diff --git a/BUILD b/BUILD
index 9fee908572364872841ee08fca964bf52ee0414c..6955cf421c9ea5128d1d7340935ecca391df7909 100644
--- a/BUILD
+++ b/BUILD
@@ -1076,8 +1076,8 @@ grpc_cc_library(
         "src/core/ext/transport/cronet/transport/cronet_transport.c",
     ],
     hdrs = [
-        "third_party/objective_c/Cronet/bidirectional_stream_c.h",
         "src/core/ext/transport/cronet/transport/cronet_transport.h",
+        "third_party/objective_c/Cronet/bidirectional_stream_c.h",
     ],
     language = "c",
     public_hdrs = [
@@ -1128,6 +1128,7 @@ grpc_cc_library(
         "src/cpp/common/channel_filter.cc",
         "src/cpp/common/completion_queue_cc.cc",
         "src/cpp/common/core_codegen.cc",
+        "src/cpp/common/resource_quota_cc.cc",
         "src/cpp/common/rpc_method.cc",
         "src/cpp/common/version_cc.cc",
         "src/cpp/server/async_generic_service.cc",
@@ -1298,3 +1299,22 @@ grpc_cc_library(
         "grpc++_codegen_base",
     ],
 )
+
+grpc_cc_library(
+    name = "grpc++_reflection",
+    srcs = [
+        "src/cpp/ext/proto_server_reflection.cc",
+        "src/cpp/ext/proto_server_reflection_plugin.cc",
+    ],
+    hdrs = [
+        "src/cpp/ext/proto_server_reflection.h",
+    ],
+    language = "c++",
+    public_hdrs = [
+        "include/grpc++/ext/proto_server_reflection_plugin.h",
+    ],
+    deps = [
+        ":grpc++",
+        "//src/proto/grpc/reflection/v1alpha:reflection_proto",
+    ],
+)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d1bc3bf6bec336c8e8ae6068192ad0ac71170656..383d575a34375c09f4b3566ab2662ca874b6f395 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1340,6 +1340,8 @@ add_library(grpc_cronet
   src/core/lib/tsi/ssl_transport_security.c
   src/core/lib/tsi/transport_security.c
   src/core/ext/transport/chttp2/client/chttp2_connector.c
+  src/core/ext/load_reporting/load_reporting.c
+  src/core/ext/load_reporting/load_reporting_filter.c
   src/core/plugin_registry/grpc_cronet_plugin_registry.c
 )
 
diff --git a/Makefile b/Makefile
index c8e1b10df0d9f43c4117b0afccd634afd61b3129..0e1bcd2c3751c0e9b23aeb78f4080adc9dc526c7 100644
--- a/Makefile
+++ b/Makefile
@@ -2646,15 +2646,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE): $(LIBGPR_OBJS)  $(ZLIB_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/gpr$(SHARED_VERSION_CORE).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE)-dll.a -o $(LIBDIR)/$(CONFIG)/gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGPR_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/gpr$(SHARED_VERSION_CORE).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE)-dll.a -o $(LIBDIR)/$(CONFIG)/gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGPR_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
 $(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE): $(LIBGPR_OBJS)  $(ZLIB_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGPR_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGPR_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgpr.so.3 -o $(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGPR_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgpr.so.3 -o $(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGPR_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 	$(Q) ln -sf $(SHARED_PREFIX)gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE).so.3
 	$(Q) ln -sf $(SHARED_PREFIX)gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgpr$(SHARED_VERSION_CORE).so
 endif
@@ -2979,15 +2979,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE): $(LIBGRPC_OBJS)  $(ZLIB_DEP) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc$(SHARED_VERSION_CORE).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc$(SHARED_VERSION_CORE).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
 $(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE): $(LIBGRPC_OBJS)  $(ZLIB_DEP) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 	$(Q) ln -sf $(SHARED_PREFIX)grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE).so.3
 	$(Q) ln -sf $(SHARED_PREFIX)grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgrpc$(SHARED_VERSION_CORE).so
 endif
@@ -3197,6 +3197,8 @@ LIBGRPC_CRONET_SRC = \
     src/core/lib/tsi/ssl_transport_security.c \
     src/core/lib/tsi/transport_security.c \
     src/core/ext/transport/chttp2/client/chttp2_connector.c \
+    src/core/ext/load_reporting/load_reporting.c \
+    src/core/ext/load_reporting/load_reporting_filter.c \
     src/core/plugin_registry/grpc_cronet_plugin_registry.c \
 
