-    obj.$jspbMessageInstance = msg
+    obj.$jspbMessageInstance = msg;
   }
   return obj;
 };
@@ -436,7 +436,7 @@ proto.math.FibArgs.toObject = function(includeInstance, msg) {
   };
 
   if (includeInstance) {
-    obj.$jspbMessageInstance = msg
+    obj.$jspbMessageInstance = msg;
   }
   return obj;
 };
@@ -595,7 +595,7 @@ proto.math.Num.toObject = function(includeInstance, msg) {
   };
 
   if (includeInstance) {
-    obj.$jspbMessageInstance = msg
+    obj.$jspbMessageInstance = msg;
   }
   return obj;
 };
@@ -754,7 +754,7 @@ proto.math.FibReply.toObject = function(includeInstance, msg) {
   };
 
   if (includeInstance) {
-    obj.$jspbMessageInstance = msg
+    obj.$jspbMessageInstance = msg;
   }
   return obj;
 };
diff --git a/src/objective-c/GRPCClient/GRPCCall+Cronet.h b/src/objective-c/GRPCClient/GRPCCall+Cronet.h
index 7f7fc6c2a9..2d8f7ac8fb 100644
--- a/src/objective-c/GRPCClient/GRPCCall+Cronet.h
+++ b/src/objective-c/GRPCClient/GRPCCall+Cronet.h
@@ -30,6 +30,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
+#ifdef GRPC_COMPILE_WITH_CRONET
 #import <Cronet/Cronet.h>
 
 #import "GRPCCall.h"
@@ -53,3 +54,4 @@
 +(BOOL)isUsingCronet;
 
 @end
+#endif
diff --git a/src/objective-c/GRPCClient/GRPCCall+Cronet.m b/src/objective-c/GRPCClient/GRPCCall+Cronet.m
index 69a410e95a..76ca1a2537 100644
--- a/src/objective-c/GRPCClient/GRPCCall+Cronet.m
+++ b/src/objective-c/GRPCClient/GRPCCall+Cronet.m
@@ -33,6 +33,7 @@
 
 #import "GRPCCall+Cronet.h"
 
+#ifdef GRPC_COMPILE_WITH_CRONET
 static BOOL useCronet = NO;
 static cronet_engine *globalCronetEngine;
 
@@ -52,3 +53,4 @@ static cronet_engine *globalCronetEngine;
 }
 
 @end
+#endif
diff --git a/src/objective-c/GRPCClient/private/GRPCChannel.h b/src/objective-c/GRPCClient/private/GRPCChannel.h
index 3219835d02..40e78a92d6 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannel.h
+++ b/src/objective-c/GRPCClient/private/GRPCChannel.h
@@ -58,9 +58,10 @@ struct grpc_channel_credentials;
 /**
  * Creates a secure channel to the specified @c host using Cronet as a transport mechanism.
  */
+#ifdef GRPC_COMPILE_WITH_CRONET
 + (nullable GRPCChannel *)secureCronetChannelWithHost:(NSString *)host
                                           channelArgs:(NSDictionary *)channelArgs;
-
+#endif
 /**
  * Creates a secure channel to the specified @c host using the specified @c credentials and
  * @c channelArgs. Only in tests should @c GRPC_SSL_TARGET_NAME_OVERRIDE_ARG channel arg be set.
diff --git a/src/objective-c/GRPCClient/private/GRPCChannel.m b/src/objective-c/GRPCClient/private/GRPCChannel.m
index e4e0dbe6d2..d3192c983d 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannel.m
+++ b/src/objective-c/GRPCClient/private/GRPCChannel.m
@@ -34,13 +34,17 @@
 #import "GRPCChannel.h"
 
 #include <grpc/grpc_security.h>
+#ifdef GRPC_COMPILE_WITH_CRONET
 #include <grpc/grpc_cronet.h>
+#endif
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#ifdef GRPC_COMPILE_WITH_CRONET
 #import <Cronet/Cronet.h>
 #import <GRPCClient/GRPCCall+Cronet.h>
+#endif
 #import "GRPCCompletionQueue.h"
 
 void freeChannelArgs(grpc_channel_args *channel_args) {
@@ -102,6 +106,7 @@ grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
   grpc_channel_args *_channelArgs;
 }
 
+#ifdef GRPC_COMPILE_WITH_CRONET
 - (instancetype)initWithHost:(NSString *)host
                 cronetEngine:(cronet_engine *)cronetEngine
                  channelArgs:(NSDictionary *)channelArgs {
@@ -118,6 +123,7 @@ grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
 
   return self;
 }
+#endif
 
 - (instancetype)initWithHost:(NSString *)host
                       secure:(BOOL)secure
@@ -152,6 +158,7 @@ grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
   freeChannelArgs(_channelArgs);
 }
 
+#ifdef GRPC_COMPILE_WITH_CRONET
 + (GRPCChannel *)secureCronetChannelWithHost:(NSString *)host
                                  channelArgs:(NSDictionary *)channelArgs {
   cronet_engine *engine = [GRPCCall cronetEngine];
@@ -162,6 +169,7 @@ grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
   }
   return [[GRPCChannel alloc] initWithHost:host cronetEngine:engine channelArgs:channelArgs];
 }
+#endif
 
 + (GRPCChannel *)secureChannelWithHost:(NSString *)host {
   return [[GRPCChannel alloc] initWithHost:host secure:YES credentials:NULL channelArgs:NULL];
diff --git a/src/objective-c/GRPCClient/private/GRPCHost.m b/src/objective-c/GRPCClient/private/GRPCHost.m
index 7da508810c..fef6385cea 100644
--- a/src/objective-c/GRPCClient/private/GRPCHost.m
+++ b/src/objective-c/GRPCClient/private/GRPCHost.m
@@ -36,8 +36,10 @@
 #include <grpc/grpc.h>
 #include <grpc/grpc_security.h>
 #import <GRPCClient/GRPCCall.h>
+#ifdef GRPC_COMPILE_WITH_CRONET
 #import <GRPCClient/GRPCCall+ChannelArg.h>
 #import <GRPCClient/GRPCCall+Cronet.h>
+#endif
 
 #import "GRPCChannel.h"
 #import "GRPCCompletionQueue.h"
@@ -201,17 +203,22 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (GRPCChannel *)newChannel {
   NSDictionary *args = [self channelArgs];
+#ifdef GRPC_COMPILE_WITH_CRONET
   BOOL useCronet = [GRPCCall isUsingCronet];
+#endif
   if (_secure) {
       GRPCChannel *channel;
       @synchronized(self) {
         if (_channelCreds == nil) {
           [self setTLSPEMRootCerts:nil withPrivateKey:nil withCertChain:nil error:nil];
         }
+#ifdef GRPC_COMPILE_WITH_CRONET
         if (useCronet) {
           channel = [GRPCChannel secureCronetChannelWithHost:_address
                                                  channelArgs:args];
-        } else {
+        } else
+#endif
+        {
           channel = [GRPCChannel secureChannelWithHost:_address
                                             credentials:_channelCreds
                                             channelArgs:args];
diff --git a/src/php/ext/grpc/php_grpc.c b/src/php/ext/grpc/php_grpc.c
index 762c01385c..f4cb5b28cc 100644
--- a/src/php/ext/grpc/php_grpc.c
+++ b/src/php/ext/grpc/php_grpc.c
@@ -227,7 +227,7 @@ PHP_MINIT_FUNCTION(grpc) {
                          GRPC_CHANNEL_TRANSIENT_FAILURE,
                          CONST_CS | CONST_PERSISTENT);
   REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_FATAL_FAILURE",
-                         GRPC_CHANNEL_FATAL_FAILURE,
+                         GRPC_CHANNEL_SHUTDOWN,
                          CONST_CS | CONST_PERSISTENT);
 
   grpc_init_call(TSRMLS_C);
diff --git a/src/proto/math/math.proto b/src/proto/math/math.proto
index 311e148c02..269c60bde8 100644
--- a/src/proto/math/math.proto
+++ b/src/proto/math/math.proto
@@ -55,8 +55,8 @@ message FibReply {
 }
 
 service Math {
-  // Div divides args.dividend by args.divisor and returns the quotient and
-  // remainder.
+  // Div divides DivArgs.dividend by DivArgs.divisor and returns the quotient
+  // and remainder.
   rpc Div (DivArgs) returns (DivReply) {
   }
 
@@ -67,7 +67,7 @@ service Math {
   rpc DivMany (stream DivArgs) returns (stream DivReply) {
   }
 
-  // Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
+  // Fib generates numbers in the Fibonacci sequence.  If FibArgs.limit > 0, Fib
   // generates up to limit numbers; otherwise it continues until the call is
   // canceled.  Unlike Fib above, Fib has no final FibReply.
   rpc Fib (FibArgs) returns (stream Num) {
diff --git a/src/python/grpcio/grpc/__init__.py b/src/python/grpcio/grpc/__init__.py
index 86447314b6..5ba5a4e1fd 100644
--- a/src/python/grpcio/grpc/__init__.py
+++ b/src/python/grpcio/grpc/__init__.py
@@ -352,6 +352,85 @@ class Call(six.with_metaclass(abc.ABCMeta, RpcContext)):
     raise NotImplementedError()
 
 
+############  Authentication & Authorization Interfaces & Classes  #############
+
+
+class ChannelCredentials(object):
+  """A value encapsulating the data required to create a secure Channel.
+
+  This class has no supported interface - it exists to define the type of its
+  instances and its instances exist to be passed to other functions.
+  """
+
+  def __init__(self, credentials):
+    self._credentials = credentials
+
+
+class CallCredentials(object):
+  """A value encapsulating data asserting an identity over a channel.
+
+  A CallCredentials may be composed with ChannelCredentials to always assert
+  identity for every call over that Channel.
+
+  This class has no supported interface - it exists to define the type of its
+  instances and its instances exist to be passed to other functions.
+  """
+
+  def __init__(self, credentials):
+    self._credentials = credentials
+
+
+class AuthMetadataContext(six.with_metaclass(abc.ABCMeta)):
+  """Provides information to call credentials metadata plugins.
+
+  Attributes:
+    service_url: A string URL of the service being called into.
+    method_name: A string of the fully qualified method name being called.
+  """
+
+
+class AuthMetadataPluginCallback(six.with_metaclass(abc.ABCMeta)):
+  """Callback object received by a metadata plugin."""
+
+  def __call__(self, metadata, error):
+    """Inform the gRPC runtime of the metadata to construct a CallCredentials.
+
+    Args:
+      metadata: An iterable of 2-sequences (e.g. tuples) of metadata key/value
+        pairs.
+      error: An Exception to indicate error or None to indicate success.
+    """
+    raise NotImplementedError()
+
+
+class AuthMetadataPlugin(six.with_metaclass(abc.ABCMeta)):
+  """A specification for custom authentication."""
+
+  def __call__(self, context, callback):
+    """Implements authentication by passing metadata to a callback.
+
+    Implementations of this method must not block.
+
+    Args:
+      context: An AuthMetadataContext providing information on the RPC that the
+        plugin is being called to authenticate.
+      callback: An AuthMetadataPluginCallback to be invoked either synchronously
+        or asynchronously.
+    """
+    raise NotImplementedError()
+
+
+class ServerCredentials(object):
+  """A value encapsulating the data required to open a secure port on a Server.
+
+  This class has no supported interface - it exists to define the type of its
+  instances and its instances exist to be passed to other functions.
+  """
+
+  def __init__(self, credentials):
+    self._credentials = credentials
+
+
 ########################  Multi-Callable Interfaces  ###########################
 
 
@@ -359,7 +438,9 @@ class UnaryUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a unary-unary RPC."""
 
   @abc.abstractmethod
-  def __call__(self, request, timeout=None, metadata=None, with_call=False):
+  def __call__(
+      self, request, timeout=None, metadata=None, credentials=None,
+      with_call=False):
     """Synchronously invokes the underlying RPC.
 
     Args:
@@ -367,6 +448,7 @@ class UnaryUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
       timeout: An optional duration of time in seconds to allow for the RPC.
       metadata: An optional sequence of pairs of bytes to be transmitted to the
         service-side of the RPC.
+      credentials: An optional CallCredentials for the RPC.
       with_call: Whether or not to include return a Call for the RPC in addition
         to the response.
 
@@ -382,7 +464,7 @@ class UnaryUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
     raise NotImplementedError()
 
   @abc.abstractmethod
-  def future(self, request, timeout=None, metadata=None):
+  def future(self, request, timeout=None, metadata=None, credentials=None):
     """Asynchronously invokes the underlying RPC.
 
     Args:
@@ -390,6 +472,7 @@ class UnaryUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
       timeout: An optional duration of time in seconds to allow for the RPC.
       metadata: An optional sequence of pairs of bytes to be transmitted to the
         service-side of the RPC.
+      credentials: An optional CallCredentials for the RPC.
 
     Returns:
       An object that is both a Call for the RPC and a Future. In the event of
@@ -404,7 +487,7 @@ class UnaryStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a unary-stream RPC."""
 
   @abc.abstractmethod
-  def __call__(self, request, timeout=None, metadata=None):
+  def __call__(self, request, timeout=None, metadata=None, credentials=None):
     """Invokes the underlying RPC.
 
     Args:
@@ -412,6 +495,7 @@ class UnaryStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
       timeout: An optional duration of time in seconds to allow for the RPC.
       metadata: An optional sequence of pairs of bytes to be transmitted to the
         service-side of the RPC.
+      credentials: An optional CallCredentials for the RPC.
 
     Returns:
       An object that is both a Call for the RPC and an iterator of response
@@ -426,7 +510,8 @@ class StreamUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
 
   @abc.abstractmethod
   def __call__(
-      self, request_iterator, timeout=None, metadata=None, with_call=False):
+      self, request_iterator, timeout=None, metadata=None, credentials=None,
+      with_call=False):
     """Synchronously invokes the underlying RPC.
 
     Args:
@@ -434,6 +519,7 @@ class StreamUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
       timeout: An optional duration of time in seconds to allow for the RPC.
       metadata: An optional sequence of pairs of bytes to be transmitted to the
         service-side of the RPC.
+      credentials: An optional CallCredentials for the RPC.
       with_call: Whether or not to include return a Call for the RPC in addition
         to the response.
 
@@ -449,7 +535,8 @@ class StreamUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
     raise NotImplementedError()
 
   @abc.abstractmethod
-  def future(self, request_iterator, timeout=None, metadata=None):
+  def future(
+      self, request_iterator, timeout=None, metadata=None, credentials=None):
     """Asynchronously invokes the underlying RPC.
 
     Args:
@@ -457,6 +544,7 @@ class StreamUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
       timeout: An optional duration of time in seconds to allow for the RPC.
       metadata: An optional sequence of pairs of bytes to be transmitted to the
         service-side of the RPC.
+      credentials: An optional CallCredentials for the RPC.
 
     Returns:
       An object that is both a Call for the RPC and a Future. In the event of
@@ -471,7 +559,8 @@ class StreamStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a stream-stream RPC in any call style."""
 
   @abc.abstractmethod
-  def __call__(self, request_iterator, timeout=None, metadata=None):
+  def __call__(
+      self, request_iterator, timeout=None, metadata=None, credentials=None):
     """Invokes the underlying RPC.
 
     Args:
@@ -479,6 +568,7 @@ class StreamStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
       timeout: An optional duration of time in seconds to allow for the RPC.
       metadata: An optional sequence of pairs of bytes to be transmitted to the
         service-side of the RPC.
+      credentials: An optional CallCredentials for the RPC.
 
     Returns:
       An object that is both a Call for the RPC and an iterator of response
@@ -690,7 +780,6 @@ class RpcMethodHandler(six.with_metaclass(abc.ABCMeta)):
 
 class HandlerCallDetails(six.with_metaclass(abc.ABCMeta)):
   """Describes an RPC that has just arrived for service.
-
   Attributes:
     method: The method name of the RPC.
     invocation_metadata: The metadata from the invocation side of the RPC.
@@ -751,6 +840,25 @@ class Server(six.with_metaclass(abc.ABCMeta)):
     raise NotImplementedError()
 
   @abc.abstractmethod
+  def add_secure_port(self, address, server_credentials):
+    """Reserves a port for secure RPC service after this Server becomes active.
+
+    This method may only be called before calling this Server's start method is
+    called.
+
+    Args:
+      address: The address for which to open a port.
+      server_credentials: A ServerCredentials.
+
+    Returns:
+      An integer port on which RPCs will be serviced after this link has been
+        started. This is typically the same number as the port number contained
+        in the passed address, but will likely be different if the port number
+        contained in the passed address was zero.
+    """
+    raise NotImplementedError()
+
+  @abc.abstractmethod
   def start(self):
     """Starts this Server's service of RPCs.
 
@@ -787,3 +895,205 @@ class Server(six.with_metaclass(abc.ABCMeta)):
       very early in the grace period).
     """
     raise NotImplementedError()
+
+
+#################################  Functions    ################################
+
+
+def ssl_channel_credentials(
+    root_certificates=None, private_key=None, certificate_chain=None):
+  """Creates a ChannelCredentials for use with an SSL-enabled Channel.
+
+  Args:
+    root_certificates: The PEM-encoded root certificates or unset to ask for
+      them to be retrieved from a default location.
+    private_key: The PEM-encoded private key to use or unset if no private key
+      should be used.
+    certificate_chain: The PEM-encoded certificate chain to use or unset if no
+      certificate chain should be used.
+
+  Returns:
+    A ChannelCredentials for use with an SSL-enabled Channel.
+  """
+  if private_key is not None or certificate_chain is not None:
+    pair = _cygrpc.SslPemKeyCertPair(private_key, certificate_chain)
+  else:
+    pair = None
+  return ChannelCredentials(
+      _cygrpc.channel_credentials_ssl(root_certificates, pair))
+
+
+def metadata_call_credentials(metadata_plugin, name=None):
+  """Construct CallCredentials from an AuthMetadataPlugin.
+
+  Args:
+    metadata_plugin: An AuthMetadataPlugin to use as the authentication behavior
+      in the created CallCredentials.
+    name: A name for the plugin.
+
+  Returns:
+    A CallCredentials.
+  """
+  from grpc import _plugin_wrapping
+  if name is None:
+    try:
+      effective_name = metadata_plugin.__name__
+    except AttributeError:
+      effective_name = metadata_plugin.__class__.__name__
+  else:
+    effective_name = name
+  return CallCredentials(
+      _plugin_wrapping.call_credentials_metadata_plugin(
+          metadata_plugin, effective_name))
+
+
+def access_token_call_credentials(access_token):
+  """Construct CallCredentials from an access token.
+
+  Args:
+    access_token: A string to place directly in the http request
+      authorization header, ie "Authorization: Bearer <access_token>".
+
+  Returns:
+    A CallCredentials.
+  """
+  from grpc import _auth
+  return metadata_call_credentials(
+      _auth.AccessTokenCallCredentials(access_token))
+
+
+def composite_call_credentials(call_credentials, additional_call_credentials):
+  """Compose two CallCredentials to make a new one.
+
+  Args:
+    call_credentials: A CallCredentials object.
+    additional_call_credentials: Another CallCredentials object to compose on
+      top of call_credentials.
+
+  Returns:
+    A new CallCredentials composed of the two given CallCredentials.
+  """
+  return CallCredentials(
+      _cygrpc.call_credentials_composite(
+          call_credentials._credentials,
+          additional_call_credentials._credentials))
+
+
+def composite_channel_credentials(channel_credentials, call_credentials):
+  """Compose a ChannelCredentials and a CallCredentials.
+
+  Args:
+    channel_credentials: A ChannelCredentials.
+    call_credentials: A CallCredentials.
+
+  Returns:
+    A ChannelCredentials composed of the given ChannelCredentials and
+      CallCredentials.
+  """
+  return ChannelCredentials(
+      _cygrpc.channel_credentials_composite(
+          channel_credentials._credentials, call_credentials._credentials))
+
+
+def ssl_server_credentials(
+    private_key_certificate_chain_pairs, root_certificates=None,
+    require_client_auth=False):
+  """Creates a ServerCredentials for use with an SSL-enabled Server.
+
+  Args:
+    private_key_certificate_chain_pairs: A nonempty sequence each element of
+      which is a pair the first element of which is a PEM-encoded private key
+      and the second element of which is the corresponding PEM-encoded
+      certificate chain.
+    root_certificates: PEM-encoded client root certificates to be used for
+      verifying authenticated clients. If omitted, require_client_auth must also
+      be omitted or be False.
+    require_client_auth: A boolean indicating whether or not to require clients
+      to be authenticated. May only be True if root_certificates is not None.
+
+  Returns:
+    A ServerCredentials for use with an SSL-enabled Server.
+  """
+  if len(private_key_certificate_chain_pairs) == 0:
+    raise ValueError(
+        'At least one private key-certificate chain pair is required!')
+  elif require_client_auth and root_certificates is None:
+    raise ValueError(
+        'Illegal to require client auth without providing root certificates!')
+  else:
+    return ServerCredentials(
+        _cygrpc.server_credentials_ssl(
+        root_certificates,
+        [_cygrpc.SslPemKeyCertPair(key, pem)
+         for key, pem in private_key_certificate_chain_pairs],
+        require_client_auth))
+
+
+def channel_ready_future(channel):
+  """Creates a Future tracking when a Channel is ready.
+
+  Cancelling the returned Future does not tell the given Channel to abandon
+  attempts it may have been making to connect; cancelling merely deactivates the
+  returned Future's subscription to the given Channel's connectivity.
+
+  Args:
+    channel: A Channel.
+
+  Returns:
+    A Future that matures when the given Channel has connectivity
+      ChannelConnectivity.READY.
+  """
+  from grpc import _utilities
+  return _utilities.channel_ready_future(channel)
+
+
+def insecure_channel(target, options=None):
+  """Creates an insecure Channel to a server.
+
+  Args:
+    target: The target to which to connect.
+    options: A sequence of string-value pairs according to which to configure
+      the created channel.
+
+  Returns:
+    A Channel to the target through which RPCs may be conducted.
+  """
+  from grpc import _channel
+  return _channel.Channel(target, None, options)
+
+
+def secure_channel(target, credentials, options=None):
+  """Creates an insecure Channel to a server.
+
+  Args:
+    target: The target to which to connect.
+    credentials: A ChannelCredentials instance.
+    options: A sequence of string-value pairs according to which to configure
+      the created channel.
+
+  Returns:
+    A Channel to the target through which RPCs may be conducted.
+  """
+  from grpc import _channel
+  return _channel.Channel(target, credentials, options)
+
+
+def server(generic_rpc_handlers, thread_pool, options=None):
+  """Creates a Server with which RPCs can be serviced.
+
+  The GenericRpcHandlers passed to this function needn't be the only
+  GenericRpcHandlers that will be used to serve RPCs; others may be added later
+  by calling add_generic_rpc_handlers any time before the returned server is
+  started.
+
+  Args:
+    generic_rpc_handlers: Some number of GenericRpcHandlers that will be used
+      to service RPCs after the returned Server is started.
+    thread_pool: A futures.ThreadPoolExecutor to be used by the returned Server
+      to service RPCs.
+
+  Returns:
+    A Server with which RPCs can be serviced.
+  """
+  from grpc import _server
+  return _server.Server(generic_rpc_handlers, thread_pool)
diff --git a/src/python/grpcio/grpc/_adapter/_low.py b/src/python/grpcio/grpc/_adapter/_low.py
index 00788bd4cf..48410167a0 100644
--- a/src/python/grpcio/grpc/_adapter/_low.py
+++ b/src/python/grpcio/grpc/_adapter/_low.py
@@ -30,8 +30,8 @@
 import threading
 
 from grpc import _grpcio_metadata
+from grpc import _plugin_wrapping
 from grpc._cython import cygrpc
-from grpc._adapter import _implementations
 from grpc._adapter import _types
 
 _USER_AGENT = 'Python-gRPC-{}'.format(_grpcio_metadata.__version__)
@@ -57,78 +57,8 @@ def channel_credentials_ssl(
   return cygrpc.channel_credentials_ssl(root_certificates, pair)
 
 
-class _WrappedCygrpcCallback(object):
-
-  def __init__(self, cygrpc_callback):
-    self.is_called = False
-    self.error = None
-    self.is_called_lock = threading.Lock()
-    self.cygrpc_callback = cygrpc_callback
-
-  def _invoke_failure(self, error):
-    # TODO(atash) translate different Exception superclasses into different
-    # status codes.
-    self.cygrpc_callback(
-        cygrpc.Metadata([]), cygrpc.StatusCode.internal, error.message)
-
-  def _invoke_success(self, metadata):
-    try:
-      cygrpc_metadata = cygrpc.Metadata(
-          cygrpc.Metadatum(key, value)
-          for key, value in metadata)
-    except Exception as error:
-      self._invoke_failure(error)
-      return
-    self.cygrpc_callback(cygrpc_metadata, cygrpc.StatusCode.ok, '')
-
-  def __call__(self, metadata, error):
-    with self.is_called_lock:
-      if self.is_called:
-        raise RuntimeError('callback should only ever be invoked once')
-      if self.error:
-        self._invoke_failure(self.error)
-        return
-      self.is_called = True
-    if error is None:
-      self._invoke_success(metadata)
-    else:
-      self._invoke_failure(error)
-
-  def notify_failure(self, error):
-    with self.is_called_lock:
-      if not self.is_called:
-        self.error = error
-
-
-class _WrappedPlugin(object):
-
-  def __init__(self, plugin):
-    self.plugin = plugin
-
-  def __call__(self, context, cygrpc_callback):
-    wrapped_cygrpc_callback = _WrappedCygrpcCallback(cygrpc_callback)
-    wrapped_context = _implementations.AuthMetadataContext(context.service_url,
-                                                           context.method_name)
-    try:
-      self.plugin(
-          wrapped_context,
-          _implementations.AuthMetadataPluginCallback(wrapped_cygrpc_callback))
-    except Exception as error:
-      wrapped_cygrpc_callback.notify_failure(error)
-      raise
-
-
-def call_credentials_metadata_plugin(plugin, name):
-  """
-  Args:
-    plugin: A callable accepting a _types.AuthMetadataContext
-      object and a callback (itself accepting a list of metadata key/value
-      2-tuples and a None-able exception value). The callback must be eventually
-      called, but need not be called in plugin's invocation.
-      plugin's invocation must be non-blocking.
-  """
-  return cygrpc.call_credentials_metadata_plugin(
-      cygrpc.CredentialsMetadataPlugin(_WrappedPlugin(plugin), name))
+call_credentials_metadata_plugin = (
+    _plugin_wrapping.call_credentials_metadata_plugin)
 
 
 class CompletionQueue(_types.CompletionQueue):
diff --git a/src/python/grpcio/grpc/_adapter/_implementations.py b/src/python/grpcio/grpc/_auth.py
index b85f228bf6..3ae00ca23a 100644
--- a/src/python/grpcio/grpc/_adapter/_implementations.py
+++ b/src/python/grpcio/grpc/_auth.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -27,22 +27,47 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-import collections
+"""GRPCAuthMetadataPlugins for standard authentication."""
 
