Merge branch 'master' into poll-cv-disable

117 files changed, 1644 insertions, 370 deletions

diff --git a/BUILD b/BUILD
index 5053860baf..0200b14bca 100644
--- a/BUILD
+++ b/BUILD
@@ -1183,6 +1183,7 @@ grpc_cc_library(
         "include/grpc++/impl/codegen/core_codegen_interface.h",
         "include/grpc++/impl/codegen/create_auth_context.h",
         "include/grpc++/impl/codegen/grpc_library.h",
+        "include/grpc++/impl/codegen/metadata_map.h",
         "include/grpc++/impl/codegen/method_handler_impl.h",
         "include/grpc++/impl/codegen/rpc_method.h",
         "include/grpc++/impl/codegen/rpc_service_method.h",
@@ -1191,6 +1192,7 @@ grpc_cc_library(
         "include/grpc++/impl/codegen/server_context.h",
         "include/grpc++/impl/codegen/server_interface.h",
         "include/grpc++/impl/codegen/service_type.h",
+        "include/grpc++/impl/codegen/slice.h",
         "include/grpc++/impl/codegen/status.h",
         "include/grpc++/impl/codegen/status_code_enum.h",
         "include/grpc++/impl/codegen/status_helper.h",
@@ -1233,6 +1235,9 @@ grpc_cc_library(
     public_hdrs = [
         "include/grpc++/impl/codegen/config_protobuf.h",
     ],
+    external_deps = [
+        "protobuf",
+    ],
 )
 
 grpc_cc_library(
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6467cfa12f..8cada50ea3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1615,6 +1615,7 @@ foreach(_hdr
   include/grpc++/impl/codegen/core_codegen_interface.h
   include/grpc++/impl/codegen/create_auth_context.h
   include/grpc++/impl/codegen/grpc_library.h
+  include/grpc++/impl/codegen/metadata_map.h
   include/grpc++/impl/codegen/method_handler_impl.h
   include/grpc++/impl/codegen/rpc_method.h
   include/grpc++/impl/codegen/rpc_service_method.h
@@ -1960,6 +1961,7 @@ foreach(_hdr
   include/grpc++/impl/codegen/core_codegen_interface.h
   include/grpc++/impl/codegen/create_auth_context.h
   include/grpc++/impl/codegen/grpc_library.h
+  include/grpc++/impl/codegen/metadata_map.h
   include/grpc++/impl/codegen/method_handler_impl.h
   include/grpc++/impl/codegen/rpc_method.h
   include/grpc++/impl/codegen/rpc_service_method.h
@@ -2225,6 +2227,7 @@ foreach(_hdr
   include/grpc++/impl/codegen/core_codegen_interface.h
   include/grpc++/impl/codegen/create_auth_context.h
   include/grpc++/impl/codegen/grpc_library.h
+  include/grpc++/impl/codegen/metadata_map.h
   include/grpc++/impl/codegen/method_handler_impl.h
   include/grpc++/impl/codegen/rpc_method.h
   include/grpc++/impl/codegen/rpc_service_method.h
@@ -2383,6 +2386,7 @@ foreach(_hdr
   include/grpc++/impl/codegen/core_codegen_interface.h
   include/grpc++/impl/codegen/create_auth_context.h
   include/grpc++/impl/codegen/grpc_library.h
+  include/grpc++/impl/codegen/metadata_map.h
   include/grpc++/impl/codegen/method_handler_impl.h
   include/grpc++/impl/codegen/rpc_method.h
   include/grpc++/impl/codegen/rpc_service_method.h
diff --git a/Makefile b/Makefile
index 08aa4fae82..5ed7440912 100644
--- a/Makefile
+++ b/Makefile
@@ -3896,6 +3896,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/core_codegen_interface.h \
     include/grpc++/impl/codegen/create_auth_context.h \
     include/grpc++/impl/codegen/grpc_library.h \
+    include/grpc++/impl/codegen/metadata_map.h \
     include/grpc++/impl/codegen/method_handler_impl.h \
     include/grpc++/impl/codegen/rpc_method.h \
     include/grpc++/impl/codegen/rpc_service_method.h \
@@ -4268,6 +4269,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/core_codegen_interface.h \
     include/grpc++/impl/codegen/create_auth_context.h \
     include/grpc++/impl/codegen/grpc_library.h \
+    include/grpc++/impl/codegen/metadata_map.h \
     include/grpc++/impl/codegen/method_handler_impl.h \
     include/grpc++/impl/codegen/rpc_method.h \
     include/grpc++/impl/codegen/rpc_service_method.h \
@@ -4626,6 +4628,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/core_codegen_interface.h \
     include/grpc++/impl/codegen/create_auth_context.h \
     include/grpc++/impl/codegen/grpc_library.h \
+    include/grpc++/impl/codegen/metadata_map.h \
     include/grpc++/impl/codegen/method_handler_impl.h \
     include/grpc++/impl/codegen/rpc_method.h \
     include/grpc++/impl/codegen/rpc_service_method.h \
@@ -4807,6 +4810,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/core_codegen_interface.h \
     include/grpc++/impl/codegen/create_auth_context.h \
     include/grpc++/impl/codegen/grpc_library.h \
+    include/grpc++/impl/codegen/metadata_map.h \
     include/grpc++/impl/codegen/method_handler_impl.h \
     include/grpc++/impl/codegen/rpc_method.h \
     include/grpc++/impl/codegen/rpc_service_method.h \
diff --git a/build.yaml b/build.yaml
index c35ce32b40..59678324c2 100644
--- a/build.yaml
+++ b/build.yaml
@@ -825,6 +825,7 @@ filegroups:
   - include/grpc++/impl/codegen/core_codegen_interface.h
   - include/grpc++/impl/codegen/create_auth_context.h
   - include/grpc++/impl/codegen/grpc_library.h
+  - include/grpc++/impl/codegen/metadata_map.h
   - include/grpc++/impl/codegen/method_handler_impl.h
   - include/grpc++/impl/codegen/rpc_method.h
   - include/grpc++/impl/codegen/rpc_service_method.h
diff --git a/composer.json b/composer.json
index 711ee82b79..c5c7ae81d8 100644
--- a/composer.json
+++ b/composer.json
@@ -7,7 +7,6 @@
   "license": "BSD-3-Clause",
   "require": {
     "php": ">=5.5.0",
-    "ext-grpc": "*",
     "google/protobuf": "v3.1.0-alpha-1"
   },
   "require-dev": {
diff --git a/src/compiler/php_generator.cc b/src/compiler/php_generator.cc
index 5dac02cec4..fba8cbaa97 100644
--- a/src/compiler/php_generator.cc
+++ b/src/compiler/php_generator.cc
@@ -134,29 +134,15 @@ void PrintService(const ServiceDescriptor *service, Printer *out) {
   out->Outdent();
   out->Print("}\n\n");
 }
-
-void PrintServices(const FileDescriptor *file, Printer *out) {
-  map<grpc::string, grpc::string> vars;
-  vars["package"] = MessageIdentifierName(file->package());
-  out->Print(vars, "namespace $package$ {\n\n");
-  out->Indent();
-  for (int i = 0; i < file->service_count(); i++) {
-    PrintService(file->service(i), out);
-  }
-  out->Outdent();
-  out->Print("}\n");
-}
 }
 
-grpc::string GenerateFile(const FileDescriptor *file) {
+grpc::string GenerateFile(const FileDescriptor *file,
+                          const ServiceDescriptor *service) {
   grpc::string output;
   {
     StringOutputStream output_stream(&output);
     Printer out(&output_stream, '$');
 
-    if (file->service_count() == 0) {
-      return output;
-    }
     out.Print("<?php\n");
     out.Print("// GENERATED CODE -- DO NOT EDIT!\n\n");
 
@@ -166,7 +152,15 @@ grpc::string GenerateFile(const FileDescriptor *file) {
       out.Print(leading_comments.c_str());
     }
 
-    PrintServices(file, &out);
+    map<grpc::string, grpc::string> vars;
+    vars["package"] = MessageIdentifierName(file->package());
+    out.Print(vars, "namespace $package$ {\n\n");
+    out.Indent();
+
+    PrintService(service, &out);
+
+    out.Outdent();
+    out.Print("}\n");
   }
   return output;
 }
diff --git a/src/compiler/php_generator.h b/src/compiler/php_generator.h
index 905dc909a9..c3061f178e 100644
--- a/src/compiler/php_generator.h
+++ b/src/compiler/php_generator.h
@@ -38,7 +38,8 @@
 
 namespace grpc_php_generator {
 
-grpc::string GenerateFile(const grpc::protobuf::FileDescriptor *file);
+grpc::string GenerateFile(const grpc::protobuf::FileDescriptor *file,
+                          const grpc::protobuf::ServiceDescriptor *service);
 
 }  // namespace grpc_php_generator
 
diff --git a/src/compiler/php_generator_helpers.h b/src/compiler/php_generator_helpers.h
index 61c4d21fff..97eb2d3e70 100644
--- a/src/compiler/php_generator_helpers.h
+++ b/src/compiler/php_generator_helpers.h
@@ -41,14 +41,23 @@
 
 namespace grpc_php_generator {
 
-inline grpc::string GetPHPServiceFilename(const grpc::string& filename) {
-  return grpc_generator::StripProto(filename) + "_grpc_pb.php";
+inline grpc::string GetPHPServiceFilename(
+    const grpc::protobuf::FileDescriptor *file,
+    const grpc::protobuf::ServiceDescriptor *service) {
+  std::vector<grpc::string> tokens =
+      grpc_generator::tokenize(file->package(), ".");
+  std::ostringstream oss;
+  for (unsigned int i = 0; i < tokens.size(); i++) {
+    oss << (i == 0 ? "" : "/")
+        << grpc_generator::CapitalizeFirstLetter(tokens[i]);
+  }
+  return oss.str() + "/" + service->name() + "Client.php";
 }
 
 // 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 GetPHPComments(const DescriptorType* desc,
+inline grpc::string GetPHPComments(const DescriptorType *desc,
                                    grpc::string prefix) {
   return grpc_generator::GetPrefixedComments(desc, true, prefix);
 }
diff --git a/src/compiler/php_plugin.cc b/src/compiler/php_plugin.cc
index 88acad6524..00d4cd5a85 100644
--- a/src/compiler/php_plugin.cc
+++ b/src/compiler/php_plugin.cc
@@ -51,18 +51,22 @@ class PHPGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
                 const grpc::string &parameter,
                 grpc::protobuf::compiler::GeneratorContext *context,
                 grpc::string *error) const {
-    grpc::string code = GenerateFile(file);
-    if (code.size() == 0) {
+    if (file->service_count() == 0) {
       return true;
     }
 
-    // Get output file name
-    grpc::string file_name = GetPHPServiceFilename(file->name());
+    for (int i = 0; i < file->service_count(); i++) {
+      grpc::string code = GenerateFile(file, file->service(i));
+
+      // Get output file name
+      grpc::string file_name = GetPHPServiceFilename(file, file->service(i));
+
+      std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> output(
+          context->Open(file_name));
+      grpc::protobuf::io::CodedOutputStream coded_out(output.get());
+      coded_out.WriteRaw(code.data(), code.size());
+    }
 
-    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> output(
-        context->Open(file_name));
-    grpc::protobuf::io::CodedOutputStream coded_out(output.get());
-    coded_out.WriteRaw(code.data(), code.size());
     return true;
   }
 };
diff --git a/src/core/ext/client_channel/connector.c b/src/core/ext/client_channel/connector.c
index 0582e5b372..7a720fd1bd 100644
--- a/src/core/ext/client_channel/connector.c
+++ b/src/core/ext/client_channel/connector.c
@@ -49,7 +49,7 @@ void grpc_connector_connect(grpc_exec_ctx* exec_ctx, grpc_connector* connector,
   connector->vtable->connect(exec_ctx, connector, in_args, out_args, notify);
 }
 
-void grpc_connector_shutdown(grpc_exec_ctx* exec_ctx,
-                             grpc_connector* connector) {
-  connector->vtable->shutdown(exec_ctx, connector);
+void grpc_connector_shutdown(grpc_exec_ctx* exec_ctx, grpc_connector* connector,
+                             grpc_error* why) {
+  connector->vtable->shutdown(exec_ctx, connector, why);
 }
diff --git a/src/core/ext/client_channel/connector.h b/src/core/ext/client_channel/connector.h
index 395f89b3b2..9bff41f003 100644
--- a/src/core/ext/client_channel/connector.h
+++ b/src/core/ext/client_channel/connector.h
@@ -68,7 +68,8 @@ struct grpc_connector_vtable {
   void (*ref)(grpc_connector *connector);
   void (*unref)(grpc_exec_ctx *exec_ctx, grpc_connector *connector);
   /** Implementation of grpc_connector_shutdown */
-  void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_connector *connector);
+  void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
+                   grpc_error *why);
   /** Implementation of grpc_connector_connect */
   void (*connect)(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
                   const grpc_connect_in_args *in_args,
@@ -83,7 +84,7 @@ void grpc_connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
                             grpc_connect_out_args *out_args,
                             grpc_closure *notify);
 /** Cancel any pending connection */
-void grpc_connector_shutdown(grpc_exec_ctx *exec_ctx,
-                             grpc_connector *connector);
+void grpc_connector_shutdown(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
+                             grpc_error *why);
 
 #endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_CONNECTOR_H */
diff --git a/src/core/ext/client_channel/http_connect_handshaker.c b/src/core/ext/client_channel/http_connect_handshaker.c
index 622d236320..58ab233f1b 100644
--- a/src/core/ext/client_channel/http_connect_handshaker.c
+++ b/src/core/ext/client_channel/http_connect_handshaker.c
@@ -123,7 +123,8 @@ static void handshake_failed_locked(grpc_exec_ctx* exec_ctx,
     // before destroying them, even if we know that there are no
     // pending read/write callbacks.  This should be fixed, at which
     // point this can be removed.
-    grpc_endpoint_shutdown(exec_ctx, handshaker->args->endpoint);
+    grpc_endpoint_shutdown(exec_ctx, handshaker->args->endpoint,
+                           GRPC_ERROR_REF(error));
     // Not shutting down, so the handshake failed.  Clean up before
     // invoking the callback.
     cleanup_args_for_failure_locked(exec_ctx, handshaker);
@@ -251,15 +252,18 @@ static void http_connect_handshaker_destroy(grpc_exec_ctx* exec_ctx,
 }
 
 static void http_connect_handshaker_shutdown(grpc_exec_ctx* exec_ctx,
-                                             grpc_handshaker* handshaker_in) {
+                                             grpc_handshaker* handshaker_in,
+                                             grpc_error* why) {
   http_connect_handshaker* handshaker = (http_connect_handshaker*)handshaker_in;
   gpr_mu_lock(&handshaker->mu);
   if (!handshaker->shutdown) {
     handshaker->shutdown = true;
-    grpc_endpoint_shutdown(exec_ctx, handshaker->args->endpoint);
+    grpc_endpoint_shutdown(exec_ctx, handshaker->args->endpoint,
+                           GRPC_ERROR_REF(why));
     cleanup_args_for_failure_locked(exec_ctx, handshaker);
   }
   gpr_mu_unlock(&handshaker->mu);
+  GRPC_ERROR_UNREF(why);
 }
 
 static void http_connect_handshaker_do_handshake(
diff --git a/src/core/ext/client_channel/subchannel.c b/src/core/ext/client_channel/subchannel.c
index c5041f6924..f1e4e079e2 100644
--- a/src/core/ext/client_channel/subchannel.c
+++ b/src/core/ext/client_channel/subchannel.c
@@ -273,7 +273,8 @@ static void disconnect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
   gpr_mu_lock(&c->mu);
   GPR_ASSERT(!c->disconnected);
   c->disconnected = true;
-  grpc_connector_shutdown(exec_ctx, c->connector);
+  grpc_connector_shutdown(exec_ctx, c->connector,
+                          GRPC_ERROR_CREATE("Subchannel disconnected"));
   con = GET_CONNECTED_SUBCHANNEL(c, no_barrier);
   if (con != NULL) {
     GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, con, "connection");
diff --git a/src/core/ext/transport/chttp2/client/chttp2_connector.c b/src/core/ext/transport/chttp2/client/chttp2_connector.c
index 013c96dc70..d0a762a280 100644
--- a/src/core/ext/transport/chttp2/client/chttp2_connector.c
+++ b/src/core/ext/transport/chttp2/client/chttp2_connector.c
@@ -92,19 +92,21 @@ static void chttp2_connector_unref(grpc_exec_ctx *exec_ctx,
 }
 
 static void chttp2_connector_shutdown(grpc_exec_ctx *exec_ctx,
-                                      grpc_connector *con) {
+                                      grpc_connector *con, grpc_error *why) {
   chttp2_connector *c = (chttp2_connector *)con;
   gpr_mu_lock(&c->mu);
   c->shutdown = true;
   if (c->handshake_mgr != NULL) {
-    grpc_handshake_manager_shutdown(exec_ctx, c->handshake_mgr);
+    grpc_handshake_manager_shutdown(exec_ctx, c->handshake_mgr,
+                                    GRPC_ERROR_REF(why));
   }
   // If handshaking is not yet in progress, shutdown the endpoint.
   // Otherwise, the handshaker will do this for us.
   if (!c->connecting && c->endpoint != NULL) {
-    grpc_endpoint_shutdown(exec_ctx, c->endpoint);
+    grpc_endpoint_shutdown(exec_ctx, c->endpoint, GRPC_ERROR_REF(why));
   }
   gpr_mu_unlock(&c->mu);
+  GRPC_ERROR_UNREF(why);
 }
 
 static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
@@ -121,7 +123,7 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
       // before destroying them, even if we know that there are no
       // pending read/write callbacks.  This should be fixed, at which
       // point this can be removed.
-      grpc_endpoint_shutdown(exec_ctx, args->endpoint);
+      grpc_endpoint_shutdown(exec_ctx, args->endpoint, GRPC_ERROR_REF(error));
       grpc_endpoint_destroy(exec_ctx, args->endpoint);
       grpc_channel_args_destroy(exec_ctx, args->args);
       grpc_slice_buffer_destroy_internal(exec_ctx, args->read_buffer);
@@ -195,7 +197,9 @@ static void connected(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
     grpc_closure *notify = c->notify;
     c->notify = NULL;
     grpc_closure_sched(exec_ctx, notify, error);
-    if (c->endpoint != NULL) grpc_endpoint_shutdown(exec_ctx, c->endpoint);
+    if (c->endpoint != NULL) {
+      grpc_endpoint_shutdown(exec_ctx, c->endpoint, GRPC_ERROR_REF(error));
+    }
     gpr_mu_unlock(&c->mu);
     chttp2_connector_unref(exec_ctx, arg);
   } else {
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.c b/src/core/ext/transport/chttp2/server/chttp2_server.c
index 56a1a0de9b..ae2c3838ed 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.c
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.c
@@ -101,16 +101,19 @@ static void pending_handshake_manager_remove_locked(
 }
 
 static void pending_handshake_manager_shutdown_locked(grpc_exec_ctx *exec_ctx,
-                                                      server_state *state) {
+                                                      server_state *state,
+                                                      grpc_error *why) {
   pending_handshake_manager_node *prev_node = NULL;
   for (pending_handshake_manager_node *node = state->pending_handshake_mgrs;
        node != NULL; node = node->next) {
-    grpc_handshake_manager_shutdown(exec_ctx, node->handshake_mgr);
+    grpc_handshake_manager_shutdown(exec_ctx, node->handshake_mgr,
+                                    GRPC_ERROR_REF(why));
     gpr_free(prev_node);
     prev_node = node;
   }
   gpr_free(prev_node);
   state->pending_handshake_mgrs = NULL;
+  GRPC_ERROR_UNREF(why);
 }
 
 static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
@@ -129,7 +132,7 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
       // before destroying them, even if we know that there are no
       // pending read/write callbacks.  This should be fixed, at which
       // point this can be removed.
-      grpc_endpoint_shutdown(exec_ctx, args->endpoint);
+      grpc_endpoint_shutdown(exec_ctx, args->endpoint, GRPC_ERROR_NONE);
       grpc_endpoint_destroy(exec_ctx, args->endpoint);
       grpc_channel_args_destroy(exec_ctx, args->args);
       grpc_slice_buffer_destroy_internal(exec_ctx, args->read_buffer);
@@ -210,7 +213,8 @@ static void tcp_server_shutdown_complete(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_mu_lock(&state->mu);
   grpc_closure *destroy_done = state->server_destroy_listener_done;
   GPR_ASSERT(state->shutdown);
-  pending_handshake_manager_shutdown_locked(exec_ctx, state);
+  pending_handshake_manager_shutdown_locked(exec_ctx, state,
+                                            GRPC_ERROR_REF(error));
   gpr_mu_unlock(&state->mu);
   // Flush queued work before destroying handshaker factory, since that
   // may do a synchronous unref.
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 2004bc6437..15f486d676 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -417,7 +417,7 @@ static void close_transport_locked(grpc_exec_ctx *exec_ctx,
     t->closed = 1;
     connectivity_state_set(exec_ctx, t, GRPC_CHANNEL_SHUTDOWN,
                            GRPC_ERROR_REF(error), "close_transport");
-    grpc_endpoint_shutdown(exec_ctx, t->ep);
+    grpc_endpoint_shutdown(exec_ctx, t->ep, GRPC_ERROR_REF(error));
 