 PUBLIC_HEADERS_C += \
@@ -3261,15 +3263,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE): $(LIBGRPC_CRONET_OBJS)  $(ZLIB_DEP) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc_cronet$(SHARED_VERSION_CORE).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_CRONET_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc_cronet$(SHARED_VERSION_CORE).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_CRONET_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
 $(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE): $(LIBGRPC_CRONET_OBJS)  $(ZLIB_DEP) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_CRONET_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_CRONET_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc_cronet.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_CRONET_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc_cronet.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_CRONET_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBS)
 	$(Q) ln -sf $(SHARED_PREFIX)grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE).so.3
 	$(Q) ln -sf $(SHARED_PREFIX)grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgrpc_cronet$(SHARED_VERSION_CORE).so
 endif
@@ -3780,15 +3782,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE): $(LIBGRPC_UNSECURE_OBJS)  $(ZLIB_DEP) $(LIBDIR)/$(CONFIG)/libgpr.a
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc_unsecure$(SHARED_VERSION_CORE).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_UNSECURE_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc_unsecure$(SHARED_VERSION_CORE).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_UNSECURE_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
 $(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE): $(LIBGRPC_UNSECURE_OBJS)  $(ZLIB_DEP) $(LIBDIR)/$(CONFIG)/libgpr.a
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_UNSECURE_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_UNSECURE_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
-	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc_unsecure.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_UNSECURE_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc_unsecure.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBGRPC_UNSECURE_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS) $(LDLIBS)
 	$(Q) ln -sf $(SHARED_PREFIX)grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE).so.3
 	$(Q) ln -sf $(SHARED_PREFIX)grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure$(SHARED_VERSION_CORE).so
 endif
@@ -4055,15 +4057,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/grpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP): $(LIBGRPC++_OBJS)  $(ZLIB_DEP) $(PROTOBUF_DEP) $(LIBDIR)/$(CONFIG)/grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc++$(SHARED_VERSION_CPP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgrpc$(SHARED_VERSION_CORE)-dll
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc++$(SHARED_VERSION_CPP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgrpc$(SHARED_VERSION_CORE)-dll
 else
 $(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP): $(LIBGRPC++_OBJS)  $(ZLIB_DEP) $(PROTOBUF_DEP) $(LIBDIR)/$(CONFIG)/libgrpc.$(SHARED_EXT_CORE) $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgrpc
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgrpc
 else
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc++.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgrpc
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc++.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgrpc
 	$(Q) ln -sf $(SHARED_PREFIX)grpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP).so.1
 	$(Q) ln -sf $(SHARED_PREFIX)grpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBDIR)/$(CONFIG)/libgrpc++$(SHARED_VERSION_CPP).so
 endif
@@ -4446,15 +4448,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/grpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP): $(LIBGRPC++_CRONET_OBJS)  $(ZLIB_DEP) $(PROTOBUF_DEP) $(LIBDIR)/$(CONFIG)/gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc++_cronet$(SHARED_VERSION_CPP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_CRONET_OBJS) $(LDLIBS) $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgpr$(SHARED_VERSION_CORE)-dll -lgrpc_cronet$(SHARED_VERSION_CORE)-dll
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc++_cronet$(SHARED_VERSION_CPP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_CRONET_OBJS) $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgpr$(SHARED_VERSION_CORE)-dll -lgrpc_cronet$(SHARED_VERSION_CORE)-dll
 else
 $(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP): $(LIBGRPC++_CRONET_OBJS)  $(ZLIB_DEP) $(PROTOBUF_DEP) $(LIBDIR)/$(CONFIG)/libgpr.$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgrpc_cronet.$(SHARED_EXT_CORE) $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_CRONET_OBJS) $(LDLIBS) $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgpr -lgrpc_cronet
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_CRONET_OBJS) $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgpr -lgrpc_cronet
 else
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc++_cronet.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_CRONET_OBJS) $(LDLIBS) $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgpr -lgrpc_cronet
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc++_cronet.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_CRONET_OBJS) $(OPENSSL_MERGE_LIBS) $(LDLIBS_SECURE) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgpr -lgrpc_cronet
 	$(Q) ln -sf $(SHARED_PREFIX)grpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP).so.1
 	$(Q) ln -sf $(SHARED_PREFIX)grpc++_cronet$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBDIR)/$(CONFIG)/libgrpc++_cronet$(SHARED_VERSION_CPP).so
 endif
@@ -4569,15 +4571,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/grpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP): $(LIBGRPC++_REFLECTION_OBJS)  $(ZLIB_DEP) $(PROTOBUF_DEP) $(LIBDIR)/$(CONFIG)/grpc++$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc++_reflection$(SHARED_VERSION_CPP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_REFLECTION_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgrpc++$(SHARED_VERSION_CPP)-dll
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc++_reflection$(SHARED_VERSION_CPP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_REFLECTION_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgrpc++$(SHARED_VERSION_CPP)-dll