-from grpc.beta import interfaces
+from concurrent import futures
 
-class AuthMetadataContext(collections.namedtuple(
-    'AuthMetadataContext', [
-        'service_url',
-        'method_name'
-    ]), interfaces.GRPCAuthMetadataContext):
-  pass
+import grpc
 
 
-class AuthMetadataPluginCallback(interfaces.GRPCAuthMetadataContext):
+def _sign_request(callback, token, error):
+  metadata = (('authorization', 'Bearer {}'.format(token)),)
+  callback(metadata, error)
 
-  def __init__(self, callback):
-    self._callback = callback
 
-  def __call__(self, metadata, error):
-    self._callback(metadata, error)
+class GoogleCallCredentials(grpc.AuthMetadataPlugin):
+  """Metadata wrapper for GoogleCredentials from the oauth2client library."""
+
+  def __init__(self, credentials):
+    self._credentials = credentials
+    self._pool = futures.ThreadPoolExecutor(max_workers=1)
+
+  def __call__(self, context, callback):
+    # MetadataPlugins cannot block (see grpc.beta.interfaces.py)
+    future = self._pool.submit(self._credentials.get_access_token)
+    future.add_done_callback(lambda x: self._get_token_callback(callback, x))
+
+  def _get_token_callback(self, callback, future):
+    try:
+      access_token = future.result().access_token
+    except Exception as e:
+      _sign_request(callback, None, e)
+    else:
+      _sign_request(callback, access_token, None)
+
+  def __del__(self):
+    self._pool.shutdown(wait=False)
+
+
+class AccessTokenCallCredentials(grpc.AuthMetadataPlugin):
+  """Metadata wrapper for raw access token credentials."""
+
+  def __init__(self, access_token):
+    self._access_token = access_token
+
+  def __call__(self, context, callback):
+    _sign_request(callback, self._access_token, None)
diff --git a/src/python/grpcio/grpc/_channel.py b/src/python/grpcio/grpc/_channel.py
new file mode 100644
index 0000000000..d9eb5a4b77
--- /dev/null
+++ b/src/python/grpcio/grpc/_channel.py
@@ -0,0 +1,852 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Invocation-side implementation of gRPC Python."""
+
+import sys
+import threading
+import time
+
+import grpc
+from grpc import _common
+from grpc import _grpcio_metadata
+from grpc.framework.foundation import callable_util
+from grpc._cython import cygrpc
+
+_USER_AGENT = 'Python-gRPC-{}'.format(_grpcio_metadata.__version__)
+
+_EMPTY_FLAGS = 0
+_INFINITE_FUTURE = cygrpc.Timespec(float('+inf'))
+_EMPTY_METADATA = cygrpc.Metadata(())
+
+_UNARY_UNARY_INITIAL_DUE = (
+    cygrpc.OperationType.send_initial_metadata,
+    cygrpc.OperationType.send_message,
+    cygrpc.OperationType.send_close_from_client,
+    cygrpc.OperationType.receive_initial_metadata,
+    cygrpc.OperationType.receive_message,
+    cygrpc.OperationType.receive_status_on_client,
+)
+_UNARY_STREAM_INITIAL_DUE = (
+    cygrpc.OperationType.send_initial_metadata,
+    cygrpc.OperationType.send_message,
+    cygrpc.OperationType.send_close_from_client,
+    cygrpc.OperationType.receive_initial_metadata,
+    cygrpc.OperationType.receive_status_on_client,
+)
+_STREAM_UNARY_INITIAL_DUE = (
+    cygrpc.OperationType.send_initial_metadata,
+    cygrpc.OperationType.receive_initial_metadata,
+    cygrpc.OperationType.receive_message,
+    cygrpc.OperationType.receive_status_on_client,
+)
+_STREAM_STREAM_INITIAL_DUE = (
+    cygrpc.OperationType.send_initial_metadata,
+    cygrpc.OperationType.receive_initial_metadata,
+    cygrpc.OperationType.receive_status_on_client,
+)
+
+_CHANNEL_SUBSCRIPTION_CALLBACK_ERROR_LOG_MESSAGE = (
+    'Exception calling channel subscription callback!')
+
+
+def _deadline(timeout):
+  if timeout is None:
+    return None, _INFINITE_FUTURE
+  else:
+    deadline = time.time() + timeout
+    return deadline, cygrpc.Timespec(deadline)
+
+
+def _unknown_code_details(unknown_cygrpc_code, details):
+  return b'Server sent unknown code {} and details "{}"'.format(
+      unknown_cygrpc_code, details)
+
+
+def _wait_once_until(condition, until):
+  if until is None:
+    condition.wait()
+  else:
+    remaining = until - time.time()
+    if remaining < 0:
+      raise grpc.FutureTimeoutError()
+    else:
+      condition.wait(timeout=remaining)
+
+
+class _RPCState(object):
+
+  def __init__(self, due, initial_metadata, trailing_metadata, code, details):
+    self.condition = threading.Condition()
+    # The cygrpc.OperationType objects representing events due from the RPC's
+    # completion queue.
+    self.due = set(due)
+    self.initial_metadata = initial_metadata
+    self.response = None
+    self.trailing_metadata = trailing_metadata
+    self.code = code
+    self.details = details
+    # The semantics of grpc.Future.cancel and grpc.Future.cancelled are
+    # slightly wonky, so they have to be tracked separately from the rest of the
+    # result of the RPC. This field tracks whether cancellation was requested
+    # prior to termination of the RPC.
+    self.cancelled = False
+    self.callbacks = []
+
+
+def _abort(state, code, details):
+  if state.code is None:
+    state.code = code
+    state.details = details
+    if state.initial_metadata is None:
+      state.initial_metadata = _EMPTY_METADATA
+    state.trailing_metadata = _EMPTY_METADATA
+
+
+def _handle_event(event, state, response_deserializer):
+  callbacks = []
+  for batch_operation in event.batch_operations:
+    operation_type = batch_operation.type
+    state.due.remove(operation_type)
+    if operation_type is cygrpc.OperationType.receive_initial_metadata:
+      state.initial_metadata = batch_operation.received_metadata
+    elif operation_type is cygrpc.OperationType.receive_message:
+      serialized_response = batch_operation.received_message.bytes()
+      if serialized_response is not None:
+        response = _common.deserialize(
+            serialized_response, response_deserializer)
+        if response is None:
+          details = b'Exception deserializing response!'
+          _abort(state, grpc.StatusCode.INTERNAL, details)
+        else:
+          state.response = response
+    elif operation_type is cygrpc.OperationType.receive_status_on_client:
+      state.trailing_metadata = batch_operation.received_metadata
+      if state.code is None:
+        code = _common.CYGRPC_STATUS_CODE_TO_STATUS_CODE.get(
+            batch_operation.received_status_code)
+        if code is None:
+          state.code = grpc.StatusCode.UNKNOWN
+          state.details = _unknown_code_details(
+              batch_operation.received_status_code,
+              batch_operation.received_status_details)
+        else:
+          state.code = code
+          state.details = batch_operation.received_status_details
+      callbacks.extend(state.callbacks)
+      state.callbacks = None
+  return callbacks
+
+
+def _event_handler(state, call, response_deserializer):
+  def handle_event(event):
+    with state.condition:
+      callbacks = _handle_event(event, state, response_deserializer)
+      state.condition.notify_all()
+      done = not state.due
+    for callback in callbacks:
+      callback()
+    return call if done else None
+  return handle_event
+
+
+def _consume_request_iterator(
+    request_iterator, state, call, request_serializer):
+  event_handler = _event_handler(state, call, None)
+  def consume_request_iterator():
+    for request in request_iterator:
+      serialized_request = _common.serialize(request, request_serializer)
+      with state.condition:
+        if state.code is None and not state.cancelled:
+          if serialized_request is None:
+            call.cancel()
+            details = b'Exception serializing request!'
+            _abort(state, grpc.StatusCode.INTERNAL, details)
+            return
+          else:
+            operations = (
+                cygrpc.operation_send_message(
+                    serialized_request, _EMPTY_FLAGS),
+            )
+            call.start_batch(cygrpc.Operations(operations), event_handler)
+            state.due.add(cygrpc.OperationType.send_message)
+            while True:
+              state.condition.wait()
+              if state.code is None:
+                if cygrpc.OperationType.send_message not in state.due:
+                  break
+              else:
+                return
+        else:
+          return
+    with state.condition:
+      if state.code is None:
+        operations = (
+            cygrpc.operation_send_close_from_client(_EMPTY_FLAGS),
+        )
+        call.start_batch(cygrpc.Operations(operations), event_handler)
+        state.due.add(cygrpc.OperationType.send_close_from_client)
+  thread = threading.Thread(target=consume_request_iterator)
+  thread.start()
+
+
+class _Rendezvous(grpc.RpcError, grpc.Future, grpc.Call):
+
+  def __init__(self, state, call, response_deserializer, deadline):
+    super(_Rendezvous, self).__init__()
+    self._state = state
+    self._call = call
+    self._response_deserializer = response_deserializer
+    self._deadline = deadline
+
+  def cancel(self):
+    with self._state.condition:
+      if self._state.code is None:
+        self._call.cancel()
+        self._state.cancelled = True
+        _abort(self._state, grpc.StatusCode.CANCELLED, b'Cancelled!')
+        self._state.condition.notify_all()
+      return False
+
+  def cancelled(self):
+    with self._state.condition:
+      return self._state.cancelled
+
+  def running(self):
+    with self._state.condition:
+      return self._state.code is None
+
+  def done(self):
+    with self._state.condition:
+      return self._state.code is not None
+
+  def result(self, timeout=None):
+    until = None if timeout is None else time.time() + timeout
+    with self._state.condition:
+      while True:
+        if self._state.code is None:
+          _wait_once_until(self._state.condition, until)
+        elif self._state.code is grpc.StatusCode.OK:
+          return self._state.response
+        elif self._state.cancelled:
+          raise grpc.FutureCancelledError()
+        else:
+          raise self
+
+  def exception(self, timeout=None):
+    until = None if timeout is None else time.time() + timeout
+    with self._state.condition:
+      while True:
+        if self._state.code is None:
+          _wait_once_until(self._state.condition, until)
+        elif self._state.code is grpc.StatusCode.OK:
+          return None
+        elif self._state.cancelled:
+          raise grpc.FutureCancelledError()
+        else:
+          return self
+
+  def traceback(self, timeout=None):
+    until = None if timeout is None else time.time() + timeout
+    with self._state.condition:
+      while True:
+        if self._state.code is None:
+          _wait_once_until(self._state.condition, until)
+        elif self._state.code is grpc.StatusCode.OK:
+          return None
+        elif self._state.cancelled:
+          raise grpc.FutureCancelledError()
+        else:
+          try:
+            raise self
+          except grpc.RpcError:
+            return sys.exc_info()[2]
+
+  def add_done_callback(self, fn):
+    with self._state.condition:
+      if self._state.code is None:
+        self._state.callbacks.append(lambda: fn(self))
+        return
+
+    fn(self)
+
+  def _next(self):
+    with self._state.condition:
+      if self._state.code is None:
+        event_handler = _event_handler(
+            self._state, self._call, self._response_deserializer)
+        self._call.start_batch(
+            cygrpc.Operations(
+                (cygrpc.operation_receive_message(_EMPTY_FLAGS),)),
+            event_handler)
+        self._state.due.add(cygrpc.OperationType.receive_message)
+      elif self._state.code is grpc.StatusCode.OK:
+        raise StopIteration()
+      else:
+        raise self
+      while True:
+        self._state.condition.wait()
+        if self._state.response is not None:
+          response = self._state.response
+          self._state.response = None
+          return response
+        elif cygrpc.OperationType.receive_message not in self._state.due:
+          if self._state.code is grpc.StatusCode.OK:
+            raise StopIteration()
+          elif self._state.code is not None:
+            raise self
+
+  def __iter__(self):
+    return self
+
+  def __next__(self):
+    return self._next()
+
+  def next(self):
+    return self._next()
+
+  def is_active(self):
+    with self._state.condition:
+      return self._state.code is None
+
+  def time_remaining(self):
+    if self._deadline is None:
+      return None
+    else:
+      return max(self._deadline - time.time(), 0)
+
+  def add_cancellation_callback(self, callback):
+    with self._state.condition:
+      if self._state.callbacks is None:
+        return False
+      else:
+        self._state.callbacks.append(lambda unused_future: callback())
+        return True
+
+  def initial_metadata(self):
+    with self._state.condition:
+      while self._state.initial_metadata is None:
+        self._state.condition.wait()
+      return self._state.initial_metadata
+
+  def trailing_metadata(self):
+    with self._state.condition:
+      while self._state.trailing_metadata is None:
+        self._state.condition.wait()
+      return self._state.trailing_metadata
+
+  def code(self):
+    with self._state.condition:
+      while self._state.code is None:
+        self._state.condition.wait()
+      return self._state.code
+
+  def details(self):
+    with self._state.condition:
+      while self._state.details is None:
+        self._state.condition.wait()
+      return self._state.details
+
+  def _repr(self):
+    with self._state.condition:
+      if self._state.code is None:
+        return '<_Rendezvous object of in-flight RPC>'
+      else:
+        return '<_Rendezvous of RPC that terminated with ({}, {})>'.format(
+            self._state.code, self._state.details)
+
+  def __repr__(self):
+    return self._repr()
+
+  def __str__(self):
+    return self._repr()
+
+  def __del__(self):
+    with self._state.condition:
+      if self._state.code is None:
+        self._call.cancel()
+        self._state.cancelled = True
+        self._state.code = grpc.StatusCode.CANCELLED
+        self._state.condition.notify_all()
+
+
+def _start_unary_request(request, timeout, request_serializer):
+  deadline, deadline_timespec = _deadline(timeout)
+  serialized_request = _common.serialize(request, request_serializer)
+  if serialized_request is None:
+    state = _RPCState(
+        (), _EMPTY_METADATA, _EMPTY_METADATA, grpc.StatusCode.INTERNAL,
+        b'Exception serializing request!')
+    rendezvous = _Rendezvous(state, None, None, deadline)
+    return deadline, deadline_timespec, None, rendezvous
+  else:
+    return deadline, deadline_timespec, serialized_request, None
+
+
+def _end_unary_response_blocking(state, with_call, deadline):
+  if state.code is grpc.StatusCode.OK:
+    if with_call:
+      rendezvous = _Rendezvous(state, None, None, deadline)
+      return state.response, rendezvous
+    else:
+      return state.response
+  else:
+    raise _Rendezvous(state, None, None, deadline)
+
+
+class _UnaryUnaryMultiCallable(grpc.UnaryUnaryMultiCallable):
+
+  def __init__(
+      self, channel, create_managed_call, method, request_serializer,
+      response_deserializer):
+    self._channel = channel
+    self._create_managed_call = create_managed_call
+    self._method = method
+    self._request_serializer = request_serializer
+    self._response_deserializer = response_deserializer
+
+  def _prepare(self, request, timeout, metadata):
+    deadline, deadline_timespec, serialized_request, rendezvous = (
+        _start_unary_request(request, timeout, self._request_serializer))
+    if serialized_request is None:
+      return None, None, None, None, rendezvous
+    else:
+      state = _RPCState(_UNARY_UNARY_INITIAL_DUE, None, None, None, None)
+      operations = (
+          cygrpc.operation_send_initial_metadata(
+              _common.metadata(metadata), _EMPTY_FLAGS),
+          cygrpc.operation_send_message(serialized_request, _EMPTY_FLAGS),
+          cygrpc.operation_send_close_from_client(_EMPTY_FLAGS),
+          cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),
+          cygrpc.operation_receive_message(_EMPTY_FLAGS),
+          cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
+      )
+      return state, operations, deadline, deadline_timespec, None
+
+  def __call__(
+      self, request, timeout=None, metadata=None, credentials=None,
+      with_call=False):
+    state, operations, deadline, deadline_timespec, rendezvous = self._prepare(
+        request, timeout, metadata)
+    if rendezvous:
+      raise rendezvous
+    else:
+      completion_queue = cygrpc.CompletionQueue()
+      call = self._channel.create_call(
+          None, 0, completion_queue, self._method, None, deadline_timespec)
+      if credentials is not None:
+        call.set_credentials(credentials._credentials)
+      call.start_batch(cygrpc.Operations(operations), None)
+      _handle_event(completion_queue.poll(), state, self._response_deserializer)
+      return _end_unary_response_blocking(state, with_call, deadline)
+
+  def future(self, request, timeout=None, metadata=None, credentials=None):
+    state, operations, deadline, deadline_timespec, rendezvous = self._prepare(
+        request, timeout, metadata)
+    if rendezvous:
+      return rendezvous
+    else:
+      call = self._create_managed_call(
+          None, 0, self._method, None, deadline_timespec)
+      if credentials is not None:
+        call.set_credentials(credentials._credentials)
+      event_handler = _event_handler(state, call, self._response_deserializer)
+      with state.condition:
+        call.start_batch(cygrpc.Operations(operations), event_handler)
+      return _Rendezvous(state, call, self._response_deserializer, deadline)
+
+
+class _UnaryStreamMultiCallable(grpc.UnaryStreamMultiCallable):
+
+  def __init__(
+      self, channel, create_managed_call, method, request_serializer,
+      response_deserializer):
+    self._channel = channel
+    self._create_managed_call = create_managed_call
+    self._method = method
+    self._request_serializer = request_serializer
+    self._response_deserializer = response_deserializer
+
+  def __call__(self, request, timeout=None, metadata=None, credentials=None):
+    deadline, deadline_timespec, serialized_request, rendezvous = (
+        _start_unary_request(request, timeout, self._request_serializer))
+    if serialized_request is None:
+      raise rendezvous
+    else:
+      state = _RPCState(_UNARY_STREAM_INITIAL_DUE, None, None, None, None)
+      call = self._create_managed_call(
+          None, 0, self._method, None, deadline_timespec)
+      if credentials is not None:
+        call.set_credentials(credentials._credentials)
+      event_handler = _event_handler(state, call, self._response_deserializer)
+      with state.condition:
+        call.start_batch(
+            cygrpc.Operations(
+                (cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),)),
+            event_handler)
+        operations = (
+            cygrpc.operation_send_initial_metadata(
+                _common.metadata(metadata), _EMPTY_FLAGS),
+            cygrpc.operation_send_message(serialized_request, _EMPTY_FLAGS),
+            cygrpc.operation_send_close_from_client(_EMPTY_FLAGS),
+            cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
+        )
+        call.start_batch(cygrpc.Operations(operations), event_handler)
+      return _Rendezvous(state, call, self._response_deserializer, deadline)
+
+
+class _StreamUnaryMultiCallable(grpc.StreamUnaryMultiCallable):
+
+  def __init__(
+      self, channel, create_managed_call, method, request_serializer,
+      response_deserializer):
+    self._channel = channel
+    self._create_managed_call = create_managed_call
+    self._method = method
+    self._request_serializer = request_serializer
+    self._response_deserializer = response_deserializer
+
+  def __call__(
+      self, request_iterator, timeout=None, metadata=None, credentials=None,
+      with_call=False):
+    deadline, deadline_timespec = _deadline(timeout)
+    state = _RPCState(_STREAM_UNARY_INITIAL_DUE, None, None, None, None)
+    completion_queue = cygrpc.CompletionQueue()
+    call = self._channel.create_call(
+        None, 0, completion_queue, self._method, None, deadline_timespec)
+    if credentials is not None:
+      call.set_credentials(credentials._credentials)
+    with state.condition:
+      call.start_batch(
+          cygrpc.Operations(
+              (cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),)),
+          None)
+      operations = (
+          cygrpc.operation_send_initial_metadata(
+              _common.metadata(metadata), _EMPTY_FLAGS),
+          cygrpc.operation_receive_message(_EMPTY_FLAGS),
+          cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
+      )
+      call.start_batch(cygrpc.Operations(operations), None)
+      _consume_request_iterator(
+          request_iterator, state, call, self._request_serializer)
+    while True:
+      event = completion_queue.poll()
+      with state.condition:
+        _handle_event(event, state, self._response_deserializer)
+        state.condition.notify_all()
+        if not state.due:
+          break
+    return _end_unary_response_blocking(state, with_call, deadline)
+
+  def future(
+      self, request_iterator, timeout=None, metadata=None, credentials=None):
+    deadline, deadline_timespec = _deadline(timeout)
+    state = _RPCState(_STREAM_UNARY_INITIAL_DUE, None, None, None, None)
+    call = self._create_managed_call(
+        None, 0, self._method, None, deadline_timespec)
+    if credentials is not None:
+      call.set_credentials(credentials._credentials)
+    event_handler = _event_handler(state, call, self._response_deserializer)
+    with state.condition:
+      call.start_batch(
+          cygrpc.Operations(
+              (cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),)),
+          event_handler)
+      operations = (
+          cygrpc.operation_send_initial_metadata(
+              _common.metadata(metadata), _EMPTY_FLAGS),
+          cygrpc.operation_receive_message(_EMPTY_FLAGS),
+          cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
+      )
+      call.start_batch(cygrpc.Operations(operations), event_handler)
+      _consume_request_iterator(
+          request_iterator, state, call, self._request_serializer)
+    return _Rendezvous(state, call, self._response_deserializer, deadline)
+
+
+class _StreamStreamMultiCallable(grpc.StreamStreamMultiCallable):
+
+  def __init__(
+      self, channel, create_managed_call, method, request_serializer,
+      response_deserializer):
+    self._channel = channel
+    self._create_managed_call = create_managed_call
+    self._method = method
+    self._request_serializer = request_serializer
+    self._response_deserializer = response_deserializer
+
+  def __call__(
+      self, request_iterator, timeout=None, metadata=None, credentials=None):
+    deadline, deadline_timespec = _deadline(timeout)
+    state = _RPCState(_STREAM_STREAM_INITIAL_DUE, None, None, None, None)
+    call = self._create_managed_call(
+        None, 0, self._method, None, deadline_timespec)
+    if credentials is not None:
+      call.set_credentials(credentials._credentials)
+    event_handler = _event_handler(state, call, self._response_deserializer)
+    with state.condition:
+      call.start_batch(
+          cygrpc.Operations(
+              (cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),)),
+          event_handler)
+      operations = (
+          cygrpc.operation_send_initial_metadata(
+              _common.metadata(metadata), _EMPTY_FLAGS),
+          cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
+      )
+      call.start_batch(cygrpc.Operations(operations), event_handler)
+      _consume_request_iterator(
+          request_iterator, state, call, self._request_serializer)
+    return _Rendezvous(state, call, self._response_deserializer, deadline)
+
+
+class _ChannelCallState(object):
+
+  def __init__(self, channel):
+    self.lock = threading.Lock()
+    self.channel = channel
+    self.completion_queue = cygrpc.CompletionQueue()
+    self.managed_calls = None
+
+
+def _call_spin(state):
+  while True:
+    event = state.completion_queue.poll()
+    completed_call = event.tag(event)
+    if completed_call is not None:
+      with state.lock:
+        state.managed_calls.remove(completed_call)
+        if not state.managed_calls:
+          state.managed_calls = None
+          return
+
+
+def _create_channel_managed_call(state):
+  def create_channel_managed_call(parent, flags, method, host, deadline):
+    """Creates a managed cygrpc.Call.
+
+    Callers of this function must conduct at least one operation on the returned
+    call. The tags associated with operations conducted on the returned call
+    must be no-argument callables that return None to indicate that this channel
+    should continue polling for events associated with the call and return the
+    call itself to indicate that no more events associated with the call will be
+    generated.
+
+    Args:
+      parent: A cygrpc.Call to be used as the parent of the created call.
+      flags: An integer bitfield of call flags.
+      method: The RPC method.
+      host: A host string for the created call.
+      deadline: A cygrpc.Timespec to be the deadline of the created call.
+
+    Returns:
+      A cygrpc.Call with which to conduct an RPC.
+    """
+    with state.lock:
+      call = state.channel.create_call(
+          parent, flags, state.completion_queue, method, host, deadline)
+      if state.managed_calls is None:
+        state.managed_calls = set((call,))
+        spin_thread = threading.Thread(target=_call_spin, args=(state,))
+        spin_thread.start()
+      else:
+        state.managed_calls.add(call)
+      return call
+  return create_channel_managed_call
+
+
+class _ChannelConnectivityState(object):
+
+  def __init__(self, channel):
+    self.lock = threading.Lock()
+    self.channel = channel
+    self.polling = False
+    self.connectivity = None
+    self.try_to_connect = False
+    self.callbacks_and_connectivities = []
+    self.delivering = False
+
+
+def _deliveries(state):
+  callbacks_needing_update = []
+  for callback_and_connectivity in state.callbacks_and_connectivities:
+    callback, callback_connectivity, = callback_and_connectivity
+    if callback_connectivity is not state.connectivity:
+      callbacks_needing_update.append(callback)
+      callback_and_connectivity[1] = state.connectivity
+  return callbacks_needing_update
+
+
+def _deliver(state, initial_connectivity, initial_callbacks):
+  connectivity = initial_connectivity
+  callbacks = initial_callbacks
+  while True:
+    for callback in callbacks:
+      callable_util.call_logging_exceptions(
+          callback, _CHANNEL_SUBSCRIPTION_CALLBACK_ERROR_LOG_MESSAGE,
+          connectivity)
+    with state.lock:
+      callbacks = _deliveries(state)
+      if callbacks:
+        connectivity = state.connectivity
+      else:
+        state.delivering = False
+        return
+
+
+def _spawn_delivery(state, callbacks):
+  delivering_thread = threading.Thread(
+      target=_deliver, args=(state, state.connectivity, callbacks,))
+  delivering_thread.start()
+  state.delivering = True
+
+
+# NOTE(https://github.com/grpc/grpc/issues/3064): We'd rather not poll.
+def _poll_connectivity(state, channel, initial_try_to_connect):
+  try_to_connect = initial_try_to_connect
+  connectivity = channel.check_connectivity_state(try_to_connect)
+  with state.lock:
+    state.connectivity = (
+        _common.CYGRPC_CONNECTIVITY_STATE_TO_CHANNEL_CONNECTIVITY[
+            connectivity])
+    callbacks = tuple(
+        callback for callback, unused_but_known_to_be_none_connectivity
+        in state.callbacks_and_connectivities)
+    for callback_and_connectivity in state.callbacks_and_connectivities:
+      callback_and_connectivity[1] = state.connectivity
+    if callbacks:
+      _spawn_delivery(state, callbacks)
+  completion_queue = cygrpc.CompletionQueue()
+  while True:
+    channel.watch_connectivity_state(
+        connectivity, cygrpc.Timespec(time.time() + 0.2),
+        completion_queue, None)
+    event = completion_queue.poll()
+    with state.lock:
+      if not state.callbacks_and_connectivities and not state.try_to_connect:
+        state.polling = False
+        state.connectivity = None
+        break
+      try_to_connect = state.try_to_connect
+      state.try_to_connect = False
+    if event.success or try_to_connect:
+      connectivity = channel.check_connectivity_state(try_to_connect)
+      with state.lock:
+        state.connectivity = (
+            _common.CYGRPC_CONNECTIVITY_STATE_TO_CHANNEL_CONNECTIVITY[
+                connectivity])
+        if not state.delivering:
+          callbacks = _deliveries(state)
+          if callbacks:
+            _spawn_delivery(state, callbacks)
+
+
+def _subscribe(state, callback, try_to_connect):
+  with state.lock:
+    if not state.callbacks_and_connectivities and not state.polling:
+      polling_thread = threading.Thread(
+          target=_poll_connectivity,
+          args=(state, state.channel, bool(try_to_connect)))
+      polling_thread.start()
+      state.polling = True
+      state.callbacks_and_connectivities.append([callback, None])
+    elif not state.delivering and state.connectivity is not None:
+      _spawn_delivery(state, (callback,))
+      state.try_to_connect |= bool(try_to_connect)
+      state.callbacks_and_connectivities.append(
+          [callback, state.connectivity])
+    else:
+      state.try_to_connect |= bool(try_to_connect)
+      state.callbacks_and_connectivities.append([callback, None])
+
+
+def _unsubscribe(state, callback):
+  with state.lock:
+    for index, (subscribed_callback, unused_connectivity) in enumerate(
+        state.callbacks_and_connectivities):
+      if callback == subscribed_callback:
+        state.callbacks_and_connectivities.pop(index)
+        break
+
+
+def _moot(state):
+  with state.lock:
+    del state.callbacks_and_connectivities[:]
+
+
+def _options(options):
+  if options is None:
+    pairs = ((cygrpc.ChannelArgKey.primary_user_agent_string, _USER_AGENT),)
+  else:
+    pairs = list(options) + [
+        (cygrpc.ChannelArgKey.primary_user_agent_string, _USER_AGENT)]
+  return cygrpc.ChannelArgs(
+      cygrpc.ChannelArg(arg_name, arg_value) for arg_name, arg_value in pairs)
+
+
+class Channel(grpc.Channel):
+
+  def __init__(self, target, options, credentials):
+    self._channel = cygrpc.Channel(target, _options(options), credentials)
+    self._call_state = _ChannelCallState(self._channel)
+    self._connectivity_state = _ChannelConnectivityState(self._channel)
+
+  def subscribe(self, callback, try_to_connect=None):
+    _subscribe(self._connectivity_state, callback, try_to_connect)
+
+  def unsubscribe(self, callback):
+    _unsubscribe(self._connectivity_state, callback)
+
+  def unary_unary(
+      self, method, request_serializer=None, response_deserializer=None):
+    return _UnaryUnaryMultiCallable(
+        self._channel, _create_channel_managed_call(self._call_state), method,
+        request_serializer, response_deserializer)
+
+  def unary_stream(
+      self, method, request_serializer=None, response_deserializer=None):
+    return _UnaryStreamMultiCallable(
+        self._channel, _create_channel_managed_call(self._call_state), method,
+        request_serializer, response_deserializer)
+
+  def stream_unary(
+      self, method, request_serializer=None, response_deserializer=None):
+    return _StreamUnaryMultiCallable(
+        self._channel, _create_channel_managed_call(self._call_state), method,
+        request_serializer, response_deserializer)
+
+  def stream_stream(
+      self, method, request_serializer=None, response_deserializer=None):
+    return _StreamStreamMultiCallable(
+        self._channel, _create_channel_managed_call(self._call_state), method,
+        request_serializer, response_deserializer)
+
+  def __del__(self):
+    _moot(self._connectivity_state)
diff --git a/src/python/grpcio/grpc/_common.py b/src/python/grpcio/grpc/_common.py
new file mode 100644
index 0000000000..a3fb66cd07
--- /dev/null
+++ b/src/python/grpcio/grpc/_common.py
@@ -0,0 +1,99 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Shared implementation."""
+
+import logging
+
+import six
+
+import grpc
+from grpc._cython import cygrpc
+
+_EMPTY_METADATA = cygrpc.Metadata(())
+
+CYGRPC_CONNECTIVITY_STATE_TO_CHANNEL_CONNECTIVITY = {
+    cygrpc.ConnectivityState.idle: grpc.ChannelConnectivity.IDLE,
+    cygrpc.ConnectivityState.connecting: grpc.ChannelConnectivity.CONNECTING,
+    cygrpc.ConnectivityState.ready: grpc.ChannelConnectivity.READY,
+    cygrpc.ConnectivityState.transient_failure:
+        grpc.ChannelConnectivity.TRANSIENT_FAILURE,
+    cygrpc.ConnectivityState.fatal_failure:
+        grpc.ChannelConnectivity.FATAL_FAILURE,
+}
+
+CYGRPC_STATUS_CODE_TO_STATUS_CODE = {
+    cygrpc.StatusCode.ok: grpc.StatusCode.OK,
+    cygrpc.StatusCode.cancelled: grpc.StatusCode.CANCELLED,
+    cygrpc.StatusCode.unknown: grpc.StatusCode.UNKNOWN,
+    cygrpc.StatusCode.invalid_argument: grpc.StatusCode.INVALID_ARGUMENT,
+    cygrpc.StatusCode.deadline_exceeded: grpc.StatusCode.DEADLINE_EXCEEDED,
+    cygrpc.StatusCode.not_found: grpc.StatusCode.NOT_FOUND,
+    cygrpc.StatusCode.already_exists: grpc.StatusCode.ALREADY_EXISTS,
+    cygrpc.StatusCode.permission_denied: grpc.StatusCode.PERMISSION_DENIED,
+    cygrpc.StatusCode.unauthenticated: grpc.StatusCode.UNAUTHENTICATED,
+    cygrpc.StatusCode.resource_exhausted: grpc.StatusCode.RESOURCE_EXHAUSTED,
+    cygrpc.StatusCode.failed_precondition: grpc.StatusCode.FAILED_PRECONDITION,
+    cygrpc.StatusCode.aborted: grpc.StatusCode.ABORTED,
+    cygrpc.StatusCode.out_of_range: grpc.StatusCode.OUT_OF_RANGE,
+    cygrpc.StatusCode.unimplemented: grpc.StatusCode.UNIMPLEMENTED,
+    cygrpc.StatusCode.internal: grpc.StatusCode.INTERNAL,
+    cygrpc.StatusCode.unavailable: grpc.StatusCode.UNAVAILABLE,
+    cygrpc.StatusCode.data_loss: grpc.StatusCode.DATA_LOSS,
+}
+STATUS_CODE_TO_CYGRPC_STATUS_CODE = {
+    grpc_code: cygrpc_code
+    for cygrpc_code, grpc_code in six.iteritems(
+        CYGRPC_STATUS_CODE_TO_STATUS_CODE)
+}
+
+
+def metadata(application_metadata):
+  return _EMPTY_METADATA if application_metadata is None else cygrpc.Metadata(
+      cygrpc.Metadatum(key, value) for key, value in application_metadata)
+
+
+def _transform(message, transformer, exception_message):
+  if transformer is None:
+    return message
+  else:
+    try:
+      return transformer(message)
+    except Exception:  # pylint: disable=broad-except
+      logging.exception(exception_message)
+      return None
+
+
+def serialize(message, serializer):
+  return _transform(message, serializer, 'Exception serializing message!')
+
+
+def deserialize(serialized_message, deserializer):
+  return _transform(serialized_message, deserializer,
+                    'Exception deserializing message!')
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pxd.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pxd.pxi
index c793c8f5e5..19a59e08f3 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pxd.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pxd.pxi
@@ -68,4 +68,4 @@ cdef void plugin_get_metadata(
     void *state, grpc_auth_metadata_context context,
     grpc_credentials_plugin_metadata_cb cb, void *user_data) with gil
 
-cdef void plugin_destroy_c_plugin_state(void *state)
+cdef void plugin_destroy_c_plugin_state(void *state) with gil
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi
index 94d13b5999..1ba86457af 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi
@@ -137,7 +137,7 @@ cdef void plugin_get_metadata(
   cy_context.context = context
   self.plugin_callback(cy_context, python_callback)
 