     /* flush writable stream list to avoid dangling references */
     grpc_chttp2_stream *s;
diff --git a/src/core/lib/channel/handshaker.c b/src/core/lib/channel/handshaker.c
index c052ca5385..5bed2d041d 100644
--- a/src/core/lib/channel/handshaker.c
+++ b/src/core/lib/channel/handshaker.c
@@ -55,8 +55,8 @@ void grpc_handshaker_destroy(grpc_exec_ctx* exec_ctx,
 }
 
 void grpc_handshaker_shutdown(grpc_exec_ctx* exec_ctx,
-                              grpc_handshaker* handshaker) {
-  handshaker->vtable->shutdown(exec_ctx, handshaker);
+                              grpc_handshaker* handshaker, grpc_error* why) {
+  handshaker->vtable->shutdown(exec_ctx, handshaker, why);
 }
 
 void grpc_handshaker_do_handshake(grpc_exec_ctx* exec_ctx,
@@ -141,14 +141,17 @@ void grpc_handshake_manager_destroy(grpc_exec_ctx* exec_ctx,
 }
 
 void grpc_handshake_manager_shutdown(grpc_exec_ctx* exec_ctx,
-                                     grpc_handshake_manager* mgr) {
+                                     grpc_handshake_manager* mgr,
+                                     grpc_error* why) {
   gpr_mu_lock(&mgr->mu);
   // Shutdown the handshaker that's currently in progress, if any.
   if (!mgr->shutdown && mgr->index > 0) {
     mgr->shutdown = true;
-    grpc_handshaker_shutdown(exec_ctx, mgr->handshakers[mgr->index - 1]);
+    grpc_handshaker_shutdown(exec_ctx, mgr->handshakers[mgr->index - 1],
+                             GRPC_ERROR_REF(why));
   }
   gpr_mu_unlock(&mgr->mu);
+  GRPC_ERROR_UNREF(why);
 }
 
 // Helper function to call either the next handshaker or the
@@ -197,7 +200,8 @@ static void call_next_handshaker(grpc_exec_ctx* exec_ctx, void* arg,
 static void on_timeout(grpc_exec_ctx* exec_ctx, void* arg, grpc_error* error) {
   grpc_handshake_manager* mgr = arg;
   if (error == GRPC_ERROR_NONE) {  // Timer fired, rather than being cancelled.
-    grpc_handshake_manager_shutdown(exec_ctx, mgr);
+    grpc_handshake_manager_shutdown(exec_ctx, mgr,
+                                    GRPC_ERROR_CREATE("Handshake timed out"));
   }
   grpc_handshake_manager_unref(exec_ctx, mgr);
 }
diff --git a/src/core/lib/channel/handshaker.h b/src/core/lib/channel/handshaker.h
index 450b7adaee..a8e3692add 100644
--- a/src/core/lib/channel/handshaker.h
+++ b/src/core/lib/channel/handshaker.h
@@ -86,7 +86,8 @@ typedef struct {
 
   /// Shuts down the handshaker (e.g., to clean up when the operation is
   /// aborted in the middle).
-  void (*shutdown)(grpc_exec_ctx* exec_ctx, grpc_handshaker* handshaker);
+  void (*shutdown)(grpc_exec_ctx* exec_ctx, grpc_handshaker* handshaker,
+                   grpc_error* why);
 
   /// Performs handshaking, modifying \a args as needed (e.g., to
   /// replace \a endpoint with a wrapped endpoint).
@@ -111,7 +112,7 @@ void grpc_handshaker_init(const grpc_handshaker_vtable* vtable,
 void grpc_handshaker_destroy(grpc_exec_ctx* exec_ctx,
                              grpc_handshaker* handshaker);
 void grpc_handshaker_shutdown(grpc_exec_ctx* exec_ctx,
-                              grpc_handshaker* handshaker);
+                              grpc_handshaker* handshaker, grpc_error* why);
 void grpc_handshaker_do_handshake(grpc_exec_ctx* exec_ctx,
                                   grpc_handshaker* handshaker,
                                   grpc_tcp_server_acceptor* acceptor,
@@ -141,7 +142,8 @@ void grpc_handshake_manager_destroy(grpc_exec_ctx* exec_ctx,
 /// The caller must still call grpc_handshake_manager_destroy() after
 /// calling this function.
 void grpc_handshake_manager_shutdown(grpc_exec_ctx* exec_ctx,
-                                     grpc_handshake_manager* mgr);
+                                     grpc_handshake_manager* mgr,
+                                     grpc_error* why);
 
 /// Invokes handshakers in the order they were added.
 /// Takes ownership of \a endpoint, and then passes that ownership to
diff --git a/src/core/lib/iomgr/endpoint.c b/src/core/lib/iomgr/endpoint.c
index 2d300f4560..bf6e98146a 100644
--- a/src/core/lib/iomgr/endpoint.c
+++ b/src/core/lib/iomgr/endpoint.c
@@ -54,8 +54,9 @@ void grpc_endpoint_add_to_pollset_set(grpc_exec_ctx* exec_ctx,
   ep->vtable->add_to_pollset_set(exec_ctx, ep, pollset_set);
 }
 
-void grpc_endpoint_shutdown(grpc_exec_ctx* exec_ctx, grpc_endpoint* ep) {
-  ep->vtable->shutdown(exec_ctx, ep);
+void grpc_endpoint_shutdown(grpc_exec_ctx* exec_ctx, grpc_endpoint* ep,
+                            grpc_error* why) {
+  ep->vtable->shutdown(exec_ctx, ep, why);
 }
 
 void grpc_endpoint_destroy(grpc_exec_ctx* exec_ctx, grpc_endpoint* ep) {
diff --git a/src/core/lib/iomgr/endpoint.h b/src/core/lib/iomgr/endpoint.h
index 1609b64f2b..740357ecc5 100644
--- a/src/core/lib/iomgr/endpoint.h
+++ b/src/core/lib/iomgr/endpoint.h
@@ -57,7 +57,7 @@ struct grpc_endpoint_vtable {
                          grpc_pollset *pollset);
   void (*add_to_pollset_set)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
                              grpc_pollset_set *pollset);
-  void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep);
+  void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep, grpc_error *why);
   void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep);
   grpc_resource_user *(*get_resource_user)(grpc_endpoint *ep);
   char *(*get_peer)(grpc_endpoint *ep);
@@ -96,7 +96,8 @@ void grpc_endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
 /* Causes any pending and future read/write callbacks to run immediately with
    success==0 */
-void grpc_endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep);
+void grpc_endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                            grpc_error *why);
 void grpc_endpoint_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep);
 
 /* Add an endpoint to a pollset, so that when the pollset is polled, events from
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index 39b4d9cbd7..51842fc208 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -143,6 +143,7 @@ struct grpc_fd {
   /* Indicates that the fd is shutdown and that any pending read/write closures
      should fail */
   bool shutdown;
+  grpc_error *shutdown_error; /* reason for shutdown: set iff shutdown==true */
 
   /* The fd is either closed or we relinquished control of it. In either cases,
      this indicates that the 'fd' on this structure is no longer valid */
@@ -907,6 +908,7 @@ static void unref_by(grpc_fd *fd, int n) {
     fd->freelist_next = fd_freelist;
     fd_freelist = fd;
     grpc_iomgr_unregister_object(&fd->iomgr_object);
+    if (fd->shutdown) GRPC_ERROR_UNREF(fd->shutdown_error);
 
     gpr_mu_unlock(&fd_freelist_mu);
   } else {
@@ -1058,11 +1060,11 @@ static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   GRPC_ERROR_UNREF(error);
 }
 
-static grpc_error *fd_shutdown_error(bool shutdown) {
-  if (!shutdown) {
+static grpc_error *fd_shutdown_error(grpc_fd *fd) {
+  if (!fd->shutdown) {
     return GRPC_ERROR_NONE;
   } else {
-    return GRPC_ERROR_CREATE("FD shutdown");
+    return GRPC_ERROR_CREATE_REFERENCING("FD shutdown", &fd->shutdown_error, 1);
   }
 }
 
@@ -1076,7 +1078,7 @@ static void notify_on_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   } else if (*st == CLOSURE_READY) {
     /* already ready ==> queue the closure to run immediately */
     *st = CLOSURE_NOT_READY;
-    grpc_closure_sched(exec_ctx, closure, fd_shutdown_error(fd->shutdown));
+    grpc_closure_sched(exec_ctx, closure, fd_shutdown_error(fd));
   } else {
     /* upcallptr was set to a different closure.  This is an error! */
     gpr_log(GPR_ERROR,
@@ -1098,7 +1100,7 @@ static int set_ready_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
     return 0;
   } else {
     /* waiting ==> queue closure */
-    grpc_closure_sched(exec_ctx, *st, fd_shutdown_error(fd->shutdown));
+    grpc_closure_sched(exec_ctx, *st, fd_shutdown_error(fd));
     *st = CLOSURE_NOT_READY;
     return 1;
   }
@@ -1123,17 +1125,20 @@ static bool fd_is_shutdown(grpc_fd *fd) {
 }
 
 /* Might be called multiple times */
-static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_error *why) {
   gpr_mu_lock(&fd->po.mu);
   /* Do the actual shutdown only once */
   if (!fd->shutdown) {
     fd->shutdown = true;
+    fd->shutdown_error = why;
 
     shutdown(fd->fd, SHUT_RDWR);
     /* Flush any pending read and write closures. Since fd->shutdown is 'true'
        at this point, the closures would be called with 'success = false' */
     set_ready_locked(exec_ctx, fd, &fd->read_closure);
     set_ready_locked(exec_ctx, fd, &fd->write_closure);
+  } else {
+    GRPC_ERROR_UNREF(why);
   }
   gpr_mu_unlock(&fd->po.mu);
 }
diff --git a/src/core/lib/iomgr/ev_poll_posix.c b/src/core/lib/iomgr/ev_poll_posix.c
index 9477ac3688..ca12932219 100644
--- a/src/core/lib/iomgr/ev_poll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_posix.c
@@ -82,6 +82,7 @@ struct grpc_fd {
   int shutdown;
   int closed;
   int released;
+  grpc_error *shutdown_error;
 
   /* The watcher list.
 
@@ -306,6 +307,7 @@ static void unref_by(grpc_fd *fd, int n) {
   if (old == n) {
     gpr_mu_destroy(&fd->mu);
     grpc_iomgr_unregister_object(&fd->iomgr_object);
+    if (fd->shutdown) GRPC_ERROR_UNREF(fd->shutdown_error);
     gpr_free(fd);
   } else {
     GPR_ASSERT(old > n);
@@ -444,11 +446,11 @@ static void fd_ref(grpc_fd *fd) { ref_by(fd, 2); }
 static void fd_unref(grpc_fd *fd) { unref_by(fd, 2); }
 #endif
 
-static grpc_error *fd_shutdown_error(bool shutdown) {
-  if (!shutdown) {
+static grpc_error *fd_shutdown_error(grpc_fd *fd) {
+  if (!fd->shutdown) {
     return GRPC_ERROR_NONE;
   } else {
-    return GRPC_ERROR_CREATE("FD shutdown");
+    return GRPC_ERROR_CREATE_REFERENCING("FD shutdown", &fd->shutdown_error, 1);
   }
 }
 
@@ -462,7 +464,7 @@ static void notify_on_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   } else if (*st == CLOSURE_READY) {
     /* already ready ==> queue the closure to run immediately */
     *st = CLOSURE_NOT_READY;
-    grpc_closure_sched(exec_ctx, closure, fd_shutdown_error(fd->shutdown));
+    grpc_closure_sched(exec_ctx, closure, fd_shutdown_error(fd));
     maybe_wake_one_watcher_locked(fd);
   } else {
     /* upcallptr was set to a different closure.  This is an error! */
@@ -485,7 +487,7 @@ static int set_ready_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
     return 0;
   } else {
     /* waiting ==> queue closure */
-    grpc_closure_sched(exec_ctx, *st, fd_shutdown_error(fd->shutdown));
+    grpc_closure_sched(exec_ctx, *st, fd_shutdown_error(fd));
     *st = CLOSURE_NOT_READY;
     return 1;
   }
@@ -496,15 +498,18 @@ static void set_read_notifier_pollset_locked(
   fd->read_notifier_pollset = read_notifier_pollset;
 }
 
-static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_error *why) {
   gpr_mu_lock(&fd->mu);
   /* only shutdown once */
   if (!fd->shutdown) {
     fd->shutdown = 1;
+    fd->shutdown_error = why;
     /* signal read/write closed to OS so that future operations fail */
     shutdown(fd->fd, SHUT_RDWR);
     set_ready_locked(exec_ctx, fd, &fd->read_closure);
     set_ready_locked(exec_ctx, fd, &fd->write_closure);
+  } else {
+    GRPC_ERROR_UNREF(why);
   }
   gpr_mu_unlock(&fd->mu);
 }
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index c106ba5400..5bb55631d6 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -162,8 +162,8 @@ void grpc_fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done,
   g_event_engine->fd_orphan(exec_ctx, fd, on_done, release_fd, reason);
 }
 
-void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  g_event_engine->fd_shutdown(exec_ctx, fd);
+void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_error *why) {
+  g_event_engine->fd_shutdown(exec_ctx, fd, why);
 }
 
 bool grpc_fd_is_shutdown(grpc_fd *fd) {
diff --git a/src/core/lib/iomgr/ev_posix.h b/src/core/lib/iomgr/ev_posix.h
index 1068a4bad5..a589efdeec 100644
--- a/src/core/lib/iomgr/ev_posix.h
+++ b/src/core/lib/iomgr/ev_posix.h
@@ -51,7 +51,7 @@ typedef struct grpc_event_engine_vtable {
   int (*fd_wrapped_fd)(grpc_fd *fd);
   void (*fd_orphan)(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done,
                     int *release_fd, const char *reason);
-  void (*fd_shutdown)(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
+  void (*fd_shutdown)(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_error *why);
   void (*fd_notify_on_read)(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
                             grpc_closure *closure);
   void (*fd_notify_on_write)(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
@@ -140,7 +140,7 @@ void grpc_fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done,
 bool grpc_fd_is_shutdown(grpc_fd *fd);
 
 /* Cause any current and future callbacks to fail. */
-void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
+void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_error *why);
 
 /* Register read interest, causing read_cb to be called once when fd becomes
    readable, on deadline specified by deadline, or on shutdown triggered by
diff --git a/src/core/lib/iomgr/network_status_tracker.c b/src/core/lib/iomgr/network_status_tracker.c
index a5ca9ed2c3..1601a39002 100644
--- a/src/core/lib/iomgr/network_status_tracker.c
+++ b/src/core/lib/iomgr/network_status_tracker.c
@@ -117,7 +117,8 @@ void grpc_network_status_shutdown_all_endpoints() {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
   for (endpoint_ll_node *curr = head; curr != NULL; curr = curr->next) {
-    curr->ep->vtable->shutdown(&exec_ctx, curr->ep);
+    curr->ep->vtable->shutdown(&exec_ctx, curr->ep,
+                               GRPC_ERROR_CREATE("Network unavailable"));
   }
   gpr_mu_unlock(&g_endpoint_mutex);
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/src/core/lib/iomgr/tcp_client_posix.c b/src/core/lib/iomgr/tcp_client_posix.c
index 16b0f4e73c..0144192b71 100644
--- a/src/core/lib/iomgr/tcp_client_posix.c
+++ b/src/core/lib/iomgr/tcp_client_posix.c
@@ -121,7 +121,8 @@ static void tc_on_alarm(grpc_exec_ctx *exec_ctx, void *acp, grpc_error *error) {
   }
   gpr_mu_lock(&ac->mu);
   if (ac->fd != NULL) {
-    grpc_fd_shutdown(exec_ctx, ac->fd);
+    grpc_fd_shutdown(exec_ctx, ac->fd,
+                     GRPC_ERROR_CREATE("connect() timed out"));
   }
   done = (--ac->refs == 0);
   gpr_mu_unlock(&ac->mu);
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index a33e63e845..a4381f8fc9 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -119,9 +119,10 @@ static void tcp_handle_read(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
 static void tcp_handle_write(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
                              grpc_error *error);
 
-static void tcp_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+static void tcp_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                         grpc_error *why) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
-  grpc_fd_shutdown(exec_ctx, tcp->em_fd);
+  grpc_fd_shutdown(exec_ctx, tcp->em_fd, why);
   grpc_resource_user_shutdown(exec_ctx, tcp->resource_user);
 }
 
diff --git a/src/core/lib/iomgr/tcp_server_posix.c b/src/core/lib/iomgr/tcp_server_posix.c
index 20efb678b2..e9e7511c9c 100644
--- a/src/core/lib/iomgr/tcp_server_posix.c
+++ b/src/core/lib/iomgr/tcp_server_posix.c
@@ -276,7 +276,8 @@ static void tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
   if (s->active_ports) {
     grpc_tcp_listener *sp;
     for (sp = s->head; sp; sp = sp->next) {
-      grpc_fd_shutdown(exec_ctx, sp->emfd);
+      grpc_fd_shutdown(exec_ctx, sp->emfd,
+                       GRPC_ERROR_CREATE("Server destroyed"));
     }
     gpr_mu_unlock(&s->mu);
   } else {
@@ -773,7 +774,8 @@ void grpc_tcp_server_shutdown_listeners(grpc_exec_ctx *exec_ctx,
   if (s->active_ports) {
     grpc_tcp_listener *sp;
     for (sp = s->head; sp; sp = sp->next) {
-      grpc_fd_shutdown(exec_ctx, sp->emfd);
+      grpc_fd_shutdown(exec_ctx, sp->emfd,
+                       GRPC_ERROR_CREATE("Server shutdown"));
     }
   }
   gpr_mu_unlock(&s->mu);
diff --git a/src/core/lib/iomgr/tcp_uv.c b/src/core/lib/iomgr/tcp_uv.c
index 7f4ea49a1c..5fb398c50b 100644
--- a/src/core/lib/iomgr/tcp_uv.c
+++ b/src/core/lib/iomgr/tcp_uv.c
@@ -298,13 +298,15 @@ static void uv_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
 static void shutdown_callback(uv_shutdown_t *req, int status) {}
 
-static void uv_endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+static void uv_endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                                 grpc_error *why) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   if (!tcp->shutting_down) {
     tcp->shutting_down = true;
     uv_shutdown_t *req = &tcp->shutdown_req;
     uv_shutdown(req, (uv_stream_t *)tcp->handle, shutdown_callback);
   }
+  GRPC_ERROR_UNREF(why);
 }
 
 static void uv_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index 84f791ba07..6c413971e3 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -116,6 +116,7 @@ typedef struct grpc_tcp {
      to protect ourselves when requesting a shutdown. */
   gpr_mu mu;
   int shutting_down;
+  grpc_error *shutdown_error;
 
   char *peer_string;
 } grpc_tcp;
@@ -125,6 +126,7 @@ static void tcp_free(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
   gpr_mu_destroy(&tcp->mu);
   gpr_free(tcp->peer_string);
   grpc_resource_user_unref(exec_ctx, tcp->resource_user);
+  if (tcp->shutting_down) GRPC_ERROR_UNREF(tcp->shutdown_error);
   gpr_free(tcp);
 }
 
@@ -182,7 +184,10 @@ static void on_read(grpc_exec_ctx *exec_ctx, void *tcpp, grpc_error *error) {
         grpc_slice_buffer_add(tcp->read_slices, sub);
       } else {
         grpc_slice_unref_internal(exec_ctx, tcp->read_slice);
-        error = GRPC_ERROR_CREATE("End of TCP stream");
+        error = tcp->shutting_down
+                    ? GRPC_ERROR_CREATE_REFERENCING("TCP stream shutting down",
+                                                    &tcp->shutdown_error, 1)
+                    : GRPC_ERROR_CREATE("End of TCP stream");
       }
     }
   }
@@ -203,8 +208,9 @@ static void win_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   WSABUF buffer;
 
   if (tcp->shutting_down) {
-    grpc_closure_sched(exec_ctx, cb,
-                       GRPC_ERROR_CREATE("TCP socket is shutting down"));
+    grpc_closure_sched(exec_ctx, cb, GRPC_ERROR_CREATE_REFERENCING(
+                                         "TCP socket is shutting down",
+                                         &tcp->shutdown_error, 1));
     return;
   }
 
@@ -291,8 +297,9 @@ static void win_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   size_t len;
 
   if (tcp->shutting_down) {
-    grpc_closure_sched(exec_ctx, cb,
-                       GRPC_ERROR_CREATE("TCP socket is shutting down"));
+    grpc_closure_sched(exec_ctx, cb, GRPC_ERROR_CREATE_REFERENCING(
+                                         "TCP socket is shutting down",
+                                         &tcp->shutdown_error, 1));
     return;
   }
 