 else
 $(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP): $(LIBGRPC++_REFLECTION_OBJS)  $(ZLIB_DEP) $(PROTOBUF_DEP) $(LIBDIR)/$(CONFIG)/libgrpc++.$(SHARED_EXT_CPP) $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_REFLECTION_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgrpc++
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_REFLECTION_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgrpc++
 else
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc++_reflection.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_REFLECTION_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgrpc++
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc++_reflection.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_REFLECTION_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgrpc++
 	$(Q) ln -sf $(SHARED_PREFIX)grpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP).so.1
 	$(Q) ln -sf $(SHARED_PREFIX)grpc++_reflection$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBDIR)/$(CONFIG)/libgrpc++_reflection$(SHARED_VERSION_CPP).so
 endif
@@ -4925,15 +4927,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/grpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP): $(LIBGRPC++_UNSECURE_OBJS)  $(ZLIB_DEP) $(PROTOBUF_DEP) $(LIBDIR)/$(CONFIG)/gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc++_unsecure$(SHARED_VERSION_CPP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_UNSECURE_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgpr$(SHARED_VERSION_CORE)-dll -lgrpc_unsecure$(SHARED_VERSION_CORE)-dll
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc++_unsecure$(SHARED_VERSION_CPP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_UNSECURE_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgpr$(SHARED_VERSION_CORE)-dll -lgrpc_unsecure$(SHARED_VERSION_CORE)-dll
 else
 $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP): $(LIBGRPC++_UNSECURE_OBJS)  $(ZLIB_DEP) $(PROTOBUF_DEP) $(LIBDIR)/$(CONFIG)/libgpr.$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.$(SHARED_EXT_CORE)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_UNSECURE_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgpr -lgrpc_unsecure
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_UNSECURE_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgpr -lgrpc_unsecure
 else
-	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc++_unsecure.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_UNSECURE_OBJS) $(LDLIBS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) -lgpr -lgrpc_unsecure
+	$(Q) $(LDXX) $(LDFLAGS) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc++_unsecure.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBGRPC++_UNSECURE_OBJS) $(ZLIB_MERGE_LIBS) $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) -lgpr -lgrpc_unsecure
 	$(Q) ln -sf $(SHARED_PREFIX)grpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP).so.1
 	$(Q) ln -sf $(SHARED_PREFIX)grpc++_unsecure$(SHARED_VERSION_CPP).$(SHARED_EXT_CPP) $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure$(SHARED_VERSION_CPP).so
 endif
@@ -5466,15 +5468,15 @@ ifeq ($(SYSTEM),MINGW32)
 $(LIBDIR)/$(CONFIG)/grpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP): $(LIBGRPC_CSHARP_EXT_OBJS)  $(ZLIB_DEP) $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LD) $(LDFLAGS) $(if $(subst Linux,,$(SYSTEM)),,-Wl$(comma)-wrap$(comma)memcpy) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc_csharp_ext$(SHARED_VERSION_CSHARP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) $(LIBGRPC_CSHARP_EXT_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) $(if $(subst Linux,,$(SYSTEM)),,-Wl$(comma)-wrap$(comma)memcpy) -L$(LIBDIR)/$(CONFIG) -shared -Wl,--output-def=$(LIBDIR)/$(CONFIG)/grpc_csharp_ext$(SHARED_VERSION_CSHARP).def -Wl,--out-implib=$(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP)-dll.a -o $(LIBDIR)/$(CONFIG)/grpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) $(LIBGRPC_CSHARP_EXT_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
 $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP): $(LIBGRPC_CSHARP_EXT_OBJS)  $(ZLIB_DEP) $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(OPENSSL_DEP)
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
 ifeq ($(SYSTEM),Darwin)
-	$(Q) $(LD) $(LDFLAGS) $(if $(subst Linux,,$(SYSTEM)),,-Wl$(comma)-wrap$(comma)memcpy) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) $(LIBGRPC_CSHARP_EXT_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) $(if $(subst Linux,,$(SYSTEM)),,-Wl$(comma)-wrap$(comma)memcpy) -L$(LIBDIR)/$(CONFIG) -install_name $(SHARED_PREFIX)grpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) -dynamiclib -o $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) $(LIBGRPC_CSHARP_EXT_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS) $(LDLIBS)
 else
-	$(Q) $(LD) $(LDFLAGS) $(if $(subst Linux,,$(SYSTEM)),,-Wl$(comma)-wrap$(comma)memcpy) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc_csharp_ext.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) $(LIBGRPC_CSHARP_EXT_OBJS) $(LDLIBS) $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS)
+	$(Q) $(LD) $(LDFLAGS) $(if $(subst Linux,,$(SYSTEM)),,-Wl$(comma)-wrap$(comma)memcpy) -L$(LIBDIR)/$(CONFIG) -shared -Wl,-soname,libgrpc_csharp_ext.so.3 -o $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) $(LIBGRPC_CSHARP_EXT_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(ZLIB_MERGE_LIBS) $(LDLIBS)
 	$(Q) ln -sf $(SHARED_PREFIX)grpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP).so.1
 	$(Q) ln -sf $(SHARED_PREFIX)grpc_csharp_ext$(SHARED_VERSION_CSHARP).$(SHARED_EXT_CSHARP) $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext$(SHARED_VERSION_CSHARP).so
 endif
diff --git a/Rakefile b/Rakefile
index c8bca20ad1de671f5a65c5342097da1df4ffc478..12ac12710fb8876d8d5f77edd7d17174d0c6d7a0 100755
--- a/Rakefile
+++ b/Rakefile
@@ -93,7 +93,7 @@ task 'dlls' do
   [ w64, w32 ].each do |opt|
     env_comp = "CC=#{opt[:cross]}-gcc "
     env_comp += "LD=#{opt[:cross]}-gcc "
-    docker_for_windows "#{env} #{env_comp} make -j #{out} && #{opt[:cross]}-strip -x -S #{out} && cp #{out} #{opt[:out]}"
+    docker_for_windows "gem update --system && #{env} #{env_comp} make -j #{out} && #{opt[:cross]}-strip -x -S #{out} && cp #{out} #{opt[:out]}"
   end
 