-cdef void plugin_destroy_c_plugin_state(void *state):
+cdef void plugin_destroy_c_plugin_state(void *state) with gil:
   cpython.Py_DECREF(<CredentialsMetadataPlugin>state)
 
 def channel_credentials_google_default():
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
index d42c58050f..05b8886df7 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
@@ -208,7 +208,7 @@ cdef extern from "grpc/_cython/loader.h":
     GRPC_CHANNEL_CONNECTING
     GRPC_CHANNEL_READY
     GRPC_CHANNEL_TRANSIENT_FAILURE
-    GRPC_CHANNEL_FATAL_FAILURE
+    GRPC_CHANNEL_SHUTDOWN
 
   ctypedef struct grpc_metadata:
     const char *key
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
index c7539f0d49..e0219b0086 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
@@ -33,7 +33,7 @@ class ConnectivityState:
   connecting = GRPC_CHANNEL_CONNECTING
   ready = GRPC_CHANNEL_READY
   transient_failure = GRPC_CHANNEL_TRANSIENT_FAILURE
-  fatal_failure = GRPC_CHANNEL_FATAL_FAILURE
+  fatal_failure = GRPC_CHANNEL_SHUTDOWN
 
 
 class ChannelArgKey:
@@ -274,6 +274,7 @@ cdef class ByteBuffer:
           data_slice_length = gpr_slice_length(data_slice)
           with gil:
             result += (<char *>data_slice_pointer)[:data_slice_length]
+          gpr_slice_unref(data_slice)
       with nogil:
         grpc_byte_buffer_reader_destroy(&reader)
       return bytes(result)
diff --git a/src/python/grpcio/grpc/_cython/imports.generated.c b/src/python/grpcio/grpc/_cython/imports.generated.c
index f71cf12844..c80ee66c06 100644
--- a/src/python/grpcio/grpc/_cython/imports.generated.c
+++ b/src/python/grpcio/grpc/_cython/imports.generated.c
@@ -35,7 +35,7 @@
 
 #include "imports.generated.h"
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 census_initialize_type census_initialize_import;
 census_shutdown_type census_shutdown_import;
@@ -126,7 +126,6 @@ grpc_header_key_is_legal_type grpc_header_key_is_legal_import;
 grpc_header_nonbin_value_is_legal_type grpc_header_nonbin_value_is_legal_import;
 grpc_is_binary_header_type grpc_is_binary_header_import;
 grpc_call_error_to_string_type grpc_call_error_to_string_import;
-grpc_cronet_secure_channel_create_type grpc_cronet_secure_channel_create_import;
 grpc_auth_property_iterator_next_type grpc_auth_property_iterator_next_import;
 grpc_auth_context_property_iterator_type grpc_auth_context_property_iterator_import;
 grpc_auth_context_peer_identity_type grpc_auth_context_peer_identity_import;
@@ -398,7 +397,6 @@ void pygrpc_load_imports(HMODULE library) {
   grpc_header_nonbin_value_is_legal_import = (grpc_header_nonbin_value_is_legal_type) GetProcAddress(library, "grpc_header_nonbin_value_is_legal");
   grpc_is_binary_header_import = (grpc_is_binary_header_type) GetProcAddress(library, "grpc_is_binary_header");
   grpc_call_error_to_string_import = (grpc_call_error_to_string_type) GetProcAddress(library, "grpc_call_error_to_string");
-  grpc_cronet_secure_channel_create_import = (grpc_cronet_secure_channel_create_type) GetProcAddress(library, "grpc_cronet_secure_channel_create");
   grpc_auth_property_iterator_next_import = (grpc_auth_property_iterator_next_type) GetProcAddress(library, "grpc_auth_property_iterator_next");
   grpc_auth_context_property_iterator_import = (grpc_auth_context_property_iterator_type) GetProcAddress(library, "grpc_auth_context_property_iterator");
   grpc_auth_context_peer_identity_import = (grpc_auth_context_peer_identity_type) GetProcAddress(library, "grpc_auth_context_peer_identity");
@@ -581,4 +579,4 @@ void pygrpc_load_imports(HMODULE library) {
 }
 #endif  /* __cpluslus */
 
-#endif /* !GPR_WIN32 */
+#endif /* !GPR_WINDOWS */
diff --git a/src/python/grpcio/grpc/_cython/imports.generated.h b/src/python/grpcio/grpc/_cython/imports.generated.h
index a364075e9e..7b8e98d9bf 100644
--- a/src/python/grpcio/grpc/_cython/imports.generated.h
+++ b/src/python/grpcio/grpc/_cython/imports.generated.h
@@ -36,14 +36,13 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 #include <windows.h>
 
 #include <grpc/census.h>
 #include <grpc/compression.h>
 #include <grpc/grpc.h>
-#include <grpc/grpc_cronet.h>
 #include <grpc/grpc_security.h>
 #include <grpc/impl/codegen/alloc.h>
 #include <grpc/impl/codegen/byte_buffer.h>
@@ -57,7 +56,7 @@
 #include <grpc/support/cpu.h>
 #include <grpc/support/histogram.h>
 #include <grpc/support/host_port.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/subprocess.h>
 #include <grpc/support/thd.h>
@@ -329,9 +328,6 @@ extern grpc_is_binary_header_type grpc_is_binary_header_import;
 typedef const char *(*grpc_call_error_to_string_type)(grpc_call_error error);
 extern grpc_call_error_to_string_type grpc_call_error_to_string_import;
 #define grpc_call_error_to_string grpc_call_error_to_string_import
-typedef grpc_channel *(*grpc_cronet_secure_channel_create_type)(void *engine, const char *target, const grpc_channel_args *args, void *reserved);
-extern grpc_cronet_secure_channel_create_type grpc_cronet_secure_channel_create_import;
-#define grpc_cronet_secure_channel_create grpc_cronet_secure_channel_create_import
 typedef const grpc_auth_property *(*grpc_auth_property_iterator_next_type)(grpc_auth_property_iterator *it);
 extern grpc_auth_property_iterator_next_type grpc_auth_property_iterator_next_import;
 #define grpc_auth_property_iterator_next grpc_auth_property_iterator_next_import
@@ -871,7 +867,7 @@ void pygrpc_load_imports(HMODULE library);
 }
 #endif  /* __cpluslus */
 
-#else /* !GPR_WIN32 */
+#else /* !GPR_WINDOWS */
 
 #include <grpc/byte_buffer.h>
 #include <grpc/byte_buffer_reader.h>
@@ -883,6 +879,6 @@ void pygrpc_load_imports(HMODULE library);
 #include <grpc/support/time.h>
 #include <grpc/status.h>
 
-#endif /* !GPR_WIN32 */
+#endif /* !GPR_WINDOWS */
 
 #endif
diff --git a/src/python/grpcio/grpc/_cython/loader.c b/src/python/grpcio/grpc/_cython/loader.c
index 3b72806ea1..b909ad594e 100644
--- a/src/python/grpcio/grpc/_cython/loader.c
+++ b/src/python/grpcio/grpc/_cython/loader.c
@@ -37,7 +37,7 @@
 extern "C" {
 #endif  /* __cpluslus  */
 
-#if GPR_WIN32
+#if GPR_WINDOWS
 
 int pygrpc_load_core(char *path) {
   HMODULE grpc_c;
@@ -60,7 +60,7 @@ int pygrpc_load_core(char *path) {
 