@@ -373,12 +380,18 @@ static void win_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
    we're not going to protect against these. However the IO Completion Port
    callback will happen from another thread, so we need to protect against
    concurrent access of the data structure in that regard. */
-static void win_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+static void win_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                         grpc_error *why) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   gpr_mu_lock(&tcp->mu);
   /* At that point, what may happen is that we're already inside the IOCP
      callback. See the comments in on_read and on_write. */
-  tcp->shutting_down = 1;
+  if (!tcp->shutting_down) {
+    tcp->shutting_down = 1;
+    tcp->shutdown_error = why;
+  } else {
+    GRPC_ERROR_UNREF(why);
+  }
   grpc_winsocket_shutdown(tcp->socket);
   gpr_mu_unlock(&tcp->mu);
   grpc_resource_user_shutdown(exec_ctx, tcp->resource_user);
diff --git a/src/core/lib/iomgr/udp_server.c b/src/core/lib/iomgr/udp_server.c
index dfbd295c91..3b23b47d4f 100644
--- a/src/core/lib/iomgr/udp_server.c
+++ b/src/core/lib/iomgr/udp_server.c
@@ -203,7 +203,8 @@ void grpc_udp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_udp_server *s,
     for (sp = s->head; sp; sp = sp->next) {
       GPR_ASSERT(sp->orphan_cb);
       sp->orphan_cb(sp->emfd);
-      grpc_fd_shutdown(exec_ctx, sp->emfd);
+      grpc_fd_shutdown(exec_ctx, sp->emfd,
+                       GRPC_ERROR_CREATE("Server destroyed"));
     }
     gpr_mu_unlock(&s->mu);
   } else {
diff --git a/src/core/lib/security/transport/secure_endpoint.c b/src/core/lib/security/transport/secure_endpoint.c
index 18a7a6f7e7..7d58843d69 100644
--- a/src/core/lib/security/transport/secure_endpoint.c
+++ b/src/core/lib/security/transport/secure_endpoint.c
@@ -341,10 +341,10 @@ static void endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *secure_ep,
   GPR_TIMER_END("secure_endpoint.endpoint_write", 0);
 }
 
-static void endpoint_shutdown(grpc_exec_ctx *exec_ctx,
-                              grpc_endpoint *secure_ep) {
+static void endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *secure_ep,
+                              grpc_error *why) {
   secure_endpoint *ep = (secure_endpoint *)secure_ep;
-  grpc_endpoint_shutdown(exec_ctx, ep->wrapped_ep);
+  grpc_endpoint_shutdown(exec_ctx, ep->wrapped_ep, why);
 }
 
 static void endpoint_destroy(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/lib/security/transport/security_handshaker.c b/src/core/lib/security/transport/security_handshaker.c
index 37d57d759b..bb8a3bf6cd 100644
--- a/src/core/lib/security/transport/security_handshaker.c
+++ b/src/core/lib/security/transport/security_handshaker.c
@@ -130,7 +130,7 @@ static void security_handshake_failed_locked(grpc_exec_ctx *exec_ctx,
     // before destroying them, even if we know that there are no
     // pending read/write callbacks.  This should be fixed, at which
     // point this can be removed.
-    grpc_endpoint_shutdown(exec_ctx, h->args->endpoint);
+    grpc_endpoint_shutdown(exec_ctx, h->args->endpoint, GRPC_ERROR_REF(error));
     // Not shutting down, so the write failed.  Clean up before
     // invoking the callback.
     cleanup_args_for_failure_locked(exec_ctx, h);
@@ -347,15 +347,17 @@ static void security_handshaker_destroy(grpc_exec_ctx *exec_ctx,
 }
 
 static void security_handshaker_shutdown(grpc_exec_ctx *exec_ctx,
-                                         grpc_handshaker *handshaker) {
+                                         grpc_handshaker *handshaker,
+                                         grpc_error *why) {
   security_handshaker *h = (security_handshaker *)handshaker;
   gpr_mu_lock(&h->mu);
   if (!h->shutdown) {
     h->shutdown = true;
-    grpc_endpoint_shutdown(exec_ctx, h->args->endpoint);
+    grpc_endpoint_shutdown(exec_ctx, h->args->endpoint, GRPC_ERROR_REF(why));
     cleanup_args_for_failure_locked(exec_ctx, h);
   }
   gpr_mu_unlock(&h->mu);
+  GRPC_ERROR_UNREF(why);
 }
 
 static void security_handshaker_do_handshake(grpc_exec_ctx *exec_ctx,
@@ -417,7 +419,10 @@ static void fail_handshaker_destroy(grpc_exec_ctx *exec_ctx,
 }
 
 static void fail_handshaker_shutdown(grpc_exec_ctx *exec_ctx,
-                                     grpc_handshaker *handshaker) {}
+                                     grpc_handshaker *handshaker,
+                                     grpc_error *why) {
+  GRPC_ERROR_UNREF(why);
+}
 
 static void fail_handshaker_do_handshake(grpc_exec_ctx *exec_ctx,
                                          grpc_handshaker *handshaker,
diff --git a/src/csharp/Grpc.Core.Tests/ClientServerTest.cs b/src/csharp/Grpc.Core.Tests/ClientServerTest.cs
index dcdddc769e..6bf9756962 100644
--- a/src/csharp/Grpc.Core.Tests/ClientServerTest.cs
+++ b/src/csharp/Grpc.Core.Tests/ClientServerTest.cs
@@ -336,6 +336,22 @@ namespace Grpc.Core.Tests
         }
 
         [Test]
+        public void StatusDetailIsUtf8()
+        {
+            // some japanese and chinese characters
+            var nonAsciiString = "\u30a1\u30a2\u30a3 \u62b5\u6297\u662f\u5f92\u52b3\u7684";
+            helper.UnaryHandler = new UnaryServerMethod<string, string>(async (request, context) =>
+            {
+                context.Status = new Status(StatusCode.Unknown, nonAsciiString);
+                return "";
+            });
+
+            var ex = Assert.Throws<RpcException>(() => Calls.BlockingUnaryCall(helper.CreateUnaryCall(), "abc"));
+            Assert.AreEqual(StatusCode.Unknown, ex.Status.StatusCode);
+            Assert.AreEqual(nonAsciiString, ex.Status.Detail);
+        }
+
+        [Test]
         public void ServerCallContext_PeerInfoPresent()
         {
             helper.UnaryHandler = new UnaryServerMethod<string, string>(async (request, context) =>
diff --git a/src/csharp/Grpc.Core/Internal/BatchContextSafeHandle.cs b/src/csharp/Grpc.Core/Internal/BatchContextSafeHandle.cs
index 0e4a77be81..efae149f09 100644
--- a/src/csharp/Grpc.Core/Internal/BatchContextSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/BatchContextSafeHandle.cs
@@ -33,6 +33,7 @@
 
 using System;
 using System.Runtime.InteropServices;
+using System.Text;
 using Grpc.Core;
 
 namespace Grpc.Core.Internal
@@ -42,6 +43,7 @@ namespace Grpc.Core.Internal
     /// </summary>
     internal class BatchContextSafeHandle : SafeHandleZeroIsInvalid
     {
+        static readonly Encoding EncodingUTF8 = System.Text.Encoding.UTF8;
         static readonly NativeMethods Native = NativeMethods.Get();
 
         private BatchContextSafeHandle()
@@ -73,7 +75,7 @@ namespace Grpc.Core.Internal
         {
             UIntPtr detailsLength;
             IntPtr detailsPtr = Native.grpcsharp_batch_context_recv_status_on_client_details(this, out detailsLength);
-            string details = Marshal.PtrToStringAnsi(detailsPtr, (int) detailsLength.ToUInt32());
+            string details = PtrToStringUtf8(detailsPtr, (int) detailsLength.ToUInt32());
             var status = new Status(Native.grpcsharp_batch_context_recv_status_on_client_status(this), details);
 
             IntPtr metadataArrayPtr = Native.grpcsharp_batch_context_recv_status_on_client_trailing_metadata(this);
@@ -106,5 +108,12 @@ namespace Grpc.Core.Internal
             Native.grpcsharp_batch_context_destroy(handle);
             return true;
         }
+
+        string PtrToStringUtf8(IntPtr ptr, int len)
+        {
+            var bytes = new byte[len];
+            Marshal.Copy(ptr, bytes, 0, len);
+            return EncodingUTF8.GetString(bytes);
+        }
     }
 }
diff --git a/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs b/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
index 6bfcc7fa74..710ca480e8 100644
--- a/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
@@ -32,6 +32,7 @@
 using System;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
+using System.Text;
 using Grpc.Core;
 using Grpc.Core.Utils;
 using Grpc.Core.Profiling;
@@ -44,6 +45,7 @@ namespace Grpc.Core.Internal
     internal class CallSafeHandle : SafeHandleZeroIsInvalid, INativeCall
     {
         public static readonly CallSafeHandle NullInstance = new CallSafeHandle();
+        static readonly Encoding EncodingUTF8 = System.Text.Encoding.UTF8;
         static readonly NativeMethods Native = NativeMethods.Get();
 
         const uint GRPC_WRITE_BUFFER_HINT = 1;
@@ -138,7 +140,8 @@ namespace Grpc.Core.Internal
                 var ctx = BatchContextSafeHandle.Create();
                 var optionalPayloadLength = optionalPayload != null ? new UIntPtr((ulong)optionalPayload.Length) : UIntPtr.Zero;
                 completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
-                Native.grpcsharp_call_send_status_from_server(this, ctx, status.StatusCode, status.Detail, metadataArray, sendEmptyInitialMetadata,
+                var statusDetailBytes = EncodingUTF8.GetBytes(status.Detail);
+                Native.grpcsharp_call_send_status_from_server(this, ctx, status.StatusCode, statusDetailBytes, new UIntPtr((ulong)statusDetailBytes.Length), metadataArray, sendEmptyInitialMetadata,
                     optionalPayload, optionalPayloadLength, writeFlags).CheckOk();
             }
         }
diff --git a/src/csharp/Grpc.Core/Internal/NativeMethods.cs b/src/csharp/Grpc.Core/Internal/NativeMethods.cs
index 2f377071f7..aff9550e8d 100644
--- a/src/csharp/Grpc.Core/Internal/NativeMethods.cs
+++ b/src/csharp/Grpc.Core/Internal/NativeMethods.cs
@@ -336,7 +336,7 @@ namespace Grpc.Core.Internal
             public delegate CallError grpcsharp_call_send_close_from_client_delegate(CallSafeHandle call,
                 BatchContextSafeHandle ctx);
             public delegate CallError grpcsharp_call_send_status_from_server_delegate(CallSafeHandle call,
-                BatchContextSafeHandle ctx, StatusCode statusCode, string statusMessage, MetadataArraySafeHandle metadataArray, bool sendEmptyInitialMetadata,
+                BatchContextSafeHandle ctx, StatusCode statusCode, byte[] statusMessage, UIntPtr statusMessageLen, MetadataArraySafeHandle metadataArray, bool sendEmptyInitialMetadata,
                 byte[] optionalSendBuffer, UIntPtr optionalSendBufferLen, WriteFlags writeFlags);
             public delegate CallError grpcsharp_call_recv_message_delegate(CallSafeHandle call,
                 BatchContextSafeHandle ctx);
diff --git a/src/csharp/ext/grpc_csharp_ext.c b/src/csharp/ext/grpc_csharp_ext.c
index e308b0229c..e1f4d7cdf3 100644
--- a/src/csharp/ext/grpc_csharp_ext.c
+++ b/src/csharp/ext/grpc_csharp_ext.c
@@ -734,14 +734,15 @@ grpcsharp_call_send_close_from_client(grpc_call *call,
 
 GPR_EXPORT grpc_call_error GPR_CALLTYPE grpcsharp_call_send_status_from_server(
     grpc_call *call, grpcsharp_batch_context *ctx, grpc_status_code status_code,
-    const char *status_details, grpc_metadata_array *trailing_metadata,
+    const char *status_details, size_t status_details_len,
+    grpc_metadata_array *trailing_metadata,
     int32_t send_empty_initial_metadata, const char* optional_send_buffer,
     size_t optional_send_buffer_len, uint32_t write_flags) {
   /* TODO: don't use magic number */
   grpc_op ops[3];
   memset(ops, 0, sizeof(ops));
   size_t nops = 1;
-  grpc_slice status_details_slice = grpc_slice_from_copied_string(status_details);
+  grpc_slice status_details_slice = grpc_slice_from_copied_buffer(status_details, status_details_len);
   ops[0].op = GRPC_OP_SEND_STATUS_FROM_SERVER;
   ops[0].data.send_status_from_server.status = status_code;
   ops[0].data.send_status_from_server.status_details = &status_details_slice;
diff --git a/src/php/composer.json b/src/php/composer.json
index 2d5d555bc2..992f6ac3f6 100644
--- a/src/php/composer.json
+++ b/src/php/composer.json
@@ -1,14 +1,10 @@
 {
-  "name": "grpc/grpc",
-  "type": "library",
-  "description": "gRPC library for PHP",
-  "keywords": ["rpc"],
-  "homepage": "http://grpc.io",
+  "name": "grpc/grpc-dev",
+  "description": "gRPC library for PHP - for Developement use only",
   "license": "BSD-3-Clause",
   "version": "1.1.0",
   "require": {
     "php": ">=5.5.0",
-    "ext-grpc": "*",
     "google/protobuf": "v3.1.0-alpha-1"
   },
   "require-dev": {
@@ -16,7 +12,11 @@
   },
   "autoload": {
     "psr-4": {
-      "Grpc\\": "lib/Grpc/"
+      "Grpc\\": "lib/Grpc/",
+      "Grpc\\Testing\\": "tests/interop/Grpc/Testing/",
+      "GPBMetadata\\Src\\Proto\\Grpc\\Testing\\": "tests/interop/GPBMetadata/Src/Proto/Grpc/Testing/",
+      "Math\\": "tests/generated_code/Math/",
+      "GPBMetadata\\": "tests/generated_code/GPBMetadata/"
     }
   }
 }
diff --git a/src/php/tests/generated_code/AbstractGeneratedCodeTest.php b/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
index 8fe9bc26d8..c50b1c6943 100644
--- a/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
+++ b/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
@@ -32,8 +32,11 @@
  *
  */
 require_once realpath(dirname(__FILE__).'/../../vendor/autoload.php');
-require_once dirname(__FILE__).'/math.pb.php';
-require_once dirname(__FILE__).'/math_grpc_pb.php';
+
+// The following includes are needed when using protobuf 3.1.0
+// and will suppress warnings when using protobuf 3.2.0+
+@include_once dirname(__FILE__).'/math.pb.php';
+@include_once dirname(__FILE__).'/math_grpc_pb.php';
 
 abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 {
@@ -70,7 +73,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
     public function testClose()
     {
         self::$client->close();
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $call = self::$client->Div($div_arg);
     }
 
@@ -79,20 +82,20 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
      */
     public function testInvalidMetadata()
     {
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $call = self::$client->Div($div_arg, [' ' => 'abc123']);
     }
 
     public function testGetCallMetadata()
     {
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $call = self::$client->Div($div_arg);
         $this->assertTrue(is_array($call->getMetadata()));
     }
 
     public function testTimeout()
     {
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $call = self::$client->Div($div_arg, [], ['timeout' => 1]);
         list($response, $status) = $call->wait();
         $this->assertSame(\Grpc\STATUS_DEADLINE_EXCEEDED, $status->code);
@@ -100,7 +103,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 
     public function testCancel()
     {
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $call = self::$client->Div($div_arg);
         $call->cancel();
         list($response, $status) = $call->wait();
@@ -109,7 +112,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 
     public function testCallCredentialsCallback()
     {
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $call = self::$client->Div($div_arg, array(), array(
             'call_credentials_callback' => function ($context) {
                 return array();
@@ -122,7 +125,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 
     public function testCallCredentialsCallback2()
     {
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $call = self::$client->Div($div_arg);
         $call_credentials = Grpc\CallCredentials::createFromPlugin(
             function ($context) {
@@ -143,7 +146,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
         $invalid_client = new DummyInvalidClient('host', [
             'credentials' => Grpc\ChannelCredentials::createInsecure(),
         ]);
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $invalid_client->InvalidUnaryCall($div_arg);
     }
 
@@ -166,7 +169,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 
     public function testWriteFlags()
     {
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $div_arg->setDividend(7);
         $div_arg->setDivisor(4);
         $call = self::$client->Div($div_arg, [],
@@ -180,7 +183,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 
     public function testWriteFlagsServerStreaming()
     {
-        $fib_arg = new math\FibArgs();
+        $fib_arg = new Math\FibArgs();
         $fib_arg->setLimit(7);
         $call = self::$client->Fib($fib_arg, [],
                                    ['flags' => Grpc\WRITE_NO_COMPRESS]);
@@ -192,7 +195,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
     public function testWriteFlagsClientStreaming()
     {
         $call = self::$client->Sum();
-        $num = new math\Num();
+        $num = new Math\Num();
         $num->setNum(1);
         $call->write($num, ['flags' => Grpc\WRITE_NO_COMPRESS]);
         list($response, $status) = $call->wait();
@@ -202,7 +205,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
     public function testWriteFlagsBidiStreaming()
     {
         $call = self::$client->DivMany();
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $div_arg->setDividend(7);
         $div_arg->setDivisor(4);
         $call->write($div_arg, ['flags' => Grpc\WRITE_NO_COMPRESS]);
@@ -214,7 +217,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 
     public function testSimpleRequest()
     {
-        $div_arg = new math\DivArgs();
+        $div_arg = new Math\DivArgs();
         $div_arg->setDividend(7);
         $div_arg->setDivisor(4);
         $call = self::$client->Div($div_arg);
@@ -227,7 +230,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 
     public function testServerStreaming()
     {
-        $fib_arg = new math\FibArgs();
+        $fib_arg = new Math\FibArgs();
         $fib_arg->setLimit(7);
         $call = self::$client->Fib($fib_arg);
         $this->assertTrue(is_string($call->getPeer()));
@@ -246,7 +249,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
         $call = self::$client->Sum();
         $this->assertTrue(is_string($call->getPeer()));
         for ($i = 0; $i < 7; ++$i) {
-            $num = new math\Num();
+            $num = new Math\Num();
             $num->setNum($i);
             $call->write($num);
         }
@@ -260,7 +263,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
         $call = self::$client->DivMany();
         $this->assertTrue(is_string($call->getPeer()));
         for ($i = 0; $i < 7; ++$i) {
-            $div_arg = new math\DivArgs();
+            $div_arg = new Math\DivArgs();
             $div_arg->setDividend(2 * $i + 1);
             $div_arg->setDivisor(2);
             $call->write($div_arg);
@@ -276,7 +279,7 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
 
 class DummyInvalidClient extends \Grpc\BaseStub
 {
-    public function InvalidUnaryCall(\math\DivArgs $argument,
+    public function InvalidUnaryCall(\Math\DivArgs $argument,
                                      $metadata = [],
                                      $options = [])
     {
diff --git a/src/php/tests/generated_code/GeneratedCodeTest.php b/src/php/tests/generated_code/GeneratedCodeTest.php
index 0cdce6cf92..12ba012910 100755
--- a/src/php/tests/generated_code/GeneratedCodeTest.php
+++ b/src/php/tests/generated_code/GeneratedCodeTest.php
@@ -37,7 +37,7 @@ class GeneratedCodeTest extends AbstractGeneratedCodeTest
 {
     public function setUp()
     {
-        self::$client = new math\MathClient(
+        self::$client = new Math\MathClient(
             getenv('GRPC_TEST_HOST'), [
                 'credentials' => Grpc\ChannelCredentials::createInsecure(),
             ]);
diff --git a/src/php/tests/generated_code/GeneratedCodeWithCallbackTest.php b/src/php/tests/generated_code/GeneratedCodeWithCallbackTest.php
index 6b70b8ac10..e1899484ec 100644
--- a/src/php/tests/generated_code/GeneratedCodeWithCallbackTest.php
+++ b/src/php/tests/generated_code/GeneratedCodeWithCallbackTest.php
@@ -37,7 +37,7 @@ class GeneratedCodeWithCallbackTest extends AbstractGeneratedCodeTest
 {
     public function setUp()
     {
-        self::$client = new math\MathClient(
+        self::$client = new Math\MathClient(
         getenv('GRPC_TEST_HOST'),
         ['credentials' => Grpc\ChannelCredentials::createInsecure(),
          'update_metadata' => function ($a_hash,
diff --git a/src/php/tests/interop/interop_client.php b/src/php/tests/interop/interop_client.php
index 2acf5612c7..cf93ac39e0 100755
--- a/src/php/tests/interop/interop_client.php
+++ b/src/php/tests/interop/interop_client.php
@@ -32,8 +32,12 @@
  *
  */
 require_once realpath(dirname(__FILE__).'/../../vendor/autoload.php');
-require 'src/proto/grpc/testing/test.pb.php';
-require 'src/proto/grpc/testing/test_grpc_pb.php';
+
+// The following includes are needed when using protobuf 3.1.0
+// and will suppress warnings when using protobuf 3.2.0+
+@include_once 'src/proto/grpc/testing/test.pb.php';
+@include_once 'src/proto/grpc/testing/test_grpc_pb.php';
+
 use Google\Auth\CredentialsLoader;
 use Google\Auth\ApplicationDefaultCredentials;
 use GuzzleHttp\ClientInterface;
@@ -70,7 +74,7 @@ function hardAssertIfStatusOk($status)
 function emptyUnary($stub)
 {
     list($result, $status) =
-        $stub->EmptyCall(new grpc\testing\EmptyMessage())->wait();
+        $stub->EmptyCall(new Grpc\Testing\EmptyMessage())->wait();
     hardAssertIfStatusOk($status);
     hardAssert($result !== null, 'Call completed with a null response');
 }
@@ -98,11 +102,11 @@ function performLargeUnary($stub, $fillUsername = false,
     $request_len = 271828;
     $response_len = 314159;
 