 end
@@ -107,10 +107,10 @@ task 'gem:native' do
   if RUBY_PLATFORM =~ /darwin/
     FileUtils.touch 'grpc_c.32.ruby'
     FileUtils.touch 'grpc_c.64.ruby'
-    system "rake cross native gem RUBY_CC_VERSION=2.3.0:2.2.2:2.1.5:2.0.0 V=#{verbose} GRPC_CONFIG=#{grpc_config}"
+    system "rake cross native gem RUBY_CC_VERSION=2.4.0:2.3.0:2.2.2:2.1.5:2.0.0 V=#{verbose} GRPC_CONFIG=#{grpc_config}"
   else
     Rake::Task['dlls'].execute
-    docker_for_windows "bundle && rake cross native gem RUBY_CC_VERSION=2.3.0:2.2.2:2.1.5:2.0.0 V=#{verbose} GRPC_CONFIG=#{grpc_config}"
+    docker_for_windows "gem update --system && bundle && rake cross native gem RUBY_CC_VERSION=2.4.0:2.3.0:2.2.2:2.1.5:2.0.0 V=#{verbose} GRPC_CONFIG=#{grpc_config}"
   end
 end
 
diff --git a/binding.gyp b/binding.gyp
index 8ff3d8c1a3459b17316527368bdffec12cfa33bd..71900829092bed4506d769e0acd698da319e700c 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -51,7 +51,9 @@
     'conditions': [
       ['runtime=="node"', {
         'defines': [
-          'GRPC_UV'
+          # Disabling this while bugs are ironed out. Uncomment this to
+          # re-enable libuv integration in C core.
+          # 'GRPC_UV'
         ]
       }],
       ['OS!="win" and runtime=="electron"', {
diff --git a/build.yaml b/build.yaml
index 9c4da69b6cf90e931318f3569d9c84403a1d5136..19bdb796d77fb8e51affabf66b188b48bc70980f 100644
--- a/build.yaml
+++ b/build.yaml
@@ -978,6 +978,7 @@ libs:
   - grpc_base
   - grpc_transport_cronet_client_secure
   - grpc_transport_chttp2_client_secure
+  - grpc_load_reporting
   generate_plugin_registry: true
   platforms:
   - linux
@@ -3071,10 +3072,14 @@ targets:
   - gpr
   args:
   - --benchmark_min_time=0
+  excluded_poll_engines:
+  - poll
+  - poll-cv
   platforms:
   - mac
   - linux
   - posix
+  timeout_seconds: 1200
 - name: bm_metadata
   build: test
   language: c++
diff --git a/examples/ruby/grpc-demo.gemspec b/examples/ruby/grpc-demo.gemspec
index e1b77a56ac9af6ac3f657a63398d6f22daf4600d..4423fd34d428543238fd710c9674c48e7b44ec38 100644
--- a/examples/ruby/grpc-demo.gemspec
+++ b/examples/ruby/grpc-demo.gemspec
@@ -17,7 +17,7 @@ Gem::Specification.new do |s|
   s.require_paths = ['lib']
   s.platform      = Gem::Platform::RUBY
 
-  s.add_dependency 'grpc', '~> 1.0.0'
+  s.add_dependency 'grpc', '~> 1.0'
 