 int pygrpc_load_core(char *path) { return 1; }
 
-#endif  /* !GPR_WIN32 */
+#endif  /* !GPR_WINDOWS */
 
 #ifdef __cplusplus
 }
diff --git a/src/python/grpcio/grpc/_plugin_wrapping.py b/src/python/grpcio/grpc/_plugin_wrapping.py
new file mode 100644
index 0000000000..4e9cfe710c
--- /dev/null
+++ b/src/python/grpcio/grpc/_plugin_wrapping.py
@@ -0,0 +1,123 @@
+# 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.
+
+import collections
+import threading
+
+import grpc
+from grpc._cython import cygrpc
+
+
+class AuthMetadataContext(
+    collections.namedtuple(
+        'AuthMetadataContext', ('service_url', 'method_name',)),
+    grpc.AuthMetadataContext):
+  pass
+
+
+class AuthMetadataPluginCallback(grpc.AuthMetadataContext):
+
+  def __init__(self, callback):
+    self._callback = callback
+
+  def __call__(self, metadata, error):
+    self._callback(metadata, error)
+
+
+class _WrappedCygrpcCallback(object):
+
+  def __init__(self, cygrpc_callback):
+    self.is_called = False
+    self.error = None
+    self.is_called_lock = threading.Lock()
+    self.cygrpc_callback = cygrpc_callback
+
+  def _invoke_failure(self, error):
+    # TODO(atash) translate different Exception superclasses into different
+    # status codes.
+    self.cygrpc_callback(
+        cygrpc.Metadata([]), cygrpc.StatusCode.internal, error.message)
+
+  def _invoke_success(self, metadata):
+    try:
+      cygrpc_metadata = cygrpc.Metadata(
+          cygrpc.Metadatum(key, value)
+          for key, value in metadata)
+    except Exception as error:
+      self._invoke_failure(error)
+      return
+    self.cygrpc_callback(cygrpc_metadata, cygrpc.StatusCode.ok, '')
+
+  def __call__(self, metadata, error):
+    with self.is_called_lock:
+      if self.is_called:
+        raise RuntimeError('callback should only ever be invoked once')
+      if self.error:
+        self._invoke_failure(self.error)
+        return
+      self.is_called = True
+    if error is None:
+      self._invoke_success(metadata)
+    else:
+      self._invoke_failure(error)
+
+  def notify_failure(self, error):
+    with self.is_called_lock:
+      if not self.is_called:
+        self.error = error
+
+
+class _WrappedPlugin(object):
+
+  def __init__(self, plugin):
+    self.plugin = plugin
+
+  def __call__(self, context, cygrpc_callback):
+    wrapped_cygrpc_callback = _WrappedCygrpcCallback(cygrpc_callback)
+    wrapped_context = AuthMetadataContext(
+        context.service_url, context.method_name)
+    try:
+      self.plugin(
+          wrapped_context, AuthMetadataPluginCallback(wrapped_cygrpc_callback))
+    except Exception as error:
+      wrapped_cygrpc_callback.notify_failure(error)
+      raise
+
+
+def call_credentials_metadata_plugin(plugin, name):
+  """
+  Args:
+    plugin: A callable accepting a grpc.AuthMetadataContext
+      object and a callback (itself accepting a list of metadata key/value
+      2-tuples and a None-able exception value). The callback must be eventually
+      called, but need not be called in plugin's invocation.
+      plugin's invocation must be non-blocking.
+  """
+  return cygrpc.call_credentials_metadata_plugin(
+      cygrpc.CredentialsMetadataPlugin(_WrappedPlugin(plugin), name))
diff --git a/src/python/grpcio/grpc/_server.py b/src/python/grpcio/grpc/_server.py
new file mode 100644
index 0000000000..aae9f48ae6
--- /dev/null
+++ b/src/python/grpcio/grpc/_server.py
@@ -0,0 +1,747 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Service-side implementation of gRPC Python."""
+
+import collections
+import enum
+import logging
+import threading
+import time
+
+import grpc
+from grpc import _common
+from grpc._cython import cygrpc
+from grpc.framework.foundation import callable_util
+
+_SHUTDOWN_TAG = 'shutdown'
+_REQUEST_CALL_TAG = 'request_call'
+
+_RECEIVE_CLOSE_ON_SERVER_TOKEN = 'receive_close_on_server'
+_SEND_INITIAL_METADATA_TOKEN = 'send_initial_metadata'
+_RECEIVE_MESSAGE_TOKEN = 'receive_message'
+_SEND_MESSAGE_TOKEN = 'send_message'
+_SEND_INITIAL_METADATA_AND_SEND_MESSAGE_TOKEN = (
+    'send_initial_metadata * send_message')
+_SEND_STATUS_FROM_SERVER_TOKEN = 'send_status_from_server'
+_SEND_INITIAL_METADATA_AND_SEND_STATUS_FROM_SERVER_TOKEN = (
+    'send_initial_metadata * send_status_from_server')
+
+_OPEN = 'open'
+_CLOSED = 'closed'
+_CANCELLED = 'cancelled'
+
+_EMPTY_FLAGS = 0
+_EMPTY_METADATA = cygrpc.Metadata(())
+
+
+def _serialized_request(request_event):
+  return request_event.batch_operations[0].received_message.bytes()
+
+
+def _application_code(code):
+  cygrpc_code = _common.STATUS_CODE_TO_CYGRPC_STATUS_CODE.get(code)
+  return cygrpc.StatusCode.unknown if cygrpc_code is None else cygrpc_code
+
+
+def _completion_code(state):
+  if state.code is None:
+    return cygrpc.StatusCode.ok
+  else:
+    return _application_code(state.code)
+
+
+def _abortion_code(state, code):
+  if state.code is None:
+    return code
+  else:
+    return _application_code(state.code)
+
+
+def _details(state):
+  return b'' if state.details is None else state.details
+
+
+class _HandlerCallDetails(
+    collections.namedtuple(
+        '_HandlerCallDetails', ('method', 'invocation_metadata',)),
+    grpc.HandlerCallDetails):
+  pass
+
+
+class _RPCState(object):
+
+  def __init__(self):
+    self.condition = threading.Condition()
+    self.due = set()
+    self.request = None
+    self.client = _OPEN
+    self.initial_metadata_allowed = True
+    self.disable_next_compression = False
+    self.trailing_metadata = None
+    self.code = None
+    self.details = None
+    self.statused = False
+    self.rpc_errors = []
+    self.callbacks = []
+
+
+def _raise_rpc_error(state):
+  rpc_error = grpc.RpcError()
+  state.rpc_errors.append(rpc_error)
+  raise rpc_error
+
+
+def _possibly_finish_call(state, token):
+  state.due.remove(token)
+  if (state.client is _CANCELLED or state.statused) and not state.due:
+    callbacks = state.callbacks
+    state.callbacks = None
+    return state, callbacks
+  else:
+    return None, ()
+
+
+def _send_status_from_server(state, token):
+  def send_status_from_server(unused_send_status_from_server_event):
+    with state.condition:
+      return _possibly_finish_call(state, token)
+  return send_status_from_server
+
+
+def _abort(state, call, code, details):
+  if state.client is not _CANCELLED:
+    effective_code = _abortion_code(state, code)
+    effective_details = details if state.details is None else state.details
+    if state.initial_metadata_allowed:
+      operations = (
+          cygrpc.operation_send_initial_metadata(
+              _EMPTY_METADATA, _EMPTY_FLAGS),
+          cygrpc.operation_send_status_from_server(
+              _common.metadata(state.trailing_metadata), effective_code,
+              effective_details, _EMPTY_FLAGS),
+      )
+      token = _SEND_INITIAL_METADATA_AND_SEND_STATUS_FROM_SERVER_TOKEN
+    else:
+      operations = (
+          cygrpc.operation_send_status_from_server(
+              _common.metadata(state.trailing_metadata), effective_code,
+              effective_details, _EMPTY_FLAGS),
+      )
+      token = _SEND_STATUS_FROM_SERVER_TOKEN
+    call.start_batch(
+        cygrpc.Operations(operations),
+        _send_status_from_server(state, token))
+    state.statused = True
+    state.due.add(token)
+
+
+def _receive_close_on_server(state):
+  def receive_close_on_server(receive_close_on_server_event):
+    with state.condition:
+      if receive_close_on_server_event.batch_operations[0].received_cancelled:
+        state.client = _CANCELLED
+      elif state.client is _OPEN:
+        state.client = _CLOSED
+      state.condition.notify_all()
+      return _possibly_finish_call(state, _RECEIVE_CLOSE_ON_SERVER_TOKEN)
+  return receive_close_on_server
+
+
+def _receive_message(state, call, request_deserializer):
+  def receive_message(receive_message_event):
+    serialized_request = _serialized_request(receive_message_event)
+    if serialized_request is None:
+      with state.condition:
+        if state.client is _OPEN:
+          state.client = _CLOSED
+        state.condition.notify_all()
+        return _possibly_finish_call(state, _RECEIVE_MESSAGE_TOKEN)
+    else:
+      request = _common.deserialize(serialized_request, request_deserializer)
+      with state.condition:
+        if request is None:
+          _abort(
+              state, call, cygrpc.StatusCode.internal,
+              b'Exception deserializing request!')
+        else:
+          state.request = request
+        state.condition.notify_all()
+        return _possibly_finish_call(state, _RECEIVE_MESSAGE_TOKEN)
+  return receive_message
+
+
+def _send_initial_metadata(state):
+  def send_initial_metadata(unused_send_initial_metadata_event):
+    with state.condition:
+      return _possibly_finish_call(state, _SEND_INITIAL_METADATA_TOKEN)
+  return send_initial_metadata
+
+
+def _send_message(state, token):
+  def send_message(unused_send_message_event):
+    with state.condition:
+      state.condition.notify_all()
+      return _possibly_finish_call(state, token)
+  return send_message
+
+
+class _Context(grpc.ServicerContext):
+
+  def __init__(self, rpc_event, state, request_deserializer):
+    self._rpc_event = rpc_event
+    self._state = state
+    self._request_deserializer = request_deserializer
+
+  def is_active(self):
+    with self._state.condition:
+      return self._state.client is not _CANCELLED and not self._state.statused
+
+  def time_remaining(self):
+    return max(self._rpc_event.request_call_details.deadline - time.time(), 0)
+
+  def cancel(self):
+    self._rpc_event.operation_call.cancel()
+
+  def add_callback(self, callback):
+    with self._state.condition:
+      if self._state.callbacks is None:
+        return False
+      else:
+        self._state.callbacks.append(callback)
+        return True
+
+  def disable_next_message_compression(self):
+    with self._state.condition:
+      self._state.disable_next_compression = True
+
+  def invocation_metadata(self):
+    return self._rpc_event.request_metadata
+
+  def peer(self):
+    return self._rpc_event.operation_call.peer()
+
+  def send_initial_metadata(self, initial_metadata):
+    with self._state.condition:
+      if self._state.client is _CANCELLED:
+        _raise_rpc_error(self._state)
+      else:
+        if self._state.initial_metadata_allowed:
+          operation = cygrpc.operation_send_initial_metadata(
+              cygrpc.Metadata(initial_metadata), _EMPTY_FLAGS)
+          self._rpc_event.operation_call.start_batch(
+              cygrpc.Operations((operation,)),
+              _send_initial_metadata(self._state))
+          self._state.initial_metadata_allowed = False
+          self._state.due.add(_SEND_INITIAL_METADATA_TOKEN)
+        else:
+          raise ValueError('Initial metadata no longer allowed!')
+
+  def set_trailing_metadata(self, trailing_metadata):
+    with self._state.condition:
+      self._state.trailing_metadata = trailing_metadata
+
+  def set_code(self, code):
+    with self._state.condition:
+      self._state.code = code
+
+  def set_details(self, details):
+    with self._state.condition:
+      self._state.details = details
+
+
+class _RequestIterator(object):
+
+  def __init__(self, state, call, request_deserializer):
+    self._state = state
+    self._call = call
+    self._request_deserializer = request_deserializer
+
+  def _raise_or_start_receive_message(self):
+    if self._state.client is _CANCELLED:
+      _raise_rpc_error(self._state)
+    elif self._state.client is _CLOSED or self._state.statused:
+      raise StopIteration()
+    else:
+      self._call.start_batch(
+          cygrpc.Operations((cygrpc.operation_receive_message(_EMPTY_FLAGS),)),
+          _receive_message(self._state, self._call, self._request_deserializer))
+      self._state.due.add(_RECEIVE_MESSAGE_TOKEN)
+
+  def _look_for_request(self):
+    if self._state.client is _CANCELLED:
+      _raise_rpc_error(self._state)
+    elif (self._state.request is None and
+          _RECEIVE_MESSAGE_TOKEN not in self._state.due):
+      raise StopIteration()
+    else:
+      request = self._state.request
+      self._state.request = None
+      return request
+
+  def _next(self):
+    with self._state.condition:
+      self._raise_or_start_receive_message()
+      while True:
+        self._state.condition.wait()
+        request = self._look_for_request()
+        if request is not None:
+          return request
+
+  def __iter__(self):
+    return self
+
+  def __next__(self):
+    return self._next()
+
+  def next(self):
+    return self._next()
+
+
+def _unary_request(rpc_event, state, request_deserializer):
+  def unary_request():
+    with state.condition:
+      if state.client is _CANCELLED or state.statused:
+        return None
+      else:
+        start_batch_result = rpc_event.operation_call.start_batch(
+            cygrpc.Operations(
+                (cygrpc.operation_receive_message(_EMPTY_FLAGS),)),
+            _receive_message(
+                state, rpc_event.operation_call, request_deserializer))
+        state.due.add(_RECEIVE_MESSAGE_TOKEN)
+        while True:
+          state.condition.wait()
+          if state.request is None:
+            if state.client is _CLOSED:
+              details = b'"{}" requires exactly one request message.'.format(
+                  rpc_event.request_call_details.method)
+              # TODO(5992#issuecomment-220761992): really, what status code?
+              _abort(
+                  state, rpc_event.operation_call,
+                  cygrpc.StatusCode.unavailable, details)
+              return None
+            elif state.client is _CANCELLED:
+              return None
+          else:
+            request = state.request
+            state.request = None
+            return request
+  return unary_request
+
+
+def _call_behavior(rpc_event, state, behavior, argument, request_deserializer):
+  context = _Context(rpc_event, state, request_deserializer)
+  try:
+    return behavior(argument, context), True
+  except Exception as e:  # pylint: disable=broad-except
+    with state.condition:
+      if e not in state.rpc_errors:
+        details = b'Exception calling application: {}'.format(e)
+        logging.exception(details)
+        _abort(
+            state, rpc_event.operation_call, cygrpc.StatusCode.unknown, details)
+    return None, False
+
+
+def _take_response_from_response_iterator(rpc_event, state, response_iterator):
+  try:
+    return next(response_iterator), True
+  except StopIteration:
+    return None, True
+  except Exception as e:  # pylint: disable=broad-except
+    with state.condition:
+      if e not in state.rpc_errors:
+        details = b'Exception iterating responses: {}'.format(e)
+        logging.exception(details)
+        _abort(
+            state, rpc_event.operation_call, cygrpc.StatusCode.unknown, details)
+    return None, False
+
+
+def _serialize_response(rpc_event, state, response, response_serializer):
+  serialized_response = _common.serialize(response, response_serializer)
+  if serialized_response is None:
+    with state.condition:
+      _abort(
+          state, rpc_event.operation_call, cygrpc.StatusCode.internal,
+          b'Failed to serialize response!')
+    return None
+  else:
+    return serialized_response
+
+
+def _send_response(rpc_event, state, serialized_response):
+  with state.condition:
+    if state.client is _CANCELLED or state.statused:
+      return False
+    else:
+      if state.initial_metadata_allowed:
+        operations = (
+            cygrpc.operation_send_initial_metadata(
+                _EMPTY_METADATA, _EMPTY_FLAGS),
+            cygrpc.operation_send_message(serialized_response, _EMPTY_FLAGS),
+        )
+        state.initial_metadata_allowed = False
+        token = _SEND_INITIAL_METADATA_AND_SEND_MESSAGE_TOKEN
+      else:
+        operations = (
+            cygrpc.operation_send_message(serialized_response, _EMPTY_FLAGS),
+        )
+        token = _SEND_MESSAGE_TOKEN
+      rpc_event.operation_call.start_batch(
+          cygrpc.Operations(operations), _send_message(state, token))
+      state.due.add(token)
+      while True:
+        state.condition.wait()
+        if token not in state.due:
+          return state.client is not _CANCELLED and not state.statused
+
+
+def _status(rpc_event, state, serialized_response):
+  with state.condition:
+    if state.client is not _CANCELLED:
+      trailing_metadata = _common.metadata(state.trailing_metadata)
+      code = _completion_code(state)
+      details = _details(state)
+      operations = [
+          cygrpc.operation_send_status_from_server(
+              trailing_metadata, code, details, _EMPTY_FLAGS),
+      ]
+      if state.initial_metadata_allowed:
+        operations.append(
+            cygrpc.operation_send_initial_metadata(
+                _EMPTY_METADATA, _EMPTY_FLAGS))
+      if serialized_response is not None:
+        operations.append(cygrpc.operation_send_message(
+            serialized_response, _EMPTY_FLAGS))
+      rpc_event.operation_call.start_batch(
+          cygrpc.Operations(operations),
+          _send_status_from_server(state, _SEND_STATUS_FROM_SERVER_TOKEN))
+      state.statused = True
+      state.due.add(_SEND_STATUS_FROM_SERVER_TOKEN)
+
+
+def _unary_response_in_pool(
+    rpc_event, state, behavior, argument_thunk, request_deserializer,
+    response_serializer):
+  argument = argument_thunk()
+  if argument is not None:
+    response, proceed = _call_behavior(
+        rpc_event, state, behavior, argument, request_deserializer)
+    if proceed:
+      serialized_response = _serialize_response(
+          rpc_event, state, response, response_serializer)
+      if serialized_response is not None:
+        _status(rpc_event, state, serialized_response)
+  return
+
+
+def _stream_response_in_pool(
+    rpc_event, state, behavior, argument_thunk, request_deserializer,
+    response_serializer):
+  argument = argument_thunk()
+  if argument is not None:
+    response_iterator, proceed = _call_behavior(
+        rpc_event, state, behavior, argument, request_deserializer)
+    if proceed:
+      while True:
+        response, proceed = _take_response_from_response_iterator(
+            rpc_event, state, response_iterator)
+        if proceed:
+          if response is None:
+            _status(rpc_event, state, None)
+            break
+          else:
+            serialized_response = _serialize_response(
+                rpc_event, state, response, response_serializer)
+            if serialized_response is not None:
+              proceed = _send_response(rpc_event, state, serialized_response)
+              if not proceed:
+                break
+            else:
+              break
+        else:
+          break
+
+
+def _handle_unary_unary(rpc_event, state, method_handler, thread_pool):
+  unary_request = _unary_request(
+      rpc_event, state, method_handler.request_deserializer)
+  thread_pool.submit(
+      _unary_response_in_pool, rpc_event, state, method_handler.unary_unary,
+      unary_request, method_handler.request_deserializer,
+      method_handler.response_serializer)
+
+
+def _handle_unary_stream(rpc_event, state, method_handler, thread_pool):
+  unary_request = _unary_request(
+      rpc_event, state, method_handler.request_deserializer)
+  thread_pool.submit(
+      _stream_response_in_pool, rpc_event, state, method_handler.unary_stream,
+      unary_request, method_handler.request_deserializer,
+      method_handler.response_serializer)
+
+
+def _handle_stream_unary(rpc_event, state, method_handler, thread_pool):
+  request_iterator = _RequestIterator(
+      state, rpc_event.operation_call, method_handler.request_deserializer)
+  thread_pool.submit(
+      _unary_response_in_pool, rpc_event, state, method_handler.stream_unary,
+      lambda: request_iterator, method_handler.request_deserializer,
+      method_handler.response_serializer)
+
+
+def _handle_stream_stream(rpc_event, state, method_handler, thread_pool):
+  request_iterator = _RequestIterator(
+      state, rpc_event.operation_call, method_handler.request_deserializer)
+  thread_pool.submit(
+      _stream_response_in_pool, rpc_event, state, method_handler.stream_stream,
+      lambda: request_iterator, method_handler.request_deserializer,
+      method_handler.response_serializer)
+
+
+def _find_method_handler(rpc_event, generic_handlers):
+  for generic_handler in generic_handlers:
+    method_handler = generic_handler.service(
+        _HandlerCallDetails(
+            rpc_event.request_call_details.method, rpc_event.request_metadata))
+    if method_handler is not None:
+      return method_handler
+  else:
+    return None
+
+
+def _handle_unrecognized_method(rpc_event):
+  operations = (
+      cygrpc.operation_send_initial_metadata(_EMPTY_METADATA, _EMPTY_FLAGS),
+      cygrpc.operation_receive_close_on_server(_EMPTY_FLAGS),
+      cygrpc.operation_send_status_from_server(
+          _EMPTY_METADATA, cygrpc.StatusCode.unimplemented,
+          b'Method not found!', _EMPTY_FLAGS),
+  )
+  rpc_state = _RPCState()
+  rpc_event.operation_call.start_batch(
+      operations, lambda ignored_event: (rpc_state, (),))
+  return rpc_state
+
+
+def _handle_with_method_handler(rpc_event, method_handler, thread_pool):
+  state = _RPCState()
+  with state.condition:
+    rpc_event.operation_call.start_batch(
+        cygrpc.Operations(
+            (cygrpc.operation_receive_close_on_server(_EMPTY_FLAGS),)),
+        _receive_close_on_server(state))
+    state.due.add(_RECEIVE_CLOSE_ON_SERVER_TOKEN)
+    if method_handler.request_streaming:
+      if method_handler.response_streaming:
+        _handle_stream_stream(rpc_event, state, method_handler, thread_pool)
+      else:
+        _handle_stream_unary(rpc_event, state, method_handler, thread_pool)
+    else:
+      if method_handler.response_streaming:
+        _handle_unary_stream(rpc_event, state, method_handler, thread_pool)
+      else:
+        _handle_unary_unary(rpc_event, state, method_handler, thread_pool)
+    return state
+
+
+def _handle_call(rpc_event, generic_handlers, thread_pool):
+  if rpc_event.request_call_details.method is not None:
+    method_handler = _find_method_handler(rpc_event, generic_handlers)
+    if method_handler is None:
+      return _handle_unrecognized_method(rpc_event)
+    else:
+      return _handle_with_method_handler(rpc_event, method_handler, thread_pool)
+  else:
+    return None
+
+
+@enum.unique
+class _ServerStage(enum.Enum):
+  STOPPED = 'stopped'
+  STARTED = 'started'
+  GRACE = 'grace'
+
+
+class _ServerState(object):
+
+  def __init__(self, completion_queue, server, generic_handlers, thread_pool):
+    self.lock = threading.Lock()
+    self.completion_queue = completion_queue
+    self.server = server
+    self.generic_handlers = list(generic_handlers)
+    self.thread_pool = thread_pool
+    self.stage = _ServerStage.STOPPED
+    self.shutdown_events = None
+
+    # TODO(https://github.com/grpc/grpc/issues/6597): eliminate these fields.
+    self.rpc_states = set()
+    self.due = set()
+
+
+def _add_generic_handlers(state, generic_handlers):
+  with state.lock:
+    state.generic_handlers.extend(generic_handlers)
+
+
+def _add_insecure_port(state, address):
+  with state.lock:
+    return state.server.add_http2_port(address)
+
+
+def _add_secure_port(state, address, server_credentials):
+  with state.lock:
+    return state.server.add_http2_port(address, server_credentials._credentials)
+
+
+def _request_call(state):
+  state.server.request_call(
+      state.completion_queue, state.completion_queue, _REQUEST_CALL_TAG)
+  state.due.add(_REQUEST_CALL_TAG)
+
+
+# TODO(https://github.com/grpc/grpc/issues/6597): delete this function.
+def _stop_serving(state):
+  if not state.rpc_states and not state.due:
+    for shutdown_event in state.shutdown_events:
+      shutdown_event.set()
+    state.stage = _ServerStage.STOPPED
+    return True
+  else:
+    return False
+
+
+def _serve(state):
+  while True:
+    event = state.completion_queue.poll()
+    if event.tag is _SHUTDOWN_TAG:
+      with state.lock:
+        state.due.remove(_SHUTDOWN_TAG)
+        if _stop_serving(state):
+          return
+    elif event.tag is _REQUEST_CALL_TAG:
+      with state.lock:
+        state.due.remove(_REQUEST_CALL_TAG)
+        rpc_state = _handle_call(
+            event, state.generic_handlers, state.thread_pool)
+        if rpc_state is not None:
+          state.rpc_states.add(rpc_state)
+        if state.stage is _ServerStage.STARTED:
+          _request_call(state)
+        elif _stop_serving(state):
+          return
+    else:
+      rpc_state, callbacks = event.tag(event)
+      for callback in callbacks:
+        callable_util.call_logging_exceptions(
+            callback, 'Exception calling callback!')
+      if rpc_state is not None:
+        with state.lock:
+          state.rpc_states.remove(rpc_state)
+          if _stop_serving(state):
+            return
+
+
+def _start(state):
+  with state.lock:
+    if state.stage is not _ServerStage.STOPPED:
+      raise ValueError('Cannot start already-started server!')
+    state.server.start()
+    state.stage = _ServerStage.STARTED
+    _request_call(state)
+    thread = threading.Thread(target=_serve, args=(state,))
+    thread.start()
+
+
+def _stop(state, grace):
+  with state.lock:
+    if state.stage is _ServerStage.STOPPED:
+      shutdown_event = threading.Event()
+      shutdown_event.set()
+      return shutdown_event
+    else:
+      if state.stage is _ServerStage.STARTED:
+        state.server.shutdown(state.completion_queue, _SHUTDOWN_TAG)
+        state.stage = _ServerStage.GRACE
+        state.shutdown_events = []
+        state.due.add(_SHUTDOWN_TAG)
+      shutdown_event = threading.Event()
+      state.shutdown_events.append(shutdown_event)
+      if grace is None:
+        state.server.cancel_all_calls()
+        # TODO(https://github.com/grpc/grpc/issues/6597): delete this loop.
+        for rpc_state in state.rpc_states:
+          with rpc_state.condition:
+            rpc_state.client = _CANCELLED
+            rpc_state.condition.notify_all()
+      else:
+        def cancel_all_calls_after_grace():
+          shutdown_event.wait(timeout=grace)
+          with state.lock:
+            state.server.cancel_all_calls()
+            # TODO(https://github.com/grpc/grpc/issues/6597): delete this loop.
+            for rpc_state in state.rpc_states:
+              with rpc_state.condition:
+                rpc_state.client = _CANCELLED
+                rpc_state.condition.notify_all()
+        thread = threading.Thread(target=cancel_all_calls_after_grace)
+        thread.start()
+        return shutdown_event
+  shutdown_event.wait()
+  return shutdown_event
+
+
+class Server(grpc.Server):
+
+  def __init__(self, generic_handlers, thread_pool):
+    completion_queue = cygrpc.CompletionQueue()
+    server = cygrpc.Server()
+    server.register_completion_queue(completion_queue)
+    self._state = _ServerState(
+        completion_queue, server, generic_handlers, thread_pool)
+
+  def add_generic_rpc_handlers(self, generic_rpc_handlers):
+    _add_generic_handlers(self._state, generic_rpc_handlers)
+
+  def add_insecure_port(self, address):
+    return _add_insecure_port(self._state, address)
+
+  def add_secure_port(self, address, server_credentials):
+    return _add_secure_port(self._state, address, server_credentials)
+
+  def start(self):
+    _start(self._state)
+
+  def stop(self, grace):
+    return _stop(self._state, grace)
+
+  def __del__(self):
+    _stop(self._state, None)
diff --git a/src/python/grpcio/grpc/_utilities.py b/src/python/grpcio/grpc/_utilities.py
new file mode 100644
index 0000000000..a4ca9b7282
--- /dev/null
+++ b/src/python/grpcio/grpc/_utilities.py
@@ -0,0 +1,147 @@
+# 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.
+
+"""Internal utilities for gRPC Python."""
+
+import threading
+import time
+
+import grpc
+from grpc.framework.foundation import callable_util
+
+_DONE_CALLBACK_EXCEPTION_LOG_MESSAGE = (
+    'Exception calling connectivity future "done" callback!')
+
+
+class _ChannelReadyFuture(grpc.Future):
+
+  def __init__(self, channel):
+    self._condition = threading.Condition()
+    self._channel = channel
+
+    self._matured = False
+    self._cancelled = False
+    self._done_callbacks = []
+
+  def _block(self, timeout):
+    until = None if timeout is None else time.time() + timeout
+    with self._condition:
+      while True:
+        if self._cancelled:
+          raise grpc.FutureCancelledError()
+        elif self._matured:
+          return
+        else:
+          if until is None:
+            self._condition.wait()
+          else:
+            remaining = until - time.time()
+            if remaining < 0:
+              raise grpc.FutureTimeoutError()
+            else:
+              self._condition.wait(timeout=remaining)
+
+  def _update(self, connectivity):
+    with self._condition:
+      if (not self._cancelled and
+          connectivity is grpc.ChannelConnectivity.READY):
+        self._matured = True
+        self._channel.unsubscribe(self._update)
+        self._condition.notify_all()
+        done_callbacks = tuple(self._done_callbacks)
+        self._done_callbacks = None
+      else:
+        return
+
+    for done_callback in done_callbacks:
+      callable_util.call_logging_exceptions(
+          done_callback, _DONE_CALLBACK_EXCEPTION_LOG_MESSAGE, self)
+
+  def cancel(self):
+    with self._condition:
+      if not self._matured:
+        self._cancelled = True
+        self._channel.unsubscribe(self._update)
+        self._condition.notify_all()
+        done_callbacks = tuple(self._done_callbacks)
+        self._done_callbacks = None
+      else:
+        return False
+
+    for done_callback in done_callbacks:
+      callable_util.call_logging_exceptions(
+          done_callback, _DONE_CALLBACK_EXCEPTION_LOG_MESSAGE, self)
+
+  def cancelled(self):
+    with self._condition:
+      return self._cancelled
+
+  def running(self):
+    with self._condition:
+      return not self._cancelled and not self._matured
+
+  def done(self):
+    with self._condition:
+      return self._cancelled or self._matured
+
+  def result(self, timeout=None):
+    self._block(timeout)
+    return None
+
+  def exception(self, timeout=None):
+    self._block(timeout)
+    return None
+
+  def traceback(self, timeout=None):
+    self._block(timeout)
+    return None
+
+  def add_done_callback(self, fn):
+    with self._condition:
+      if not self._cancelled and not self._matured:
+        self._done_callbacks.append(fn)
+        return
+
+    fn(self)
+
+  def start(self):
+    with self._condition:
+      self._channel.subscribe(self._update, try_to_connect=True)
+
+  def __del__(self):
+    with self._condition:
+      if not self._cancelled and not self._matured:
+        self._channel.unsubscribe(self._update)
+
+
+def channel_ready_future(channel):
+  ready_future = _ChannelReadyFuture(channel)
+  ready_future.start()
+  return ready_future
+
diff --git a/src/python/grpcio/grpc/beta/_client_adaptations.py b/src/python/grpcio/grpc/beta/_client_adaptations.py
new file mode 100644
index 0000000000..621fcf2174
--- /dev/null
+++ b/src/python/grpcio/grpc/beta/_client_adaptations.py
@@ -0,0 +1,566 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Translates gRPC's client-side API into gRPC's client-side Beta API."""
+
+import grpc
+from grpc._cython import cygrpc
+from grpc.beta import interfaces
+from grpc.framework.common import cardinality
+from grpc.framework.foundation import future
+from grpc.framework.interfaces.face import face
+
+_STATUS_CODE_TO_ABORTION_KIND_AND_ABORTION_ERROR_CLASS = {
+    grpc.StatusCode.CANCELLED: (
+        face.Abortion.Kind.CANCELLED, face.CancellationError),
+    grpc.StatusCode.UNKNOWN: (
+        face.Abortion.Kind.REMOTE_FAILURE, face.RemoteError),
+    grpc.StatusCode.DEADLINE_EXCEEDED: (
+        face.Abortion.Kind.EXPIRED, face.ExpirationError),
+    grpc.StatusCode.UNIMPLEMENTED: (
+        face.Abortion.Kind.LOCAL_FAILURE, face.LocalError),
+}
+
+
+def _fully_qualified_method(group, method):
+  return b'/{}/{}'.format(group, method)
+
+
+def _effective_metadata(metadata, metadata_transformer):
+  non_none_metadata = () if metadata is None else metadata
+  if metadata_transformer is None:
+    return non_none_metadata
+  else:
+    return metadata_transformer(non_none_metadata)
+
+
+def _credentials(grpc_call_options):
+  return None if grpc_call_options is None else grpc_call_options.credentials
+
+
+def _abortion(rpc_error_call):
+  code = rpc_error_call.code()
+  pair = _STATUS_CODE_TO_ABORTION_KIND_AND_ABORTION_ERROR_CLASS.get(code)
+  error_kind = face.Abortion.Kind.LOCAL_FAILURE if pair is None else pair[0]
+  return face.Abortion(
+      error_kind, rpc_error_call.initial_metadata(),
+      rpc_error_call.trailing_metadata(), code, rpc_error_code.details())
+
+
+def _abortion_error(rpc_error_call):
+  code = rpc_error_call.code()
+  pair = _STATUS_CODE_TO_ABORTION_KIND_AND_ABORTION_ERROR_CLASS.get(code)
+  exception_class = face.AbortionError if pair is None else pair[1]
+  return exception_class(
+      rpc_error_call.initial_metadata(), rpc_error_call.trailing_metadata(),
+      code, rpc_error_call.details())
+
+
+class _InvocationProtocolContext(interfaces.GRPCInvocationContext):
+
+  def disable_next_request_compression(self):
+    pass  # TODO(https://github.com/grpc/grpc/issues/4078): design, implement.
+
+
+class _Rendezvous(future.Future, face.Call):
+
+  def __init__(self, response_future, response_iterator, call):
+    self._future = response_future
+    self._iterator = response_iterator
+    self._call = call
+
+  def cancel(self):
+    return self._call.cancel()
+
+  def cancelled(self):
+    return self._future.cancelled()
+
+  def running(self):
+    return self._future.running()
+
+  def done(self):
+    return self._future.done()
+
+  def result(self, timeout=None):
+    try:
+      return self._future.result(timeout=timeout)
+    except grpc.RpcError as rpc_error_call:
+      raise _abortion_error(rpc_error_call)
+    except grpc.FutureTimeoutError:
+      raise future.TimeoutError()
+    except grpc.FutureCancelledError:
+      raise future.CancelledError()
+
+  def exception(self, timeout=None):
+    try:
+      rpc_error_call = self._future.exception(timeout=timeout)
+      return _abortion_error(rpc_error_call)
+    except grpc.FutureTimeoutError:
+      raise future.TimeoutError()
+    except grpc.FutureCancelledError:
+      raise future.CancelledError()
+
+  def traceback(self, timeout=None):
+    try:
+      return self._future.traceback(timeout=timeout)
+    except grpc.FutureTimeoutError:
+      raise future.TimeoutError()
+    except grpc.FutureCancelledError:
+      raise future.CancelledError()
+
+  def add_done_callback(self, fn):
+    self._future.add_done_callback(lambda ignored_callback: fn(self))
+
+  def __iter__(self):
+    return self
+
+  def _next(self):
+    try:
+      return next(self._iterator)
+    except grpc.RpcError as rpc_error_call:
+      raise _abortion_error(rpc_error_call)
+
+  def __next__(self):
+    return self._next()
+
+  def next(self):
+    return self._next()
+
+  def is_active(self):
+    return self._call.is_active()
+
+  def time_remaining(self):
+    return self._call.time_remaining()
+
+  def add_abortion_callback(self, abortion_callback):
+    registered = self._call.add_callback(
+        lambda: abortion_callback(_abortion(self._call)))
+    return None if registered else _abortion(self._call)
+
+  def protocol_context(self):
+    return _InvocationProtocolContext()
+
+  def initial_metadata(self):
+    return self._call.initial_metadata()
+
+  def terminal_metadata(self):
+    return self._call.terminal_metadata()
+
+  def code(self):
+    return self._call.code()
+
+  def details(self):
+    return self._call.details()
+
+
+def _blocking_unary_unary(
+    channel, group, method, timeout, with_call, protocol_options, metadata,
+    metadata_transformer, request, request_serializer, response_deserializer):
+  try:
+    multi_callable = channel.unary_unary(
+        _fully_qualified_method(group, method),
+        request_serializer=request_serializer,
+        response_deserializer=response_deserializer)
+    effective_metadata = _effective_metadata(metadata, metadata_transformer)
+    if with_call:
+      response, call = multi_callable(
+          request, timeout=timeout, metadata=effective_metadata,
+          credentials=_credentials(protocol_options), with_call=True)
+      return response, _Rendezvous(None, None, call)
+    else:
+      return multi_callable(
+          request, timeout=timeout, metadata=effective_metadata,
+          credentials=_credentials(protocol_options))
+  except grpc.RpcError as rpc_error_call:
+    raise _abortion_error(rpc_error_call)
+
+
+def _future_unary_unary(
+    channel, group, method, timeout, protocol_options, metadata,
+    metadata_transformer, request, request_serializer, response_deserializer):
+  multi_callable = channel.unary_unary(
+      _fully_qualified_method(group, method),
+      request_serializer=request_serializer,
+      response_deserializer=response_deserializer)
+  effective_metadata = _effective_metadata(metadata, metadata_transformer)
+  response_future = multi_callable.future(
+      request, timeout=timeout, metadata=effective_metadata,
+      credentials=_credentials(protocol_options))
+  return _Rendezvous(response_future, None, response_future)
+
+
+def _unary_stream(
+    channel, group, method, timeout, protocol_options, metadata,
+    metadata_transformer, request, request_serializer, response_deserializer):
+  multi_callable = channel.unary_stream(
+      _fully_qualified_method(group, method),
+      request_serializer=request_serializer,
+      response_deserializer=response_deserializer)
+  effective_metadata = _effective_metadata(metadata, metadata_transformer)
+  response_iterator = multi_callable(
+      request, timeout=timeout, metadata=effective_metadata,
+      credentials=_credentials(protocol_options))
+  return _Rendezvous(None, response_iterator, response_iterator)
+
+
+def _blocking_stream_unary(
+    channel, group, method, timeout, with_call, protocol_options, metadata,
+    metadata_transformer, request_iterator, request_serializer,
+    response_deserializer):
+  try:
+    multi_callable = channel.stream_unary(
+        _fully_qualified_method(group, method),
+        request_serializer=request_serializer,
+        response_deserializer=response_deserializer)
+    effective_metadata = _effective_metadata(metadata, metadata_transformer)
+    if with_call:
+      response, call = multi_callable(
+          request_iterator, timeout=timeout, metadata=effective_metadata,
+          credentials=_credentials(protocol_options), with_call=True)
+      return response, _Rendezvous(None, None, call)
+    else:
+      return multi_callable(
+          request_iterator, timeout=timeout, metadata=effective_metadata,
+          credentials=_credentials(protocol_options))
+  except grpc.RpcError as rpc_error_call:
+    raise _abortion_error(rpc_error_call)
+
+
+def _future_stream_unary(
+    channel, group, method, timeout, protocol_options, metadata,
+    metadata_transformer, request_iterator, request_serializer,
+    response_deserializer):
+  multi_callable = channel.stream_unary(
+      _fully_qualified_method(group, method),
+      request_serializer=request_serializer,
+      response_deserializer=response_deserializer)
+  effective_metadata = _effective_metadata(metadata, metadata_transformer)
+  response_future = multi_callable.future(
+      request_iterator, timeout=timeout, metadata=effective_metadata,
+      credentials=_credentials(protocol_options))
+  return _Rendezvous(response_future, None, response_future)
+
+
+def _stream_stream(
+    channel, group, method, timeout, protocol_options, metadata,
+    metadata_transformer, request_iterator, request_serializer,
+    response_deserializer):
+  multi_callable = channel.stream_stream(
+      _fully_qualified_method(group, method),
+      request_serializer=request_serializer,
+      response_deserializer=response_deserializer)
+  effective_metadata = _effective_metadata(metadata, metadata_transformer)
+  response_iterator = multi_callable(
+      request_iterator, timeout=timeout, metadata=effective_metadata,
+      credentials=_credentials(protocol_options))
+  return _Rendezvous(None, response_iterator, response_iterator)
+
+
+class _UnaryUnaryMultiCallable(face.UnaryUnaryMultiCallable):
+
+  def __init__(
+      self, channel, group, method, metadata_transformer, request_serializer,
+      response_deserializer):
+    self._channel = channel
+    self._group = group
+    self._method = method
+    self._metadata_transformer = metadata_transformer
+    self._request_serializer = request_serializer
+    self._response_deserializer = response_deserializer
+
+  def __call__(
+      self, request, timeout, metadata=None, with_call=False,
+      protocol_options=None):
+    return _blocking_unary_unary(
+        self._channel, self._group, self._method, timeout, with_call,
+        protocol_options, metadata, self._metadata_transformer, request,
+        self._request_serializer, self._response_deserializer)
+
+  def future(self, request, timeout, metadata=None, protocol_options=None):
+    return _future_unary_unary(
+        self._channel, self._group, self._method, timeout, protocol_options,
+        metadata, self._metadata_transformer, request, self._request_serializer,
+        self._response_deserializer)
+
+  def event(
+      self, request, receiver, abortion_callback, timeout,
+      metadata=None, protocol_options=None):
+    raise NotImplementedError()
+
+
+class _UnaryStreamMultiCallable(face.UnaryStreamMultiCallable):
+
+  def __init__(
+      self, channel, group, method, metadata_transformer, request_serializer,
+      response_deserializer):
+    self._channel = channel
+    self._group = group
+    self._method = method
+    self._metadata_transformer = metadata_transformer
+    self._request_serializer = request_serializer
+    self._response_deserializer = response_deserializer
+
+  def __call__(self, request, timeout, metadata=None, protocol_options=None):
+    return _unary_stream(
+        self._channel, self._group, self._method, timeout, protocol_options,
+        metadata, self._metadata_transformer, request, self._request_serializer,
+        self._response_deserializer)
+
+  def event(
+      self, request, receiver, abortion_callback, timeout,
+      metadata=None, protocol_options=None):
+    raise NotImplementedError()
+
+
+class _StreamUnaryMultiCallable(face.StreamUnaryMultiCallable):
+
+  def __init__(
+      self, channel, group, method, metadata_transformer, request_serializer,
+      response_deserializer):
+    self._channel = channel
+    self._group = group
+    self._method = method
+    self._metadata_transformer = metadata_transformer
+    self._request_serializer = request_serializer
+    self._response_deserializer = response_deserializer
+
+  def __call__(
+      self, request_iterator, timeout, metadata=None, with_call=False,
+      protocol_options=None):
+    return _blocking_stream_unary(
+        self._channel, self._group, self._method, timeout, with_call,
+        protocol_options, metadata, self._metadata_transformer,
+        request_iterator, self._request_serializer, self._response_deserializer)
+
+  def future(
+      self, request_iterator, timeout, metadata=None, protocol_options=None):
+    return _future_stream_unary(
+        self._channel, self._group, self._method, timeout, protocol_options,
+        metadata, self._metadata_transformer, request_iterator,
+        self._request_serializer, self._response_deserializer)
+
+  def event(
+      self, receiver, abortion_callback, timeout, metadata=None,
+      protocol_options=None):
+    raise NotImplementedError()
+
+
+class _StreamStreamMultiCallable(face.StreamStreamMultiCallable):
+
+  def __init__(
+      self, channel, group, method, metadata_transformer, request_serializer,
+      response_deserializer):
+    self._channel = channel
+    self._group = group
+    self._method = method
+    self._metadata_transformer = metadata_transformer
+    self._request_serializer = request_serializer
+    self._response_deserializer = response_deserializer
+
+  def __call__(
+      self, request_iterator, timeout, metadata=None, protocol_options=None):
+    return _stream_stream(
+        self._channel, self._group, self._method, timeout, protocol_options,
+        metadata, self._metadata_transformer, request_iterator,
+        self._request_serializer, self._response_deserializer)
+
+  def event(
+      self, receiver, abortion_callback, timeout, metadata=None,
+      protocol_options=None):
+    raise NotImplementedError()
+
+
+class _GenericStub(face.GenericStub):
+
+  def __init__(
+      self, channel, metadata_transformer, request_serializers,
+      response_deserializers):
+    self._channel = channel
+    self._metadata_transformer = metadata_transformer
+    self._request_serializers = request_serializers or {}
+    self._response_deserializers = response_deserializers or {}
+
+  def blocking_unary_unary(
+      self, group, method, request, timeout, metadata=None,
+      with_call=None, protocol_options=None):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _blocking_unary_unary(
+        self._channel, group, method, timeout, with_call, protocol_options,
+        metadata, self._metadata_transformer, request, request_serializer,
+        response_deserializer)
+
+  def future_unary_unary(
+      self, group, method, request, timeout, metadata=None,
+      protocol_options=None):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _future_unary_unary(
+        self._channel, group, method, timeout, protocol_options, metadata,
+        self._metadata_transformer, request, request_serializer,
+        response_deserializer)
+
+  def inline_unary_stream(
+      self, group, method, request, timeout, metadata=None,
+      protocol_options=None):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _unary_stream(
+        self._channel, group, method, timeout, protocol_options, metadata,
+        self._metadata_transformer, request, request_serializer,
+        response_deserializer)
+
+  def blocking_stream_unary(
+      self, group, method, request_iterator, timeout, metadata=None,
+      with_call=None, protocol_options=None):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _blocking_stream_unary(
+        self._channel, group, method, timeout, with_call, protocol_options,
+        metadata, self._metadata_transformer, request_iterator,
+        request_serializer, response_deserializer)
+
+  def future_stream_unary(
+      self, group, method, request_iterator, timeout, metadata=None,
+      protocol_options=None):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _future_stream_unary(
+        self._channel, group, method, timeout, protocol_options, metadata,
+        self._metadata_transformer, request_iterator, request_serializer,
+        response_deserializer)
+
+  def inline_stream_stream(
+      self, group, method, request_iterator, timeout, metadata=None,
+      protocol_options=None):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _stream_stream(
+        self._channel, group, method, timeout, protocol_options, metadata,
+        self._metadata_transformer, request_iterator, request_serializer,
+        response_deserializer)
+
+  def event_unary_unary(
+      self, group, method, request, receiver, abortion_callback, timeout,
+      metadata=None, protocol_options=None):
+    raise NotImplementedError()
+
+  def event_unary_stream(
+      self, group, method, request, receiver, abortion_callback, timeout,
+      metadata=None, protocol_options=None):
+    raise NotImplementedError()
+
+  def event_stream_unary(
+      self, group, method, receiver, abortion_callback, timeout,
+      metadata=None, protocol_options=None):
+    raise NotImplementedError()
+
+  def event_stream_stream(
+      self, group, method, receiver, abortion_callback, timeout,
+      metadata=None, protocol_options=None):
+    raise NotImplementedError()
+
+  def unary_unary(self, group, method):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _UnaryUnaryMultiCallable(
+        self._channel, group, method, self._metadata_transformer,
+        request_serializer, response_deserializer)
+
+  def unary_stream(self, group, method):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _UnaryStreamMultiCallable(
+        self._channel, group, method, self._metadata_transformer,
+        request_serializer, response_deserializer)
+
+  def stream_unary(self, group, method):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _StreamUnaryMultiCallable(
+        self._channel, group, method, self._metadata_transformer,
+        request_serializer, response_deserializer)
+
+  def stream_stream(self, group, method):
+    request_serializer = self._request_serializers.get((group, method,))
+    response_deserializer = self._response_deserializers.get((group, method,))
+    return _StreamStreamMultiCallable(
+        self._channel, group, method, self._metadata_transformer,
+        request_serializer, response_deserializer)
+
+  def __enter__(self):
+    return self
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    return False
+
+
+class _DynamicStub(face.DynamicStub):
+
+  def __init__(self, generic_stub, group, cardinalities):
+    self._generic_stub = generic_stub
+    self._group = group
+    self._cardinalities = cardinalities
+
+  def __getattr__(self, attr):
+    method_cardinality = self._cardinalities.get(attr)
+    if method_cardinality is cardinality.Cardinality.UNARY_UNARY:
+      return self._generic_stub.unary_unary(self._group, attr)
+    elif method_cardinality is cardinality.Cardinality.UNARY_STREAM:
+      return self._generic_stub.unary_stream(self._group, attr)
+    elif method_cardinality is cardinality.Cardinality.STREAM_UNARY:
+      return self._generic_stub.stream_unary(self._group, attr)
+    elif method_cardinality is cardinality.Cardinality.STREAM_STREAM:
+      return self._generic_stub.stream_stream(self._group, attr)
+    else:
+      raise AttributeError('_DynamicStub object has no attribute "%s"!' % attr)
+
+  def __enter__(self):
+    return self
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    return False
+
+
+def generic_stub(
+    channel, host, metadata_transformer, request_serializers,
+    response_deserializers):
+  return _GenericStub(
+      channel, metadata_transformer, request_serializers,
+      response_deserializers)
+
+
+def dynamic_stub(
+    channel, service, cardinalities, host, metadata_transformer,
+    request_serializers, response_deserializers):
+  return _DynamicStub(
+      _GenericStub(
+          channel, metadata_transformer, request_serializers,
+          response_deserializers),
+      service, cardinalities)
diff --git a/src/python/grpcio/grpc/beta/_server_adaptations.py b/src/python/grpcio/grpc/beta/_server_adaptations.py
new file mode 100644
index 0000000000..52eadf2315
--- /dev/null
+++ b/src/python/grpcio/grpc/beta/_server_adaptations.py
@@ -0,0 +1,359 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Translates gRPC's server-side API into gRPC's server-side Beta API."""
+
+import collections
+import threading
+
+import grpc
+from grpc.beta import interfaces
+from grpc.framework.common import cardinality
+from grpc.framework.common import style
+from grpc.framework.foundation import abandonment
+from grpc.framework.foundation import logging_pool
+from grpc.framework.foundation import stream
+from grpc.framework.interfaces.face import face
+
+_DEFAULT_POOL_SIZE = 8
+
+
+class _ServerProtocolContext(interfaces.GRPCServicerContext):
+
+  def __init__(self, servicer_context):
+    self._servicer_context = servicer_context
+
+  def peer(self):
+    return self._servicer_context.peer()
+
+  def disable_next_response_compression(self):
+    pass  # TODO(https://github.com/grpc/grpc/issues/4078): design, implement.
+
+
+class _FaceServicerContext(face.ServicerContext):
+
+  def __init__(self, servicer_context):
+    self._servicer_context = servicer_context
+
+  def is_active(self):
+    return self._servicer_context.is_active()
+
+  def time_remaining(self):
+    return self._servicer_context.time_remaining()
+
+  def add_abortion_callback(self, abortion_callback):
+    raise NotImplementedError(
+        'add_abortion_callback no longer supported server-side!')
+
+  def cancel(self):
+    self._servicer_context.cancel()
+
+  def protocol_context(self):
+    return _ServerProtocolContext(self._servicer_context)
+
+  def invocation_metadata(self):
+    return self._servicer_context.invocation_metadata()
+
+  def initial_metadata(self, initial_metadata):
+    self._servicer_context.send_initial_metadata(initial_metadata)
+
+  def terminal_metadata(self, terminal_metadata):
+    self._servicer_context.set_terminal_metadata(terminal_metadata)
+
+  def code(self, code):
+    self._servicer_context.set_code(code)
+
+  def details(self, details):
+    self._servicer_context.set_details(details)
+
+
+def _adapt_unary_request_inline(unary_request_inline):
+  def adaptation(request, servicer_context):
+    return unary_request_inline(request, _FaceServicerContext(servicer_context))
+  return adaptation
+
+
+def _adapt_stream_request_inline(stream_request_inline):
+  def adaptation(request_iterator, servicer_context):
+    return stream_request_inline(
+        request_iterator, _FaceServicerContext(servicer_context))
+  return adaptation
+
+
+class _Callback(stream.Consumer):
+
+  def __init__(self):
+    self._condition = threading.Condition()
+    self._values = []
+    self._terminated = False
+    self._cancelled = False
+
+  def consume(self, value):
+    with self._condition:
+      self._values.append(value)
+      self._condition.notify_all()
+
+  def terminate(self):
+    with self._condition:
+      self._terminated = True
+      self._condition.notify_all()
+
+  def consume_and_terminate(self, value):
+    with self._condition:
+      self._values.append(value)
+      self._terminated = True
+      self._condition.notify_all()
+
+  def cancel(self):
+    with self._condition:
+      self._cancelled = True
+      self._condition.notify_all()
+
+  def draw_one_value(self):
+    with self._condition:
+      while True:
+        if self._cancelled:
+          raise abandonment.Abandoned()
+        elif self._values:
+          return self._values.pop(0)
+        elif self._terminated:
+          return None
+        else:
+          self._condition.wait()
+
+  def draw_all_values(self):
+    with self._condition:
+      while True:
+        if self._cancelled:
+          raise abandonment.Abandoned()
+        elif self._terminated:
+          all_values = tuple(self._values)
+          self._values = None
+          return all_values
+        else:
+          self._condition.wait()
+
+
+def _pipe_requests(request_iterator, request_consumer, servicer_context):
+  for request in request_iterator:
+    if not servicer_context.is_active():
+      return
+    request_consumer.consume(request)
+    if not servicer_context.is_active():
+      return
+  request_consumer.terminate()
+
+
+def _adapt_unary_unary_event(unary_unary_event):
+  def adaptation(request, servicer_context):
+    callback = _Callback()
+    if not servicer_context.add_callback(callback.cancel):
+      raise abandonment.Abandoned()
+    unary_unary_event(
+        request, callback.consume_and_terminate,
+        _FaceServicerContext(servicer_context))
+    return callback.draw_all_values()[0]
+  return adaptation
+
+
+def _adapt_unary_stream_event(unary_stream_event):
+  def adaptation(request, servicer_context):
+    callback = _Callback()
+    if not servicer_context.add_callback(callback.cancel):
+      raise abandonment.Abandoned()
+    unary_stream_event(
+        request, callback, _FaceServicerContext(servicer_context))
+    while True:
+      response = callback.draw_one_value()
+      if response is None:
+        return
+      else:
+        yield response
+  return adaptation
+
+
+def _adapt_stream_unary_event(stream_unary_event):
+  def adaptation(request_iterator, servicer_context):
+    callback = _Callback()
+    if not servicer_context.add_callback(callback.cancel):
+      raise abandonment.Abandoned()
+    request_consumer = stream_unary_event(
+        callback.consume_and_terminate, _FaceServicerContext(servicer_context))
+    request_pipe_thread = threading.Thread(
+        target=_pipe_requests,
+        args=(request_iterator, request_consumer, servicer_context,))
+    request_pipe_thread.start()
+    return callback.draw_all_values()[0]
+  return adaptation
+
+
+def _adapt_stream_stream_event(stream_stream_event):
+  def adaptation(request_iterator, servicer_context):
+    callback = _Callback()
+    if not servicer_context.add_callback(callback.cancel):
+      raise abandonment.Abandoned()
+    request_consumer = stream_stream_event(
+        callback, _FaceServicerContext(servicer_context))
+    request_pipe_thread = threading.Thread(
+        target=_pipe_requests,
+        args=(request_iterator, request_consumer, servicer_context,))
+    request_pipe_thread.start()
+    while True:
+      response = callback.draw_one_value()
+      if response is None:
+        return
+      else:
+        yield response
+  return adaptation
+
+
+class _SimpleMethodHandler(
+    collections.namedtuple(
+        '_MethodHandler',
+        ('request_streaming', 'response_streaming', 'request_deserializer',
+         'response_serializer', 'unary_unary', 'unary_stream', 'stream_unary',
+         'stream_stream',)),
+    grpc.RpcMethodHandler):
+  pass
+
+
+def _simple_method_handler(
+    implementation, request_deserializer, response_serializer):
+  if implementation.style is style.Service.INLINE:
+    if implementation.cardinality is cardinality.Cardinality.UNARY_UNARY:
+      return _SimpleMethodHandler(
+          False, False, request_deserializer, response_serializer,
+          _adapt_unary_request_inline(implementation.unary_unary_inline), None,
+          None, None)
+    elif implementation.cardinality is cardinality.Cardinality.UNARY_STREAM:
+      return _SimpleMethodHandler(
+          False, True, request_deserializer, response_serializer, None,
+          _adapt_unary_request_inline(implementation.unary_stream_inline), None,
+          None)
+    elif implementation.cardinality is cardinality.Cardinality.STREAM_UNARY:
+      return _SimpleMethodHandler(
+          True, False, request_deserializer, response_serializer, None, None,
+          _adapt_stream_request_inline(implementation.stream_unary_inline),
+          None)
+    elif implementation.cardinality is cardinality.Cardinality.STREAM_STREAM:
+      return _SimpleMethodHandler(
+          True, True, request_deserializer, response_serializer, None, None,
+          None,
+          _adapt_stream_request_inline(implementation.stream_stream_inline))
+  elif implementation.style is style.Service.EVENT:
+    if implementation.cardinality is cardinality.Cardinality.UNARY_UNARY:
+      return _SimpleMethodHandler(
+          False, False, request_deserializer, response_serializer,
+          _adapt_unary_unary_event(implementation.unary_unary_event), None,
+          None, None)
+    elif implementation.cardinality is cardinality.Cardinality.UNARY_STREAM:
+      return _SimpleMethodHandler(
+          False, True, request_deserializer, response_serializer, None,
+          _adapt_unary_stream_event(implementation.unary_stream_event), None,
+          None)
+    elif implementation.cardinality is cardinality.Cardinality.STREAM_UNARY:
+      return _SimpleMethodHandler(
+          True, False, request_deserializer, response_serializer, None, None,
+          _adapt_stream_unary_event(implementation.stream_unary_event), None)
+    elif implementation.cardinality is cardinality.Cardinality.STREAM_STREAM:
+      return _SimpleMethodHandler(
+          True, True, request_deserializer, response_serializer, None, None,
+          None, _adapt_stream_stream_event(implementation.stream_stream_event))
+
+
+class _GenericRpcHandler(grpc.GenericRpcHandler):
+
+  def __init__(
+      self, method_implementations, multi_method_implementation,
+      request_deserializers, response_serializers):
+    self._method_implementations = method_implementations
+    self._multi_method_implementation = multi_method_implementation
+    self._request_deserializers = request_deserializers or {}
+    self._response_serializers = response_serializers or {}
+
+  def service(self, handler_call_details):
+    try:
+      group_name, method_name = handler_call_details.method.split(b'/')[1:3]
+    except ValueError:
+      return None
+    else:
+      method_implementation = self._method_implementations.get(
+          (group_name, method_name,))
+      if method_implementation is not None:
+        return _simple_method_handler(
+            method_implementation,
+            self._request_deserializers.get((group_name, method_name,)),
+            self._response_serializers.get((group_name, method_name,)))
+      elif self._multi_method_implementation is None:
+        return None
+      else:
+        try:
+          return None  #TODO(nathaniel): call the multimethod.
+        except face.NoSuchMethodError:
+          return None
+
+
+class _Server(interfaces.Server):
+
+  def __init__(self, server):
+    self._server = server
+
+  def add_insecure_port(self, address):
+    return self._server.add_insecure_port(address)
+
+  def add_secure_port(self, address, server_credentials):
+    return self._server.add_secure_port(address, server_credentials)
+
+  def start(self):
+    self._server.start()
+
+  def stop(self, grace):
+    return self._server.stop(grace)
+
+  def __enter__(self):
+    self._server.start()
+    return self
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    self._server.stop(None)
+    return False
+
+
+def server(
+    service_implementations, multi_method_implementation, request_deserializers,
+    response_serializers, thread_pool, thread_pool_size):
+  generic_rpc_handler = _GenericRpcHandler(
+      service_implementations, multi_method_implementation,
+      request_deserializers, response_serializers)
+  if thread_pool is None:
+    effective_thread_pool = logging_pool.pool(
+        _DEFAULT_POOL_SIZE if thread_pool_size is None else thread_pool_size)
+  else:
+    effective_thread_pool = thread_pool
+  return _Server(grpc.server((generic_rpc_handler,), effective_thread_pool))
diff --git a/src/python/grpcio/grpc/beta/implementations.py b/src/python/grpcio/grpc/beta/implementations.py
index 822f593323..4ae6e7d675 100644
--- a/src/python/grpcio/grpc/beta/implementations.py
+++ b/src/python/grpcio/grpc/beta/implementations.py
@@ -35,112 +35,36 @@ import enum
 import threading  # pylint: disable=unused-import
 