-    $request = new grpc\testing\SimpleRequest();
-    $request->setResponseType(grpc\testing\PayloadType::COMPRESSABLE);
+    $request = new Grpc\Testing\SimpleRequest();
+    $request->setResponseType(Grpc\Testing\PayloadType::COMPRESSABLE);
     $request->setResponseSize($response_len);
-    $payload = new grpc\testing\Payload();
-    $payload->setType(grpc\testing\PayloadType::COMPRESSABLE);
+    $payload = new Grpc\Testing\Payload();
+    $payload->setType(Grpc\Testing\PayloadType::COMPRESSABLE);
     $payload->setBody(str_repeat("\0", $request_len));
     $request->setPayload($payload);
     $request->setFillUsername($fillUsername);
@@ -117,7 +121,7 @@ function performLargeUnary($stub, $fillUsername = false,
     hardAssertIfStatusOk($status);
     hardAssert($result !== null, 'Call returned a null response');
     $payload = $result->getPayload();
-    hardAssert($payload->getType() === grpc\testing\PayloadType::COMPRESSABLE,
+    hardAssert($payload->getType() === Grpc\Testing\PayloadType::COMPRESSABLE,
                'Payload had the wrong type');
     hardAssert(strlen($payload->getBody()) === $response_len,
                'Payload had the wrong length');
@@ -249,8 +253,8 @@ function clientStreaming($stub)
 
     $requests = array_map(
         function ($length) {
-            $request = new grpc\testing\StreamingInputCallRequest();
-            $payload = new grpc\testing\Payload();
+            $request = new Grpc\Testing\StreamingInputCallRequest();
+            $payload = new Grpc\Testing\Payload();
             $payload->setBody(str_repeat("\0", $length));
             $request->setPayload($payload);
 
@@ -276,10 +280,10 @@ function serverStreaming($stub)
 {
     $sizes = [31415, 9, 2653, 58979];
 
-    $request = new grpc\testing\StreamingOutputCallRequest();
-    $request->setResponseType(grpc\testing\PayloadType::COMPRESSABLE);
+    $request = new Grpc\Testing\StreamingOutputCallRequest();
+    $request->setResponseType(Grpc\Testing\PayloadType::COMPRESSABLE);
     foreach ($sizes as $size) {
-        $response_parameters = new grpc\testing\ResponseParameters();
+        $response_parameters = new Grpc\Testing\ResponseParameters();
         $response_parameters->setSize($size);
         $request->getResponseParameters()[] = $response_parameters;
     }
@@ -290,7 +294,7 @@ function serverStreaming($stub)
         hardAssert($i < 4, 'Too many responses');
         $payload = $value->getPayload();
         hardAssert(
-            $payload->getType() === grpc\testing\PayloadType::COMPRESSABLE,
+            $payload->getType() === Grpc\Testing\PayloadType::COMPRESSABLE,
             'Payload '.$i.' had the wrong type');
         hardAssert(strlen($payload->getBody()) === $sizes[$i],
                    'Response '.$i.' had the wrong length');
@@ -311,12 +315,12 @@ function pingPong($stub)
 
     $call = $stub->FullDuplexCall();
     for ($i = 0; $i < 4; ++$i) {
-        $request = new grpc\testing\StreamingOutputCallRequest();
-        $request->setResponseType(grpc\testing\PayloadType::COMPRESSABLE);
-        $response_parameters = new grpc\testing\ResponseParameters();
+        $request = new Grpc\Testing\StreamingOutputCallRequest();
+        $request->setResponseType(Grpc\Testing\PayloadType::COMPRESSABLE);
+        $response_parameters = new Grpc\Testing\ResponseParameters();
         $response_parameters->setSize($response_lengths[$i]);
         $request->getResponseParameters()[] = $response_parameters;
-        $payload = new grpc\testing\Payload();
+        $payload = new Grpc\Testing\Payload();
         $payload->setBody(str_repeat("\0", $request_lengths[$i]));
         $request->setPayload($payload);
 
@@ -326,7 +330,7 @@ function pingPong($stub)
         hardAssert($response !== null, 'Server returned too few responses');
         $payload = $response->getPayload();
         hardAssert(
-            $payload->getType() === grpc\testing\PayloadType::COMPRESSABLE,
+            $payload->getType() === Grpc\Testing\PayloadType::COMPRESSABLE,
             'Payload '.$i.' had the wrong type');
         hardAssert(strlen($payload->getBody()) === $response_lengths[$i],
                    'Payload '.$i.' had the wrong length');
@@ -371,12 +375,12 @@ function cancelAfterBegin($stub)
 function cancelAfterFirstResponse($stub)
 {
     $call = $stub->FullDuplexCall();
-    $request = new grpc\testing\StreamingOutputCallRequest();
-    $request->setResponseType(grpc\testing\PayloadType::COMPRESSABLE);
-    $response_parameters = new grpc\testing\ResponseParameters();
+    $request = new Grpc\Testing\StreamingOutputCallRequest();
+    $request->setResponseType(Grpc\Testing\PayloadType::COMPRESSABLE);
+    $response_parameters = new Grpc\Testing\ResponseParameters();
     $response_parameters->setSize(31415);
     $request->getResponseParameters()[] = $response_parameters;
-    $payload = new grpc\testing\Payload();
+    $payload = new Grpc\Testing\Payload();
     $payload->setBody(str_repeat("\0", 27182));
     $request->setPayload($payload);
 
@@ -391,12 +395,12 @@ function cancelAfterFirstResponse($stub)
 function timeoutOnSleepingServer($stub)
 {
     $call = $stub->FullDuplexCall([], ['timeout' => 1000]);
-    $request = new grpc\testing\StreamingOutputCallRequest();
-    $request->setResponseType(grpc\testing\PayloadType::COMPRESSABLE);
-    $response_parameters = new grpc\testing\ResponseParameters();
+    $request = new Grpc\Testing\StreamingOutputCallRequest();
+    $request->setResponseType(Grpc\Testing\PayloadType::COMPRESSABLE);
+    $response_parameters = new Grpc\Testing\ResponseParameters();
     $response_parameters->setSize(8);
     $request->getResponseParameters()[] = $response_parameters;
-    $payload = new grpc\testing\Payload();
+    $payload = new Grpc\Testing\Payload();
     $payload->setBody(str_repeat("\0", 9));
     $request->setPayload($payload);
 
@@ -416,11 +420,11 @@ function customMetadata($stub)
     $request_len = 271828;
     $response_len = 314159;
 
-    $request = new grpc\testing\SimpleRequest();
-    $request->setResponseType(grpc\testing\PayloadType::COMPRESSABLE);
+    $request = new Grpc\Testing\SimpleRequest();
+    $request->setResponseType(Grpc\Testing\PayloadType::COMPRESSABLE);
     $request->setResponseSize($response_len);
-    $payload = new grpc\testing\Payload();
-    $payload->setType(grpc\testing\PayloadType::COMPRESSABLE);
+    $payload = new Grpc\Testing\Payload();
+    $payload->setType(Grpc\Testing\PayloadType::COMPRESSABLE);
     $payload->setBody(str_repeat("\0", $request_len));
     $request->setPayload($payload);
 
@@ -449,9 +453,9 @@ function customMetadata($stub)
 
     $streaming_call = $stub->FullDuplexCall($metadata);
 
-    $streaming_request = new grpc\testing\StreamingOutputCallRequest();
+    $streaming_request = new Grpc\Testing\StreamingOutputCallRequest();
     $streaming_request->setPayload($payload);
-    $response_parameters = new grpc\testing\ResponseParameters();
+    $response_parameters = new Grpc\Testing\ResponseParameters();
     $response_parameters->setSize($response_len);
     $streaming_request->getResponseParameters()[] = $response_parameters;
     $streaming_call->write($streaming_request);
@@ -477,11 +481,11 @@ function customMetadata($stub)
 
 function statusCodeAndMessage($stub)
 {
-    $echo_status = new grpc\testing\EchoStatus();
+    $echo_status = new Grpc\Testing\EchoStatus();
     $echo_status->setCode(2);
     $echo_status->setMessage('test status message');
 
-    $request = new grpc\testing\SimpleRequest();
+    $request = new Grpc\Testing\SimpleRequest();
     $request->setResponseStatus($echo_status);
 
     $call = $stub->UnaryCall($request);
@@ -496,7 +500,7 @@ function statusCodeAndMessage($stub)
 
     $streaming_call = $stub->FullDuplexCall();
 
-    $streaming_request = new grpc\testing\StreamingOutputCallRequest();
+    $streaming_request = new Grpc\Testing\StreamingOutputCallRequest();
     $streaming_request->setResponseStatus($echo_status);
     $streaming_call->write($streaming_request);
     $streaming_call->writesDone();
@@ -514,7 +518,7 @@ function statusCodeAndMessage($stub)
 # NOTE: the stub input to this function is from UnimplementedService
 function unimplementedService($stub)
 {
-    $call = $stub->UnimplementedCall(new grpc\testing\EmptyMessage());
+    $call = $stub->UnimplementedCall(new Grpc\Testing\EmptyMessage());
     list($result, $status) = $call->wait();
     hardAssert($status->code === Grpc\STATUS_UNIMPLEMENTED,
                'Received unexpected status code');
@@ -523,7 +527,7 @@ function unimplementedService($stub)
 # NOTE: the stub input to this function is from TestService
 function unimplementedMethod($stub)
 {
-    $call = $stub->UnimplementedCall(new grpc\testing\EmptyMessage());
+    $call = $stub->UnimplementedCall(new Grpc\Testing\EmptyMessage());
     list($result, $status) = $call->wait();
     hardAssert($status->code === Grpc\STATUS_UNIMPLEMENTED,
                'Received unexpected status code');
@@ -614,10 +618,10 @@ function _makeStub($args)
     }
 
     if ($test_case === 'unimplemented_service') {
-        $stub = new grpc\testing\UnimplementedServiceClient($server_address,
+        $stub = new Grpc\Testing\UnimplementedServiceClient($server_address,
                                                             $opts);
     } else {
-        $stub = new grpc\testing\TestServiceClient($server_address, $opts);
+        $stub = new Grpc\Testing\TestServiceClient($server_address, $opts);
     }
 
     return $stub;
diff --git a/src/proto/grpc/testing/BUILD b/src/proto/grpc/testing/BUILD
index 283740839d..23a16a7cfc 100644
--- a/src/proto/grpc/testing/BUILD
+++ b/src/proto/grpc/testing/BUILD
@@ -42,11 +42,13 @@ grpc_proto_library(
     name = "control_proto",
     srcs = ["control.proto"],
     deps = ["payloads_proto", "stats_proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
     name = "echo_messages_proto",
     srcs = ["echo_messages.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
@@ -58,11 +60,13 @@ grpc_proto_library(
 grpc_proto_library(
     name = "empty_proto",
     srcs = ["empty.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
     name = "messages_proto",
     srcs = ["messages.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
@@ -73,6 +77,7 @@ grpc_proto_library(
 grpc_proto_library(
     name = "payloads_proto",
     srcs = ["payloads.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
@@ -84,6 +89,7 @@ grpc_proto_library(
 grpc_proto_library(
     name = "stats_proto",
     srcs = ["stats.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
diff --git a/src/python/grpcio/grpc/_channel.py b/src/python/grpcio/grpc/_channel.py
index 5a8a3d487a..77412236cc 100644
--- a/src/python/grpcio/grpc/_channel.py
+++ b/src/python/grpcio/grpc/_channel.py
@@ -842,8 +842,8 @@ def _poll_connectivity(state, channel, 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])
+            _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)
diff --git a/src/python/grpcio/grpc/beta/_server_adaptations.py b/src/python/grpcio/grpc/beta/_server_adaptations.py
index bb7c0960d5..206bd7e468 100644
--- a/src/python/grpcio/grpc/beta/_server_adaptations.py
+++ b/src/python/grpcio/grpc/beta/_server_adaptations.py
@@ -393,5 +393,4 @@ def server(service_implementations, multi_method_implementation,
     else:
         effective_thread_pool = thread_pool
     return _Server(
-        grpc.server(
-            effective_thread_pool, handlers=(generic_rpc_handler,)))
+        grpc.server(effective_thread_pool, handlers=(generic_rpc_handler,)))
diff --git a/src/python/grpcio/grpc/framework/foundation/logging_pool.py b/src/python/grpcio/grpc/framework/foundation/logging_pool.py
index 9164173d34..7ee37373fa 100644
--- a/src/python/grpcio/grpc/framework/foundation/logging_pool.py
+++ b/src/python/grpcio/grpc/framework/foundation/logging_pool.py
@@ -64,9 +64,8 @@ class _LoggingPool(object):
         return self._backing_pool.submit(_wrap(fn), *args, **kwargs)
 
     def map(self, func, *iterables, **kwargs):
-        return self._backing_pool.map(_wrap(func),
-                                      *iterables,
-                                      timeout=kwargs.get('timeout', None))
+        return self._backing_pool.map(
+            _wrap(func), *iterables, timeout=kwargs.get('timeout', None))
 
     def shutdown(self, wait=True):
         self._backing_pool.shutdown(wait=wait)
diff --git a/src/python/grpcio_tests/tests/interop/methods.py b/src/python/grpcio_tests/tests/interop/methods.py
index bdb258591e..1f9b356eb2 100644
--- a/src/python/grpcio_tests/tests/interop/methods.py
+++ b/src/python/grpcio_tests/tests/interop/methods.py
@@ -351,8 +351,7 @@ def _status_code_and_message(stub):
         response_type=messages_pb2.COMPRESSABLE,
         response_size=1,
         payload=messages_pb2.Payload(body=b'\x00'),
-        response_status=messages_pb2.EchoStatus(
-            code=code, message=details))
+        response_status=messages_pb2.EchoStatus(code=code, message=details))
     response_future = stub.UnaryCall.future(request)
     _validate_status_code_and_details(response_future, status, details)
 
@@ -363,8 +362,7 @@ def _status_code_and_message(stub):
             response_type=messages_pb2.COMPRESSABLE,
             response_parameters=(messages_pb2.ResponseParameters(size=1),),
             payload=messages_pb2.Payload(body=b'\x00'),
-            response_status=messages_pb2.EchoStatus(
-                code=code, message=details))
+            response_status=messages_pb2.EchoStatus(code=code, message=details))
         pipe.add(request)  # sends the initial request.
     # Dropping out of with block closes the pipe
     _validate_status_code_and_details(response_iterator, status, details)
@@ -428,8 +426,8 @@ def _compute_engine_creds(stub, args):
 
 
 def _oauth2_auth_token(stub, args):
-    json_key_filename = os.environ[oauth2client_client.
-                                   GOOGLE_APPLICATION_CREDENTIALS]
+    json_key_filename = os.environ[
+        oauth2client_client.GOOGLE_APPLICATION_CREDENTIALS]
     wanted_email = json.load(open(json_key_filename, 'rb'))['client_email']
     response = _large_unary_common_behavior(stub, True, True, None)
     if wanted_email != response.username:
@@ -441,8 +439,8 @@ def _oauth2_auth_token(stub, args):
 
 
 def _jwt_token_creds(stub, args):
-    json_key_filename = os.environ[oauth2client_client.
-                                   GOOGLE_APPLICATION_CREDENTIALS]
+    json_key_filename = os.environ[
+        oauth2client_client.GOOGLE_APPLICATION_CREDENTIALS]
     wanted_email = json.load(open(json_key_filename, 'rb'))['client_email']
     response = _large_unary_common_behavior(stub, True, False, None)
     if wanted_email != response.username:
@@ -451,8 +449,8 @@ def _jwt_token_creds(stub, args):
 
 
 def _per_rpc_creds(stub, args):
-    json_key_filename = os.environ[oauth2client_client.
-                                   GOOGLE_APPLICATION_CREDENTIALS]
+    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])
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_channel_test.py b/src/python/grpcio_tests/tests/unit/_cython/_channel_test.py
index 0ca06868b2..5c7f903015 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_channel_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_channel_test.py
@@ -59,8 +59,7 @@ def _create_loop_destroy():
 
 def _in_parallel(behavior, arguments):
     threads = tuple(
-        threading.Thread(
-            target=behavior, args=arguments)
+        threading.Thread(target=behavior, args=arguments)
         for _ in range(test_constants.THREAD_CONCURRENCY))
     for thread in threads:
         thread.start()
diff --git a/templates/composer.json.template b/templates/composer.json.template
index 3b4d62f24d..accfb382a9 100644
--- a/templates/composer.json.template
+++ b/templates/composer.json.template
@@ -9,7 +9,6 @@
     "license": "BSD-3-Clause",
     "require": {
       "php": ">=5.5.0",
-      "ext-grpc": "*",
       "google/protobuf": "v3.1.0-alpha-1"
     },
     "require-dev": {
diff --git a/templates/src/php/composer.json.template b/templates/src/php/composer.json.template
index 12a4ce8f83..5223efd23f 100644
--- a/templates/src/php/composer.json.template
+++ b/templates/src/php/composer.json.template
@@ -1,16 +1,12 @@
 %YAML 1.2
 --- |
   {
-    "name": "grpc/grpc",
-    "type": "library",
-    "description": "gRPC library for PHP",
-    "keywords": ["rpc"],
-    "homepage": "http://grpc.io",
+    "name": "grpc/grpc-dev",
+    "description": "gRPC library for PHP - for Developement use only",
     "license": "BSD-3-Clause",
     "version": "${settings.php_version.php_composer()}",
     "require": {
       "php": ">=5.5.0",
-      "ext-grpc": "*",
       "google/protobuf": "v3.1.0-alpha-1"
     },
     "require-dev": {
@@ -18,7 +14,11 @@
     },
     "autoload": {
       "psr-4": {
-        "Grpc\\": "lib/Grpc/"
+        "Grpc\\": "lib/Grpc/",
+        "Grpc\\Testing\\": "tests/interop/Grpc/Testing/",
+        "GPBMetadata\\Src\\Proto\\Grpc\\Testing\\": "tests/interop/GPBMetadata/Src/Proto/Grpc/Testing/",
+        "Math\\": "tests/generated_code/Math/",
+        "GPBMetadata\\": "tests/generated_code/GPBMetadata/"
       }
     }
   }
diff --git a/test/core/bad_client/bad_client.c b/test/core/bad_client/bad_client.c
index a84086804c..b7e7606b18 100644
--- a/test/core/bad_client/bad_client.c
+++ b/test/core/bad_client/bad_client.c
@@ -163,7 +163,8 @@ void grpc_run_bad_client_test(
       gpr_event_wait(&a.done_write, GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5)));
 
   if (flags & GRPC_BAD_CLIENT_DISCONNECT) {
-    grpc_endpoint_shutdown(&exec_ctx, sfd.client);
+    grpc_endpoint_shutdown(&exec_ctx, sfd.client,
+                           GRPC_ERROR_CREATE("Forced Disconnect"));
     grpc_endpoint_destroy(&exec_ctx, sfd.client);
     grpc_exec_ctx_finish(&exec_ctx);
     sfd.client = NULL;
@@ -189,7 +190,8 @@ void grpc_run_bad_client_test(
       grpc_slice_buffer_destroy_internal(&exec_ctx, &args.incoming);
     }
     // Shutdown.
-    grpc_endpoint_shutdown(&exec_ctx, sfd.client);
+    grpc_endpoint_shutdown(&exec_ctx, sfd.client,
+                           GRPC_ERROR_CREATE("Test Shutdown"));
     grpc_endpoint_destroy(&exec_ctx, sfd.client);
     grpc_exec_ctx_finish(&exec_ctx);
   }
diff --git a/test/core/client_channel/set_initial_connect_string_test.c b/test/core/client_channel/set_initial_connect_string_test.c
index fc0aca0434..a0a33667cc 100644
--- a/test/core/client_channel/set_initial_connect_string_test.c
+++ b/test/core/client_channel/set_initial_connect_string_test.c
@@ -81,7 +81,9 @@ static void handle_read(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
           state.incoming_buffer.length, strlen(magic_connect_string));
   if (state.incoming_buffer.length > strlen(magic_connect_string)) {
     gpr_atm_rel_store(&state.done_atm, 1);
-    grpc_endpoint_shutdown(exec_ctx, state.tcp);
+    grpc_endpoint_shutdown(
+        exec_ctx, state.tcp,
+        GRPC_ERROR_CREATE("Incoming buffer longer than magic_connect_string"));
     grpc_endpoint_destroy(exec_ctx, state.tcp);
   } else {
     grpc_endpoint_read(exec_ctx, state.tcp, &state.temp_incoming_buffer,
diff --git a/test/core/end2end/bad_server_response_test.c b/test/core/end2end/bad_server_response_test.c
index 42bf4fa235..d5f428eb82 100644
--- a/test/core/end2end/bad_server_response_test.c
+++ b/test/core/end2end/bad_server_response_test.c
@@ -298,7 +298,8 @@ static void run_test(const char *response_payload,
   gpr_event_wait(&ev, gpr_inf_future(GPR_CLOCK_REALTIME));
 