   s.add_development_dependency 'bundler', '~> 1.7'
 end
diff --git a/examples/ruby/without_protobuf/README.md b/examples/ruby/without_protobuf/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..f9611648ca2bdd4b05a03bbc07d5a3af607af2b6
--- /dev/null
+++ b/examples/ruby/without_protobuf/README.md
@@ -0,0 +1,6 @@
+gRPC (Ruby) without protobuf
+========================
+
+This directory contains a simple example of using gRPC without protobuf.
+
+This is mainly intended to show basic usage of the GRPC::GenericService module
diff --git a/examples/ruby/without_protobuf/echo_client.rb b/examples/ruby/without_protobuf/echo_client.rb
new file mode 100755
index 0000000000000000000000000000000000000000..4a7b92a4a7f5cdc0ab5e38b4e75573c31e59f508
--- /dev/null
+++ b/examples/ruby/without_protobuf/echo_client.rb
@@ -0,0 +1,49 @@
+#!/usr/bin/env ruby
+
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Sample app that connects to a 'EchoWithoutProtobuf' service.
+#
+# Usage: $ path/to/echo_client.rb
+
+this_dir = File.expand_path(File.dirname(__FILE__))
+$LOAD_PATH.unshift(this_dir) unless $LOAD_PATH.include?(this_dir)
+
+require 'grpc'
+require 'echo_services_noprotobuf'
+
+def main
+  stub = EchoWithoutProtobuf::Stub.new('localhost:50051', :this_channel_is_insecure)
+  user = ARGV.size > 0 ?  ARGV[0] : 'world'
+  message = stub.echo("hello #{user}")
+  p "Reponse: #{message}"
+end
+
+main
diff --git a/examples/ruby/without_protobuf/echo_server.rb b/examples/ruby/without_protobuf/echo_server.rb
new file mode 100755
index 0000000000000000000000000000000000000000..e60f684f6553db49a5fd6b4622692ed068bbefd0
--- /dev/null
+++ b/examples/ruby/without_protobuf/echo_server.rb
@@ -0,0 +1,59 @@
+#!/usr/bin/env ruby
+
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Sample gRPC server that implements the EchoWithoutProtobuf service.
+#
+# Usage: $ path/to/echo_server.rb
+
+this_dir = File.expand_path(File.dirname(__FILE__))
+$LOAD_PATH.unshift(this_dir) unless $LOAD_PATH.include?(this_dir)
+
+require 'grpc'
+require 'echo_services_noprotobuf'
+
+# EchoServer is simple server that implements the EchoWithoutProtobuf server.
+class EchoServer < EchoWithoutProtobuf::Service
+  # echo implements the EchoWithoutProtobuf 'Echo' rpc method.
+  def echo(echo_req, _unused_call)
+    echo_req
+  end
+end
+
+# main starts an RpcServer that receives requests to EchoWithoutProtobuf at the sample
+# server port.
+def main
+  s = GRPC::RpcServer.new
+  s.add_http2_port('0.0.0.0:50051', :this_port_is_insecure)
+  s.handle(EchoServer)
+  s.run_till_terminated
+end
+
+main
diff --git a/examples/ruby/without_protobuf/echo_services_noprotobuf.rb b/examples/ruby/without_protobuf/echo_services_noprotobuf.rb
new file mode 100644
index 0000000000000000000000000000000000000000..276ced67f328b25f117ae01dbe6b098b9c279506
--- /dev/null
+++ b/examples/ruby/without_protobuf/echo_services_noprotobuf.rb
@@ -0,0 +1,49 @@
+# Original file comments:
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+require 'grpc'
+
+module EchoWithoutProtobuf
+  # The 'echo without protobuf' service definition.
+  class Service
+
+    include GRPC::GenericService
+
+    self.marshal_class_method = :try_convert
+    self.unmarshal_class_method = :try_convert
+    self.service_name = 'EchoWithoutProtobuf'
+
+    # Request and response are plain strings
+    rpc :Echo, String, String
+  end
+
+  Stub = Service.rpc_stub_class
+end
diff --git a/grpc.gemspec b/grpc.gemspec
index 82c9d680801f7b6c23b61cda9b20b4808b63b78d..5cc73915f3b6aa8d5a58fc181db437528a1c7be7 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -27,7 +27,7 @@ Gem::Specification.new do |s|
   s.require_paths = %w( src/ruby/bin src/ruby/lib src/ruby/pb )
   s.platform      = Gem::Platform::RUBY
 
-  s.add_dependency 'google-protobuf', '~> 3.1.0'
+  s.add_dependency 'google-protobuf', '~> 3.1'
   s.add_dependency 'googleauth',      '~> 0.5.1'
 
   s.add_development_dependency 'bundler',            '~> 1.9'
@@ -35,7 +35,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'logging',            '~> 2.0'
   s.add_development_dependency 'simplecov',          '~> 0.9'
   s.add_development_dependency 'rake',               '~> 10.4'
-  s.add_development_dependency 'rake-compiler',      '~> 0.9'
+  s.add_development_dependency 'rake-compiler',      '~> 1.0'
   s.add_development_dependency 'rake-compiler-dock', '~> 0.5.1'
   s.add_development_dependency 'rspec',              '~> 3.2'
   s.add_development_dependency 'rubocop',            '~> 0.30.0'
diff --git a/include/grpc++/impl/codegen/server_context.h b/include/grpc++/impl/codegen/server_context.h
index 43bbff6ce9c19266e4b1250546673d19cfedcbf2..bf9a9b6f1a52b52eb4bf3262cd6e7334cba1e4ce 100644
--- a/include/grpc++/impl/codegen/server_context.h
+++ b/include/grpc++/impl/codegen/server_context.h
@@ -213,8 +213,7 @@ class ServerContext {
 
   void BeginCompletionOp(Call* call);
 
-  ServerContext(gpr_timespec deadline, grpc_metadata* metadata,
-                size_t metadata_count);
+  ServerContext(gpr_timespec deadline, grpc_metadata_array* arr);
 
   void set_call(grpc_call* call) { call_ = call; }
 
diff --git a/include/grpc/impl/codegen/port_platform.h b/include/grpc/impl/codegen/port_platform.h
index 4633fa12e84767d836b53b245024387759579992..e565cd31d75f6216fe1c3cff90c21352dd5b4c25 100644
--- a/include/grpc/impl/codegen/port_platform.h
+++ b/include/grpc/impl/codegen/port_platform.h
@@ -297,6 +297,10 @@
 #endif
 