 # cardinality and face are referenced from specification in this module.
-from grpc._adapter import _intermediary_low
-from grpc._adapter import _low
+import grpc
+from grpc import _auth
 from grpc._adapter import _types
-from grpc.beta import _connectivity_channel
-from grpc.beta import _server
-from grpc.beta import _stub
+from grpc.beta import _client_adaptations
+from grpc.beta import _server_adaptations
 from grpc.beta import interfaces
 from grpc.framework.common import cardinality  # pylint: disable=unused-import
 from grpc.framework.interfaces.face import face  # pylint: disable=unused-import
 
-_CHANNEL_SUBSCRIPTION_CALLBACK_ERROR_LOG_MESSAGE = (
-    'Exception calling channel subscription callback!')
 
+ChannelCredentials = grpc.ChannelCredentials
+ssl_channel_credentials = grpc.ssl_channel_credentials
+CallCredentials = grpc.CallCredentials
+metadata_call_credentials = grpc.metadata_call_credentials
 
-class ChannelCredentials(object):
-  """A value encapsulating the data required to create a secure Channel.
 
-  This class and its instances have no supported interface - it exists to define
-  the type of its instances and its instances exist to be passed to other
-  functions.
-  """
-
-  def __init__(self, low_credentials):
-    self._low_credentials = low_credentials
-
-
-def ssl_channel_credentials(root_certificates=None, private_key=None,
-                            certificate_chain=None):
-  """Creates a ChannelCredentials for use with an SSL-enabled Channel.
-
-  Args:
-    root_certificates: The PEM-encoded root certificates or unset to ask for
-      them to be retrieved from a default location.
-    private_key: The PEM-encoded private key to use or unset if no private key
-      should be used.
-    certificate_chain: The PEM-encoded certificate chain to use or unset if no
-      certificate chain should be used.
-
-  Returns:
-    A ChannelCredentials for use with an SSL-enabled Channel.
-  """
-  return ChannelCredentials(_low.channel_credentials_ssl(
-      root_certificates, private_key, certificate_chain))
-
-
-class CallCredentials(object):
-  """A value encapsulating data asserting an identity over an *established*
-  channel. May be composed with ChannelCredentials to always assert identity for
-  every call over that channel.
-
-  This class and its instances have no supported interface - it exists to define
-  the type of its instances and its instances exist to be passed to other
-  functions.
-  """
-
-  def __init__(self, low_credentials):
-    self._low_credentials = low_credentials
-
-
-def metadata_call_credentials(metadata_plugin, name=None):
-  """Construct CallCredentials from an interfaces.GRPCAuthMetadataPlugin.
-
-  Args:
-    metadata_plugin: An interfaces.GRPCAuthMetadataPlugin to use in constructing
-      the CallCredentials object.
-
-  Returns:
-    A CallCredentials object for use in a GRPCCallOptions object.
-  """
-  if name is None:
-    name = metadata_plugin.__name__
-  return CallCredentials(
-      _low.call_credentials_metadata_plugin(metadata_plugin, name))
-
-def composite_call_credentials(call_credentials, additional_call_credentials):
-  """Compose two CallCredentials to make a new one.
+def google_call_credentials(credentials):
+  """Construct CallCredentials from GoogleCredentials.
 
   Args:
-    call_credentials: A CallCredentials object.
-    additional_call_credentials: Another CallCredentials object to compose on
-      top of call_credentials.
+    credentials: A GoogleCredentials object from the oauth2client library.
 
   Returns:
     A CallCredentials object for use in a GRPCCallOptions object.
   """
-  return CallCredentials(
-      _low.call_credentials_composite(
-          call_credentials._low_credentials,
-          additional_call_credentials._low_credentials))
+  return metadata_call_credentials(_auth.GoogleCallCredentials(credentials))
 
-def composite_channel_credentials(channel_credentials,
-                                 additional_call_credentials):
-  """Compose ChannelCredentials on top of client credentials to make a new one.
-
-  Args:
-    channel_credentials: A ChannelCredentials object.
-    additional_call_credentials: A CallCredentials object to compose on
-      top of channel_credentials.
-
-  Returns:
-    A ChannelCredentials object for use in a GRPCCallOptions object.
-  """
-  return ChannelCredentials(
-      _low.channel_credentials_composite(
-          channel_credentials._low_credentials,
-          additional_call_credentials._low_credentials))
+access_token_call_credentials = grpc.access_token_call_credentials
+composite_call_credentials = grpc.composite_call_credentials
+composite_channel_credentials = grpc.composite_channel_credentials
 
 
 class Channel(object):
@@ -151,11 +75,8 @@ class Channel(object):
   unsupported.
   """
 
-  def __init__(self, low_channel, intermediary_low_channel):
-    self._low_channel = low_channel
-    self._intermediary_low_channel = intermediary_low_channel
-    self._connectivity_channel = _connectivity_channel.ConnectivityChannel(
-        low_channel)
+  def __init__(self, channel):
+    self._channel = channel
 
   def subscribe(self, callback, try_to_connect=None):
     """Subscribes to this Channel's connectivity.
@@ -170,7 +91,7 @@ class Channel(object):
         attempt to connect if it is not already connected and ready to conduct
         RPCs.
     """
-    self._connectivity_channel.subscribe(callback, try_to_connect)
+    self._channel.subscribe(callback, try_to_connect=try_to_connect)
 
   def unsubscribe(self, callback):
     """Unsubscribes a callback from this Channel's connectivity.
@@ -179,7 +100,7 @@ class Channel(object):
       callback: A callable previously registered with this Channel from having
         been passed to its "subscribe" method.
     """
-    self._connectivity_channel.unsubscribe(callback)
+    self._channel.unsubscribe(callback)
 
 
 def insecure_channel(host, port):
@@ -193,9 +114,9 @@ def insecure_channel(host, port):
   Returns:
     A Channel to the remote host through which RPCs may be conducted.
   """
-  intermediary_low_channel = _intermediary_low.Channel(
-      '%s:%d' % (host, port) if port else host, None)
-  return Channel(intermediary_low_channel._internal, intermediary_low_channel)  # pylint: disable=protected-access
+  channel = grpc.insecure_channel(
+      host if port is None else '%s:%d' % (host, port))
+  return Channel(channel)
 
 
 def secure_channel(host, port, channel_credentials):
@@ -210,10 +131,9 @@ def secure_channel(host, port, channel_credentials):
   Returns:
     A secure Channel to the remote host through which RPCs may be conducted.
   """
-  intermediary_low_channel = _intermediary_low.Channel(
-      '%s:%d' % (host, port) if port else host,
-      channel_credentials._low_credentials)
-  return Channel(intermediary_low_channel._internal, intermediary_low_channel)  # pylint: disable=protected-access
+  channel = grpc.secure_channel(
+      host if port is None else '%s:%d' % (host, port), channel_credentials)
+  return Channel(channel)
 
 
 class StubOptions(object):
@@ -277,12 +197,11 @@ def generic_stub(channel, options=None):
     A face.GenericStub on which RPCs can be made.
   """
   effective_options = _EMPTY_STUB_OPTIONS if options is None else options
-  return _stub.generic_stub(
-      channel._intermediary_low_channel, effective_options.host,  # pylint: disable=protected-access
-      effective_options.metadata_transformer,
+  return _client_adaptations.generic_stub(
+      channel._channel,  # pylint: disable=protected-access
+      effective_options.host, effective_options.metadata_transformer,
       effective_options.request_serializers,
-      effective_options.response_deserializers, effective_options.thread_pool,
-      effective_options.thread_pool_size)
+      effective_options.response_deserializers)
 
 
 def dynamic_stub(channel, service, cardinalities, options=None):
@@ -300,55 +219,16 @@ def dynamic_stub(channel, service, cardinalities, options=None):
     A face.DynamicStub with which RPCs can be invoked.
   """
   effective_options = StubOptions() if options is None else options
-  return _stub.dynamic_stub(
-      channel._intermediary_low_channel, effective_options.host, service,  # pylint: disable=protected-access
-      cardinalities, effective_options.metadata_transformer,
+  return _client_adaptations.dynamic_stub(
+      channel._channel,  # pylint: disable=protected-access
+      service, cardinalities, effective_options.host,
+      effective_options.metadata_transformer,
       effective_options.request_serializers,
-      effective_options.response_deserializers, effective_options.thread_pool,
-      effective_options.thread_pool_size)
-
+      effective_options.response_deserializers)
 
-class ServerCredentials(object):
-  """A value encapsulating the data required to open a secure port on a Server.
 
-  This class and its instances have no supported interface - it exists to define
-  the type of its instances and its instances exist to be passed to other
-  functions.
-  """
-
-  def __init__(self, low_credentials):
-    self._low_credentials = low_credentials
-
-
-def ssl_server_credentials(
-    private_key_certificate_chain_pairs, root_certificates=None,
-    require_client_auth=False):
-  """Creates a ServerCredentials for use with an SSL-enabled Server.
-
-  Args:
-    private_key_certificate_chain_pairs: A nonempty sequence each element of
-      which is a pair the first element of which is a PEM-encoded private key
-      and the second element of which is the corresponding PEM-encoded
-      certificate chain.
-    root_certificates: PEM-encoded client root certificates to be used for
-      verifying authenticated clients. If omitted, require_client_auth must also
-      be omitted or be False.
-    require_client_auth: A boolean indicating whether or not to require clients
-      to be authenticated. May only be True if root_certificates is not None.
-
-  Returns:
-    A ServerCredentials for use with an SSL-enabled Server.
-  """
-  if len(private_key_certificate_chain_pairs) == 0:
-    raise ValueError(
-        'At least one private key-certificate chain pairis required!')
-  elif require_client_auth and root_certificates is None:
-    raise ValueError(
-        'Illegal to require client auth without providing root certificates!')
-  else:
-    return ServerCredentials(_low.server_credentials_ssl(
-        root_certificates, private_key_certificate_chain_pairs,
-        require_client_auth))
+ServerCredentials = grpc.ServerCredentials
+ssl_server_credentials = grpc.ssl_server_credentials
 
 
 class ServerOptions(object):
@@ -421,9 +301,8 @@ def server(service_implementations, options=None):
     An interfaces.Server with which RPCs can be serviced.
   """
   effective_options = _EMPTY_SERVER_OPTIONS if options is None else options
-  return _server.server(
+  return _server_adaptations.server(
       service_implementations, effective_options.multi_method_implementation,
       effective_options.request_deserializers,
       effective_options.response_serializers, effective_options.thread_pool,
-      effective_options.thread_pool_size, effective_options.default_timeout,
-      effective_options.maximum_timeout)
+      effective_options.thread_pool_size)
diff --git a/src/python/grpcio/grpc/beta/interfaces.py b/src/python/grpcio/grpc/beta/interfaces.py
index 24de9ad1a8..4343b6c4b5 100644
--- a/src/python/grpcio/grpc/beta/interfaces.py
+++ b/src/python/grpcio/grpc/beta/interfaces.py
@@ -30,53 +30,13 @@
 """Constants and interfaces of the Beta API of gRPC Python."""
 
 import abc
-import enum
 
 import six
 
-from grpc._adapter import _types
+import grpc
 
-
-@enum.unique
-class ChannelConnectivity(enum.Enum):
-  """Mirrors grpc_connectivity_state in the gRPC Core.
-
-  Attributes:
-    IDLE: The channel is idle.
-    CONNECTING: The channel is connecting.
-    READY: The channel is ready to conduct RPCs.
-    TRANSIENT_FAILURE: The channel has seen a failure from which it expects to
-      recover.
-    FATAL_FAILURE: The channel has seen a failure from which it cannot recover.
-  """
-  IDLE = (_types.ConnectivityState.IDLE, 'idle',)
-  CONNECTING = (_types.ConnectivityState.CONNECTING, 'connecting',)
-  READY = (_types.ConnectivityState.READY, 'ready',)
-  TRANSIENT_FAILURE = (
-      _types.ConnectivityState.TRANSIENT_FAILURE, 'transient failure',)
-  FATAL_FAILURE = (_types.ConnectivityState.FATAL_FAILURE, 'fatal failure',)
-
-
-@enum.unique
-class StatusCode(enum.Enum):
-  """Mirrors grpc_status_code in the C core."""
-  OK                  = 0
-  CANCELLED           = 1
-  UNKNOWN             = 2
-  INVALID_ARGUMENT    = 3
-  DEADLINE_EXCEEDED   = 4
-  NOT_FOUND           = 5
-  ALREADY_EXISTS      = 6
-  PERMISSION_DENIED   = 7
-  RESOURCE_EXHAUSTED  = 8
-  FAILED_PRECONDITION = 9
-  ABORTED             = 10
-  OUT_OF_RANGE        = 11
-  UNIMPLEMENTED       = 12
-  INTERNAL            = 13
-  UNAVAILABLE         = 14
-  DATA_LOSS           = 15
-  UNAUTHENTICATED     = 16
+ChannelConnectivity = grpc.ChannelConnectivity
+StatusCode = grpc.StatusCode
 
 
 class GRPCCallOptions(object):
@@ -106,46 +66,9 @@ def grpc_call_options(disable_compression=False, credentials=None):
   """
   return GRPCCallOptions(disable_compression, None, credentials)
 
-
-class GRPCAuthMetadataContext(six.with_metaclass(abc.ABCMeta)):
-  """Provides information to call credentials metadata plugins.
-
-  Attributes:
-    service_url: A string URL of the service being called into.
-    method_name: A string of the fully qualified method name being called.
-  """
-
-
-class GRPCAuthMetadataPluginCallback(six.with_metaclass(abc.ABCMeta)):
-  """Callback object received by a metadata plugin."""
-
-  def __call__(self, metadata, error):
-    """Inform the gRPC runtime of the metadata to construct a CallCredentials.
-
-    Args:
-      metadata: An iterable of 2-sequences (e.g. tuples) of metadata key/value
-        pairs.
-      error: An Exception to indicate error or None to indicate success.
-    """
-    raise NotImplementedError()
-
-
-class GRPCAuthMetadataPlugin(six.with_metaclass(abc.ABCMeta)):
-  """
-  """
-
-  def __call__(self, context, callback):
-    """Invoke the plugin.
-
-    Must not block. Need only be called by the gRPC runtime.
-
-    Args:
-      context: A GRPCAuthMetadataContext providing information on what the
-        plugin is being used for.
-      callback: A GRPCAuthMetadataPluginCallback to be invoked either
-        synchronously or asynchronously.
-    """
-    raise NotImplementedError()
+GRPCAuthMetadataContext = grpc.AuthMetadataContext
+GRPCAuthMetadataPluginCallback = grpc.AuthMetadataPluginCallback
+GRPCAuthMetadataPlugin = grpc.AuthMetadataPlugin
 
 
 class GRPCServicerContext(six.with_metaclass(abc.ABCMeta)):
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index d0f23f42cc..b83c82cb92 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -42,7 +42,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/support/cpu_windows.c',
   'src/core/lib/support/env_linux.c',
   'src/core/lib/support/env_posix.c',
-  'src/core/lib/support/env_win32.c',
+  'src/core/lib/support/env_windows.c',
   'src/core/lib/support/histogram.c',
   'src/core/lib/support/host_port.c',
   'src/core/lib/support/load_file.c',
@@ -50,31 +50,31 @@ CORE_SOURCE_FILES = [
   'src/core/lib/support/log_android.c',
   'src/core/lib/support/log_linux.c',
   'src/core/lib/support/log_posix.c',
-  'src/core/lib/support/log_win32.c',
+  'src/core/lib/support/log_windows.c',
   'src/core/lib/support/murmur_hash.c',
   'src/core/lib/support/slice.c',
   'src/core/lib/support/slice_buffer.c',
   'src/core/lib/support/stack_lockfree.c',
   'src/core/lib/support/string.c',
   'src/core/lib/support/string_posix.c',
-  'src/core/lib/support/string_util_win32.c',
-  'src/core/lib/support/string_win32.c',
+  'src/core/lib/support/string_util_windows.c',
+  'src/core/lib/support/string_windows.c',
   'src/core/lib/support/subprocess_posix.c',
   'src/core/lib/support/subprocess_windows.c',
   'src/core/lib/support/sync.c',
   'src/core/lib/support/sync_posix.c',
-  'src/core/lib/support/sync_win32.c',
+  'src/core/lib/support/sync_windows.c',
   'src/core/lib/support/thd.c',
   'src/core/lib/support/thd_posix.c',
-  'src/core/lib/support/thd_win32.c',
+  'src/core/lib/support/thd_windows.c',
   'src/core/lib/support/time.c',
   'src/core/lib/support/time_posix.c',
   'src/core/lib/support/time_precise.c',
-  'src/core/lib/support/time_win32.c',
+  'src/core/lib/support/time_windows.c',
   'src/core/lib/support/tls_pthread.c',
   'src/core/lib/support/tmpfile_msys.c',
   'src/core/lib/support/tmpfile_posix.c',
-  'src/core/lib/support/tmpfile_win32.c',
+  'src/core/lib/support/tmpfile_windows.c',
   'src/core/lib/support/wrap_memcpy.c',
   'src/core/lib/surface/init.c',
   'src/core/lib/channel/channel_args.c',
@@ -103,6 +103,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/iomgr/iomgr.c',
   'src/core/lib/iomgr/iomgr_posix.c',
   'src/core/lib/iomgr/iomgr_windows.c',
+  'src/core/lib/iomgr/polling_entity.c',
   'src/core/lib/iomgr/pollset_set_windows.c',
   'src/core/lib/iomgr/pollset_windows.c',
   'src/core/lib/iomgr/resolve_address_posix.c',
@@ -189,7 +190,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/security/credentials/credentials_metadata.c',
   'src/core/lib/security/credentials/fake/fake_credentials.c',
   'src/core/lib/security/credentials/google_default/credentials_posix.c',
-  'src/core/lib/security/credentials/google_default/credentials_win32.c',
+  'src/core/lib/security/credentials/google_default/credentials_windows.c',
   'src/core/lib/security/credentials/google_default/google_default_credentials.c',
   'src/core/lib/security/credentials/iam/iam_credentials.c',
   'src/core/lib/security/credentials/jwt/json_token.c',
@@ -231,9 +232,6 @@ CORE_SOURCE_FILES = [
   'src/core/ext/client_config/uri_parser.c',
   'src/core/ext/transport/chttp2/server/insecure/server_chttp2.c',
   'src/core/ext/transport/chttp2/client/insecure/channel_create.c',
-  'src/core/ext/transport/cronet/client/secure/cronet_channel_create.c',
-  'src/core/ext/transport/cronet/transport/cronet_api_dummy.c',
-  'src/core/ext/transport/cronet/transport/cronet_transport.c',
   'src/core/ext/lb_policy/grpclb/load_balancer_api.c',
   'src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.c',
   'third_party/nanopb/pb_common.c',
@@ -243,6 +241,8 @@ CORE_SOURCE_FILES = [
   'src/core/ext/lb_policy/round_robin/round_robin.c',
   'src/core/ext/resolver/dns/native/dns_resolver.c',
   'src/core/ext/resolver/sockaddr/sockaddr_resolver.c',
+  'src/core/ext/load_reporting/load_reporting.c',
+  'src/core/ext/load_reporting/load_reporting_filter.c',
   'src/core/ext/census/context.c',
   'src/core/ext/census/gen/census.pb.c',
   'src/core/ext/census/grpc_context.c',
diff --git a/src/python/grpcio/tests/interop/client.py b/src/python/grpcio/tests/interop/client.py
index db29eb4aa7..e3d5545a02 100644
--- a/src/python/grpcio/tests/interop/client.py
+++ b/src/python/grpcio/tests/interop/client.py
@@ -65,39 +65,34 @@ def _args():
       help='email address of the default service account', type=str)
   return parser.parse_args()
 
-def _oauth_access_token(args):
-  credentials = oauth2client_client.GoogleCredentials.get_application_default()
-  scoped_credentials = credentials.create_scoped([args.oauth_scope])
-  return scoped_credentials.get_access_token().access_token
 
 def _stub(args):
-  if args.oauth_scope:
-    if args.test_case == 'oauth2_auth_token':
-      # TODO(jtattermusch): This testcase sets the auth metadata key-value
-      # manually, which also means that the user would need to do the same
-      # thing every time he/she would like to use and out of band oauth token.
-      # The transformer function that produces the metadata key-value from
-      # the access token should be provided by gRPC auth library.
-      access_token = _oauth_access_token(args)
-      metadata_transformer = lambda x: [
-          ('authorization', 'Bearer %s' % access_token)]
-    else:
-      metadata_transformer = lambda x: [
-          ('authorization', 'Bearer %s' % _oauth_access_token(args))]
+  if args.test_case == 'oauth2_auth_token':
+    creds = oauth2client_client.GoogleCredentials.get_application_default()
+    scoped_creds = creds.create_scoped([args.oauth_scope])
+    access_token = scoped_creds.get_access_token().access_token
+    call_creds = implementations.access_token_call_credentials(access_token)
+  elif args.test_case == 'compute_engine_creds':
+    creds = oauth2client_client.GoogleCredentials.get_application_default()
+    scoped_creds = creds.create_scoped([args.oauth_scope])
+    call_creds = implementations.google_call_credentials(scoped_creds)
   else:
-    metadata_transformer = lambda x: []
+    call_creds = None
   if args.use_tls:
     if args.use_test_ca:
       root_certificates = resources.test_root_certificates()
     else:
       root_certificates = None  # will load default roots.
 