   /* clean up */
-  grpc_endpoint_shutdown(&exec_ctx, state.tcp);
+  grpc_endpoint_shutdown(&exec_ctx, state.tcp,
+                         GRPC_ERROR_CREATE("Test Shutdown"));
   grpc_endpoint_destroy(&exec_ctx, state.tcp);
   cleanup_rpc(&exec_ctx);
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/test/core/end2end/fixtures/http_proxy.c b/test/core/end2end/fixtures/http_proxy.c
index dac9baf3ce..6fdc86fc12 100644
--- a/test/core/end2end/fixtures/http_proxy.c
+++ b/test/core/end2end/fixtures/http_proxy.c
@@ -133,9 +133,12 @@ static void proxy_connection_failed(grpc_exec_ctx* exec_ctx,
   const char* msg = grpc_error_string(error);
   gpr_log(GPR_INFO, "%s: %s", prefix, msg);
 
-  grpc_endpoint_shutdown(exec_ctx, conn->client_endpoint);
-  if (conn->server_endpoint != NULL)
-    grpc_endpoint_shutdown(exec_ctx, conn->server_endpoint);
+  grpc_endpoint_shutdown(exec_ctx, conn->client_endpoint,
+                         GRPC_ERROR_REF(error));
+  if (conn->server_endpoint != NULL) {
+    grpc_endpoint_shutdown(exec_ctx, conn->server_endpoint,
+                           GRPC_ERROR_REF(error));
+  }
   proxy_connection_unref(exec_ctx, conn);
 }
 
diff --git a/test/core/end2end/fuzzers/api_fuzzer.c b/test/core/end2end/fuzzers/api_fuzzer.c
index 593c1bb69a..2569579739 100644
--- a/test/core/end2end/fuzzers/api_fuzzer.c
+++ b/test/core/end2end/fuzzers/api_fuzzer.c
@@ -604,12 +604,12 @@ static call_state *maybe_delete_call_state(call_state *call) {
   grpc_slice_unref(call->recv_status_details);
   grpc_call_details_destroy(&call->call_details);
 
-  for (size_t i = 0; i < call->num_to_free; i++) {
-    gpr_free(call->to_free[i]);
-  }
   for (size_t i = 0; i < call->num_slices_to_unref; i++) {
     grpc_slice_unref(call->slices_to_unref[i]);
   }
+  for (size_t i = 0; i < call->num_to_free; i++) {
+    gpr_free(call->to_free[i]);
+  }
   gpr_free(call->to_free);
   gpr_free(call->slices_to_unref);
 
@@ -627,7 +627,7 @@ static void add_to_free(call_state *call, void *p) {
   call->to_free[call->num_to_free++] = p;
 }
 
-static grpc_slice *add_to_slice_unref(call_state *call, grpc_slice s) {
+static grpc_slice *add_slice_to_unref(call_state *call, grpc_slice s) {
   if (call->num_slices_to_unref == call->cap_slices_to_unref) {
     call->cap_slices_to_unref = GPR_MAX(8, 2 * call->cap_slices_to_unref);
     call->slices_to_unref =
@@ -648,8 +648,8 @@ static void read_metadata(input_stream *inp, size_t *count,
       (*metadata)[i].key = read_string_like_slice(inp);
       (*metadata)[i].value = read_buffer_like_slice(inp);
       (*metadata)[i].flags = read_uint32(inp);
-      add_to_slice_unref(cs, (*metadata)[i].key);
-      add_to_slice_unref(cs, (*metadata)[i].value);
+      add_slice_to_unref(cs, (*metadata)[i].key);
+      add_slice_to_unref(cs, (*metadata)[i].value);
     }
   } else {
     *metadata = gpr_malloc(1);
@@ -1008,7 +1008,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
                   g_active_call);
               op->data.send_status_from_server.status = next_byte(&inp);
               op->data.send_status_from_server.status_details =
-                  add_to_slice_unref(g_active_call,
+                  add_slice_to_unref(g_active_call,
                                      read_buffer_like_slice(&inp));
               break;
             case GRPC_OP_RECV_INITIAL_METADATA:
@@ -1056,22 +1056,6 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
           grpc_byte_buffer_destroy(g_active_call->send_message);
           g_active_call->send_message = NULL;
         }
-        for (i = 0; i < num_ops; i++) {
-          op = &ops[i];
-          switch (op->op) {
-            case GRPC_OP_SEND_STATUS_FROM_SERVER:
-              gpr_free((void *)op->data.send_status_from_server.status_details);
-              break;
-            case GRPC_OP_SEND_MESSAGE:
-            case GRPC_OP_SEND_INITIAL_METADATA:
-            case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
-            case GRPC_OP_RECV_INITIAL_METADATA:
-            case GRPC_OP_RECV_MESSAGE:
-            case GRPC_OP_RECV_STATUS_ON_CLIENT:
-            case GRPC_OP_RECV_CLOSE_ON_SERVER:
-              break;
-          }
-        }
         gpr_free(ops);
 
         break;
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/0242a9f4d4fafc96ee9ed762b610e3c68d6efdec b/test/core/end2end/fuzzers/api_fuzzer_corpus/0242a9f4d4fafc96ee9ed762b610e3c68d6efdec
new file mode 100644
index 0000000000..392ad08c09
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/0242a9f4d4fafc96ee9ed762b610e3c68d6efdec
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/0cd9696699bd190463ecef91968624601b64cd8b b/test/core/end2end/fuzzers/api_fuzzer_corpus/0cd9696699bd190463ecef91968624601b64cd8b
new file mode 100644
index 0000000000..92125efaa5
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/0cd9696699bd190463ecef91968624601b64cd8b
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/122b6fc72956541812dd653b726b073b77ca33be b/test/core/end2end/fuzzers/api_fuzzer_corpus/122b6fc72956541812dd653b726b073b77ca33be
new file mode 100644
index 0000000000..e6eb181351
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/122b6fc72956541812dd653b726b073b77ca33be
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/315d27e12f2214a56fb9901dacff14852ff2ac0f b/test/core/end2end/fuzzers/api_fuzzer_corpus/315d27e12f2214a56fb9901dacff14852ff2ac0f
new file mode 100644
index 0000000000..379a1576a9
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/315d27e12f2214a56fb9901dacff14852ff2ac0f
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/3f2429e3255ae36fecb57559b57d2b0cb88f5dd1 b/test/core/end2end/fuzzers/api_fuzzer_corpus/3f2429e3255ae36fecb57559b57d2b0cb88f5dd1
new file mode 100644
index 0000000000..83419944d4
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/3f2429e3255ae36fecb57559b57d2b0cb88f5dd1
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/41bda7ff09175f821992adf4314a8ec3007ffe55 b/test/core/end2end/fuzzers/api_fuzzer_corpus/41bda7ff09175f821992adf4314a8ec3007ffe55
new file mode 100644
index 0000000000..a89e88e48f
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/41bda7ff09175f821992adf4314a8ec3007ffe55
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/49d0085058d7fa81247f51b802c0f4206854b4dc b/test/core/end2end/fuzzers/api_fuzzer_corpus/49d0085058d7fa81247f51b802c0f4206854b4dc
new file mode 100644
index 0000000000..052fa854ee
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/49d0085058d7fa81247f51b802c0f4206854b4dc
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/614dbc86b17270ef1d5ab705ecbe88c742815ce7 b/test/core/end2end/fuzzers/api_fuzzer_corpus/614dbc86b17270ef1d5ab705ecbe88c742815ce7
new file mode 100644
index 0000000000..8fdff18222
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/614dbc86b17270ef1d5ab705ecbe88c742815ce7
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/6cb17148d52be437332b6fd6f2fc8328bfb63fb0 b/test/core/end2end/fuzzers/api_fuzzer_corpus/6cb17148d52be437332b6fd6f2fc8328bfb63fb0
new file mode 100644
index 0000000000..36d98fea76
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/6cb17148d52be437332b6fd6f2fc8328bfb63fb0
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/6ea192b1d4c4577ca7511f8ce5027b31b2e0d75d b/test/core/end2end/fuzzers/api_fuzzer_corpus/6ea192b1d4c4577ca7511f8ce5027b31b2e0d75d
new file mode 100644
index 0000000000..a31fcf596c
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/6ea192b1d4c4577ca7511f8ce5027b31b2e0d75d
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/746477e7e8f093f87cb6924ab6476cda9689607d b/test/core/end2end/fuzzers/api_fuzzer_corpus/746477e7e8f093f87cb6924ab6476cda9689607d
new file mode 100644
index 0000000000..e348c19028
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/746477e7e8f093f87cb6924ab6476cda9689607d
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/7752153d87017b85112a49ea95aa25ca78d24431 b/test/core/end2end/fuzzers/api_fuzzer_corpus/7752153d87017b85112a49ea95aa25ca78d24431
new file mode 100644
index 0000000000..8e9b21a777
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/7752153d87017b85112a49ea95aa25ca78d24431
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/7e75ea44aa7347c2f827beecb27e3bf5b1907b8a b/test/core/end2end/fuzzers/api_fuzzer_corpus/7e75ea44aa7347c2f827beecb27e3bf5b1907b8a
new file mode 100644
index 0000000000..c5963737d3
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/7e75ea44aa7347c2f827beecb27e3bf5b1907b8a
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/95e73caecc0ab06beaa9b84125adcb2e6eee2eff b/test/core/end2end/fuzzers/api_fuzzer_corpus/95e73caecc0ab06beaa9b84125adcb2e6eee2eff
new file mode 100644
index 0000000000..67fecc095d
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/95e73caecc0ab06beaa9b84125adcb2e6eee2eff
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/9e273a94bf3c60f1c7875874c81d0b9309428752 b/test/core/end2end/fuzzers/api_fuzzer_corpus/9e273a94bf3c60f1c7875874c81d0b9309428752
new file mode 100644
index 0000000000..8c91bb1f0d
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/9e273a94bf3c60f1c7875874c81d0b9309428752
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/a65bda38b60ae084a5dcc3b616660aa338feef17 b/test/core/end2end/fuzzers/api_fuzzer_corpus/a65bda38b60ae084a5dcc3b616660aa338feef17
new file mode 100644
index 0000000000..cd7537592c
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/a65bda38b60ae084a5dcc3b616660aa338feef17
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/b39f27387a256019038cddb91f65651c01afb825 b/test/core/end2end/fuzzers/api_fuzzer_corpus/b39f27387a256019038cddb91f65651c01afb825
new file mode 100644
index 0000000000..a1e335bd01
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/b39f27387a256019038cddb91f65651c01afb825
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/b6f721156f8dc6a353555929e459e61bab8b394a b/test/core/end2end/fuzzers/api_fuzzer_corpus/b6f721156f8dc6a353555929e459e61bab8b394a
new file mode 100644
index 0000000000..43986eae54
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/b6f721156f8dc6a353555929e459e61bab8b394a
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/bbb2429766a7c4ef9cb7110d567fd48cd6507dc5 b/test/core/end2end/fuzzers/api_fuzzer_corpus/bbb2429766a7c4ef9cb7110d567fd48cd6507dc5
new file mode 100644
index 0000000000..017a4775f8
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/bbb2429766a7c4ef9cb7110d567fd48cd6507dc5
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/bc330aa616a792ff22a8c7428dcdb4d99accbe4b b/test/core/end2end/fuzzers/api_fuzzer_corpus/bc330aa616a792ff22a8c7428dcdb4d99accbe4b
new file mode 100644
index 0000000000..a046eae7b3
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/bc330aa616a792ff22a8c7428dcdb4d99accbe4b
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/cd4ccfa79f65f31716296e690f3a76007edde2e3 b/test/core/end2end/fuzzers/api_fuzzer_corpus/cd4ccfa79f65f31716296e690f3a76007edde2e3
new file mode 100644
index 0000000000..2a19daf6c7
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/cd4ccfa79f65f31716296e690f3a76007edde2e3
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/crash-5d73de981fb75553a7b2606e111716ee9f2af844 b/test/core/end2end/fuzzers/api_fuzzer_corpus/crash-5d73de981fb75553a7b2606e111716ee9f2af844
new file mode 100644
index 0000000000..6c25c18eae
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/crash-5d73de981fb75553a7b2606e111716ee9f2af844
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/e6b74f64e8bdfdf98177aee58b8729ff2aa7ffb2 b/test/core/end2end/fuzzers/api_fuzzer_corpus/e6b74f64e8bdfdf98177aee58b8729ff2aa7ffb2
new file mode 100644
index 0000000000..cc011513d3
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/e6b74f64e8bdfdf98177aee58b8729ff2aa7ffb2
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/edecc59c5809796f266abd8df4d5ecf6aae304ca b/test/core/end2end/fuzzers/api_fuzzer_corpus/edecc59c5809796f266abd8df4d5ecf6aae304ca
new file mode 100644
index 0000000000..805106a4fc
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/edecc59c5809796f266abd8df4d5ecf6aae304ca
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/f1b2889ae7091d6a14332343fe7a2bffd81039a7 b/test/core/end2end/fuzzers/api_fuzzer_corpus/f1b2889ae7091d6a14332343fe7a2bffd81039a7
new file mode 100644
index 0000000000..e7f28070f6
--- /dev/null
+++ b/test/core/end2end/fuzzers/api_fuzzer_corpus/f1b2889ae7091d6a14332343fe7a2bffd81039a7
diff --git a/test/core/internal_api_canaries/iomgr.c b/test/core/internal_api_canaries/iomgr.c
index 3225b9dc19..d73d5c175c 100644
--- a/test/core/internal_api_canaries/iomgr.c
+++ b/test/core/internal_api_canaries/iomgr.c
@@ -92,7 +92,7 @@ static void test_code(void) {
   grpc_endpoint_read(&exec_ctx, &endpoint, NULL, NULL);
   grpc_endpoint_get_peer(&endpoint);
   grpc_endpoint_write(&exec_ctx, &endpoint, NULL, NULL);
-  grpc_endpoint_shutdown(&exec_ctx, &endpoint);
+  grpc_endpoint_shutdown(&exec_ctx, &endpoint, GRPC_ERROR_CANCELLED);
   grpc_endpoint_destroy(&exec_ctx, &endpoint);
   grpc_endpoint_add_to_pollset(&exec_ctx, &endpoint, NULL);
   grpc_endpoint_add_to_pollset_set(&exec_ctx, &endpoint, NULL);
diff --git a/test/core/iomgr/endpoint_tests.c b/test/core/iomgr/endpoint_tests.c
index df5dd20903..bbc5f383f6 100644
--- a/test/core/iomgr/endpoint_tests.c
+++ b/test/core/iomgr/endpoint_tests.c
@@ -233,9 +233,11 @@ static void read_and_write_test(grpc_endpoint_test_config config,
 
   if (shutdown) {
     gpr_log(GPR_DEBUG, "shutdown read");
-    grpc_endpoint_shutdown(&exec_ctx, state.read_ep);
+    grpc_endpoint_shutdown(&exec_ctx, state.read_ep,
+                           GRPC_ERROR_CREATE("Test Shutdown"));
     gpr_log(GPR_DEBUG, "shutdown write");
-    grpc_endpoint_shutdown(&exec_ctx, state.write_ep);
+    grpc_endpoint_shutdown(&exec_ctx, state.write_ep,
+                           GRPC_ERROR_CREATE("Test Shutdown"));
   }
   grpc_exec_ctx_flush(&exec_ctx);
 
@@ -296,7 +298,8 @@ static void multiple_shutdown_test(grpc_endpoint_test_config config) {
                      grpc_closure_create(inc_on_failure, &fail_count,
                                          grpc_schedule_on_exec_ctx));
   wait_for_fail_count(&exec_ctx, &fail_count, 0);
-  grpc_endpoint_shutdown(&exec_ctx, f.client_ep);
+  grpc_endpoint_shutdown(&exec_ctx, f.client_ep,
+                         GRPC_ERROR_CREATE("Test Shutdown"));
   wait_for_fail_count(&exec_ctx, &fail_count, 1);
   grpc_endpoint_read(&exec_ctx, f.client_ep, &slice_buffer,
                      grpc_closure_create(inc_on_failure, &fail_count,
@@ -307,7 +310,8 @@ static void multiple_shutdown_test(grpc_endpoint_test_config config) {
                       grpc_closure_create(inc_on_failure, &fail_count,
                                           grpc_schedule_on_exec_ctx));
   wait_for_fail_count(&exec_ctx, &fail_count, 3);
-  grpc_endpoint_shutdown(&exec_ctx, f.client_ep);
+  grpc_endpoint_shutdown(&exec_ctx, f.client_ep,
+                         GRPC_ERROR_CREATE("Test Shutdown"));
   wait_for_fail_count(&exec_ctx, &fail_count, 3);
 
   grpc_slice_buffer_destroy_internal(&exec_ctx, &slice_buffer);
diff --git a/test/core/iomgr/ev_epoll_linux_test.c b/test/core/iomgr/ev_epoll_linux_test.c
index a10be7f81b..5b05ea3338 100644
--- a/test/core/iomgr/ev_epoll_linux_test.c
+++ b/test/core/iomgr/ev_epoll_linux_test.c
@@ -89,7 +89,8 @@ static void test_fd_cleanup(grpc_exec_ctx *exec_ctx, test_fd *tfds,
   int i;
 
   for (i = 0; i < num_fds; i++) {
-    grpc_fd_shutdown(exec_ctx, tfds[i].fd);
+    grpc_fd_shutdown(exec_ctx, tfds[i].fd,
+                     GRPC_ERROR_CREATE("test_fd_cleanup"));
     grpc_exec_ctx_flush(exec_ctx);
 
     grpc_fd_orphan(exec_ctx, tfds[i].fd, NULL, &release_fd, "test_fd_cleanup");
diff --git a/test/core/iomgr/fd_posix_test.c b/test/core/iomgr/fd_posix_test.c
index a617bfc646..4726e935d8 100644
--- a/test/core/iomgr/fd_posix_test.c
+++ b/test/core/iomgr/fd_posix_test.c
@@ -132,7 +132,8 @@ static void session_shutdown_cb(grpc_exec_ctx *exec_ctx, void *arg, /*session */
   grpc_fd_orphan(exec_ctx, se->em_fd, NULL, NULL, "a");
   gpr_free(se);
   /* Start to shutdown listen fd. */
-  grpc_fd_shutdown(exec_ctx, sv->em_fd);
+  grpc_fd_shutdown(exec_ctx, sv->em_fd,
+                   GRPC_ERROR_CREATE("session_shutdown_cb"));
 }
 
 /* Called when data become readable in a session. */
diff --git a/test/core/iomgr/tcp_client_posix_test.c b/test/core/iomgr/tcp_client_posix_test.c
index 0ea7a000eb..6bb00bc787 100644
--- a/test/core/iomgr/tcp_client_posix_test.c
+++ b/test/core/iomgr/tcp_client_posix_test.c
@@ -72,7 +72,8 @@ static void must_succeed(grpc_exec_ctx *exec_ctx, void *arg,
                          grpc_error *error) {
   GPR_ASSERT(g_connecting != NULL);
   GPR_ASSERT(error == GRPC_ERROR_NONE);
-  grpc_endpoint_shutdown(exec_ctx, g_connecting);
+  grpc_endpoint_shutdown(exec_ctx, g_connecting,
+                         GRPC_ERROR_CREATE("must_succeed called"));
   grpc_endpoint_destroy(exec_ctx, g_connecting);
   g_connecting = NULL;
   finish_connection();
diff --git a/test/core/iomgr/tcp_server_posix_test.c b/test/core/iomgr/tcp_server_posix_test.c
index 020f005980..417bc5111a 100644
--- a/test/core/iomgr/tcp_server_posix_test.c
+++ b/test/core/iomgr/tcp_server_posix_test.c
@@ -121,7 +121,7 @@ static void server_weak_ref_set(server_weak_ref *weak_ref,
 static void on_connect(grpc_exec_ctx *exec_ctx, void *arg, grpc_endpoint *tcp,
                        grpc_pollset *pollset,
                        grpc_tcp_server_acceptor *acceptor) {
-  grpc_endpoint_shutdown(exec_ctx, tcp);
+  grpc_endpoint_shutdown(exec_ctx, tcp, GRPC_ERROR_CREATE("Connected"));
   grpc_endpoint_destroy(exec_ctx, tcp);
 
   on_connect_result temp_result;
diff --git a/test/core/security/secure_endpoint_test.c b/test/core/security/secure_endpoint_test.c
index bcc50d0bb0..97e9c3d6db 100644
--- a/test/core/security/secure_endpoint_test.c
+++ b/test/core/security/secure_endpoint_test.c
@@ -166,8 +166,10 @@ static void test_leftover(grpc_endpoint_test_config config, size_t slice_size) {
   GPR_ASSERT(incoming.count == 1);
   GPR_ASSERT(grpc_slice_eq(s, incoming.slices[0]));
 