 #ifdef _MSC_VER
+#ifdef _PYTHON_MSVC
+// The Python 3.5 Windows runtime is missing InetNtop
+#define GPR_WIN_INET_NTOP
+#endif  // _PYTHON_MSVC
 #if _MSC_VER < 1700
 typedef __int8 int8_t;
 typedef __int16 int16_t;
diff --git a/setup.py b/setup.py
index ab217433a3b0d37c89e5284ed0d7dd970869f87c..234252a16ca27baac02e48adc8725a12558eaeae 100644
--- a/setup.py
+++ b/setup.py
@@ -105,8 +105,11 @@ if EXTRA_ENV_COMPILE_ARGS is None:
       EXTRA_ENV_COMPILE_ARGS += ' -D_ftime=_ftime32 -D_timeb=__timeb32 -D_ftime_s=_ftime32_s'
     else:
       EXTRA_ENV_COMPILE_ARGS += ' -D_ftime=_ftime64 -D_timeb=__timeb64'
+  elif 'win32' in sys.platform:
+    EXTRA_ENV_COMPILE_ARGS += ' -D_PYTHON_MSVC'
   elif "linux" in sys.platform or "darwin" in sys.platform:
     EXTRA_ENV_COMPILE_ARGS += ' -fvisibility=hidden -fno-wrapv'
+
 if EXTRA_ENV_LINK_ARGS is None:
   EXTRA_ENV_LINK_ARGS = ''
   if "linux" in sys.platform or "darwin" in sys.platform:
diff --git a/src/core/ext/client_channel/client_channel.c b/src/core/ext/client_channel/client_channel.c
index 6cbc333b832f6e294375ee0f3970a1451432278c..21ba4301ff02993d46a297390e9a4f4839c80151 100644
--- a/src/core/ext/client_channel/client_channel.c
+++ b/src/core/ext/client_channel/client_channel.c
@@ -183,7 +183,7 @@ typedef struct client_channel_channel_data {
   grpc_pollset_set *interested_parties;
 
   /* the following properties are guarded by a mutex since API's require them
-     to be instantaniously available */
+     to be instantaneously available */
   gpr_mu info_mu;
   char *info_lb_policy_name;
   /** service config in JSON form */
@@ -200,9 +200,9 @@ typedef struct {
   grpc_lb_policy *lb_policy;
 } lb_policy_connectivity_watcher;
 
-static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand,
-                            grpc_lb_policy *lb_policy,
-                            grpc_connectivity_state current_state);
+static void watch_lb_policy_locked(grpc_exec_ctx *exec_ctx, channel_data *chand,
+                                   grpc_lb_policy *lb_policy,
+                                   grpc_connectivity_state current_state);
 
 static void set_channel_connectivity_state_locked(grpc_exec_ctx *exec_ctx,
                                                   channel_data *chand,
@@ -213,7 +213,7 @@ static void set_channel_connectivity_state_locked(grpc_exec_ctx *exec_ctx,
        state == GRPC_CHANNEL_SHUTDOWN) &&
       chand->lb_policy != NULL) {
     /* cancel picks with wait_for_ready=false */
-    grpc_lb_policy_cancel_picks(
+    grpc_lb_policy_cancel_picks_locked(
         exec_ctx, chand->lb_policy,
         /* mask= */ GRPC_INITIAL_METADATA_WAIT_FOR_READY,
         /* check= */ 0, GRPC_ERROR_REF(error));
@@ -237,7 +237,7 @@ static void on_lb_policy_state_changed_locked(grpc_exec_ctx *exec_ctx,
     set_channel_connectivity_state_locked(exec_ctx, w->chand, publish_state,
                                           GRPC_ERROR_REF(error), "lb_changed");
     if (w->state != GRPC_CHANNEL_SHUTDOWN) {
-      watch_lb_policy(exec_ctx, w->chand, w->lb_policy, w->state);
+      watch_lb_policy_locked(exec_ctx, w->chand, w->lb_policy, w->state);
     }
   }
 
@@ -245,9 +245,9 @@ static void on_lb_policy_state_changed_locked(grpc_exec_ctx *exec_ctx,
   gpr_free(w);
 }
 
-static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand,
-                            grpc_lb_policy *lb_policy,
-                            grpc_connectivity_state current_state) {
+static void watch_lb_policy_locked(grpc_exec_ctx *exec_ctx, channel_data *chand,
+                                   grpc_lb_policy *lb_policy,
+                                   grpc_connectivity_state current_state) {
   lb_policy_connectivity_watcher *w = gpr_malloc(sizeof(*w));
   GRPC_CHANNEL_STACK_REF(chand->owning_stack, "watch_lb_policy");
 
@@ -256,8 +256,8 @@ static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand,
                     grpc_combiner_scheduler(chand->combiner, false));
   w->state = current_state;
   w->lb_policy = lb_policy;
-  grpc_lb_policy_notify_on_state_change(exec_ctx, lb_policy, &w->state,
-                                        &w->on_changed);
+  grpc_lb_policy_notify_on_state_change_locked(exec_ctx, lb_policy, &w->state,
+                                               &w->on_changed);
 }
 