+    channel_creds = implementations.ssl_channel_credentials(root_certificates)
+    if call_creds is not None:
+      channel_creds = implementations.composite_channel_credentials(
+          channel_creds, call_creds)
+
     channel = test_utilities.not_really_secure_channel(
-        args.server_host, args.server_port,
-        implementations.ssl_channel_credentials(root_certificates),
+        args.server_host, args.server_port, channel_creds,
         args.server_host_override)
-    stub = test_pb2.beta_create_TestService_stub(
-        channel, metadata_transformer=metadata_transformer)
+    stub = test_pb2.beta_create_TestService_stub(channel)
   else:
     channel = implementations.insecure_channel(
         args.server_host, args.server_port)
diff --git a/src/python/grpcio/tests/interop/methods.py b/src/python/grpcio/tests/interop/methods.py
index 67862ed7d3..d5ef0c68bb 100644
--- a/src/python/grpcio/tests/interop/methods.py
+++ b/src/python/grpcio/tests/interop/methods.py
@@ -39,6 +39,8 @@ import time
 
 from oauth2client import client as oauth2client_client
 
+from grpc.beta import implementations
+from grpc.beta import interfaces
 from grpc.framework.common import cardinality
 from grpc.framework.interfaces.face import face
 
@@ -88,13 +90,15 @@ class TestService(test_pb2.BetaTestServiceServicer):
     return self.FullDuplexCall(request_iterator, context)
 
 
-def _large_unary_common_behavior(stub, fill_username, fill_oauth_scope):
+def _large_unary_common_behavior(stub, fill_username, fill_oauth_scope,
+                                 protocol_options=None):
   with stub:
     request = messages_pb2.SimpleRequest(
         response_type=messages_pb2.COMPRESSABLE, response_size=314159,
         payload=messages_pb2.Payload(body=b'\x00' * 271828),
         fill_username=fill_username, fill_oauth_scope=fill_oauth_scope)
-    response_future = stub.UnaryCall.future(request, _TIMEOUT)
+    response_future = stub.UnaryCall.future(request, _TIMEOUT,
+                                            protocol_options=protocol_options)
     response = response_future.result()
     if response.payload.type is not messages_pb2.COMPRESSABLE:
       raise ValueError(
@@ -303,7 +307,24 @@ def _oauth2_auth_token(stub, args):
   if args.oauth_scope.find(response.oauth_scope) == -1:
     raise ValueError(
         'expected to find oauth scope "%s" in received "%s"' %
-            (response.oauth_scope, args.oauth_scope))
+        (response.oauth_scope, args.oauth_scope))
+
+
+def _per_rpc_creds(stub, args):
+  json_key_filename = os.environ[
+      oauth2client_client.GOOGLE_APPLICATION_CREDENTIALS]
+  wanted_email = json.load(open(json_key_filename, 'rb'))['client_email']
+  credentials = oauth2client_client.GoogleCredentials.get_application_default()
+  scoped_credentials = credentials.create_scoped([args.oauth_scope])
+  call_creds = implementations.google_call_credentials(scoped_credentials)
+  options = interfaces.grpc_call_options(disable_compression=False,
+                                         credentials=call_creds)
+  response = _large_unary_common_behavior(stub, True, False,
+                                          protocol_options=options)
+  if wanted_email != response.username:
+    raise ValueError(
+        'expected username %s, got %s' % (wanted_email, response.username))
+
 
 @enum.unique
 class TestCase(enum.Enum):
@@ -317,6 +338,7 @@ class TestCase(enum.Enum):
   EMPTY_STREAM = 'empty_stream'
   COMPUTE_ENGINE_CREDS = 'compute_engine_creds'
   OAUTH2_AUTH_TOKEN = 'oauth2_auth_token'
+  PER_RPC_CREDS = 'per_rpc_creds'
   TIMEOUT_ON_SLEEPING_SERVER = 'timeout_on_sleeping_server'
 
   def test_interoperability(self, stub, args):
@@ -342,5 +364,7 @@ class TestCase(enum.Enum):
       _compute_engine_creds(stub, args)
     elif self is TestCase.OAUTH2_AUTH_TOKEN:
       _oauth2_auth_token(stub, args)
+    elif self is TestCase.PER_RPC_CREDS:
+      _per_rpc_creds(stub, args)
     else:
       raise NotImplementedError('Test case "%s" not implemented!' % self.name)
diff --git a/src/python/grpcio/tests/tests.json b/src/python/grpcio/tests/tests.json
index 1beb619f87..8dc47bf69d 100644
--- a/src/python/grpcio/tests/tests.json
+++ b/src/python/grpcio/tests/tests.json
@@ -1,4 +1,6 @@
 [
+  "_auth_test.AccessTokenCallCredentialsTest",
+  "_auth_test.GoogleCallCredentialsTest",
   "_base_interface_test.AsyncEasyTest", 
   "_base_interface_test.AsyncPeasyTest", 
   "_base_interface_test.SyncEasyTest", 
@@ -6,6 +8,8 @@
   "_beta_features_test.BetaFeaturesTest", 
   "_beta_features_test.ContextManagementAndLifecycleTest", 
   "_cancel_many_calls_test.CancelManyCallsTest",
+  "_channel_connectivity_test.ChannelConnectivityTest",
+  "_channel_ready_future_test.ChannelReadyFutureTest",
   "_channel_test.ChannelTest", 
   "_connectivity_channel_test.ChannelConnectivityTest", 
   "_core_over_links_base_interface_test.AsyncEasyTest", 
@@ -31,6 +35,7 @@
   "_face_interface_test.MultiCallableInvokerBlockingInvocationInlineServiceTest", 
   "_face_interface_test.MultiCallableInvokerFutureInvocationAsynchronousEventServiceTest",
   "_health_servicer_test.HealthServicerTest",
+  "_implementations_test.CallCredentialsTest",
   "_implementations_test.ChannelCredentialsTest", 
   "_insecure_interop_test.InsecureInteropTest", 
   "_intermediary_low_test.CancellationTest", 
@@ -43,6 +48,8 @@
   "_low_test.HangingServerShutdown", 
   "_low_test.InsecureServerInsecureClient", 
   "_not_found_test.NotFoundTest", 
+  "_read_some_but_not_all_responses_test.ReadSomeButNotAllResponsesTest",
+  "_rpc_test.RPCTest",
   "_sanity_test.Sanity", 
   "_secure_interop_test.SecureInteropTest", 
   "_transmission_test.RoundTripTest", 
diff --git a/src/python/grpcio/tests/unit/_auth_test.py b/src/python/grpcio/tests/unit/_auth_test.py
new file mode 100644
index 0000000000..c31f7b06f7
--- /dev/null
+++ b/src/python/grpcio/tests/unit/_auth_test.py
@@ -0,0 +1,96 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Tests of standard AuthMetadataPlugins."""
+
+import collections
+import threading
+import unittest
+
+from grpc import _auth
+
+
+class MockGoogleCreds(object):
+
+  def get_access_token(self):
+    token = collections.namedtuple('MockAccessTokenInfo',
+                                   ('access_token', 'expires_in'))
+    token.access_token = 'token'
+    return token
+
+
+class MockExceptionGoogleCreds(object):
+
+  def get_access_token(self):
+    raise Exception()
+
+
+class GoogleCallCredentialsTest(unittest.TestCase):
+
+  def test_google_call_credentials_success(self):
+    callback_event = threading.Event()
+
+    def mock_callback(metadata, error):
+      self.assertEqual(metadata, (('authorization', 'Bearer token'),))
+      self.assertIsNone(error)
+      callback_event.set()
+
+    call_creds = _auth.GoogleCallCredentials(MockGoogleCreds())
+    call_creds(None, mock_callback)
+    self.assertTrue(callback_event.wait(1.0))
+
+  def test_google_call_credentials_error(self):
+    callback_event = threading.Event()
+
+    def mock_callback(metadata, error):
+      self.assertIsNotNone(error)
+      callback_event.set()
+
+    call_creds = _auth.GoogleCallCredentials(MockExceptionGoogleCreds())
+    call_creds(None, mock_callback)
+    self.assertTrue(callback_event.wait(1.0))
+
+
+class AccessTokenCallCredentialsTest(unittest.TestCase):
+
+  def test_google_call_credentials_success(self):
+    callback_event = threading.Event()
+
+    def mock_callback(metadata, error):
+      self.assertEqual(metadata, (('authorization', 'Bearer token'),))
+      self.assertIsNone(error)
+      callback_event.set()
+
+    call_creds = _auth.AccessTokenCallCredentials('token')
+    call_creds(None, mock_callback)
+    self.assertTrue(callback_event.wait(1.0))
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
diff --git a/src/python/grpcio/tests/unit/_channel_connectivity_test.py b/src/python/grpcio/tests/unit/_channel_connectivity_test.py
new file mode 100644
index 0000000000..a1575efada
--- /dev/null
+++ b/src/python/grpcio/tests/unit/_channel_connectivity_test.py
@@ -0,0 +1,161 @@
+# 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.
+
+"""Tests of grpc._channel.Channel connectivity."""
+
+import threading
+import time
+import unittest
+from concurrent import futures
+
+import grpc
+from grpc import _channel
+from grpc import _server
+from tests.unit.framework.common import test_constants
+
+
+def _ready_in_connectivities(connectivities):
+  return grpc.ChannelConnectivity.READY in connectivities
+
+
+def _last_connectivity_is_not_ready(connectivities):
+  return connectivities[-1] is not grpc.ChannelConnectivity.READY
+
+
+class _Callback(object):
+
+  def __init__(self):
+    self._condition = threading.Condition()
+    self._connectivities = []
+
+  def update(self, connectivity):
+    with self._condition:
+      self._connectivities.append(connectivity)
+      self._condition.notify()
+
+  def connectivities(self):
+    with self._condition:
+      return tuple(self._connectivities)
+
+  def block_until_connectivities_satisfy(self, predicate):
+    with self._condition:
+      while True:
+        connectivities = tuple(self._connectivities)
+        if predicate(connectivities):
+          return connectivities
+        else:
+          self._condition.wait()
+
+
+class ChannelConnectivityTest(unittest.TestCase):
+
+  def test_lonely_channel_connectivity(self):
+    callback = _Callback()
+
+    channel = _channel.Channel('localhost:12345', None, None)
+    channel.subscribe(callback.update, try_to_connect=False)
+    first_connectivities = callback.block_until_connectivities_satisfy(bool)
+    channel.subscribe(callback.update, try_to_connect=True)
+    second_connectivities = callback.block_until_connectivities_satisfy(
+        lambda connectivities: 2 <= len(connectivities))
+    # Wait for a connection that will never happen.
+    time.sleep(test_constants.SHORT_TIMEOUT)
+    third_connectivities = callback.connectivities()
+    channel.unsubscribe(callback.update)
+    fourth_connectivities = callback.connectivities()
+    channel.unsubscribe(callback.update)
+    fifth_connectivities = callback.connectivities()
+
+    self.assertSequenceEqual(
+        (grpc.ChannelConnectivity.IDLE,), first_connectivities)
+    self.assertNotIn(
+        grpc.ChannelConnectivity.READY, second_connectivities)
+    self.assertNotIn(
+        grpc.ChannelConnectivity.READY, third_connectivities)
+    self.assertNotIn(
+        grpc.ChannelConnectivity.READY, fourth_connectivities)
+    self.assertNotIn(
+        grpc.ChannelConnectivity.READY, fifth_connectivities)
+
+  def test_immediately_connectable_channel_connectivity(self):
+    server = _server.Server((), futures.ThreadPoolExecutor(max_workers=0))
+    port = server.add_insecure_port('[::]:0')
+    server.start()
+    first_callback = _Callback()
+    second_callback = _Callback()
+
+    channel = _channel.Channel('localhost:{}'.format(port), None, None)
+    channel.subscribe(first_callback.update, try_to_connect=False)
+    first_connectivities = first_callback.block_until_connectivities_satisfy(
+        bool)
+    # Wait for a connection that will never happen because try_to_connect=True
+    # has not yet been passed.
+    time.sleep(test_constants.SHORT_TIMEOUT)
+    second_connectivities = first_callback.connectivities()
+    channel.subscribe(second_callback.update, try_to_connect=True)
+    third_connectivities = first_callback.block_until_connectivities_satisfy(
+        lambda connectivities: 2 <= len(connectivities))
+    fourth_connectivities = second_callback.block_until_connectivities_satisfy(
+        bool)
+    # Wait for a connection that will happen (or may already have happened).
+    first_callback.block_until_connectivities_satisfy(_ready_in_connectivities)
+    second_callback.block_until_connectivities_satisfy(_ready_in_connectivities)
+    del channel
+
+    self.assertSequenceEqual(
+        (grpc.ChannelConnectivity.IDLE,), first_connectivities)
+    self.assertSequenceEqual(
+        (grpc.ChannelConnectivity.IDLE,), second_connectivities)
+    self.assertNotIn(
+        grpc.ChannelConnectivity.TRANSIENT_FAILURE, third_connectivities)
+    self.assertNotIn(
+        grpc.ChannelConnectivity.FATAL_FAILURE, third_connectivities)
+    self.assertNotIn(
+        grpc.ChannelConnectivity.TRANSIENT_FAILURE,
+        fourth_connectivities)
+    self.assertNotIn(
+        grpc.ChannelConnectivity.FATAL_FAILURE, fourth_connectivities)
+
+  def test_reachable_then_unreachable_channel_connectivity(self):
+    server = _server.Server((), futures.ThreadPoolExecutor(max_workers=0))
+    port = server.add_insecure_port('[::]:0')
+    server.start()
+    callback = _Callback()
+
+    channel = _channel.Channel('localhost:{}'.format(port), None, None)
+    channel.subscribe(callback.update, try_to_connect=True)
+    callback.block_until_connectivities_satisfy(_ready_in_connectivities)
+    # Now take down the server and confirm that channel readiness is repudiated.
+    server.stop(None)
+    callback.block_until_connectivities_satisfy(_last_connectivity_is_not_ready)
+    channel.unsubscribe(callback.update)
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
diff --git a/src/python/grpcio/tests/unit/_channel_ready_future_test.py b/src/python/grpcio/tests/unit/_channel_ready_future_test.py
new file mode 100644
index 0000000000..b84bc0197a
--- /dev/null
+++ b/src/python/grpcio/tests/unit/_channel_ready_future_test.py
@@ -0,0 +1,103 @@
+# 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.
+
+"""Tests of grpc.channel_ready_future."""
+
+import threading
+import unittest
+from concurrent import futures
+
+import grpc
+from grpc import _channel
+from grpc import _server
+from tests.unit.framework.common import test_constants
+
+
+class _Callback(object):
+
+  def __init__(self):
+    self._condition = threading.Condition()
+    self._value = None
+
+  def accept_value(self, value):
+    with self._condition:
+      self._value = value
+      self._condition.notify_all()
+
+  def block_until_called(self):
+    with self._condition:
+      while self._value is None:
+        self._condition.wait()
+      return self._value
+
+
+class ChannelReadyFutureTest(unittest.TestCase):
+
+  def test_lonely_channel_connectivity(self):
+    channel = grpc.insecure_channel('localhost:12345')
+    callback = _Callback()
+
+    ready_future = grpc.channel_ready_future(channel)
+    ready_future.add_done_callback(callback.accept_value)
+    with self.assertRaises(grpc.FutureTimeoutError):
+      ready_future.result(test_constants.SHORT_TIMEOUT)
+    self.assertFalse(ready_future.cancelled())
+    self.assertFalse(ready_future.done())
+    self.assertTrue(ready_future.running())
+    ready_future.cancel()
+    value_passed_to_callback = callback.block_until_called()
+    self.assertIs(ready_future, value_passed_to_callback)
+    self.assertTrue(ready_future.cancelled())
+    self.assertTrue(ready_future.done())
+    self.assertFalse(ready_future.running())
+
+  def test_immediately_connectable_channel_connectivity(self):
+    server = _server.Server((), futures.ThreadPoolExecutor(max_workers=0))
+    port = server.add_insecure_port('[::]:0')
+    server.start()
+    channel = grpc.insecure_channel('localhost:{}'.format(port))
+    callback = _Callback()
+
+    ready_future = grpc.channel_ready_future(channel)
+    ready_future.add_done_callback(callback.accept_value)
+    self.assertIsNone(ready_future.result(test_constants.SHORT_TIMEOUT))
+    value_passed_to_callback = callback.block_until_called()
+    self.assertIs(ready_future, value_passed_to_callback)
+    self.assertFalse(ready_future.cancelled())
+    self.assertTrue(ready_future.done())
+    self.assertFalse(ready_future.running())
+    # Cancellation after maturity has no effect.
+    ready_future.cancel()
+    self.assertFalse(ready_future.cancelled())
+    self.assertTrue(ready_future.done())
+    self.assertFalse(ready_future.running())
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
diff --git a/src/python/grpcio/tests/unit/_cython/_read_some_but_not_all_responses_test.py b/src/python/grpcio/tests/unit/_cython/_read_some_but_not_all_responses_test.py
new file mode 100644
index 0000000000..6ae7a90fbe
--- /dev/null
+++ b/src/python/grpcio/tests/unit/_cython/_read_some_but_not_all_responses_test.py
@@ -0,0 +1,251 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Test a corner-case at the level of the Cython API."""
+
+import threading
+import unittest
+
+from grpc._cython import cygrpc
+
+_INFINITE_FUTURE = cygrpc.Timespec(float('+inf'))
+_EMPTY_FLAGS = 0
+_EMPTY_METADATA = cygrpc.Metadata(())
+
+
+class _ServerDriver(object):
+
+  def __init__(self, completion_queue, shutdown_tag):
+    self._condition = threading.Condition()
+    self._completion_queue = completion_queue
+    self._shutdown_tag = shutdown_tag
+    self._events = []
+    self._saw_shutdown_tag = False
+
+  def start(self):
+    def in_thread():
+      while True:
+        event = self._completion_queue.poll()
+        with self._condition:
+          self._events.append(event)
+          self._condition.notify()
+          if event.tag is self._shutdown_tag:
+            self._saw_shutdown_tag = True
+            break
+    thread = threading.Thread(target=in_thread)
+    thread.start()
+
+  def done(self):
+    with self._condition:
+      return self._saw_shutdown_tag
+
+  def first_event(self):
+    with self._condition:
+      while not self._events:
+        self._condition.wait()
+      return self._events[0]
+
+  def events(self):
+    with self._condition:
+      while not self._saw_shutdown_tag:
+        self._condition.wait()
+      return tuple(self._events)
+
+
+class _QueueDriver(object):
+
+  def __init__(self, condition, completion_queue, due):
+    self._condition = condition
+    self._completion_queue = completion_queue
+    self._due = due
+    self._events = []
+    self._returned = False
+
+  def start(self):
+    def in_thread():
+      while True:
+        event = self._completion_queue.poll()
+        with self._condition:
+          self._events.append(event)
+          self._due.remove(event.tag)
+          self._condition.notify_all()
+          if not self._due:
+            self._returned = True
+            return
+    thread = threading.Thread(target=in_thread)
+    thread.start()
+
+  def done(self):
+    with self._condition:
+      return self._returned
+
+  def event_with_tag(self, tag):
+    with self._condition:
+      while True:
+        for event in self._events:
+          if event.tag is tag:
+            return event
+        self._condition.wait()
+
+  def events(self):
+    with self._condition:
+      while not self._returned:
+        self._condition.wait()
+      return tuple(self._events)
+
+
+class ReadSomeButNotAllResponsesTest(unittest.TestCase):
+
+  def testReadSomeButNotAllResponses(self):
+    server_completion_queue = cygrpc.CompletionQueue()
+    server = cygrpc.Server()
+    server.register_completion_queue(server_completion_queue)
+    port = server.add_http2_port('[::]:0')
+    server.start()
+    channel = cygrpc.Channel('localhost:{}'.format(port))
+
+    server_shutdown_tag = 'server_shutdown_tag'
+    server_driver = _ServerDriver(server_completion_queue, server_shutdown_tag)
+    server_driver.start()
+
+    client_condition = threading.Condition()
+    client_due = set()
+    client_completion_queue = cygrpc.CompletionQueue()
+    client_driver = _QueueDriver(
+        client_condition, client_completion_queue, client_due)
+    client_driver.start()
+
+    server_call_condition = threading.Condition()
+    server_send_initial_metadata_tag = 'server_send_initial_metadata_tag'
+    server_send_first_message_tag = 'server_send_first_message_tag'
+    server_send_second_message_tag = 'server_send_second_message_tag'
+    server_complete_rpc_tag = 'server_complete_rpc_tag'
+    server_call_due = set((
+        server_send_initial_metadata_tag,
+        server_send_first_message_tag,
+        server_send_second_message_tag,
+        server_complete_rpc_tag,
+    ))
+    server_call_completion_queue = cygrpc.CompletionQueue()
+    server_call_driver = _QueueDriver(
+        server_call_condition, server_call_completion_queue, server_call_due)
+    server_call_driver.start()
+
+    server_rpc_tag = 'server_rpc_tag'
+    request_call_result = server.request_call(
+        server_call_completion_queue, server_completion_queue, server_rpc_tag)
+
+    client_call = channel.create_call(
+        None, _EMPTY_FLAGS, client_completion_queue, b'/twinkies', None,
+        _INFINITE_FUTURE)
+    client_receive_initial_metadata_tag = 'client_receive_initial_metadata_tag'
+    client_complete_rpc_tag = 'client_complete_rpc_tag'
+    with client_condition:
+      client_receive_initial_metadata_start_batch_result = (
+          client_call.start_batch(cygrpc.Operations([
+              cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),
+          ]), client_receive_initial_metadata_tag))
+      client_due.add(client_receive_initial_metadata_tag)
+      client_complete_rpc_start_batch_result = (
+          client_call.start_batch(cygrpc.Operations([
+              cygrpc.operation_send_initial_metadata(
+                  _EMPTY_METADATA, _EMPTY_FLAGS),
+              cygrpc.operation_send_close_from_client(_EMPTY_FLAGS),
+              cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
+          ]), client_complete_rpc_tag))
+      client_due.add(client_complete_rpc_tag)
+
+    server_rpc_event = server_driver.first_event()
+
+    with server_call_condition:
+      server_send_initial_metadata_start_batch_result = (
+          server_rpc_event.operation_call.start_batch(cygrpc.Operations([
+              cygrpc.operation_send_initial_metadata(
+                  _EMPTY_METADATA, _EMPTY_FLAGS),
+          ]), server_send_initial_metadata_tag))
+      server_send_first_message_start_batch_result = (
+          server_rpc_event.operation_call.start_batch(cygrpc.Operations([
+              cygrpc.operation_send_message(b'\x07', _EMPTY_FLAGS),
+          ]), server_send_first_message_tag))
+    server_send_initial_metadata_event = server_call_driver.event_with_tag(
+        server_send_initial_metadata_tag)
+    server_send_first_message_event = server_call_driver.event_with_tag(
+        server_send_first_message_tag)
+    with server_call_condition:
+      server_send_second_message_start_batch_result = (
+          server_rpc_event.operation_call.start_batch(cygrpc.Operations([
+              cygrpc.operation_send_message(b'\x07', _EMPTY_FLAGS),
+          ]), server_send_second_message_tag))
+      server_complete_rpc_start_batch_result = (
+          server_rpc_event.operation_call.start_batch(cygrpc.Operations([
+              cygrpc.operation_receive_close_on_server(_EMPTY_FLAGS),
+              cygrpc.operation_send_status_from_server(
+                  cygrpc.Metadata(()), cygrpc.StatusCode.ok, b'test details',
+                  _EMPTY_FLAGS),
+          ]), server_complete_rpc_tag))
+    server_send_second_message_event = server_call_driver.event_with_tag(
+        server_send_second_message_tag)
+    server_complete_rpc_event = server_call_driver.event_with_tag(
+        server_complete_rpc_tag)
+    server_call_driver.events()
+
+    with client_condition:
+      client_receive_first_message_tag = 'client_receive_first_message_tag'
+      client_receive_first_message_start_batch_result = (
+          client_call.start_batch(cygrpc.Operations([
+              cygrpc.operation_receive_message(_EMPTY_FLAGS),
+          ]), client_receive_first_message_tag))
+      client_due.add(client_receive_first_message_tag)
+    client_receive_first_message_event = client_driver.event_with_tag(
+        client_receive_first_message_tag)
+
+    client_call_cancel_result = client_call.cancel()
+    client_driver.events()
+
+    server.shutdown(server_completion_queue, server_shutdown_tag)
+    server.cancel_all_calls()
+    server_driver.events()
+
+    self.assertEqual(cygrpc.CallError.ok, request_call_result)
+    self.assertEqual(
+        cygrpc.CallError.ok, server_send_initial_metadata_start_batch_result)
+    self.assertEqual(
+        cygrpc.CallError.ok, client_receive_initial_metadata_start_batch_result)
+    self.assertEqual(
+        cygrpc.CallError.ok, client_complete_rpc_start_batch_result)
+    self.assertEqual(cygrpc.CallError.ok, client_call_cancel_result)
+    self.assertIs(server_rpc_tag, server_rpc_event.tag)
+    self.assertEqual(
+        cygrpc.CompletionType.operation_complete, server_rpc_event.type)
+    self.assertIsInstance(server_rpc_event.operation_call, cygrpc.Call)
+    self.assertEqual(0, len(server_rpc_event.batch_operations))
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
diff --git a/src/python/grpcio/tests/unit/_rpc_test.py b/src/python/grpcio/tests/unit/_rpc_test.py
new file mode 100644
index 0000000000..1c7a14c5d0
--- /dev/null
+++ b/src/python/grpcio/tests/unit/_rpc_test.py
@@ -0,0 +1,775 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Test of gRPC Python's application-layer API."""
+
+import itertools
+import threading
+import unittest
+from concurrent import futures
+
+import grpc
+from grpc.framework.foundation import logging_pool
+
+from tests.unit.framework.common import test_constants
+from tests.unit.framework.common import test_control
+
+_SERIALIZE_REQUEST = lambda bytestring: bytestring * 2
+_DESERIALIZE_REQUEST = lambda bytestring: bytestring[len(bytestring) / 2:]
+_SERIALIZE_RESPONSE = lambda bytestring: bytestring * 3
+_DESERIALIZE_RESPONSE = lambda bytestring: bytestring[:len(bytestring) / 3]
+
+_UNARY_UNARY = b'/test/UnaryUnary'
+_UNARY_STREAM = b'/test/UnaryStream'
+_STREAM_UNARY = b'/test/StreamUnary'
+_STREAM_STREAM = b'/test/StreamStream'
+
+
+class _Callback(object):
+
+  def __init__(self):
+    self._condition = threading.Condition()
+    self._value = None
+    self._called = False
+
+  def __call__(self, value):
+    with self._condition:
+      self._value = value
+      self._called = True
+      self._condition.notify_all()
+
+  def value(self):
+    with self._condition:
+      while not self._called:
+        self._condition.wait()
+      return self._value
+
+
+class _Handler(object):
+
+  def __init__(self, control):
+    self._control = control
+
+  def handle_unary_unary(self, request, servicer_context):
+    self._control.control()
+    if servicer_context is not None:
+      servicer_context.set_trailing_metadata(((b'testkey', b'testvalue',),))
+    return request
+
+  def handle_unary_stream(self, request, servicer_context):
+    for _ in range(test_constants.STREAM_LENGTH):
+      self._control.control()
+      yield request
+    self._control.control()
+    if servicer_context is not None:
+      servicer_context.set_trailing_metadata(((b'testkey', b'testvalue',),))
+
+  def handle_stream_unary(self, request_iterator, servicer_context):
+    if servicer_context is not None:
+      servicer_context.invocation_metadata()
+    self._control.control()
+    response_elements = []
+    for request in request_iterator:
+      self._control.control()
+      response_elements.append(request)
+    self._control.control()
+    if servicer_context is not None:
+      servicer_context.set_trailing_metadata(((b'testkey', b'testvalue',),))
+    return b''.join(response_elements)
+
+  def handle_stream_stream(self, request_iterator, servicer_context):
+    self._control.control()
+    if servicer_context is not None:
+      servicer_context.set_trailing_metadata(((b'testkey', b'testvalue',),))
+    for request in request_iterator:
+      self._control.control()
+      yield request
+    self._control.control()
+
+
+class _MethodHandler(grpc.RpcMethodHandler):
+
+  def __init__(
+      self, request_streaming, response_streaming, request_deserializer,
+      response_serializer, unary_unary, unary_stream, stream_unary,
+      stream_stream):
+    self.request_streaming = request_streaming
+    self.response_streaming = response_streaming
+    self.request_deserializer = request_deserializer
+    self.response_serializer = response_serializer
+    self.unary_unary = unary_unary
+    self.unary_stream = unary_stream
+    self.stream_unary = stream_unary
+    self.stream_stream = stream_stream
+
+
+class _GenericHandler(grpc.GenericRpcHandler):
+
+  def __init__(self, handler):
+    self._handler = handler
+
+  def service(self, handler_call_details):
+    if handler_call_details.method == _UNARY_UNARY:
+      return _MethodHandler(
+          False, False, None, None, self._handler.handle_unary_unary, None,
+          None, None)
+    elif handler_call_details.method == _UNARY_STREAM:
+      return _MethodHandler(
+        False, True, _DESERIALIZE_REQUEST, _SERIALIZE_RESPONSE, None,
+        self._handler.handle_unary_stream, None, None)
+    elif handler_call_details.method == _STREAM_UNARY:
+      return _MethodHandler(
+          True, False, _DESERIALIZE_REQUEST, _SERIALIZE_RESPONSE, None, None,
+          self._handler.handle_stream_unary, None)
+    elif handler_call_details.method == _STREAM_STREAM:
+      return _MethodHandler(
+          True, True, None, None, None, None, None,
+          self._handler.handle_stream_stream)
+    else:
+      return None
+
+
+def _unary_unary_multi_callable(channel):
+  return channel.unary_unary(_UNARY_UNARY)
+
+
+def _unary_stream_multi_callable(channel):
+  return channel.unary_stream(
+      _UNARY_STREAM,
+      request_serializer=_SERIALIZE_REQUEST,
+      response_deserializer=_DESERIALIZE_RESPONSE)
+
+
+def _stream_unary_multi_callable(channel):
+  return channel.stream_unary(
+      _STREAM_UNARY,
+      request_serializer=_SERIALIZE_REQUEST,
+      response_deserializer=_DESERIALIZE_RESPONSE)
+
+
+def _stream_stream_multi_callable(channel):
+  return channel.stream_stream(_STREAM_STREAM)
+
+
+class RPCTest(unittest.TestCase):
+
+  def setUp(self):
+    self._control = test_control.PauseFailControl()
+    self._handler = _Handler(self._control)
+    self._server_pool = logging_pool.pool(test_constants.THREAD_CONCURRENCY)
+
+    self._server = grpc.server((), self._server_pool)
+    port = self._server.add_insecure_port(b'[::]:0')
+    self._server.add_generic_rpc_handlers((_GenericHandler(self._handler),))
+    self._server.start()
+
+    self._channel = grpc.insecure_channel(b'localhost:%d' % port)
+
+  # TODO(nathaniel): Why is this necessary, and only in some development
+  # environments?
+  def tearDown(self):
+    del self._channel
+    del self._server
+    del self._server_pool
+
+  def testUnrecognizedMethod(self):
+    request = b'abc'
+
+    with self.assertRaises(grpc.RpcError) as exception_context:
+      self._channel.unary_unary(b'NoSuchMethod')(request)
+
+    self.assertEqual(
+        grpc.StatusCode.UNIMPLEMENTED, exception_context.exception.code())
+
+  def testSuccessfulUnaryRequestBlockingUnaryResponse(self):
+    request = b'\x07\x08'
+    expected_response = self._handler.handle_unary_unary(request, None)
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    response = multi_callable(
+        request, metadata=(
+            (b'test', b'SuccessfulUnaryRequestBlockingUnaryResponse'),))
+
+    self.assertEqual(expected_response, response)
+
+  def testSuccessfulUnaryRequestBlockingUnaryResponseWithCall(self):
+    request = b'\x07\x08'
+    expected_response = self._handler.handle_unary_unary(request, None)
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    response, call = multi_callable(
+        request, metadata=(
+            (b'test', b'SuccessfulUnaryRequestBlockingUnaryResponseWithCall'),),
+        with_call=True)
+
+    self.assertEqual(expected_response, response)
+    self.assertIs(grpc.StatusCode.OK, call.code())
+
+  def testSuccessfulUnaryRequestFutureUnaryResponse(self):
+    request = b'\x07\x08'
+    expected_response = self._handler.handle_unary_unary(request, None)
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    response_future = multi_callable.future(
+        request, metadata=(
+            (b'test', b'SuccessfulUnaryRequestFutureUnaryResponse'),))
+    response = response_future.result()
+
+    self.assertEqual(expected_response, response)
+
+  def testSuccessfulUnaryRequestStreamResponse(self):
+    request = b'\x37\x58'
+    expected_responses = tuple(self._handler.handle_unary_stream(request, None))
+
+    multi_callable = _unary_stream_multi_callable(self._channel)
+    response_iterator = multi_callable(
+        request,
+        metadata=((b'test', b'SuccessfulUnaryRequestStreamResponse'),))
+    responses = tuple(response_iterator)
+
+    self.assertSequenceEqual(expected_responses, responses)
+
+  def testSuccessfulStreamRequestBlockingUnaryResponse(self):
+    requests = tuple(b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
+    expected_response = self._handler.handle_stream_unary(iter(requests), None)
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    response = multi_callable(
+        request_iterator,
+        metadata=((b'test', b'SuccessfulStreamRequestBlockingUnaryResponse'),))
+
+    self.assertEqual(expected_response, response)
+
+  def testSuccessfulStreamRequestBlockingUnaryResponseWithCall(self):
+    requests = tuple(b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
+    expected_response = self._handler.handle_stream_unary(iter(requests), None)
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    response, call = multi_callable(
+        request_iterator,
+        metadata=(
+            (b'test', b'SuccessfulStreamRequestBlockingUnaryResponseWithCall'),
+        ), with_call=True)
+
+    self.assertEqual(expected_response, response)
+    self.assertIs(grpc.StatusCode.OK, call.code())
+
+  def testSuccessfulStreamRequestFutureUnaryResponse(self):
+    requests = tuple(b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
+    expected_response = self._handler.handle_stream_unary(iter(requests), None)
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    response_future = multi_callable.future(
+        request_iterator,
+        metadata=(
+            (b'test', b'SuccessfulStreamRequestFutureUnaryResponse'),))
+    response = response_future.result()
+
+    self.assertEqual(expected_response, response)
+
+  def testSuccessfulStreamRequestStreamResponse(self):
+    requests = tuple(b'\x77\x58' for _ in range(test_constants.STREAM_LENGTH))
+    expected_responses = tuple(
+        self._handler.handle_stream_stream(iter(requests), None))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_stream_multi_callable(self._channel)
+    response_iterator = multi_callable(
+        request_iterator,
+        metadata=((b'test', b'SuccessfulStreamRequestStreamResponse'),))
+    responses = tuple(response_iterator)
+
+    self.assertSequenceEqual(expected_responses, responses)
+
+  def testSequentialInvocations(self):
+    first_request = b'\x07\x08'
+    second_request = b'\x0809'
+    expected_first_response = self._handler.handle_unary_unary(
+        first_request, None)
+    expected_second_response = self._handler.handle_unary_unary(
+        second_request, None)
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    first_response = multi_callable(
+        first_request, metadata=((b'test', b'SequentialInvocations'),))
+    second_response = multi_callable(
+        second_request, metadata=((b'test', b'SequentialInvocations'),))
+
+    self.assertEqual(expected_first_response, first_response)
+    self.assertEqual(expected_second_response, second_response)
+
+  def testConcurrentBlockingInvocations(self):
+    pool = logging_pool.pool(test_constants.THREAD_CONCURRENCY)
+    requests = tuple(b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
+    expected_response = self._handler.handle_stream_unary(iter(requests), None)
+    expected_responses = [expected_response] * test_constants.THREAD_CONCURRENCY
+    response_futures = [None] * test_constants.THREAD_CONCURRENCY
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    for index in range(test_constants.THREAD_CONCURRENCY):
+      request_iterator = iter(requests)
+      response_future = pool.submit(
+          multi_callable, request_iterator,
+          metadata=((b'test', b'ConcurrentBlockingInvocations'),))
+      response_futures[index] = response_future
+    responses = tuple(
+        response_future.result() for response_future in response_futures)
+
+    pool.shutdown(wait=True)
+    self.assertSequenceEqual(expected_responses, responses)
+
+  def testConcurrentFutureInvocations(self):
+    requests = tuple(b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
+    expected_response = self._handler.handle_stream_unary(iter(requests), None)
+    expected_responses = [expected_response] * test_constants.THREAD_CONCURRENCY
+    response_futures = [None] * test_constants.THREAD_CONCURRENCY
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    for index in range(test_constants.THREAD_CONCURRENCY):
+      request_iterator = iter(requests)
+      response_future = multi_callable.future(
+          request_iterator,
+          metadata=((b'test', b'ConcurrentFutureInvocations'),))
+      response_futures[index] = response_future
+    responses = tuple(
+        response_future.result() for response_future in response_futures)
+
+    self.assertSequenceEqual(expected_responses, responses)
+
+  def testWaitingForSomeButNotAllConcurrentFutureInvocations(self):
+    pool = logging_pool.pool(test_constants.THREAD_CONCURRENCY)
+    request = b'\x67\x68'
+    expected_response = self._handler.handle_unary_unary(request, None)
+    response_futures = [None] * test_constants.THREAD_CONCURRENCY
+    lock = threading.Lock()
+    test_is_running_cell = [True]
+    def wrap_future(future):
+      def wrap():
+        try:
+          return future.result()
+        except grpc.RpcError:
+          with lock:
+            if test_is_running_cell[0]:
+              raise
+          return None
+      return wrap
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    for index in range(test_constants.THREAD_CONCURRENCY):
+      inner_response_future = multi_callable.future(
+          request,
+          metadata=(
+              (b'test',
+               b'WaitingForSomeButNotAllConcurrentFutureInvocations'),))
+      outer_response_future = pool.submit(wrap_future(inner_response_future))
+      response_futures[index] = outer_response_future
+
+    some_completed_response_futures_iterator = itertools.islice(
+        futures.as_completed(response_futures),
+        test_constants.THREAD_CONCURRENCY // 2)
+    for response_future in some_completed_response_futures_iterator:
+      self.assertEqual(expected_response, response_future.result())
+    with lock:
+      test_is_running_cell[0] = False
+
+  def testConsumingOneStreamResponseUnaryRequest(self):
+    request = b'\x57\x38'
+
+    multi_callable = _unary_stream_multi_callable(self._channel)
+    response_iterator = multi_callable(
+        request,
+        metadata=(
+            (b'test', b'ConsumingOneStreamResponseUnaryRequest'),))
+    next(response_iterator)
+
+  def testConsumingSomeButNotAllStreamResponsesUnaryRequest(self):
+    request = b'\x57\x38'
+
+    multi_callable = _unary_stream_multi_callable(self._channel)
+    response_iterator = multi_callable(
+        request,
+        metadata=(
+            (b'test', b'ConsumingSomeButNotAllStreamResponsesUnaryRequest'),))
+    for _ in range(test_constants.STREAM_LENGTH // 2):
+      next(response_iterator)
+
+  def testConsumingSomeButNotAllStreamResponsesStreamRequest(self):
+    requests = tuple(b'\x67\x88' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_stream_multi_callable(self._channel)
+    response_iterator = multi_callable(
+        request_iterator,
+        metadata=(
+            (b'test', b'ConsumingSomeButNotAllStreamResponsesStreamRequest'),))
+    for _ in range(test_constants.STREAM_LENGTH // 2):
+      next(response_iterator)
+
+  def testConsumingTooManyStreamResponsesStreamRequest(self):
+    requests = tuple(b'\x67\x88' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_stream_multi_callable(self._channel)
+    response_iterator = multi_callable(
+        request_iterator,
+        metadata=(
+            (b'test', b'ConsumingTooManyStreamResponsesStreamRequest'),))
+    for _ in range(test_constants.STREAM_LENGTH):
+      next(response_iterator)
+    for _ in range(test_constants.STREAM_LENGTH):
+      with self.assertRaises(StopIteration):
+        next(response_iterator)
+
+    self.assertIsNotNone(response_iterator.initial_metadata())
+    self.assertIs(grpc.StatusCode.OK, response_iterator.code())
+    self.assertIsNotNone(response_iterator.details())
+    self.assertIsNotNone(response_iterator.trailing_metadata())
+
+  def testCancelledUnaryRequestUnaryResponse(self):
+    request = b'\x07\x17'
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    with self._control.pause():
+      response_future = multi_callable.future(
+          request,
+          metadata=((b'test', b'CancelledUnaryRequestUnaryResponse'),))
+      response_future.cancel()
+
+    self.assertTrue(response_future.cancelled())
+    with self.assertRaises(grpc.FutureCancelledError):
+      response_future.result()
+    self.assertIs(grpc.StatusCode.CANCELLED, response_future.code())
+
+  def testCancelledUnaryRequestStreamResponse(self):
+    request = b'\x07\x19'
+
+    multi_callable = _unary_stream_multi_callable(self._channel)
+    with self._control.pause():
+      response_iterator = multi_callable(
+          request,
+          metadata=((b'test', b'CancelledUnaryRequestStreamResponse'),))
+      self._control.block_until_paused()
+      response_iterator.cancel()
+
+    with self.assertRaises(grpc.RpcError) as exception_context:
+      next(response_iterator)
+    self.assertIs(grpc.StatusCode.CANCELLED, exception_context.exception.code())
+    self.assertIsNotNone(response_iterator.initial_metadata())
+    self.assertIs(grpc.StatusCode.CANCELLED, response_iterator.code())
+    self.assertIsNotNone(response_iterator.details())
+    self.assertIsNotNone(response_iterator.trailing_metadata())
+
+  def testCancelledStreamRequestUnaryResponse(self):
+    requests = tuple(b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    with self._control.pause():
+      response_future = multi_callable.future(
+          request_iterator,
+          metadata=((b'test', b'CancelledStreamRequestUnaryResponse'),))
+      self._control.block_until_paused()
+      response_future.cancel()
+
+    self.assertTrue(response_future.cancelled())
+    with self.assertRaises(grpc.FutureCancelledError):
+      response_future.result()
+    self.assertIsNotNone(response_future.initial_metadata())
+    self.assertIs(grpc.StatusCode.CANCELLED, response_future.code())
+    self.assertIsNotNone(response_future.details())
+    self.assertIsNotNone(response_future.trailing_metadata())
+
+  def testCancelledStreamRequestStreamResponse(self):
+    requests = tuple(b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_stream_multi_callable(self._channel)
+    with self._control.pause():
+      response_iterator = multi_callable(
+          request_iterator,
+          metadata=((b'test', b'CancelledStreamRequestStreamResponse'),))
+      response_iterator.cancel()
+
+    with self.assertRaises(grpc.RpcError):
+      next(response_iterator)
+    self.assertIsNotNone(response_iterator.initial_metadata())
+    self.assertIs(grpc.StatusCode.CANCELLED, response_iterator.code())
+    self.assertIsNotNone(response_iterator.details())
+    self.assertIsNotNone(response_iterator.trailing_metadata())
+
+  def testExpiredUnaryRequestBlockingUnaryResponse(self):
+    request = b'\x07\x17'
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    with self._control.pause():
+      with self.assertRaises(grpc.RpcError) as exception_context:
+        multi_callable(
+            request, timeout=test_constants.SHORT_TIMEOUT,
+            metadata=((b'test', b'ExpiredUnaryRequestBlockingUnaryResponse'),),
+            with_call=True)
+
+    self.assertIsNotNone(exception_context.exception.initial_metadata())
+    self.assertIs(
+        grpc.StatusCode.DEADLINE_EXCEEDED, exception_context.exception.code())
+    self.assertIsNotNone(exception_context.exception.details())
+    self.assertIsNotNone(exception_context.exception.trailing_metadata())
+
+  def testExpiredUnaryRequestFutureUnaryResponse(self):
+    request = b'\x07\x17'
+    callback = _Callback()
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    with self._control.pause():
+      response_future = multi_callable.future(
+          request, timeout=test_constants.SHORT_TIMEOUT,
+          metadata=((b'test', b'ExpiredUnaryRequestFutureUnaryResponse'),))
+      response_future.add_done_callback(callback)
+      value_passed_to_callback = callback.value()
+
+    self.assertIs(response_future, value_passed_to_callback)
+    self.assertIsNotNone(response_future.initial_metadata())
+    self.assertIs(grpc.StatusCode.DEADLINE_EXCEEDED, response_future.code())
+    self.assertIsNotNone(response_future.details())
+    self.assertIsNotNone(response_future.trailing_metadata())
+    with self.assertRaises(grpc.RpcError) as exception_context:
+      response_future.result()
+    self.assertIs(
+        grpc.StatusCode.DEADLINE_EXCEEDED, exception_context.exception.code())
+    self.assertIsInstance(response_future.exception(), grpc.RpcError)
+    self.assertIs(
+        grpc.StatusCode.DEADLINE_EXCEEDED, response_future.exception().code())
+
+  def testExpiredUnaryRequestStreamResponse(self):
+    request = b'\x07\x19'
+
+    multi_callable = _unary_stream_multi_callable(self._channel)
+    with self._control.pause():
+      with self.assertRaises(grpc.RpcError) as exception_context:
+        response_iterator = multi_callable(
+            request, timeout=test_constants.SHORT_TIMEOUT,
+            metadata=((b'test', b'ExpiredUnaryRequestStreamResponse'),))
+        next(response_iterator)
+
+    self.assertIs(
+        grpc.StatusCode.DEADLINE_EXCEEDED, exception_context.exception.code())
+    self.assertIs(grpc.StatusCode.DEADLINE_EXCEEDED, response_iterator.code())
+
+  def testExpiredStreamRequestBlockingUnaryResponse(self):
+    requests = tuple(b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    with self._control.pause():
+      with self.assertRaises(grpc.RpcError) as exception_context:
+        multi_callable(
+            request_iterator, timeout=test_constants.SHORT_TIMEOUT,
+            metadata=((b'test', b'ExpiredStreamRequestBlockingUnaryResponse'),))
+
+    self.assertIsNotNone(exception_context.exception.initial_metadata())
+    self.assertIs(
+        grpc.StatusCode.DEADLINE_EXCEEDED, exception_context.exception.code())
+    self.assertIsNotNone(exception_context.exception.details())
+    self.assertIsNotNone(exception_context.exception.trailing_metadata())
+
+  def testExpiredStreamRequestFutureUnaryResponse(self):
+    requests = tuple(b'\x07\x18' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+    callback = _Callback()
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    with self._control.pause():
+      response_future = multi_callable.future(
+          request_iterator, timeout=test_constants.SHORT_TIMEOUT,
+          metadata=((b'test', b'ExpiredStreamRequestFutureUnaryResponse'),))
+      response_future.add_done_callback(callback)
+      value_passed_to_callback = callback.value()
+
+    with self.assertRaises(grpc.RpcError) as exception_context:
+      response_future.result()
+    self.assertIs(grpc.StatusCode.DEADLINE_EXCEEDED, response_future.code())
+    self.assertIs(
+        grpc.StatusCode.DEADLINE_EXCEEDED, exception_context.exception.code())
+    self.assertIsInstance(response_future.exception(), grpc.RpcError)
+    self.assertIs(response_future, value_passed_to_callback)
+    self.assertIsNotNone(response_future.initial_metadata())
+    self.assertIs(grpc.StatusCode.DEADLINE_EXCEEDED, response_future.code())
+    self.assertIsNotNone(response_future.details())
+    self.assertIsNotNone(response_future.trailing_metadata())
+
+  def testExpiredStreamRequestStreamResponse(self):
+    requests = tuple(b'\x67\x18' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_stream_multi_callable(self._channel)
+    with self._control.pause():
+      with self.assertRaises(grpc.RpcError) as exception_context:
+        response_iterator = multi_callable(
+            request_iterator, timeout=test_constants.SHORT_TIMEOUT,
+            metadata=((b'test', b'ExpiredStreamRequestStreamResponse'),))
+        next(response_iterator)
+
+    self.assertIs(
+        grpc.StatusCode.DEADLINE_EXCEEDED, exception_context.exception.code())
+    self.assertIs(grpc.StatusCode.DEADLINE_EXCEEDED, response_iterator.code())
+
+  def testFailedUnaryRequestBlockingUnaryResponse(self):
+    request = b'\x37\x17'
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    with self._control.fail():
+      with self.assertRaises(grpc.RpcError) as exception_context:
+        multi_callable(
+            request,
+            metadata=((b'test', b'FailedUnaryRequestBlockingUnaryResponse'),),
+            with_call=True)
+
+    self.assertIs(grpc.StatusCode.UNKNOWN, exception_context.exception.code())
+
+  def testFailedUnaryRequestFutureUnaryResponse(self):
+    request = b'\x37\x17'
+    callback = _Callback()
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    with self._control.fail():
+      response_future = multi_callable.future(
+          request,
+          metadata=((b'test', b'FailedUnaryRequestFutureUnaryResponse'),))
+      response_future.add_done_callback(callback)
+      value_passed_to_callback = callback.value()
+
+    with self.assertRaises(grpc.RpcError) as exception_context:
+      response_future.result()
+    self.assertIs(
+        grpc.StatusCode.UNKNOWN, exception_context.exception.code())
+    self.assertIsInstance(response_future.exception(), grpc.RpcError)
+    self.assertIs(grpc.StatusCode.UNKNOWN, response_future.exception().code())
+    self.assertIs(response_future, value_passed_to_callback)
+
+  def testFailedUnaryRequestStreamResponse(self):
+    request = b'\x37\x17'
+
+    multi_callable = _unary_stream_multi_callable(self._channel)
+    with self.assertRaises(grpc.RpcError) as exception_context:
+      with self._control.fail():
+        response_iterator = multi_callable(
+            request,
+            metadata=((b'test', b'FailedUnaryRequestStreamResponse'),))
+        next(response_iterator)
+
+    self.assertIs(grpc.StatusCode.UNKNOWN, exception_context.exception.code())
+
+  def testFailedStreamRequestBlockingUnaryResponse(self):
+    requests = tuple(b'\x47\x58' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    with self._control.fail():
+      with self.assertRaises(grpc.RpcError) as exception_context:
+        multi_callable(
+            request_iterator,
+            metadata=((b'test', b'FailedStreamRequestBlockingUnaryResponse'),))
+
+    self.assertIs(grpc.StatusCode.UNKNOWN, exception_context.exception.code())
+
+  def testFailedStreamRequestFutureUnaryResponse(self):
+    requests = tuple(b'\x07\x18' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+    callback = _Callback()
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    with self._control.fail():
+      response_future = multi_callable.future(
+          request_iterator,
+          metadata=((b'test', b'FailedStreamRequestFutureUnaryResponse'),))
+      response_future.add_done_callback(callback)
+      value_passed_to_callback = callback.value()
+
+    with self.assertRaises(grpc.RpcError) as exception_context:
+      response_future.result()
+    self.assertIs(grpc.StatusCode.UNKNOWN, response_future.code())
+    self.assertIs(
+        grpc.StatusCode.UNKNOWN, exception_context.exception.code())
+    self.assertIsInstance(response_future.exception(), grpc.RpcError)
+    self.assertIs(response_future, value_passed_to_callback)
+
+  def testFailedStreamRequestStreamResponse(self):
+    requests = tuple(b'\x67\x88' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_stream_multi_callable(self._channel)
+    with self._control.fail():
+      with self.assertRaises(grpc.RpcError) as exception_context:
+        response_iterator = multi_callable(
+            request_iterator,
+            metadata=((b'test', b'FailedStreamRequestStreamResponse'),))
+        tuple(response_iterator)
+
+    self.assertIs(grpc.StatusCode.UNKNOWN, exception_context.exception.code())
+    self.assertIs(grpc.StatusCode.UNKNOWN, response_iterator.code())
+
+  def testIgnoredUnaryRequestFutureUnaryResponse(self):
+    request = b'\x37\x17'
+
+    multi_callable = _unary_unary_multi_callable(self._channel)
+    multi_callable.future(
+        request,
+        metadata=((b'test', b'IgnoredUnaryRequestFutureUnaryResponse'),))
+
+  def testIgnoredUnaryRequestStreamResponse(self):
+    request = b'\x37\x17'
+
+    multi_callable = _unary_stream_multi_callable(self._channel)
+    multi_callable(
+        request,
+        metadata=((b'test', b'IgnoredUnaryRequestStreamResponse'),))
+
+  def testIgnoredStreamRequestFutureUnaryResponse(self):
+    requests = tuple(b'\x07\x18' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_unary_multi_callable(self._channel)
+    multi_callable.future(
+        request_iterator,
+        metadata=((b'test', b'IgnoredStreamRequestFutureUnaryResponse'),))
+
+  def testIgnoredStreamRequestStreamResponse(self):
+    requests = tuple(b'\x67\x88' for _ in range(test_constants.STREAM_LENGTH))
+    request_iterator = iter(requests)
+
+    multi_callable = _stream_stream_multi_callable(self._channel)
+    multi_callable(
+        request_iterator,
+        metadata=((b'test', b'IgnoredStreamRequestStreamResponse'),))
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
diff --git a/src/python/grpcio/tests/unit/beta/_implementations_test.py b/src/python/grpcio/tests/unit/beta/_implementations_test.py
index 26be670c45..127f93e9bb 100644
--- a/src/python/grpcio/tests/unit/beta/_implementations_test.py
+++ b/src/python/grpcio/tests/unit/beta/_implementations_test.py
@@ -29,8 +29,11 @@
 