-  grpc_endpoint_shutdown(&exec_ctx, f.client_ep);
-  grpc_endpoint_shutdown(&exec_ctx, f.server_ep);
+  grpc_endpoint_shutdown(&exec_ctx, f.client_ep,
+                         GRPC_ERROR_CREATE("test_leftover end"));
+  grpc_endpoint_shutdown(&exec_ctx, f.server_ep,
+                         GRPC_ERROR_CREATE("test_leftover end"));
   grpc_endpoint_destroy(&exec_ctx, f.client_ep);
   grpc_endpoint_destroy(&exec_ctx, f.server_ep);
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/test/core/security/ssl_server_fuzzer.c b/test/core/security/ssl_server_fuzzer.c
index 55e8f5e78d..f789278add 100644
--- a/test/core/security/ssl_server_fuzzer.c
+++ b/test/core/security/ssl_server_fuzzer.c
@@ -121,7 +121,8 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   // server will wait for more data. Explicitly fail the server by shutting down
   // the endpoint.
   if (!state.done_callback_called) {
-    grpc_endpoint_shutdown(&exec_ctx, mock_endpoint);
+    grpc_endpoint_shutdown(&exec_ctx, mock_endpoint,
+                           GRPC_ERROR_CREATE("Explicit close"));
     grpc_exec_ctx_flush(&exec_ctx);
   }
 
diff --git a/test/core/surface/concurrent_connectivity_test.c b/test/core/surface/concurrent_connectivity_test.c
index 8ebe8d07e4..7071f93d8d 100644
--- a/test/core/surface/concurrent_connectivity_test.c
+++ b/test/core/surface/concurrent_connectivity_test.c
@@ -107,7 +107,7 @@ static void on_connect(grpc_exec_ctx *exec_ctx, void *vargs, grpc_endpoint *tcp,
                        grpc_tcp_server_acceptor *acceptor) {
   gpr_free(acceptor);
   struct server_thread_args *args = (struct server_thread_args *)vargs;
-  grpc_endpoint_shutdown(exec_ctx, tcp);
+  grpc_endpoint_shutdown(exec_ctx, tcp, GRPC_ERROR_CREATE("Connected"));
   grpc_endpoint_destroy(exec_ctx, tcp);
   GRPC_LOG_IF_ERROR("pollset_kick", grpc_pollset_kick(args->pollset, NULL));
 }
diff --git a/test/core/util/mock_endpoint.c b/test/core/util/mock_endpoint.c
index 04793bceab..d531ec6031 100644
--- a/test/core/util/mock_endpoint.c
+++ b/test/core/util/mock_endpoint.c
@@ -78,16 +78,18 @@ static void me_add_to_pollset(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 static void me_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
                                   grpc_pollset_set *pollset) {}
 
-static void me_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+static void me_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                        grpc_error *why) {
   grpc_mock_endpoint *m = (grpc_mock_endpoint *)ep;
   gpr_mu_lock(&m->mu);
   if (m->on_read) {
-    grpc_closure_sched(exec_ctx, m->on_read,
-                       GRPC_ERROR_CREATE("Endpoint Shutdown"));
+    grpc_closure_sched(exec_ctx, m->on_read, GRPC_ERROR_CREATE_REFERENCING(
+                                                 "Endpoint Shutdown", &why, 1));
     m->on_read = NULL;
   }
   gpr_mu_unlock(&m->mu);
   grpc_resource_user_shutdown(exec_ctx, m->resource_user);
+  GRPC_ERROR_UNREF(why);
 }
 
 static void me_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
diff --git a/test/core/util/passthru_endpoint.c b/test/core/util/passthru_endpoint.c
index d42ec7f9e8..2ad019ddb0 100644
--- a/test/core/util/passthru_endpoint.c
+++ b/test/core/util/passthru_endpoint.c
@@ -109,21 +109,25 @@ static void me_add_to_pollset(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 static void me_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
                                   grpc_pollset_set *pollset) {}
 
-static void me_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+static void me_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                        grpc_error *why) {
   half *m = (half *)ep;
   gpr_mu_lock(&m->parent->mu);
   m->parent->shutdown = true;
   if (m->on_read) {
-    grpc_closure_sched(exec_ctx, m->on_read, GRPC_ERROR_CREATE("Shutdown"));
+    grpc_closure_sched(exec_ctx, m->on_read,
+                       GRPC_ERROR_CREATE_REFERENCING("Shutdown", &why, 1));
     m->on_read = NULL;
   }
   m = other_half(m);
   if (m->on_read) {
-    grpc_closure_sched(exec_ctx, m->on_read, GRPC_ERROR_CREATE("Shutdown"));
+    grpc_closure_sched(exec_ctx, m->on_read,
+                       GRPC_ERROR_CREATE_REFERENCING("Shutdown", &why, 1));
     m->on_read = NULL;
   }
   gpr_mu_unlock(&m->parent->mu);
   grpc_resource_user_shutdown(exec_ctx, m->resource_user);
+  GRPC_ERROR_UNREF(why);
 }
 
 static void me_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
diff --git a/test/core/util/reconnect_server.c b/test/core/util/reconnect_server.c
index 7bf83a74a1..7fbd0ca6aa 100644
--- a/test/core/util/reconnect_server.c
+++ b/test/core/util/reconnect_server.c
@@ -80,7 +80,7 @@ static void on_connect(grpc_exec_ctx *exec_ctx, void *arg, grpc_endpoint *tcp,
   gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
   timestamp_list *new_tail;
   peer = grpc_endpoint_get_peer(tcp);
-  grpc_endpoint_shutdown(exec_ctx, tcp);
+  grpc_endpoint_shutdown(exec_ctx, tcp, GRPC_ERROR_CREATE("Connected"));
   grpc_endpoint_destroy(exec_ctx, tcp);
   if (peer) {
     last_colon = strrchr(peer, ':');
diff --git a/test/cpp/microbenchmarks/bm_fullstack.cc b/test/cpp/microbenchmarks/bm_fullstack.cc
index bd158db522..e56c8538a7 100644
--- a/test/cpp/microbenchmarks/bm_fullstack.cc
+++ b/test/cpp/microbenchmarks/bm_fullstack.cc
@@ -84,6 +84,16 @@ static class InitializeStuff {
  * FIXTURES
  */
 
+static void ApplyCommonServerBuilderConfig(ServerBuilder* b) {
+  b->SetMaxReceiveMessageSize(INT_MAX);
+  b->SetMaxSendMessageSize(INT_MAX);
+}
+
+static void ApplyCommonChannelArguments(ChannelArguments* c) {
+  c->SetInt(GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH, INT_MAX);
+  c->SetInt(GRPC_ARG_MAX_SEND_MESSAGE_LENGTH, INT_MAX);
+}
+
 class FullstackFixture {
  public:
   FullstackFixture(Service* service, const grpc::string& address) {
@@ -91,8 +101,11 @@ class FullstackFixture {
     b.AddListeningPort(address, InsecureServerCredentials());
     cq_ = b.AddCompletionQueue(true);
     b.RegisterService(service);
+    ApplyCommonServerBuilderConfig(&b);
     server_ = b.BuildAndStart();
-    channel_ = CreateChannel(address, InsecureChannelCredentials());
+    ChannelArguments args;
+    ApplyCommonChannelArguments(&args);
+    channel_ = CreateCustomChannel(address, InsecureChannelCredentials(), args);
   }
 
   virtual ~FullstackFixture() {
@@ -146,6 +159,7 @@ class EndpointPairFixture {
     ServerBuilder b;
     cq_ = b.AddCompletionQueue(true);
     b.RegisterService(service);
+    ApplyCommonServerBuilderConfig(&b);
     server_ = b.BuildAndStart();
 
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
@@ -174,6 +188,7 @@ class EndpointPairFixture {
     {
       ChannelArguments args;
       args.SetString(GRPC_ARG_DEFAULT_AUTHORITY, "test.authority");
+      ApplyCommonChannelArguments(&args);
 
       grpc_channel_args c_args = args.c_channel_args();
       grpc_transport* transport =
@@ -343,6 +358,12 @@ static void BM_UnaryPingPong(benchmark::State& state) {
   EchoRequest send_request;
   EchoResponse send_response;
   EchoResponse recv_response;
+  if (state.range(0) > 0) {
+    send_request.set_message(std::string(state.range(0), 'a'));
+  }
+  if (state.range(1) > 0) {
+    send_response.set_message(std::string(state.range(1), 'a'));
+  }
   Status recv_status;
   struct ServerEnv {
     ServerContext ctx;
@@ -365,6 +386,7 @@ static void BM_UnaryPingPong(benchmark::State& state) {
   std::unique_ptr<EchoTestService::Stub> stub(
       EchoTestService::NewStub(fixture->channel()));
   while (state.KeepRunning()) {
+    recv_response.Clear();
     ClientContext cli_ctx;
     ClientContextMutator cli_ctx_mut(&cli_ctx);
     std::unique_ptr<ClientAsyncResponseReader<EchoResponse>> response_reader(
@@ -396,55 +418,81 @@ static void BM_UnaryPingPong(benchmark::State& state) {
   fixture.reset();
   server_env[0]->~ServerEnv();
   server_env[1]->~ServerEnv();
+  state.SetBytesProcessed(state.range(0) * state.iterations() +
+                          state.range(1) * state.iterations());
 }
 
 /*******************************************************************************
  * CONFIGURATIONS
  */
 
-BENCHMARK_TEMPLATE(BM_UnaryPingPong, TCP, NoOpMutator, NoOpMutator);
-BENCHMARK_TEMPLATE(BM_UnaryPingPong, UDS, NoOpMutator, NoOpMutator);
-BENCHMARK_TEMPLATE(BM_UnaryPingPong, SockPair, NoOpMutator, NoOpMutator);
-BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator, NoOpMutator);
+static void SweepSizesArgs(benchmark::internal::Benchmark* b) {
+  b->Args({0, 0});
+  for (int i = 1; i <= 128 * 1024 * 1024; i *= 8) {
+    b->Args({i, 0});
+    b->Args({0, i});
+    b->Args({i, i});
+  }
+}
+
+BENCHMARK_TEMPLATE(BM_UnaryPingPong, TCP, NoOpMutator, NoOpMutator)
+    ->Apply(SweepSizesArgs);
+BENCHMARK_TEMPLATE(BM_UnaryPingPong, UDS, NoOpMutator, NoOpMutator)
+    ->Args({0, 0});
+BENCHMARK_TEMPLATE(BM_UnaryPingPong, SockPair, NoOpMutator, NoOpMutator)
+    ->Args({0, 0});
+BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator, NoOpMutator)
+    ->Apply(SweepSizesArgs);
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
-                   Client_AddMetadata<RandomBinaryMetadata<10>, 1>,
-                   NoOpMutator);
+                   Client_AddMetadata<RandomBinaryMetadata<10>, 1>, NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
-                   Client_AddMetadata<RandomBinaryMetadata<31>, 1>,
-                   NoOpMutator);
+                   Client_AddMetadata<RandomBinaryMetadata<31>, 1>, NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
                    Client_AddMetadata<RandomBinaryMetadata<100>, 1>,
-                   NoOpMutator);
+                   NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
-                   Client_AddMetadata<RandomBinaryMetadata<10>, 2>,
-                   NoOpMutator);
+                   Client_AddMetadata<RandomBinaryMetadata<10>, 2>, NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
-                   Client_AddMetadata<RandomBinaryMetadata<31>, 2>,
-                   NoOpMutator);
+                   Client_AddMetadata<RandomBinaryMetadata<31>, 2>, NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
                    Client_AddMetadata<RandomBinaryMetadata<100>, 2>,
-                   NoOpMutator);
+                   NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator,
-                   Server_AddInitialMetadata<RandomBinaryMetadata<10>, 1>);
+                   Server_AddInitialMetadata<RandomBinaryMetadata<10>, 1>)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator,
-                   Server_AddInitialMetadata<RandomBinaryMetadata<31>, 1>);
+                   Server_AddInitialMetadata<RandomBinaryMetadata<31>, 1>)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator,
-                   Server_AddInitialMetadata<RandomBinaryMetadata<100>, 1>);
+                   Server_AddInitialMetadata<RandomBinaryMetadata<100>, 1>)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
-                   Client_AddMetadata<RandomAsciiMetadata<10>, 1>, NoOpMutator);
+                   Client_AddMetadata<RandomAsciiMetadata<10>, 1>, NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
-                   Client_AddMetadata<RandomAsciiMetadata<31>, 1>, NoOpMutator);
+                   Client_AddMetadata<RandomAsciiMetadata<31>, 1>, NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2,
-                   Client_AddMetadata<RandomAsciiMetadata<100>, 1>,
-                   NoOpMutator);
+                   Client_AddMetadata<RandomAsciiMetadata<100>, 1>, NoOpMutator)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator,
-                   Server_AddInitialMetadata<RandomAsciiMetadata<10>, 1>);
+                   Server_AddInitialMetadata<RandomAsciiMetadata<10>, 1>)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator,
-                   Server_AddInitialMetadata<RandomAsciiMetadata<31>, 1>);
+                   Server_AddInitialMetadata<RandomAsciiMetadata<31>, 1>)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator,
-                   Server_AddInitialMetadata<RandomAsciiMetadata<100>, 1>);
+                   Server_AddInitialMetadata<RandomAsciiMetadata<100>, 1>)
+    ->Args({0, 0});
 BENCHMARK_TEMPLATE(BM_UnaryPingPong, InProcessCHTTP2, NoOpMutator,
-                   Server_AddInitialMetadata<RandomAsciiMetadata<10>, 100>);
+                   Server_AddInitialMetadata<RandomAsciiMetadata<10>, 100>)
+    ->Args({0, 0});
 
 }  // namespace testing
 }  // namespace grpc
diff --git a/test/cpp/util/cli_call.cc b/test/cpp/util/cli_call.cc
index a02a8b2ee2..4d045da098 100644
--- a/test/cpp/util/cli_call.cc
+++ b/test/cpp/util/cli_call.cc
@@ -37,8 +37,6 @@
 
 #include <grpc++/channel.h>
 #include <grpc++/client_context.h>
-#include <grpc++/completion_queue.h>
-#include <grpc++/generic/generic_stub.h>
 #include <grpc++/support/byte_buffer.h>
 #include <grpc/grpc.h>
 #include <grpc/slice.h>
@@ -56,55 +54,172 @@ Status CliCall::Call(std::shared_ptr<grpc::Channel> channel,
                      const OutgoingMetadataContainer& metadata,
                      IncomingMetadataContainer* server_initial_metadata,
                      IncomingMetadataContainer* server_trailing_metadata) {
-  std::unique_ptr<grpc::GenericStub> stub(new grpc::GenericStub(channel));
-  grpc::ClientContext ctx;
+  CliCall call(channel, method, metadata);
+  call.Write(request);
+  call.WritesDone();
+  if (!call.Read(response, server_initial_metadata)) {
+    fprintf(stderr, "Failed to read response.\n");
+  }
+  return call.Finish(server_trailing_metadata);
+}
+
+CliCall::CliCall(std::shared_ptr<grpc::Channel> channel,
+                 const grpc::string& method,
+                 const OutgoingMetadataContainer& metadata)
+    : stub_(new grpc::GenericStub(channel)) {
+  gpr_mu_init(&write_mu_);
+  gpr_cv_init(&write_cv_);
   if (!metadata.empty()) {
     for (OutgoingMetadataContainer::const_iterator iter = metadata.begin();
          iter != metadata.end(); ++iter) {
-      ctx.AddMetadata(iter->first, iter->second);
+      ctx_.AddMetadata(iter->first, iter->second);
     }
   }
-  grpc::CompletionQueue cq;
-  std::unique_ptr<grpc::GenericClientAsyncReaderWriter> call(
-      stub->Call(&ctx, method, &cq, tag(1)));
+  call_ = stub_->Call(&ctx_, method, &cq_, tag(1));
   void* got_tag;
   bool ok;
-  cq.Next(&got_tag, &ok);
+  cq_.Next(&got_tag, &ok);
   GPR_ASSERT(ok);
+}
+
+CliCall::~CliCall() {
+  gpr_cv_destroy(&write_cv_);
+  gpr_mu_destroy(&write_mu_);
+}
+
+void CliCall::Write(const grpc::string& request) {
+  void* got_tag;
+  bool ok;
 
   grpc_slice s = grpc_slice_from_copied_string(request.c_str());
   grpc::Slice req_slice(s, grpc::Slice::STEAL_REF);
   grpc::ByteBuffer send_buffer(&req_slice, 1);
-  call->Write(send_buffer, tag(2));
-  cq.Next(&got_tag, &ok);
-  GPR_ASSERT(ok);
-  call->WritesDone(tag(3));
-  cq.Next(&got_tag, &ok);
+  call_->Write(send_buffer, tag(2));
+  cq_.Next(&got_tag, &ok);
   GPR_ASSERT(ok);
+}
+
+bool CliCall::Read(grpc::string* response,
+                   IncomingMetadataContainer* server_initial_metadata) {
+  void* got_tag;
+  bool ok;
+
   grpc::ByteBuffer recv_buffer;
-  call->Read(&recv_buffer, tag(4));
-  cq.Next(&got_tag, &ok);
-  if (!ok) {
-    std::cout << "Failed to read response." << std::endl;
+  call_->Read(&recv_buffer, tag(3));
+
+  if (!cq_.Next(&got_tag, &ok) || !ok) {
+    return false;
   }
-  grpc::Status status;
-  call->Finish(&status, tag(5));
-  cq.Next(&got_tag, &ok);
+  std::vector<grpc::Slice> slices;
+  recv_buffer.Dump(&slices);
+
+  response->clear();
+  for (size_t i = 0; i < slices.size(); i++) {
+    response->append(reinterpret_cast<const char*>(slices[i].begin()),
+                     slices[i].size());
+  }
+  if (server_initial_metadata) {
+    *server_initial_metadata = ctx_.GetServerInitialMetadata();
+  }
+  return true;
+}
+
+void CliCall::WritesDone() {
+  void* got_tag;
+  bool ok;
+
+  call_->WritesDone(tag(4));
+  cq_.Next(&got_tag, &ok);
   GPR_ASSERT(ok);
+}
 
-  if (status.ok()) {
-    std::vector<grpc::Slice> slices;
-    (void)recv_buffer.Dump(&slices);
+void CliCall::WriteAndWait(const grpc::string& request) {
+  grpc_slice s = grpc_slice_from_copied_string(request.c_str());
+  grpc::Slice req_slice(s, grpc::Slice::STEAL_REF);
+  grpc::ByteBuffer send_buffer(&req_slice, 1);
+
+  gpr_mu_lock(&write_mu_);
+  call_->Write(send_buffer, tag(2));
+  write_done_ = false;
+  while (!write_done_) {
+    gpr_cv_wait(&write_cv_, &write_mu_, gpr_inf_future(GPR_CLOCK_REALTIME));
+  }
+  gpr_mu_unlock(&write_mu_);
+}
+
+void CliCall::WritesDoneAndWait() {
+  gpr_mu_lock(&write_mu_);
+  call_->WritesDone(tag(4));
+  write_done_ = false;
+  while (!write_done_) {
+    gpr_cv_wait(&write_cv_, &write_mu_, gpr_inf_future(GPR_CLOCK_REALTIME));
+  }
+  gpr_mu_unlock(&write_mu_);
+}
 
-    response->clear();
-    for (size_t i = 0; i < slices.size(); i++) {
-      response->append(reinterpret_cast<const char*>(slices[i].begin()),
-                       slices[i].size());
+bool CliCall::ReadAndMaybeNotifyWrite(
+    grpc::string* response,
+    IncomingMetadataContainer* server_initial_metadata) {
+  void* got_tag;
+  bool ok;
+  grpc::ByteBuffer recv_buffer;
+
+  call_->Read(&recv_buffer, tag(3));
+  bool cq_result = cq_.Next(&got_tag, &ok);
+
+  while (got_tag != tag(3)) {
+    gpr_mu_lock(&write_mu_);
+    write_done_ = true;
+    gpr_cv_signal(&write_cv_);
+    gpr_mu_unlock(&write_mu_);
+
+    cq_result = cq_.Next(&got_tag, &ok);
+    if (got_tag == tag(2)) {
+      GPR_ASSERT(ok);
     }
   }
 