 static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
@@ -313,13 +313,14 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
     grpc_lb_policy_args lb_policy_args;
     lb_policy_args.args = chand->resolver_result;
     lb_policy_args.client_channel_factory = chand->client_channel_factory;
+    lb_policy_args.combiner = chand->combiner;
     lb_policy =
         grpc_lb_policy_create(exec_ctx, lb_policy_name, &lb_policy_args);
     if (lb_policy != NULL) {
       GRPC_LB_POLICY_REF(lb_policy, "config_change");
       GRPC_ERROR_UNREF(state_error);
-      state =
-          grpc_lb_policy_check_connectivity(exec_ctx, lb_policy, &state_error);
+      state = grpc_lb_policy_check_connectivity_locked(exec_ctx, lb_policy,
+                                                       &state_error);
     }
     // Find service config.
     channel_arg =
@@ -383,7 +384,7 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
     set_channel_connectivity_state_locked(
         exec_ctx, chand, state, GRPC_ERROR_REF(state_error), "new_lb+resolver");
     if (lb_policy != NULL) {
-      watch_lb_policy(exec_ctx, chand, lb_policy, state);
+      watch_lb_policy_locked(exec_ctx, chand, lb_policy, state);
     }
     GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
     grpc_resolver_next_locked(exec_ctx, chand->resolver,
@@ -404,7 +405,7 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
   }
 
   if (exit_idle) {
-    grpc_lb_policy_exit_idle(exec_ctx, lb_policy);
+    grpc_lb_policy_exit_idle_locked(exec_ctx, lb_policy);
     GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "exit_idle");
   }
 
@@ -441,7 +442,7 @@ static void start_transport_op_locked(grpc_exec_ctx *exec_ctx, void *arg,
       grpc_closure_sched(exec_ctx, op->send_ping,
                          GRPC_ERROR_CREATE("Ping with no load balancing"));
     } else {
-      grpc_lb_policy_ping_one(exec_ctx, chand->lb_policy, op->send_ping);
+      grpc_lb_policy_ping_one_locked(exec_ctx, chand->lb_policy, op->send_ping);
       op->bind_pollset = NULL;
     }
     op->send_ping = NULL;
@@ -808,8 +809,9 @@ static bool pick_subchannel_locked(
 
   if (initial_metadata == NULL) {
     if (chand->lb_policy != NULL) {
-      grpc_lb_policy_cancel_pick(exec_ctx, chand->lb_policy,
-                                 connected_subchannel, GRPC_ERROR_REF(error));
+      grpc_lb_policy_cancel_pick_locked(exec_ctx, chand->lb_policy,
+                                        connected_subchannel,
+                                        GRPC_ERROR_REF(error));
     }
     for (closure = chand->waiting_for_config_closures.head; closure != NULL;
          closure = closure->next_data.next) {
@@ -848,7 +850,7 @@ static bool pick_subchannel_locked(
     const grpc_lb_policy_pick_args inputs = {
         initial_metadata, initial_metadata_flags, &calld->lb_token_mdelem,
         gpr_inf_future(GPR_CLOCK_MONOTONIC)};
-    const bool result = grpc_lb_policy_pick(
+    const bool result = grpc_lb_policy_pick_locked(
         exec_ctx, lb_policy, &inputs, connected_subchannel, NULL, on_ready);
     GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "pick_subchannel");
     GPR_TIMER_END("pick_subchannel", 0);
@@ -1216,7 +1218,7 @@ static void try_to_connect_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                   grpc_error *error_ignored) {
   channel_data *chand = arg;
   if (chand->lb_policy != NULL) {
-    grpc_lb_policy_exit_idle(exec_ctx, chand->lb_policy);
+    grpc_lb_policy_exit_idle_locked(exec_ctx, chand->lb_policy);
   } else {
     chand->exit_idle_when_lb_policy_arrives = true;
     if (!chand->started_resolving && chand->resolver != NULL) {
diff --git a/src/core/ext/client_channel/lb_policy.c b/src/core/ext/client_channel/lb_policy.c
index 90401b586f2ab4852986230ad3144fb0bed299fc..aba51add53c73999eaa5ba36ede40b14012fbe40 100644
--- a/src/core/ext/client_channel/lb_policy.c
+++ b/src/core/ext/client_channel/lb_policy.c
@@ -32,14 +32,17 @@
  */
 
 #include "src/core/ext/client_channel/lb_policy.h"
+#include "src/core/lib/iomgr/combiner.h"
 
 #define WEAK_REF_BITS 16
 
 void grpc_lb_policy_init(grpc_lb_policy *policy,
-                         const grpc_lb_policy_vtable *vtable) {
+                         const grpc_lb_policy_vtable *vtable,
+                         grpc_combiner *combiner) {
   policy->vtable = vtable;
   gpr_atm_no_barrier_store(&policy->ref_pair, 1 << WEAK_REF_BITS);
   policy->interested_parties = grpc_pollset_set_create();
+  policy->combiner = GRPC_COMBINER_REF(combiner, "lb_policy");
 }
 
 #ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
@@ -71,6 +74,13 @@ void grpc_lb_policy_ref(grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
   ref_mutate(policy, 1 << WEAK_REF_BITS, 0 REF_MUTATE_PASS_ARGS("STRONG_REF"));
 }
 