 """Tests the implementations module of the gRPC Python Beta API."""
 
+import datetime
 import unittest
 
+from oauth2client import client as oauth2client_client
+
 from grpc.beta import implementations
 from tests.unit import resources
 
@@ -49,5 +52,19 @@ class ChannelCredentialsTest(unittest.TestCase):
         channel_credentials, implementations.ChannelCredentials)
 
 
+class CallCredentialsTest(unittest.TestCase):
+
+  def test_google_call_credentials(self):
+    creds = oauth2client_client.GoogleCredentials(
+        'token', 'client_id', 'secret', 'refresh_token',
+        datetime.datetime(2008, 6, 24), 'https://refresh.uri.com/',
+        'user_agent')
+    call_creds = implementations.google_call_credentials(creds)
+    self.assertIsInstance(call_creds, implementations.CallCredentials)
+
+  def test_access_token_call_credentials(self):
+    call_creds = implementations.access_token_call_credentials('token')
+    self.assertIsInstance(call_creds, implementations.CallCredentials)
+
 if __name__ == '__main__':
   unittest.main(verbosity=2)
diff --git a/src/python/grpcio/tests/unit/beta/test_utilities.py b/src/python/grpcio/tests/unit/beta/test_utilities.py
index 0313e06a93..66b5f72897 100644
--- a/src/python/grpcio/tests/unit/beta/test_utilities.py
+++ b/src/python/grpcio/tests/unit/beta/test_utilities.py
@@ -29,7 +29,7 @@
 
 """Test-appropriate entry points into the gRPC Python Beta API."""
 
-from grpc._adapter import _intermediary_low
+import grpc
 from grpc.beta import implementations
 
 
@@ -48,9 +48,8 @@ def not_really_secure_channel(
     An implementations.Channel to the remote host through which RPCs may be
       conducted.
   """
-  hostport = '%s:%d' % (host, port)
-  intermediary_low_channel = _intermediary_low.Channel(
-      hostport, channel_credentials._low_credentials,
-      server_host_override=server_host_override)
-  return implementations.Channel(
-      intermediary_low_channel._internal, intermediary_low_channel)
+  target = '%s:%d' % (host, port)
+  channel = grpc.secure_channel(
+      target, ((b'grpc.ssl_target_name_override', server_host_override,),),
+      channel_credentials._credentials)
+  return implementations.Channel(channel)
diff --git a/src/ruby/bin/math_services.rb b/src/ruby/bin/math_services.rb
index 2d482129c2..34c36abdda 100755
--- a/src/ruby/bin/math_services.rb
+++ b/src/ruby/bin/math_services.rb
@@ -1,13 +1,41 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # Source: math.proto for package 'math'
+# Original file comments:
+# 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.
+#
 
 require 'grpc'
 require 'math'
 
 module Math
   module Math
-
-    # TODO: add proto service documentation here
     class Service
 
       include GRPC::GenericService
@@ -16,9 +44,20 @@ module Math
       self.unmarshal_class_method = :decode
       self.service_name = 'math.Math'
 
+      # Div divides args.dividend by args.divisor and returns the quotient and
+      # remainder.
       rpc :Div, DivArgs, DivReply
+      # DivMany accepts an arbitrary number of division args from the client stream
+      # and sends back the results in the reply stream.  The stream continues until
+      # the client closes its end; the server does the same after sending all the
+      # replies.  The stream ends immediately if either end aborts.
       rpc :DivMany, stream(DivArgs), stream(DivReply)
+      # Fib generates numbers in the Fibonacci sequence.  If args.limit > 0, Fib
+      # generates up to limit numbers; otherwise it continues until the call is
+      # canceled.  Unlike Fib above, Fib has no final FibReply.
       rpc :Fib, FibArgs, stream(Num)
+      # Sum sums a stream of numbers, returning the final result once the stream
+      # is closed.
       rpc :Sum, stream(Num), Num
     end
 
diff --git a/src/ruby/ext/grpc/rb_call.c b/src/ruby/ext/grpc/rb_call.c
index 1b06273af9..b436057c16 100644
--- a/src/ruby/ext/grpc/rb_call.c
+++ b/src/ruby/ext/grpc/rb_call.c
@@ -101,30 +101,14 @@ static VALUE sym_message;
 static VALUE sym_status;
 static VALUE sym_cancelled;
 
-/* hash_all_calls is a hash of Call address -> reference count that is used to
- * track the creation and destruction of rb_call instances.
- */
-static VALUE hash_all_calls;
-
 /* Destroys a Call. */
 static void grpc_rb_call_destroy(void *p) {
-  grpc_call *call = NULL;
-  VALUE ref_count = Qnil;
+  grpc_call* call = NULL;
   if (p == NULL) {
     return;
-  };
-  call = (grpc_call *)p;
-
-  ref_count = rb_hash_aref(hash_all_calls, OFFT2NUM((VALUE)call));
-  if (ref_count == Qnil) {
-    return; /* No longer in the hash, so already deleted */
-  } else if (NUM2UINT(ref_count) == 1) {
-    rb_hash_delete(hash_all_calls, OFFT2NUM((VALUE)call));
-    grpc_call_destroy(call);
-  } else {
-    rb_hash_aset(hash_all_calls, OFFT2NUM((VALUE)call),
-                 UINT2NUM(NUM2UINT(ref_count) - 1));
   }
+  call = (grpc_call *)p;
+  grpc_call_destroy(call);
 }
 
 static size_t md_ary_datasize(const void *p) {
@@ -151,7 +135,7 @@ static const rb_data_type_t grpc_rb_md_ary_data_type = {
      * touches a hash object.
      * TODO(yugui) Directly use st_table and call the free function earlier?
      */
-    0,
+     0,
 #endif
 };
 
@@ -163,12 +147,7 @@ static const rb_data_type_t grpc_call_data_type = {
     NULL,
     NULL,
 #ifdef RUBY_TYPED_FREE_IMMEDIATELY
-    /* it is unsafe to specify RUBY_TYPED_FREE_IMMEDIATELY because
-     * grpc_rb_call_destroy
-     * touches a hash object.
-     * TODO(yugui) Directly use st_table and call the free function earlier?
-     */
-    0,
+    RUBY_TYPED_FREE_IMMEDIATELY
 #endif
 };
 
@@ -190,6 +169,11 @@ const char *grpc_call_error_detail_of(grpc_call_error err) {
 static VALUE grpc_rb_call_cancel(VALUE self) {
   grpc_call *call = NULL;
   grpc_call_error err;
+  if (RTYPEDDATA_DATA(self) == NULL) {
+    //This call has been closed
+    return Qnil;
+  }
+
   TypedData_Get_Struct(self, grpc_call, &grpc_call_data_type, call);
   err = grpc_call_cancel(call, NULL);
   if (err != GRPC_CALL_OK) {
@@ -200,11 +184,29 @@ static VALUE grpc_rb_call_cancel(VALUE self) {
   return Qnil;
 }
 
+/* Releases the c-level resources associated with a call
+   Once a call has been closed, no further requests can be
+   processed.
+*/
+static VALUE grpc_rb_call_close(VALUE self) {
+  grpc_call *call = NULL;
+  TypedData_Get_Struct(self, grpc_call, &grpc_call_data_type, call);
+  if(call != NULL) {
+    grpc_call_destroy(call);
+    RTYPEDDATA_DATA(self) = NULL;
+  }
+  return Qnil;
+}
+
 /* Called to obtain the peer that this call is connected to. */
 static VALUE grpc_rb_call_get_peer(VALUE self) {
   VALUE res = Qnil;
   grpc_call *call = NULL;
   char *peer = NULL;
+  if (RTYPEDDATA_DATA(self) == NULL) {
+    rb_raise(grpc_rb_eCallError, "Cannot get peer value on closed call");
+    return Qnil;
+  }
   TypedData_Get_Struct(self, grpc_call, &grpc_call_data_type, call);
   peer = grpc_call_get_peer(call);
   res = rb_str_new2(peer);
@@ -218,6 +220,10 @@ static VALUE grpc_rb_call_get_peer_cert(VALUE self) {
   grpc_call *call = NULL;
   VALUE res = Qnil;
   grpc_auth_context *ctx = NULL;
+  if (RTYPEDDATA_DATA(self) == NULL) {
+    rb_raise(grpc_rb_eCallError, "Cannot get peer cert on closed call");
+    return Qnil;
+  }
   TypedData_Get_Struct(self, grpc_call, &grpc_call_data_type, call);
 
   ctx = grpc_call_auth_context(call);
@@ -323,6 +329,10 @@ static VALUE grpc_rb_call_set_credentials(VALUE self, VALUE credentials) {
   grpc_call *call = NULL;
   grpc_call_credentials *creds;
   grpc_call_error err;
+  if (RTYPEDDATA_DATA(self) == NULL) {
+    rb_raise(grpc_rb_eCallError, "Cannot set credentials of closed call");
+    return Qnil;
+  }
   TypedData_Get_Struct(self, grpc_call, &grpc_call_data_type, call);
   creds = grpc_rb_get_wrapped_call_credentials(credentials);
   err = grpc_call_set_credentials(call, creds);
@@ -731,7 +741,7 @@ static VALUE grpc_run_batch_stack_build_result(run_batch_stack *st) {
    }
    tag = Object.new
    timeout = 10
-   call.start_batch(cqueue, tag, timeout, ops)
+   call.start_batch(cq, tag, timeout, ops)
 
    Start a batch of operations defined in the array ops; when complete, post a
    completion of type 'tag' to the completion queue bound to the call.
@@ -749,6 +759,10 @@ static VALUE grpc_rb_call_run_batch(VALUE self, VALUE cqueue, VALUE tag,
   VALUE result = Qnil;
   VALUE rb_write_flag = rb_ivar_get(self, id_write_flag);
   unsigned write_flag = 0;
+  if (RTYPEDDATA_DATA(self) == NULL) {
+    rb_raise(grpc_rb_eCallError, "Cannot run batch on closed call");
+    return Qnil;
+  }
   TypedData_Get_Struct(self, grpc_call, &grpc_call_data_type, call);
 
   /* Validate the ops args, adding them to a ruby array */
@@ -888,6 +902,7 @@ void Init_grpc_call() {
   /* Add ruby analogues of the Call methods. */
   rb_define_method(grpc_rb_cCall, "run_batch", grpc_rb_call_run_batch, 4);
   rb_define_method(grpc_rb_cCall, "cancel", grpc_rb_call_cancel, 0);
+  rb_define_method(grpc_rb_cCall, "close", grpc_rb_call_close, 0);
   rb_define_method(grpc_rb_cCall, "peer", grpc_rb_call_get_peer, 0);
   rb_define_method(grpc_rb_cCall, "peer_cert", grpc_rb_call_get_peer_cert, 0);
   rb_define_method(grpc_rb_cCall, "status", grpc_rb_call_get_status, 0);
@@ -925,11 +940,6 @@ void Init_grpc_call() {
       "BatchResult", "send_message", "send_metadata", "send_close",
       "send_status", "message", "metadata", "status", "cancelled", NULL);
 
-  /* The hash for reference counting calls, to ensure they can't be destroyed
-   * more than once */
-  hash_all_calls = rb_hash_new();
-  rb_define_const(grpc_rb_cCall, "INTERNAL_ALL_CALLs", hash_all_calls);
-
   Init_grpc_error_codes();
   Init_grpc_op_codes();
   Init_grpc_write_flags();
@@ -944,16 +954,8 @@ grpc_call *grpc_rb_get_wrapped_call(VALUE v) {
 