-  *server_initial_metadata = ctx.GetServerInitialMetadata();
-  *server_trailing_metadata = ctx.GetServerTrailingMetadata();
+  if (!cq_result || !ok) {
+    // If the RPC is ended on the server side, we should still wait for the
+    // pending write on the client side to be done.
+    if (!ok) {
+      gpr_mu_lock(&write_mu_);
+      if (!write_done_) {
+        cq_.Next(&got_tag, &ok);
+        GPR_ASSERT(got_tag != tag(2));
+        write_done_ = true;
+        gpr_cv_signal(&write_cv_);
+      }
+      gpr_mu_unlock(&write_mu_);
+    }
+    return false;
+  }
+
+  std::vector<grpc::Slice> slices;
+  recv_buffer.Dump(&slices);
+  response->clear();
+  for (size_t i = 0; i < slices.size(); i++) {
+    response->append(reinterpret_cast<const char*>(slices[i].begin()),
+                     slices[i].size());
+  }
+  if (server_initial_metadata) {
+    *server_initial_metadata = ctx_.GetServerInitialMetadata();
+  }
+  return true;
+}
+
+Status CliCall::Finish(IncomingMetadataContainer* server_trailing_metadata) {
+  void* got_tag;
+  bool ok;
+  grpc::Status status;
+
+  call_->Finish(&status, tag(5));
+  cq_.Next(&got_tag, &ok);
+  GPR_ASSERT(ok);
+  if (server_trailing_metadata) {
+    *server_trailing_metadata = ctx_.GetServerTrailingMetadata();
+  }
+
   return status;
 }
 
diff --git a/test/cpp/util/cli_call.h b/test/cpp/util/cli_call.h
index 65da86bd4e..91f0dbc9ed 100644
--- a/test/cpp/util/cli_call.h
+++ b/test/cpp/util/cli_call.h
@@ -37,23 +37,74 @@
 #include <map>
 
 #include <grpc++/channel.h>
+#include <grpc++/completion_queue.h>
+#include <grpc++/generic/generic_stub.h>
 #include <grpc++/support/status.h>
 #include <grpc++/support/string_ref.h>
 
 namespace grpc {
+
+class ClientContext;
+
 namespace testing {
 
+// CliCall handles the sending and receiving of generic messages given the name
+// of the remote method. This class is only used by GrpcTool. Its thread-safe
+// and thread-unsafe methods should not be used together.
 class CliCall final {
  public:
   typedef std::multimap<grpc::string, grpc::string> OutgoingMetadataContainer;
   typedef std::multimap<grpc::string_ref, grpc::string_ref>
       IncomingMetadataContainer;
+
+  CliCall(std::shared_ptr<grpc::Channel> channel, const grpc::string& method,
+          const OutgoingMetadataContainer& metadata);
+  ~CliCall();
+
+  // Perform an unary generic RPC.
   static Status Call(std::shared_ptr<grpc::Channel> channel,
                      const grpc::string& method, const grpc::string& request,
                      grpc::string* response,
                      const OutgoingMetadataContainer& metadata,
                      IncomingMetadataContainer* server_initial_metadata,
                      IncomingMetadataContainer* server_trailing_metadata);
+
+  // Send a generic request message in a synchronous manner. NOT thread-safe.
+  void Write(const grpc::string& request);
+
+  // Send a generic request message in a synchronous manner. NOT thread-safe.
+  void WritesDone();
+
+  // Receive a generic response message in a synchronous manner.NOT thread-safe.
+  bool Read(grpc::string* response,
+            IncomingMetadataContainer* server_initial_metadata);
+
+  // Thread-safe write. Must be used with ReadAndMaybeNotifyWrite. Send out a
+  // generic request message and wait for ReadAndMaybeNotifyWrite to finish it.
+  void WriteAndWait(const grpc::string& request);
+
+  // Thread-safe WritesDone. Must be used with ReadAndMaybeNotifyWrite. Send out
+  // WritesDone for gereneric request messages and wait for
+  // ReadAndMaybeNotifyWrite to finish it.
+  void WritesDoneAndWait();
+
+  // Thread-safe Read. Blockingly receive a generic response message. Notify
+  // writes if they are finished when this read is waiting for a resposne.
+  bool ReadAndMaybeNotifyWrite(
+      grpc::string* response,
+      IncomingMetadataContainer* server_initial_metadata);
+
+  // Finish the RPC.
+  Status Finish(IncomingMetadataContainer* server_trailing_metadata);
+
+ private:
+  std::unique_ptr<grpc::GenericStub> stub_;
+  grpc::ClientContext ctx_;
+  std::unique_ptr<grpc::GenericClientAsyncReaderWriter> call_;
+  grpc::CompletionQueue cq_;
+  gpr_mu write_mu_;
+  gpr_cv write_cv_;  // Protected by write_mu_;
+  bool write_done_;  // Portected by write_mu_;
 };
 
 }  // namespace testing
diff --git a/test/cpp/util/grpc_cli.cc b/test/cpp/util/grpc_cli.cc
index fe248601ee..a78bed4b90 100644
--- a/test/cpp/util/grpc_cli.cc
+++ b/test/cpp/util/grpc_cli.cc
@@ -83,10 +83,10 @@ DEFINE_string(outfile, "", "Output file (default is stdout)");
 static bool SimplePrint(const grpc::string& outfile,
                         const grpc::string& output) {
   if (outfile.empty()) {
-    std::cout << output;
+    std::cout << output << std::endl;
   } else {
-    std::ofstream output_file(outfile, std::ios::trunc | std::ios::binary);
-    output_file << output;
+    std::ofstream output_file(outfile, std::ios::app | std::ios::binary);
+    output_file << output << std::endl;
     output_file.close();
   }
   return true;
diff --git a/test/cpp/util/grpc_tool.cc b/test/cpp/util/grpc_tool.cc
index b9900ca1b7..39acd8eb4b 100644
--- a/test/cpp/util/grpc_tool.cc
+++ b/test/cpp/util/grpc_tool.cc
@@ -39,6 +39,7 @@
 #include <memory>
 #include <sstream>
 #include <string>
+#include <thread>
 
 #include <gflags/gflags.h>
 #include <grpc++/channel.h>
@@ -159,6 +160,36 @@ void PrintMetadata(const T& m, const grpc::string& message) {
   }
 }
 
+void ReadResponse(CliCall* call, const grpc::string& method_name,
+                  GrpcToolOutputCallback callback, ProtoFileParser* parser,
+                  gpr_mu* parser_mu, bool print_mode) {
+  grpc::string serialized_response_proto;
+  std::multimap<grpc::string_ref, grpc::string_ref> server_initial_metadata;
+
+  for (bool receive_initial_metadata = true; call->ReadAndMaybeNotifyWrite(
+           &serialized_response_proto,
+           receive_initial_metadata ? &server_initial_metadata : nullptr);
+       receive_initial_metadata = false) {
+    fprintf(stderr, "got response.\n");
+    if (!FLAGS_binary_output) {
+      gpr_mu_lock(parser_mu);
+      serialized_response_proto = parser->GetTextFormatFromMethod(
+          method_name, serialized_response_proto, false /* is_request */);
+      if (parser->HasError() && print_mode) {
+        fprintf(stderr, "Failed to parse response.\n");
+      }
+      gpr_mu_unlock(parser_mu);
+    }
+    if (receive_initial_metadata) {
+      PrintMetadata(server_initial_metadata,
+                    "Received initial metadata from server:");
+    }
+    if (!callback(serialized_response_proto) && print_mode) {
+      fprintf(stderr, "Failed to output response.\n");
+    }
+  }
+}
+
 struct Command {
   const char* command;
   std::function<bool(GrpcTool*, int, const char**, const CliCredentials&,
@@ -416,85 +447,191 @@ bool GrpcTool::CallMethod(int argc, const char** argv,
   grpc::string server_address(argv[0]);
   grpc::string method_name(argv[1]);
   grpc::string formatted_method_name;
-  std::unique_ptr<grpc::testing::ProtoFileParser> parser;
+  std::unique_ptr<ProtoFileParser> parser;
   grpc::string serialized_request_proto;
+  bool print_mode = false;
 
-  if (argc == 3) {
-    request_text = argv[2];
-    if (!FLAGS_infile.empty()) {
-      fprintf(stderr, "warning: request given in argv, ignoring --infile\n");
-    }
+  std::shared_ptr<grpc::Channel> channel =
+      FLAGS_remotedb
+          ? grpc::CreateChannel(server_address, cred.GetCredentials())
+          : nullptr;
+
+  parser.reset(new grpc::testing::ProtoFileParser(channel, FLAGS_proto_path,
+                                                  FLAGS_protofiles));
+
+  if (FLAGS_binary_input) {
+    formatted_method_name = method_name;
   } else {
-    std::stringstream input_stream;
+    formatted_method_name = parser->GetFormattedMethodName(method_name);
+  }
+
+  if (parser->HasError()) {
+    return false;
+  }
+
+  if (parser->IsStreaming(method_name, true /* is_request */)) {
+    std::istream* input_stream;
+    std::ifstream input_file;
+
+    if (argc == 3) {
+      request_text = argv[2];
+    }
+
+    std::multimap<grpc::string, grpc::string> client_metadata;
+    ParseMetadataFlag(&client_metadata);
+    PrintMetadata(client_metadata, "Sending client initial metadata:");
+
+    CliCall call(channel, formatted_method_name, client_metadata);
+
     if (FLAGS_infile.empty()) {
       if (isatty(STDIN_FILENO)) {
-        fprintf(stderr, "reading request message from stdin...\n");
+        print_mode = true;
+        fprintf(stderr, "reading streaming request message from stdin...\n");
       }
-      input_stream << std::cin.rdbuf();
+      input_stream = &std::cin;
     } else {
-      std::ifstream input_file(FLAGS_infile, std::ios::in | std::ios::binary);
-      input_stream << input_file.rdbuf();
+      input_file.open(FLAGS_infile, std::ios::in | std::ios::binary);
+      input_stream = &input_file;
+    }
+
+    gpr_mu parser_mu;
+    gpr_mu_init(&parser_mu);
+    std::thread read_thread(ReadResponse, &call, method_name, callback,
+                            parser.get(), &parser_mu, print_mode);
+
+    std::stringstream request_ss;
+    grpc::string line;
+    while (!request_text.empty() ||
+           (!input_stream->eof() && getline(*input_stream, line))) {
+      if (!request_text.empty()) {
+        if (FLAGS_binary_input) {
+          serialized_request_proto = request_text;
+          request_text.clear();
+        } else {
+          gpr_mu_lock(&parser_mu);
+          serialized_request_proto = parser->GetSerializedProtoFromMethod(
+              method_name, request_text, true /* is_request */);
+          request_text.clear();
+          if (parser->HasError()) {
+            if (print_mode) {
+              fprintf(stderr, "Failed to parse request.\n");
+            }
+            gpr_mu_unlock(&parser_mu);
+            continue;
+          }
+          gpr_mu_unlock(&parser_mu);
+        }
+
+        call.WriteAndWait(serialized_request_proto);
+        if (print_mode) {
+          fprintf(stderr, "Request sent.\n");
+        }
+      } else {
+        if (line.length() == 0) {
+          request_text = request_ss.str();
+          request_ss.str(grpc::string());
+          request_ss.clear();
+        } else {
+          request_ss << line << ' ';
+        }
+      }
+    }
+    if (input_file.is_open()) {
       input_file.close();
     }
-    request_text = input_stream.str();
-  }
 
-  std::shared_ptr<grpc::Channel> channel =
-      grpc::CreateChannel(server_address, cred.GetCredentials());
-  if (!FLAGS_binary_input || !FLAGS_binary_output) {
-    parser.reset(
-        new grpc::testing::ProtoFileParser(FLAGS_remotedb ? channel : nullptr,
-                                           FLAGS_proto_path, FLAGS_protofiles));
-    if (parser->HasError()) {
+    call.WritesDoneAndWait();
+    read_thread.join();
+
+    std::multimap<grpc::string_ref, grpc::string_ref> server_trailing_metadata;
+    Status status = call.Finish(&server_trailing_metadata);
+    PrintMetadata(server_trailing_metadata,
+                  "Received trailing metadata from server:");
+
+    if (status.ok()) {
+      fprintf(stderr, "Stream RPC succeeded with OK status\n");
+      return true;
+    } else {
+      fprintf(stderr, "Rpc failed with status code %d, error message: %s\n",
+              status.error_code(), status.error_message().c_str());
       return false;
     }
-  }
 
-  if (FLAGS_binary_input) {
-    serialized_request_proto = request_text;
-    formatted_method_name = method_name;
-  } else {
-    formatted_method_name = parser->GetFormattedMethodName(method_name);
-    serialized_request_proto = parser->GetSerializedProtoFromMethod(
-        method_name, request_text, true /* is_request */);
-    if (parser->HasError()) {
-      return false;
+  } else {  // parser->IsStreaming(method_name, true /* is_request */)
+    if (argc == 3) {
+      request_text = argv[2];
+      if (!FLAGS_infile.empty()) {
+        fprintf(stderr, "warning: request given in argv, ignoring --infile\n");
+      }
+    } else {
+      std::stringstream input_stream;
+      if (FLAGS_infile.empty()) {
+        if (isatty(STDIN_FILENO)) {
+          fprintf(stderr, "reading request message from stdin...\n");
+        }
+        input_stream << std::cin.rdbuf();
+      } else {
+        std::ifstream input_file(FLAGS_infile, std::ios::in | std::ios::binary);
+        input_stream << input_file.rdbuf();
+        input_file.close();
+      }
+      request_text = input_stream.str();
     }
-  }
-  fprintf(stderr, "connecting to %s\n", server_address.c_str());
 
-  grpc::string serialized_response_proto;
-  std::multimap<grpc::string, grpc::string> client_metadata;
-  std::multimap<grpc::string_ref, grpc::string_ref> server_initial_metadata,
-      server_trailing_metadata;
-  ParseMetadataFlag(&client_metadata);
-  PrintMetadata(client_metadata, "Sending client initial metadata:");
-  grpc::Status status = grpc::testing::CliCall::Call(
-      channel, formatted_method_name, serialized_request_proto,
-      &serialized_response_proto, client_metadata, &server_initial_metadata,
-      &server_trailing_metadata);
-  PrintMetadata(server_initial_metadata,
-                "Received initial metadata from server:");
-  PrintMetadata(server_trailing_metadata,
-                "Received trailing metadata from server:");
-  if (status.ok()) {
-    fprintf(stderr, "Rpc succeeded with OK status\n");
-    if (FLAGS_binary_output) {
-      output_ss << serialized_response_proto;
+    if (FLAGS_binary_input) {
+      serialized_request_proto = request_text;
+      // formatted_method_name = method_name;
     } else {
-      grpc::string response_text = parser->GetTextFormatFromMethod(
-          method_name, serialized_response_proto, false /* is_request */);
+      // formatted_method_name = parser->GetFormattedMethodName(method_name);
+      serialized_request_proto = parser->GetSerializedProtoFromMethod(
+          method_name, request_text, true /* is_request */);
       if (parser->HasError()) {
         return false;
       }
-      output_ss << "Response: \n " << response_text << std::endl;
     }
-  } else {
-    fprintf(stderr, "Rpc failed with status code %d, error message: %s\n",
-            status.error_code(), status.error_message().c_str());
+    fprintf(stderr, "connecting to %s\n", server_address.c_str());
+
+    grpc::string serialized_response_proto;
+    std::multimap<grpc::string, grpc::string> client_metadata;
+    std::multimap<grpc::string_ref, grpc::string_ref> server_initial_metadata,
+        server_trailing_metadata;
+    ParseMetadataFlag(&client_metadata);
+    PrintMetadata(client_metadata, "Sending client initial metadata:");
+
+    CliCall call(channel, formatted_method_name, client_metadata);
+    call.Write(serialized_request_proto);
+    call.WritesDone();
+
+    for (bool receive_initial_metadata = true; call.Read(
+             &serialized_response_proto,
+             receive_initial_metadata ? &server_initial_metadata : nullptr);
+         receive_initial_metadata = false) {
+      if (!FLAGS_binary_output) {
+        serialized_response_proto = parser->GetTextFormatFromMethod(
+            method_name, serialized_response_proto, false /* is_request */);
+        if (parser->HasError()) {
+          return false;
+        }
+      }
+      if (receive_initial_metadata) {
+        PrintMetadata(server_initial_metadata,
+                      "Received initial metadata from server:");
+      }
+      if (!callback(serialized_response_proto)) {
+        return false;
+      }
+    }
+    Status status = call.Finish(&server_trailing_metadata);
+    if (status.ok()) {
+      fprintf(stderr, "Rpc succeeded with OK status\n");
+      return true;
+    } else {
+      fprintf(stderr, "Rpc failed with status code %d, error message: %s\n",
+              status.error_code(), status.error_message().c_str());
+      return false;
+    }
   }
-
-  return callback(output_ss.str());
+  GPR_UNREACHABLE_CODE(return false);
 }
 
 bool GrpcTool::ParseMessage(int argc, const char** argv,
diff --git a/test/cpp/util/grpc_tool_test.cc b/test/cpp/util/grpc_tool_test.cc
index 33ce611a60..26e2b1f502 100644
--- a/test/cpp/util/grpc_tool_test.cc
+++ b/test/cpp/util/grpc_tool_test.cc
@@ -102,6 +102,8 @@ DECLARE_bool(l);
 
 namespace {
 
+const int kNumResponseStreamsMsgs = 3;
+
 class TestCliCredentials final : public grpc::testing::CliCredentials {
  public:
   std::shared_ptr<grpc::ChannelCredentials> GetCredentials() const override {
@@ -137,6 +139,71 @@ class TestServiceImpl : public ::grpc::testing::EchoTestService::Service {
     response->set_message(request->message());
     return Status::OK;
   }
+
+  Status RequestStream(ServerContext* context,
+                       ServerReader<EchoRequest>* reader,
+                       EchoResponse* response) override {
+    EchoRequest request;
+    response->set_message("");
+    if (!context->client_metadata().empty()) {
+      for (std::multimap<grpc::string_ref, grpc::string_ref>::const_iterator
+               iter = context->client_metadata().begin();
+           iter != context->client_metadata().end(); ++iter) {
+        context->AddInitialMetadata(ToString(iter->first),
+                                    ToString(iter->second));
+      }
+    }
+    context->AddTrailingMetadata("trailing_key", "trailing_value");
+    while (reader->Read(&request)) {
+      response->mutable_message()->append(request.message());
+    }
+
+    return Status::OK;
+  }
+
+  Status ResponseStream(ServerContext* context, const EchoRequest* request,
+                        ServerWriter<EchoResponse>* writer) override {
+    if (!context->client_metadata().empty()) {
+      for (std::multimap<grpc::string_ref, grpc::string_ref>::const_iterator
+               iter = context->client_metadata().begin();
+           iter != context->client_metadata().end(); ++iter) {
+        context->AddInitialMetadata(ToString(iter->first),
+                                    ToString(iter->second));
+      }
+    }
+    context->AddTrailingMetadata("trailing_key", "trailing_value");
+
+    EchoResponse response;
+    for (int i = 0; i < kNumResponseStreamsMsgs; i++) {
+      response.set_message(request->message() + grpc::to_string(i));
+      writer->Write(response);
+    }
+
+    return Status::OK;
+  }
+
+  Status BidiStream(
+      ServerContext* context,
+      ServerReaderWriter<EchoResponse, EchoRequest>* stream) override {
+    EchoRequest request;
+    EchoResponse response;
+    if (!context->client_metadata().empty()) {
+      for (std::multimap<grpc::string_ref, grpc::string_ref>::const_iterator
+               iter = context->client_metadata().begin();
+           iter != context->client_metadata().end(); ++iter) {
+        context->AddInitialMetadata(ToString(iter->first),
+                                    ToString(iter->second));
+      }
+    }
+    context->AddTrailingMetadata("trailing_key", "trailing_value");
+
+    while (stream->Read(&request)) {
+      response.set_message(request.message());
+      stream->Write(response);
+    }
+
+    return Status::OK;
+  }
 };
 
 }  // namespace
@@ -347,6 +414,132 @@ TEST_F(GrpcToolTest, CallCommand) {
   ShutdownServer();
 }
 