 /* Obtains the wrapped object for a given call */
 VALUE grpc_rb_wrap_call(grpc_call *c) {
-  VALUE obj = Qnil;
   if (c == NULL) {
     return Qnil;
   }
-  obj = rb_hash_aref(hash_all_calls, OFFT2NUM((VALUE)c));
-  if (obj == Qnil) { /* Not in the hash add it */
-    rb_hash_aset(hash_all_calls, OFFT2NUM((VALUE)c), UINT2NUM(1));
-  } else {
-    rb_hash_aset(hash_all_calls, OFFT2NUM((VALUE)c),
-                 UINT2NUM(NUM2UINT(obj) + 1));
-  }
   return TypedData_Wrap_Struct(grpc_rb_cCall, &grpc_call_data_type, c);
 }
diff --git a/src/ruby/ext/grpc/rb_channel.c b/src/ruby/ext/grpc/rb_channel.c
index 013321ffc8..6943c93d4a 100644
--- a/src/ruby/ext/grpc/rb_channel.c
+++ b/src/ruby/ext/grpc/rb_channel.c
@@ -373,7 +373,7 @@ static void Init_grpc_connectivity_states() {
   rb_define_const(grpc_rb_mConnectivityStates, "TRANSIENT_FAILURE",
                   LONG2NUM(GRPC_CHANNEL_TRANSIENT_FAILURE));
   rb_define_const(grpc_rb_mConnectivityStates, "FATAL_FAILURE",
-                  LONG2NUM(GRPC_CHANNEL_FATAL_FAILURE));
+                  LONG2NUM(GRPC_CHANNEL_SHUTDOWN));
 }
 
 void Init_grpc_channel() {
diff --git a/src/ruby/ext/grpc/rb_completion_queue.c b/src/ruby/ext/grpc/rb_completion_queue.c
index b6ddbe88dc..9466402db0 100644
--- a/src/ruby/ext/grpc/rb_completion_queue.c
+++ b/src/ruby/ext/grpc/rb_completion_queue.c
@@ -150,6 +150,14 @@ static rb_data_type_t grpc_rb_completion_queue_data_type = {
 #endif
 };
 
+/* Releases the c-level resources associated with a completion queue */
+static VALUE grpc_rb_completion_queue_close(VALUE self) {
+  grpc_completion_queue* cq = grpc_rb_get_wrapped_completion_queue(self);
+  grpc_rb_completion_queue_destroy(cq);
+  RTYPEDDATA_DATA(self) = NULL;
+  return Qnil;
+}
+
 /* Allocates a completion queue. */
 static VALUE grpc_rb_completion_queue_alloc(VALUE cls) {
   grpc_completion_queue *cq = grpc_completion_queue_create(NULL);
@@ -212,6 +220,11 @@ void Init_grpc_completion_queue() {
      this func, so no separate initialization step is necessary. */
   rb_define_alloc_func(grpc_rb_cCompletionQueue,
                        grpc_rb_completion_queue_alloc);
+
+  /* close: Provides a way to close the underlying file descriptor without
+     waiting for ruby garbage collection. */
+  rb_define_method(grpc_rb_cCompletionQueue, "close",
+                   grpc_rb_completion_queue_close, 0);
 }
 
 /* Gets the wrapped completion queue from the ruby wrapper */
diff --git a/src/ruby/ext/grpc/rb_grpc.c b/src/ruby/ext/grpc/rb_grpc.c
index 06a07ac646..9246893f9f 100644
--- a/src/ruby/ext/grpc/rb_grpc.c
+++ b/src/ruby/ext/grpc/rb_grpc.c
@@ -318,7 +318,7 @@ void Init_grpc_c() {
   grpc_rb_mGrpcCore = rb_define_module_under(grpc_rb_mGRPC, "Core");
   grpc_rb_sNewServerRpc =
       rb_struct_define("NewServerRpc", "method", "host",
-                       "deadline", "metadata", "call", NULL);
+                       "deadline", "metadata", "call", "cq", NULL);
   grpc_rb_sStatus =
       rb_struct_define("Status", "code", "details", "metadata", NULL);
   sym_code = ID2SYM(rb_intern("code"));
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.c b/src/ruby/ext/grpc/rb_grpc_imports.generated.c
index 3b62984def..f76462649d 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.c
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.c
@@ -33,7 +33,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 #include "rb_grpc_imports.generated.h"
 
@@ -126,7 +126,6 @@ grpc_header_key_is_legal_type grpc_header_key_is_legal_import;
 grpc_header_nonbin_value_is_legal_type grpc_header_nonbin_value_is_legal_import;
 grpc_is_binary_header_type grpc_is_binary_header_import;
 grpc_call_error_to_string_type grpc_call_error_to_string_import;
-grpc_cronet_secure_channel_create_type grpc_cronet_secure_channel_create_import;
 grpc_auth_property_iterator_next_type grpc_auth_property_iterator_next_import;
 grpc_auth_context_property_iterator_type grpc_auth_context_property_iterator_import;
 grpc_auth_context_peer_identity_type grpc_auth_context_peer_identity_import;
@@ -394,7 +393,6 @@ void grpc_rb_load_imports(HMODULE library) {
   grpc_header_nonbin_value_is_legal_import = (grpc_header_nonbin_value_is_legal_type) GetProcAddress(library, "grpc_header_nonbin_value_is_legal");
   grpc_is_binary_header_import = (grpc_is_binary_header_type) GetProcAddress(library, "grpc_is_binary_header");
   grpc_call_error_to_string_import = (grpc_call_error_to_string_type) GetProcAddress(library, "grpc_call_error_to_string");
-  grpc_cronet_secure_channel_create_import = (grpc_cronet_secure_channel_create_type) GetProcAddress(library, "grpc_cronet_secure_channel_create");
   grpc_auth_property_iterator_next_import = (grpc_auth_property_iterator_next_type) GetProcAddress(library, "grpc_auth_property_iterator_next");
   grpc_auth_context_property_iterator_import = (grpc_auth_context_property_iterator_type) GetProcAddress(library, "grpc_auth_context_property_iterator");
   grpc_auth_context_peer_identity_import = (grpc_auth_context_peer_identity_type) GetProcAddress(library, "grpc_auth_context_peer_identity");
@@ -573,4 +571,4 @@ void grpc_rb_load_imports(HMODULE library) {
   gpr_thd_join_import = (gpr_thd_join_type) GetProcAddress(library, "gpr_thd_join");
 }
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.h b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
index 1428e6d71c..5d690a915d 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.h
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
@@ -36,14 +36,13 @@
 
 #include <grpc/support/port_platform.h>
 
-#ifdef GPR_WIN32
+#ifdef GPR_WINDOWS
 
 #include <windows.h>
 
 #include <grpc/census.h>
 #include <grpc/compression.h>
 #include <grpc/grpc.h>
-#include <grpc/grpc_cronet.h>
 #include <grpc/grpc_security.h>
 #include <grpc/impl/codegen/alloc.h>
 #include <grpc/impl/codegen/byte_buffer.h>
@@ -57,7 +56,7 @@
 #include <grpc/support/cpu.h>
 #include <grpc/support/histogram.h>
 #include <grpc/support/host_port.h>
-#include <grpc/support/log_win32.h>
+#include <grpc/support/log_windows.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/subprocess.h>
 #include <grpc/support/thd.h>
@@ -329,9 +328,6 @@ extern grpc_is_binary_header_type grpc_is_binary_header_import;
 typedef const char *(*grpc_call_error_to_string_type)(grpc_call_error error);
 extern grpc_call_error_to_string_type grpc_call_error_to_string_import;
 #define grpc_call_error_to_string grpc_call_error_to_string_import
-typedef grpc_channel *(*grpc_cronet_secure_channel_create_type)(void *engine, const char *target, const grpc_channel_args *args, void *reserved);
-extern grpc_cronet_secure_channel_create_type grpc_cronet_secure_channel_create_import;
-#define grpc_cronet_secure_channel_create grpc_cronet_secure_channel_create_import
 typedef const grpc_auth_property *(*grpc_auth_property_iterator_next_type)(grpc_auth_property_iterator *it);
 extern grpc_auth_property_iterator_next_type grpc_auth_property_iterator_next_import;
 #define grpc_auth_property_iterator_next grpc_auth_property_iterator_next_import
@@ -863,6 +859,6 @@ extern gpr_thd_join_type gpr_thd_join_import;
 
 void grpc_rb_load_imports(HMODULE library);
 
-#endif /* GPR_WIN32 */
+#endif /* GPR_WINDOWS */
 
 #endif
diff --git a/src/ruby/ext/grpc/rb_loader.c b/src/ruby/ext/grpc/rb_loader.c
index 242535f164..19a6b33c29 100644
--- a/src/ruby/ext/grpc/rb_loader.c
+++ b/src/ruby/ext/grpc/rb_loader.c
@@ -33,7 +33,7 @@
 
 #include "rb_grpc_imports.generated.h"
 
-#if GPR_WIN32
+#if GPR_WINDOWS
 #include <tchar.h>
 
 int grpc_rb_load_core() {
diff --git a/src/ruby/ext/grpc/rb_server.c b/src/ruby/ext/grpc/rb_server.c
index 0899feb685..f108b8acfc 100644
--- a/src/ruby/ext/grpc/rb_server.c
+++ b/src/ruby/ext/grpc/rb_server.c
@@ -234,7 +234,7 @@ static VALUE grpc_rb_server_request_call(VALUE self, VALUE cqueue,
     err = grpc_server_request_call(
         s->wrapped, &call, &st.details, &st.md_ary,
         grpc_rb_get_wrapped_completion_queue(cqueue),
-        grpc_rb_get_wrapped_completion_queue(cqueue),
+        grpc_rb_get_wrapped_completion_queue(s->mark),
         ROBJECT(tag_new));
     if (err != GRPC_CALL_OK) {
       grpc_request_call_stack_cleanup(&st);
@@ -244,7 +244,7 @@ static VALUE grpc_rb_server_request_call(VALUE self, VALUE cqueue,
       return Qnil;
     }
 
-    ev = grpc_rb_completion_queue_pluck_event(cqueue, tag_new, timeout);
+    ev = grpc_rb_completion_queue_pluck_event(s->mark, tag_new, timeout);
     if (ev.type == GRPC_QUEUE_TIMEOUT) {
       grpc_request_call_stack_cleanup(&st);
       return Qnil;
@@ -262,7 +262,7 @@ static VALUE grpc_rb_server_request_call(VALUE self, VALUE cqueue,
         rb_str_new2(st.details.host),
         rb_funcall(rb_cTime, id_at, 2, INT2NUM(deadline.tv_sec),
                    INT2NUM(deadline.tv_nsec)),
-        grpc_rb_md_ary_to_h(&st.md_ary), grpc_rb_wrap_call(call), NULL);
+        grpc_rb_md_ary_to_h(&st.md_ary), grpc_rb_wrap_call(call), cqueue, NULL);
     grpc_request_call_stack_cleanup(&st);
     return result;
   }
diff --git a/src/ruby/lib/grpc/generic/active_call.rb b/src/ruby/lib/grpc/generic/active_call.rb
index e449e89176..b03ddbc193 100644
--- a/src/ruby/lib/grpc/generic/active_call.rb
+++ b/src/ruby/lib/grpc/generic/active_call.rb
@@ -103,7 +103,7 @@ module GRPC
     #
     # @param call [Call] the call used by the ActiveCall
     # @param q [CompletionQueue] the completion queue used to accept
-    #          the call
+    #          the call.  This queue will be closed on call completion.
     # @param marshal [Function] f(obj)->string that marshal requests
     # @param unmarshal [Function] f(string)->obj that unmarshals responses
     # @param deadline [Fixnum] the deadline for the call to complete
@@ -191,6 +191,8 @@ module GRPC
       @call.status = batch_result.status
       op_is_done
       batch_result.check_status
+      @call.close
+      @cq.close
     end
 
     # remote_send sends a request to the remote endpoint.
diff --git a/src/ruby/lib/grpc/generic/bidi_call.rb b/src/ruby/lib/grpc/generic/bidi_call.rb
index 1f6d5f365d..238f409a1d 100644
--- a/src/ruby/lib/grpc/generic/bidi_call.rb
+++ b/src/ruby/lib/grpc/generic/bidi_call.rb
@@ -69,6 +69,10 @@ module GRPC
       @readq = Queue.new
       @unmarshal = unmarshal
       @metadata_tag = metadata_tag
+      @reads_complete = false
+      @writes_complete = false
+      @complete = false
+      @done_mutex = Mutex.new
     end
 
     # Begins orchestration of the Bidi stream for a client sending requests.
@@ -115,6 +119,16 @@ module GRPC
       @op_notifier.notify(self)
     end
 
+    # signals that a bidi operation is complete (read + write)
+    def finished
+      @done_mutex.synchronize do
+        return unless @reads_complete && @writes_complete && !@complete
+        @call.close
+        @cq.close
+        @complete = true
+      end
+    end
+
     # performs a read using @call.run_batch, ensures metadata is set up
     def read_using_run_batch
       ops = { RECV_MESSAGE => nil }
@@ -163,12 +177,16 @@ module GRPC
                         SEND_CLOSE_FROM_CLIENT => nil)
         GRPC.logger.debug('bidi-write-loop: done')
         notify_done
+        @writes_complete = true
+        finished
       end
       GRPC.logger.debug('bidi-write-loop: finished')
     rescue StandardError => e
       GRPC.logger.warn('bidi-write-loop: failed')
       GRPC.logger.warn(e)
       notify_done
+      @writes_complete = true
+      finished
       raise e
     end
 
@@ -212,6 +230,8 @@ module GRPC
           @readq.push(e)  # let each_queued_msg terminate with this error
         end
         GRPC.logger.debug('bidi-read-loop: finished')
+        @reads_complete = true
+        finished
       end
     end
   end
diff --git a/src/ruby/lib/grpc/generic/rpc_server.rb b/src/ruby/lib/grpc/generic/rpc_server.rb
index 6b0b4ce557..ab7333d133 100644
--- a/src/ruby/lib/grpc/generic/rpc_server.rb
+++ b/src/ruby/lib/grpc/generic/rpc_server.rb
@@ -355,7 +355,7 @@ module GRPC
       return an_rpc if @pool.jobs_waiting <= @max_waiting_requests
       GRPC.logger.warn("NOT AVAILABLE: too many jobs_waiting: #{an_rpc}")
       noop = proc { |x| x }
-      c = ActiveCall.new(an_rpc.call, @cq, noop, noop, an_rpc.deadline)
+      c = ActiveCall.new(an_rpc.call, an_rpc.cq, noop, noop, an_rpc.deadline)
       c.send_status(GRPC::Core::StatusCodes::RESOURCE_EXHAUSTED, '')
       nil
     end
@@ -366,7 +366,7 @@ module GRPC
       return an_rpc if rpc_descs.key?(mth)
       GRPC.logger.warn("UNIMPLEMENTED: #{an_rpc}")
       noop = proc { |x| x }
-      c = ActiveCall.new(an_rpc.call, @cq, noop, noop, an_rpc.deadline)
+      c = ActiveCall.new(an_rpc.call, an_rpc.cq, noop, noop, an_rpc.deadline)
       c.send_status(GRPC::Core::StatusCodes::UNIMPLEMENTED, '')
       nil
     end
@@ -377,7 +377,8 @@ module GRPC
       loop_tag = Object.new
       while running_state == :running
         begin
-          an_rpc = @server.request_call(@cq, loop_tag, INFINITE_FUTURE)
+          comp_queue = Core::CompletionQueue.new
+          an_rpc = @server.request_call(comp_queue, loop_tag, INFINITE_FUTURE)
           break if (!an_rpc.nil?) && an_rpc.call.nil?
           active_call = new_active_server_call(an_rpc)
           unless active_call.nil?
@@ -416,15 +417,16 @@ module GRPC
       unless @connect_md_proc.nil?
         connect_md = @connect_md_proc.call(an_rpc.method, an_rpc.metadata)
       end
-      an_rpc.call.run_batch(@cq, handle_call_tag, INFINITE_FUTURE,
+      an_rpc.call.run_batch(an_rpc.cq, handle_call_tag, INFINITE_FUTURE,
                             SEND_INITIAL_METADATA => connect_md)
+
       return nil unless available?(an_rpc)
       return nil unless implemented?(an_rpc)
 
       # Create the ActiveCall
       GRPC.logger.info("deadline is #{an_rpc.deadline}; (now=#{Time.now})")
       rpc_desc = rpc_descs[an_rpc.method.to_sym]
-      c = ActiveCall.new(an_rpc.call, @cq,
+      c = ActiveCall.new(an_rpc.call, an_rpc.cq,
                          rpc_desc.marshal_proc, rpc_desc.unmarshal_proc(:input),
                          an_rpc.deadline)
       mth = an_rpc.method.to_sym
diff --git a/src/ruby/pb/grpc/health/v1/health_services.rb b/src/ruby/pb/grpc/health/v1/health_services.rb
index cb79b20437..68a3956f54 100644
--- a/src/ruby/pb/grpc/health/v1/health_services.rb
+++ b/src/ruby/pb/grpc/health/v1/health_services.rb
@@ -1,5 +1,35 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # Source: grpc/health/v1/health.proto for package 'grpc.health.v1'
+# Original file comments:
+# 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.
+#
 
 require 'grpc'
 require 'grpc/health/v1/health'
@@ -8,8 +38,6 @@ module Grpc
   module Health
     module V1
       module Health
-
-        # TODO: add proto service documentation here
         class Service
 
           include GRPC::GenericService
diff --git a/src/ruby/pb/grpc/testing/duplicate/echo_duplicate_services.rb b/src/ruby/pb/grpc/testing/duplicate/echo_duplicate_services.rb
index 9f6e7e0e42..eb523ffa6f 100644
--- a/src/ruby/pb/grpc/testing/duplicate/echo_duplicate_services.rb
+++ b/src/ruby/pb/grpc/testing/duplicate/echo_duplicate_services.rb
@@ -1,15 +1,45 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
-# Source: src/proto/grpc/testing/duplicate/echo_duplicate.proto for package 'grpc.testing.duplicate'
+# Source: grpc/testing/duplicate/echo_duplicate.proto for package 'grpc.testing.duplicate'
+# Original file comments:
+# 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.
+#
+# This is a partial copy of echo.proto with a different package name.
+#
 
 require 'grpc'
-require 'src/proto/grpc/testing/duplicate/echo_duplicate'
+require 'grpc/testing/duplicate/echo_duplicate'
 
 module Grpc
   module Testing
     module Duplicate
       module EchoTestService
-
-        # TODO: add proto service documentation here
         class Service
 
           include GRPC::GenericService
diff --git a/src/ruby/pb/grpc/testing/metrics_services.rb b/src/ruby/pb/grpc/testing/metrics_services.rb
index f5778bbbb1..467b7b3ee5 100644
--- a/src/ruby/pb/grpc/testing/metrics_services.rb
+++ b/src/ruby/pb/grpc/testing/metrics_services.rb
@@ -1,5 +1,41 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # Source: grpc/testing/metrics.proto for package 'grpc.testing'
+# Original file comments:
+# Copyright 2015-2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Contains the definitions for a metrics service and the type of metrics
+# exposed by the service.
+#
+# Currently, 'Gauge' (i.e a metric that represents the measured value of
+# something at an instant of time) is the only metric type supported by the
+# service.
 
 require 'grpc'
 require 'grpc/testing/metrics'
@@ -7,8 +43,6 @@ require 'grpc/testing/metrics'
 module Grpc
   module Testing
     module MetricsService
-
-      # TODO: add proto service documentation here
       class Service
 
         include GRPC::GenericService
@@ -17,7 +51,10 @@ module Grpc
         self.unmarshal_class_method = :decode
         self.service_name = 'grpc.testing.MetricsService'
 
+        # Returns the values of all the gauges that are currently being maintained by
+        # the service
         rpc :GetAllGauges, EmptyMessage, stream(GaugeResponse)
+        # Returns the value of one gauge
         rpc :GetGauge, GaugeRequest, GaugeResponse
       end
 
diff --git a/src/ruby/pb/src/proto/grpc/testing/empty.rb b/src/ruby/pb/src/proto/grpc/testing/empty.rb
new file mode 100644
index 0000000000..9c2568d605
--- /dev/null
+++ b/src/ruby/pb/src/proto/grpc/testing/empty.rb
@@ -0,0 +1,15 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/empty.proto
+
+require 'google/protobuf'
+
+Google::Protobuf::DescriptorPool.generated_pool.build do
+  add_message "grpc.testing.Empty" do
+  end
+end
+
+module Grpc
+  module Testing
+    Empty = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.Empty").msgclass
+  end
+end
diff --git a/src/ruby/pb/src/proto/grpc/testing/messages.rb b/src/ruby/pb/src/proto/grpc/testing/messages.rb
new file mode 100644
index 0000000000..2bdfe0eade
--- /dev/null
+++ b/src/ruby/pb/src/proto/grpc/testing/messages.rb
@@ -0,0 +1,84 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/messages.proto
+
+require 'google/protobuf'
+
+Google::Protobuf::DescriptorPool.generated_pool.build do
+  add_message "grpc.testing.Payload" do
+    optional :type, :enum, 1, "grpc.testing.PayloadType"
+    optional :body, :bytes, 2
+  end
+  add_message "grpc.testing.EchoStatus" do
+    optional :code, :int32, 1
+    optional :message, :string, 2
+  end
+  add_message "grpc.testing.SimpleRequest" do
+    optional :response_type, :enum, 1, "grpc.testing.PayloadType"
+    optional :response_size, :int32, 2
+    optional :payload, :message, 3, "grpc.testing.Payload"
+    optional :fill_username, :bool, 4
+    optional :fill_oauth_scope, :bool, 5
+    optional :response_compression, :enum, 6, "grpc.testing.CompressionType"
+    optional :response_status, :message, 7, "grpc.testing.EchoStatus"
+  end
+  add_message "grpc.testing.SimpleResponse" do
+    optional :payload, :message, 1, "grpc.testing.Payload"
+    optional :username, :string, 2
+    optional :oauth_scope, :string, 3
+  end
+  add_message "grpc.testing.StreamingInputCallRequest" do
+    optional :payload, :message, 1, "grpc.testing.Payload"
+  end
+  add_message "grpc.testing.StreamingInputCallResponse" do
+    optional :aggregated_payload_size, :int32, 1
+  end
+  add_message "grpc.testing.ResponseParameters" do
+    optional :size, :int32, 1
+    optional :interval_us, :int32, 2
+  end
+  add_message "grpc.testing.StreamingOutputCallRequest" do
+    optional :response_type, :enum, 1, "grpc.testing.PayloadType"
+    repeated :response_parameters, :message, 2, "grpc.testing.ResponseParameters"
+    optional :payload, :message, 3, "grpc.testing.Payload"
+    optional :response_compression, :enum, 6, "grpc.testing.CompressionType"
+    optional :response_status, :message, 7, "grpc.testing.EchoStatus"
+  end
+  add_message "grpc.testing.StreamingOutputCallResponse" do
+    optional :payload, :message, 1, "grpc.testing.Payload"
+  end
+  add_message "grpc.testing.ReconnectParams" do
+    optional :max_reconnect_backoff_ms, :int32, 1
+  end
+  add_message "grpc.testing.ReconnectInfo" do
+    optional :passed, :bool, 1
+    repeated :backoff_ms, :int32, 2
+  end
+  add_enum "grpc.testing.PayloadType" do
+    value :COMPRESSABLE, 0
+    value :UNCOMPRESSABLE, 1
+    value :RANDOM, 2
+  end
+  add_enum "grpc.testing.CompressionType" do
+    value :NONE, 0
+    value :GZIP, 1
+    value :DEFLATE, 2
+  end
+end
+
+module Grpc
+  module Testing
+    Payload = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.Payload").msgclass
+    EchoStatus = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.EchoStatus").msgclass
+    SimpleRequest = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.SimpleRequest").msgclass
+    SimpleResponse = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.SimpleResponse").msgclass
+    StreamingInputCallRequest = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.StreamingInputCallRequest").msgclass
+    StreamingInputCallResponse = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.StreamingInputCallResponse").msgclass
+    ResponseParameters = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ResponseParameters").msgclass
+    StreamingOutputCallRequest = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.StreamingOutputCallRequest").msgclass
+    StreamingOutputCallResponse = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.StreamingOutputCallResponse").msgclass
+    ReconnectParams = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ReconnectParams").msgclass
+    ReconnectInfo = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ReconnectInfo").msgclass
+    PayloadType = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.PayloadType").enummodule
+    CompressionType = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.CompressionType").enummodule
+  end
+end
diff --git a/src/ruby/pb/src/proto/grpc/testing/test.rb b/src/ruby/pb/src/proto/grpc/testing/test.rb
new file mode 100644
index 0000000000..245b5ce00c
--- /dev/null
+++ b/src/ruby/pb/src/proto/grpc/testing/test.rb
@@ -0,0 +1,14 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/test.proto
+
+require 'google/protobuf'
+
+require 'src/proto/grpc/testing/empty'
+require 'src/proto/grpc/testing/messages'
+Google::Protobuf::DescriptorPool.generated_pool.build do
+end
+
+module Grpc
+  module Testing
+  end
+end
diff --git a/src/ruby/pb/src/proto/grpc/testing/test_services.rb b/src/ruby/pb/src/proto/grpc/testing/test_services.rb
new file mode 100644
index 0000000000..2652de5e6d
--- /dev/null
+++ b/src/ruby/pb/src/proto/grpc/testing/test_services.rb
@@ -0,0 +1,110 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# Source: src/proto/grpc/testing/test.proto for package 'grpc.testing'
+# Original file comments:
+# Copyright 2015-2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# An integration test service that covers all the method signature permutations
+# of unary/streaming requests/responses.
+#
+
+require 'grpc'
+require 'src/proto/grpc/testing/test'
+
+module Grpc
+  module Testing
+    module TestService
+      # A simple service to test the various types of RPCs and experiment with
+      # performance with various types of payload.
+      class Service
+
+        include GRPC::GenericService
+
+        self.marshal_class_method = :encode
+        self.unmarshal_class_method = :decode
+        self.service_name = 'grpc.testing.TestService'
+
+        # One empty request followed by one empty response.
+        rpc :EmptyCall, Empty, Empty
+        # One request followed by one response.
+        rpc :UnaryCall, SimpleRequest, SimpleResponse
+        # One request followed by a sequence of responses (streamed download).
+        # The server returns the payload with client desired type and sizes.
+        rpc :StreamingOutputCall, StreamingOutputCallRequest, stream(StreamingOutputCallResponse)
+        # A sequence of requests followed by one response (streamed upload).
+        # The server returns the aggregated size of client payload as the result.
+        rpc :StreamingInputCall, stream(StreamingInputCallRequest), StreamingInputCallResponse
+        # A sequence of requests with each request served by the server immediately.
+        # As one request could lead to multiple responses, this interface
+        # demonstrates the idea of full duplexing.
+        rpc :FullDuplexCall, stream(StreamingOutputCallRequest), stream(StreamingOutputCallResponse)
+        # A sequence of requests followed by a sequence of responses.
+        # The server buffers all the client requests and then serves them in order. A
+        # stream of responses are returned to the client when the server starts with
+        # first request.
+        rpc :HalfDuplexCall, stream(StreamingOutputCallRequest), stream(StreamingOutputCallResponse)
+      end
+
+      Stub = Service.rpc_stub_class
+    end
+    module UnimplementedService
+      # A simple service NOT implemented at servers so clients can test for
+      # that case.
+      class Service
+
+        include GRPC::GenericService
+
+        self.marshal_class_method = :encode
+        self.unmarshal_class_method = :decode
+        self.service_name = 'grpc.testing.UnimplementedService'
+
+        # A call that no server should implement
+        rpc :UnimplementedCall, Empty, Empty
+      end
+
+      Stub = Service.rpc_stub_class
+    end
+    module ReconnectService
+      # A service used to control reconnect server.
+      class Service
+
+        include GRPC::GenericService
+
+        self.marshal_class_method = :encode
+        self.unmarshal_class_method = :decode
+        self.service_name = 'grpc.testing.ReconnectService'
+
+        rpc :Start, ReconnectParams, Empty
+        rpc :Stop, Empty, ReconnectInfo
+      end
+
+      Stub = Service.rpc_stub_class
+    end
+  end
+end
diff --git a/src/ruby/qps/src/proto/grpc/testing/services_services.rb b/src/ruby/qps/src/proto/grpc/testing/services_services.rb
index 3fd9f20f47..94b9a1e164 100644
--- a/src/ruby/qps/src/proto/grpc/testing/services_services.rb
+++ b/src/ruby/qps/src/proto/grpc/testing/services_services.rb
@@ -1,5 +1,37 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # Source: src/proto/grpc/testing/services.proto for package 'grpc.testing'
+# Original file comments:
+# 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.
+#
+# An integration test service that covers all the method signature permutations
+# of unary/streaming requests/responses.
 
 require 'grpc'
 require 'src/proto/grpc/testing/services'
@@ -7,8 +39,6 @@ require 'src/proto/grpc/testing/services'
 module Grpc
   module Testing
     module BenchmarkService
-
-      # TODO: add proto service documentation here
       class Service
 
         include GRPC::GenericService
@@ -17,15 +47,17 @@ module Grpc
         self.unmarshal_class_method = :decode
         self.service_name = 'grpc.testing.BenchmarkService'
 
+        # One request followed by one response.
+        # The server returns the client payload as-is.
         rpc :UnaryCall, SimpleRequest, SimpleResponse
+        # One request followed by one response.
+        # The server returns the client payload as-is.
         rpc :StreamingCall, stream(SimpleRequest), stream(SimpleResponse)
       end
 
       Stub = Service.rpc_stub_class
     end
     module WorkerService
-
-      # TODO: add proto service documentation here
       class Service
 
         include GRPC::GenericService
@@ -34,9 +66,23 @@ module Grpc
         self.unmarshal_class_method = :decode
         self.service_name = 'grpc.testing.WorkerService'
 
+        # Start server with specified workload.
+        # First request sent specifies the ServerConfig followed by ServerStatus
+        # response. After that, a "Mark" can be sent anytime to request the latest
+        # stats. Closing the stream will initiate shutdown of the test server
+        # and once the shutdown has finished, the OK status is sent to terminate
+        # this RPC.
         rpc :RunServer, stream(ServerArgs), stream(ServerStatus)
+        # Start client with specified workload.
+        # First request sent specifies the ClientConfig followed by ClientStatus
+        # response. After that, a "Mark" can be sent anytime to request the latest
+        # stats. Closing the stream will initiate shutdown of the test client
+        # and once the shutdown has finished, the OK status is sent to terminate
+        # this RPC.
         rpc :RunClient, stream(ClientArgs), stream(ClientStatus)
+        # Just return the core count - unary call
         rpc :CoreCount, CoreRequest, CoreResponse
+        # Quit this worker
         rpc :QuitWorker, Void, Void
       end