+TEST_F(GrpcToolTest, CallCommandRequestStream) {
+  // Test input: grpc_cli call localhost:<port> RequestStream "message:
+  // 'Hello0'"
+  std::stringstream output_stream;
+
+  const grpc::string server_address = SetUpServer();
+  const char* argv[] = {"grpc_cli", "call", server_address.c_str(),
+                        "RequestStream", "message: 'Hello0'"};
+
+  // Mock std::cin input "message: 'Hello1'\n\n message: 'Hello2'\n\n"
+  std::streambuf* orig = std::cin.rdbuf();
+  std::istringstream ss("message: 'Hello1'\n\n message: 'Hello2'\n\n");
+  std::cin.rdbuf(ss.rdbuf());
+
+  EXPECT_TRUE(0 == GrpcToolMainLib(ArraySize(argv), argv, TestCliCredentials(),
+                                   std::bind(PrintStream, &output_stream,
+                                             std::placeholders::_1)));
+
+  // Expected output: "message: \"Hello0Hello1Hello2\""
+  EXPECT_TRUE(NULL != strstr(output_stream.str().c_str(),
+                             "message: \"Hello0Hello1Hello2\""));
+  std::cin.rdbuf(orig);
+  ShutdownServer();
+}
+
+TEST_F(GrpcToolTest, CallCommandRequestStreamWithBadRequest) {
+  // Test input: grpc_cli call localhost:<port> RequestStream "message:
+  // 'Hello0'"
+  std::stringstream output_stream;
+
+  const grpc::string server_address = SetUpServer();
+  const char* argv[] = {"grpc_cli", "call", server_address.c_str(),
+                        "RequestStream", "message: 'Hello0'"};
+
+  // Mock std::cin input "bad_field: 'Hello1'\n\n message: 'Hello2'\n\n"
+  std::streambuf* orig = std::cin.rdbuf();
+  std::istringstream ss("bad_field: 'Hello1'\n\n message: 'Hello2'\n\n");
+  std::cin.rdbuf(ss.rdbuf());
+
+  EXPECT_TRUE(0 == GrpcToolMainLib(ArraySize(argv), argv, TestCliCredentials(),
+                                   std::bind(PrintStream, &output_stream,
+                                             std::placeholders::_1)));
+
+  // Expected output: "message: \"Hello0Hello2\""
+  EXPECT_TRUE(NULL !=
+              strstr(output_stream.str().c_str(), "message: \"Hello0Hello2\""));
+  std::cin.rdbuf(orig);
+  ShutdownServer();
+}
+
+TEST_F(GrpcToolTest, CallCommandResponseStream) {
+  // Test input: grpc_cli call localhost:<port> ResponseStream "message:
+  // 'Hello'"
+  std::stringstream output_stream;
+
+  const grpc::string server_address = SetUpServer();
+  const char* argv[] = {"grpc_cli", "call", server_address.c_str(),
+                        "ResponseStream", "message: 'Hello'"};
+
+  EXPECT_TRUE(0 == GrpcToolMainLib(ArraySize(argv), argv, TestCliCredentials(),
+                                   std::bind(PrintStream, &output_stream,
+                                             std::placeholders::_1)));
+
+  // Expected output: "message: \"Hello{n}\""
+  for (int i = 0; i < kNumResponseStreamsMsgs; i++) {
+    grpc::string expected_response_text =
+        "message: \"Hello" + grpc::to_string(i) + "\"\n";
+    EXPECT_TRUE(NULL != strstr(output_stream.str().c_str(),
+                               expected_response_text.c_str()));
+  }
+
+  ShutdownServer();
+}
+
+TEST_F(GrpcToolTest, CallCommandBidiStream) {
+  // Test input: grpc_cli call localhost:<port> BidiStream "message: 'Hello0'"
+  std::stringstream output_stream;
+
+  const grpc::string server_address = SetUpServer();
+  const char* argv[] = {"grpc_cli", "call", server_address.c_str(),
+                        "BidiStream", "message: 'Hello0'"};
+
+  // Mock std::cin input "message: 'Hello1'\n\n message: 'Hello2'\n\n"
+  std::streambuf* orig = std::cin.rdbuf();
+  std::istringstream ss("message: 'Hello1'\n\n message: 'Hello2'\n\n");
+  std::cin.rdbuf(ss.rdbuf());
+
+  EXPECT_TRUE(0 == GrpcToolMainLib(ArraySize(argv), argv, TestCliCredentials(),
+                                   std::bind(PrintStream, &output_stream,
+                                             std::placeholders::_1)));
+
+  // Expected output: "message: \"Hello0\"\nmessage: \"Hello1\"\nmessage:
+  // \"Hello2\"\n\n"
+  EXPECT_TRUE(NULL != strstr(output_stream.str().c_str(),
+                             "message: \"Hello0\"\nmessage: "
+                             "\"Hello1\"\nmessage: \"Hello2\"\n"));
+  std::cin.rdbuf(orig);
+  ShutdownServer();
+}
+
+TEST_F(GrpcToolTest, CallCommandBidiStreamWithBadRequest) {
+  // Test input: grpc_cli call localhost:<port> BidiStream "message: 'Hello0'"
+  std::stringstream output_stream;
+
+  const grpc::string server_address = SetUpServer();
+  const char* argv[] = {"grpc_cli", "call", server_address.c_str(),
+                        "BidiStream", "message: 'Hello0'"};
+
+  // Mock std::cin input "message: 'Hello1'\n\n message: 'Hello2'\n\n"
+  std::streambuf* orig = std::cin.rdbuf();
+  std::istringstream ss("message: 1.0\n\n message: 'Hello2'\n\n");
+  std::cin.rdbuf(ss.rdbuf());
+
+  EXPECT_TRUE(0 == GrpcToolMainLib(ArraySize(argv), argv, TestCliCredentials(),
+                                   std::bind(PrintStream, &output_stream,
+                                             std::placeholders::_1)));
+
+  // Expected output: "message: \"Hello0\"\nmessage: \"Hello1\"\nmessage:
+  // \"Hello2\"\n\n"
+  EXPECT_TRUE(NULL != strstr(output_stream.str().c_str(),
+                             "message: \"Hello0\"\nmessage: \"Hello2\"\n"));
+  std::cin.rdbuf(orig);
+
+  ShutdownServer();
+}
+
 TEST_F(GrpcToolTest, ParseCommand) {
   // Test input "grpc_cli parse localhost:<port> grpc.testing.EchoResponse
   // ECHO_RESPONSE_MESSAGE"
diff --git a/test/cpp/util/proto_file_parser.cc b/test/cpp/util/proto_file_parser.cc
index bc8a6083f4..d501c3697b 100644
--- a/test/cpp/util/proto_file_parser.cc
+++ b/test/cpp/util/proto_file_parser.cc
@@ -81,8 +81,9 @@ class ErrorPrinter : public protobuf::compiler::MultiFileErrorCollector {
 ProtoFileParser::ProtoFileParser(std::shared_ptr<grpc::Channel> channel,
                                  const grpc::string& proto_path,
                                  const grpc::string& protofiles)
-    : has_error_(false) {
-  std::vector<grpc::string> service_list;
+    : has_error_(false),
+      dynamic_factory_(new protobuf::DynamicMessageFactory()) {
+  std::vector<std::string> service_list;
   if (channel) {
     reflection_db_.reset(new grpc::ProtoReflectionDescriptorDatabase(channel));
     reflection_db_->GetServices(&service_list);
@@ -127,7 +128,6 @@ ProtoFileParser::ProtoFileParser(std::shared_ptr<grpc::Channel> channel,
   }
 
   desc_pool_.reset(new protobuf::DescriptorPool(desc_db_.get()));
-  dynamic_factory_.reset(new protobuf::DynamicMessageFactory(desc_pool_.get()));
 
   for (auto it = service_list.begin(); it != service_list.end(); it++) {
     if (known_services.find(*it) == known_services.end()) {
@@ -144,6 +144,11 @@ ProtoFileParser::~ProtoFileParser() {}
 
 grpc::string ProtoFileParser::GetFullMethodName(const grpc::string& method) {
   has_error_ = false;
+
+  if (known_methods_.find(method) != known_methods_.end()) {
+    return known_methods_[method];
+  }
+
   const protobuf::MethodDescriptor* method_descriptor = nullptr;
   for (auto it = service_desc_list_.begin(); it != service_desc_list_.end();
        it++) {
@@ -169,6 +174,8 @@ grpc::string ProtoFileParser::GetFullMethodName(const grpc::string& method) {
     return "";
   }
 
+  known_methods_[method] = method_descriptor->full_name();
+
   return method_descriptor->full_name();
 }
 
@@ -205,6 +212,25 @@ grpc::string ProtoFileParser::GetMessageTypeFromMethod(
                     : method_desc->output_type()->full_name();
 }
 
+bool ProtoFileParser::IsStreaming(const grpc::string& method, bool is_request) {
+  has_error_ = false;
+
+  grpc::string full_method_name = GetFullMethodName(method);
+  if (has_error_) {
+    return false;
+  }
+
+  const protobuf::MethodDescriptor* method_desc =
+      desc_pool_->FindMethodByName(full_method_name);
+  if (!method_desc) {
+    LogError("Method not found");
+    return false;
+  }
+
+  return is_request ? method_desc->client_streaming()
+                    : method_desc->server_streaming();
+}
+
 grpc::string ProtoFileParser::GetSerializedProtoFromMethod(
     const grpc::string& method, const grpc::string& text_format_proto,
     bool is_request) {
diff --git a/test/cpp/util/proto_file_parser.h b/test/cpp/util/proto_file_parser.h
index c1070a37b5..23d311ef8f 100644
--- a/test/cpp/util/proto_file_parser.h
+++ b/test/cpp/util/proto_file_parser.h
@@ -84,6 +84,8 @@ class ProtoFileParser {
       const grpc::string& message_type_name,
       const grpc::string& serialized_proto);
 
+  bool IsStreaming(const grpc::string& method, bool is_request);
+
   bool HasError() const { return has_error_; }
 
   void LogError(const grpc::string& error_msg);
@@ -104,6 +106,7 @@ class ProtoFileParser {
   std::unique_ptr<protobuf::DynamicMessageFactory> dynamic_factory_;
   std::unique_ptr<grpc::protobuf::Message> request_prototype_;
   std::unique_ptr<grpc::protobuf::Message> response_prototype_;
+  std::unordered_map<grpc::string, grpc::string> known_methods_;
   std::vector<const protobuf::ServiceDescriptor*> service_desc_list_;
 };
 
diff --git a/tools/doxygen/Doxyfile.c++ b/tools/doxygen/Doxyfile.c++
index 128a409df4..c6068d6e5b 100644
--- a/tools/doxygen/Doxyfile.c++
+++ b/tools/doxygen/Doxyfile.c++
@@ -814,6 +814,7 @@ include/grpc++/impl/codegen/core_codegen.h \
 include/grpc++/impl/codegen/core_codegen_interface.h \
 include/grpc++/impl/codegen/create_auth_context.h \
 include/grpc++/impl/codegen/grpc_library.h \
+include/grpc++/impl/codegen/metadata_map.h \
 include/grpc++/impl/codegen/method_handler_impl.h \
 include/grpc++/impl/codegen/rpc_method.h \
 include/grpc++/impl/codegen/rpc_service_method.h \
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index 5bd4323f3a..990bdb9438 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -815,6 +815,7 @@ include/grpc++/impl/codegen/core_codegen.h \
 include/grpc++/impl/codegen/core_codegen_interface.h \
 include/grpc++/impl/codegen/create_auth_context.h \
 include/grpc++/impl/codegen/grpc_library.h \
+include/grpc++/impl/codegen/metadata_map.h \
 include/grpc++/impl/codegen/method_handler_impl.h \
 include/grpc++/impl/codegen/rpc_method.h \
 include/grpc++/impl/codegen/rpc_service_method.h \
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index 37609d50bb..9716598606 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -8119,6 +8119,7 @@
       "include/grpc++/impl/codegen/core_codegen_interface.h", 
       "include/grpc++/impl/codegen/create_auth_context.h", 
       "include/grpc++/impl/codegen/grpc_library.h", 
+      "include/grpc++/impl/codegen/metadata_map.h", 
       "include/grpc++/impl/codegen/method_handler_impl.h", 
       "include/grpc++/impl/codegen/rpc_method.h", 
       "include/grpc++/impl/codegen/rpc_service_method.h", 
@@ -8153,6 +8154,7 @@
       "include/grpc++/impl/codegen/core_codegen_interface.h", 
       "include/grpc++/impl/codegen/create_auth_context.h", 
       "include/grpc++/impl/codegen/grpc_library.h", 
+      "include/grpc++/impl/codegen/metadata_map.h", 
       "include/grpc++/impl/codegen/method_handler_impl.h", 
       "include/grpc++/impl/codegen/rpc_method.h", 
       "include/grpc++/impl/codegen/rpc_service_method.h", 
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index d9d531959d..58dba9952c 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -40759,6 +40759,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/0242a9f4d4fafc96ee9ed762b610e3c68d6efdec"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/02434dcdaca96b9eacee76eb351e99f015eaa05e"
     ], 
     "ci_platforms": [
@@ -42519,6 +42541,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/0cd9696699bd190463ecef91968624601b64cd8b"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/0d.bin"
     ], 
     "ci_platforms": [
@@ -43311,6 +43355,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/122b6fc72956541812dd653b726b073b77ca33be"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/1239eef13562df4ff59856900eee2f871a2fd0f3"
     ], 
     "ci_platforms": [
@@ -48327,6 +48393,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/315d27e12f2214a56fb9901dacff14852ff2ac0f"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/31ef9c4ed85ae1b4e8a027fc5a1d3037dbbf3b3a"
     ], 
     "ci_platforms": [
@@ -50307,6 +50395,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/3f2429e3255ae36fecb57559b57d2b0cb88f5dd1"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/3f2e5f90e1a93df61a1c9c09b8c9116149eec526"
     ], 
     "ci_platforms": [
@@ -50637,6 +50747,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/41bda7ff09175f821992adf4314a8ec3007ffe55"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/41de80653b78b98f5caa7f6d00a96d72bc245068"
     ], 
     "ci_platforms": [
@@ -52045,6 +52177,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/49d0085058d7fa81247f51b802c0f4206854b4dc"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/49d816ae44b329820f47979c5790eebc8eadafd7"
     ], 
     "ci_platforms": [
@@ -55543,6 +55697,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/614dbc86b17270ef1d5ab705ecbe88c742815ce7"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/61614f406af22aa805e6a2cfb24519ffd058d575"
     ], 
     "ci_platforms": [
@@ -57369,6 +57545,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/6cb17148d52be437332b6fd6f2fc8328bfb63fb0"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/6cb9930369caf7584015d3a17c37e144d23b79ce"
     ], 
     "ci_platforms": [
@@ -57611,6 +57809,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/6ea192b1d4c4577ca7511f8ce5027b31b2e0d75d"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/6ef96bc0c5b6ab5f8a4453b9cf5784fd55e3b59f"
     ], 
     "ci_platforms": [
@@ -58711,6 +58931,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/746477e7e8f093f87cb6924ab6476cda9689607d"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/746d9837f0fc3c989b7fe0585b8365478f1c21fc"
     ], 
     "ci_platforms": [
@@ -59239,6 +59481,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/7752153d87017b85112a49ea95aa25ca78d24431"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/77662d88e025c080212dd2dc4dd2030810926f40"
     ], 
     "ci_platforms": [
@@ -60405,6 +60669,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/7e75ea44aa7347c2f827beecb27e3bf5b1907b8a"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/7e8f7517bb0bb95011b48f1f4f4a631d4d756a5f"
     ], 
     "ci_platforms": [
@@ -63727,6 +64013,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/95e73caecc0ab06beaa9b84125adcb2e6eee2eff"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/95f223f8964d294aafc2a6041a83cfa7761c31ab"
     ], 
     "ci_platforms": [
@@ -64915,6 +65223,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/9e273a94bf3c60f1c7875874c81d0b9309428752"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/9e48b3aa2c25dbbab21148bdac91b5169ce088bf"
     ], 
     "ci_platforms": [
@@ -66125,6 +66455,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/a65bda38b60ae084a5dcc3b616660aa338feef17"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/a660e999019a7dd3e950b51d6fa8f453390fb504"
     ], 
     "ci_platforms": [
@@ -67951,6 +68303,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/b39f27387a256019038cddb91f65651c01afb825"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/b3b9e307ce3af6fa515a33668374e15fcc909ae5"
     ], 
     "ci_platforms": [
@@ -68435,6 +68809,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/b6f721156f8dc6a353555929e459e61bab8b394a"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/b70abef1bf2c649cf31720136a099a88cff8d562"
     ], 
     "ci_platforms": [
@@ -69447,6 +69843,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/bbb2429766a7c4ef9cb7110d567fd48cd6507dc5"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/bbf053837b7e0e2adc868be62fc91248b8dce176"
     ], 
     "ci_platforms": [
@@ -69513,6 +69931,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/bc330aa616a792ff22a8c7428dcdb4d99accbe4b"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/bc5e743f85f6632110277f09847381a402e1624c"
     ], 
     "ci_platforms": [
@@ -72131,6 +72571,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/cd4ccfa79f65f31716296e690f3a76007edde2e3"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/cd4f2c59f0cf55d9a73fb0b96d701c784c446048"
     ], 
     "ci_platforms": [
@@ -73429,6 +73891,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/crash-5d73de981fb75553a7b2606e111716ee9f2af844"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/crash-603222da20c147a532188e80fc1a26e4e8bc4bee"
     ], 
     "ci_platforms": [
@@ -78511,6 +78995,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/e6b74f64e8bdfdf98177aee58b8729ff2aa7ffb2"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/e72218971bac83f556e86b0a65ec303e2a05eac8"
     ], 
     "ci_platforms": [
@@ -79611,6 +80117,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/edecc59c5809796f266abd8df4d5ecf6aae304ca"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/edfcf299569efc4788937d2cd4ca0e625fb9e527"
     ], 
     "ci_platforms": [
@@ -80249,6 +80777,28 @@
   }, 
   {
     "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/f1b2889ae7091d6a14332343fe7a2bffd81039a7"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/f1b592b7e1a5af83eea1bccc2d7bcca302173d57"
     ], 
     "ci_platforms": [
diff --git a/vsprojects/vcxproj/grpc++/grpc++.vcxproj b/vsprojects/vcxproj/grpc++/grpc++.vcxproj
index 86c2fe3641..fcd1d9def9 100644
--- a/vsprojects/vcxproj/grpc++/grpc++.vcxproj
+++ b/vsprojects/vcxproj/grpc++/grpc++.vcxproj
@@ -313,6 +313,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_service_method.h" />
diff --git a/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters b/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
index dffc70f4c9..dbf3ad90c6 100644
--- a/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters
@@ -279,6 +279,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj b/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj
index 58b87ef73e..ba12f0be60 100644
--- a/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj
+++ b/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj
@@ -160,6 +160,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_service_method.h" />
diff --git a/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj.filters b/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj.filters
index aabb45dc6a..116a639690 100644
--- a/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++_test_util/grpc++_test_util.vcxproj.filters
@@ -72,6 +72,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
index 33a74ba01e..f073ea595d 100644
--- a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
+++ b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj
@@ -313,6 +313,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_service_method.h" />
diff --git a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
index b87d789abe..a2515e23a0 100644
--- a/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters
@@ -264,6 +264,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj b/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj
index d8d4a76ebf..986217baba 100644
--- a/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj
+++ b/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj
@@ -173,6 +173,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_service_method.h" />
diff --git a/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj.filters b/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj.filters
index d79f2287e5..b48fe4fcee 100644
--- a/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj.filters
+++ b/vsprojects/vcxproj/test/codegen_test_full/codegen_test_full.vcxproj.filters
@@ -60,6 +60,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj b/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj
index 595e6730fa..fd014fdc09 100644
--- a/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj
+++ b/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj
@@ -173,6 +173,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_service_method.h" />
diff --git a/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj.filters b/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj.filters
index 78de9501b0..176204fac1 100644
--- a/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj.filters
+++ b/vsprojects/vcxproj/test/codegen_test_minimal/codegen_test_minimal.vcxproj.filters
@@ -63,6 +63,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/test/grpc_tool_test/grpc_tool_test.vcxproj b/vsprojects/vcxproj/test/grpc_tool_test/grpc_tool_test.vcxproj
index 5381be52d3..e5d4f0be93 100644
--- a/vsprojects/vcxproj/test/grpc_tool_test/grpc_tool_test.vcxproj
+++ b/vsprojects/vcxproj/test/grpc_tool_test/grpc_tool_test.vcxproj
@@ -174,6 +174,7 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\core_codegen_interface.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\create_auth_context.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h" />
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_method.h" />
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\rpc_service_method.h" />
diff --git a/vsprojects/vcxproj/test/grpc_tool_test/grpc_tool_test.vcxproj.filters b/vsprojects/vcxproj/test/grpc_tool_test/grpc_tool_test.vcxproj.filters
index 0526a0721b..5cba594b48 100644
--- a/vsprojects/vcxproj/test/grpc_tool_test/grpc_tool_test.vcxproj.filters
+++ b/vsprojects/vcxproj/test/grpc_tool_test/grpc_tool_test.vcxproj.filters
@@ -54,6 +54,9 @@
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\grpc_library.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\metadata_map.h">
+      <Filter>include\grpc++\impl\codegen</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\include\grpc++\impl\codegen\method_handler_impl.h">
       <Filter>include\grpc++\impl\codegen</Filter>
     </ClInclude>