+static void shutdown_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                            grpc_error *error) {
+  grpc_lb_policy *policy = arg;
+  policy->vtable->shutdown_locked(exec_ctx, policy);
+  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, policy, "strong-unref");
+}
+
 void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx,
                           grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
   gpr_atm old_val =
@@ -79,10 +89,15 @@ void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx,
   gpr_atm mask = ~(gpr_atm)((1 << WEAK_REF_BITS) - 1);
   gpr_atm check = 1 << WEAK_REF_BITS;
   if ((old_val & mask) == check) {
-    policy->vtable->shutdown(exec_ctx, policy);
+    grpc_closure_sched(
+        exec_ctx,
+        grpc_closure_create(shutdown_locked, policy,
+                            grpc_combiner_scheduler(policy->combiner, false)),
+        GRPC_ERROR_NONE);
+  } else {
+    grpc_lb_policy_weak_unref(exec_ctx,
+                              policy REF_FUNC_PASS_ARGS("strong-unref"));
   }
-  grpc_lb_policy_weak_unref(exec_ctx,
-                            policy REF_FUNC_PASS_ARGS("strong-unref"));
 }
 
 void grpc_lb_policy_weak_ref(grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
@@ -95,52 +110,58 @@ void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx,
       ref_mutate(policy, -(gpr_atm)1, 1 REF_MUTATE_PASS_ARGS("WEAK_UNREF"));
   if (old_val == 1) {
     grpc_pollset_set_destroy(exec_ctx, policy->interested_parties);
+    grpc_combiner *combiner = policy->combiner;
     policy->vtable->destroy(exec_ctx, policy);
+    GRPC_COMBINER_UNREF(exec_ctx, combiner, "lb_policy");
   }
 }
 
-int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                        const grpc_lb_policy_pick_args *pick_args,
-                        grpc_connected_subchannel **target, void **user_data,
-                        grpc_closure *on_complete) {
-  return policy->vtable->pick(exec_ctx, policy, pick_args, target, user_data,
-                              on_complete);
+int grpc_lb_policy_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                               const grpc_lb_policy_pick_args *pick_args,
+                               grpc_connected_subchannel **target,
+                               void **user_data, grpc_closure *on_complete) {
+  return policy->vtable->pick_locked(exec_ctx, policy, pick_args, target,
+                                     user_data, on_complete);
 }
 
-void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                                grpc_connected_subchannel **target,
-                                grpc_error *error) {
-  policy->vtable->cancel_pick(exec_ctx, policy, target, error);
+void grpc_lb_policy_cancel_pick_locked(grpc_exec_ctx *exec_ctx,
+                                       grpc_lb_policy *policy,
+                                       grpc_connected_subchannel **target,
+                                       grpc_error *error) {
+  policy->vtable->cancel_pick_locked(exec_ctx, policy, target, error);
 }
 
-void grpc_lb_policy_cancel_picks(grpc_exec_ctx *exec_ctx,
-                                 grpc_lb_policy *policy,
-                                 uint32_t initial_metadata_flags_mask,
-                                 uint32_t initial_metadata_flags_eq,
-                                 grpc_error *error) {
-  policy->vtable->cancel_picks(exec_ctx, policy, initial_metadata_flags_mask,
-                               initial_metadata_flags_eq, error);
+void grpc_lb_policy_cancel_picks_locked(grpc_exec_ctx *exec_ctx,
+                                        grpc_lb_policy *policy,
+                                        uint32_t initial_metadata_flags_mask,
+                                        uint32_t initial_metadata_flags_eq,
+                                        grpc_error *error) {
+  policy->vtable->cancel_picks_locked(exec_ctx, policy,
+                                      initial_metadata_flags_mask,
+                                      initial_metadata_flags_eq, error);
 }
 
-void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) {
-  policy->vtable->exit_idle(exec_ctx, policy);
+void grpc_lb_policy_exit_idle_locked(grpc_exec_ctx *exec_ctx,
+                                     grpc_lb_policy *policy) {
+  policy->vtable->exit_idle_locked(exec_ctx, policy);
 }
 
-void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                             grpc_closure *closure) {
-  policy->vtable->ping_one(exec_ctx, policy, closure);
+void grpc_lb_policy_ping_one_locked(grpc_exec_ctx *exec_ctx,
+                                    grpc_lb_policy *policy,
+                                    grpc_closure *closure) {
+  policy->vtable->ping_one_locked(exec_ctx, policy, closure);
 }
 
-void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
-                                           grpc_lb_policy *policy,
-                                           grpc_connectivity_state *state,
-                                           grpc_closure *closure) {
-  policy->vtable->notify_on_state_change(exec_ctx, policy, state, closure);
+void grpc_lb_policy_notify_on_state_change_locked(
+    grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+    grpc_connectivity_state *state, grpc_closure *closure) {
+  policy->vtable->notify_on_state_change_locked(exec_ctx, policy, state,
+                                                closure);
 }
 
-grpc_connectivity_state grpc_lb_policy_check_connectivity(
+grpc_connectivity_state grpc_lb_policy_check_connectivity_locked(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
     grpc_error **connectivity_error) {
-  return policy->vtable->check_connectivity(exec_ctx, policy,
-                                            connectivity_error);
+  return policy->vtable->check_connectivity_locked(exec_ctx, policy,
+                                                   connectivity_error);
 }
diff --git a/src/core/ext/client_channel/lb_policy.h b/src/core/ext/client_channel/lb_policy.h
index 120c641edc681d599a524602872a0886a45e4fd4..3405709c2cf10118fae53f5c7a6e20e98072eee9 100644
--- a/src/core/ext/client_channel/lb_policy.h
+++ b/src/core/ext/client_channel/lb_policy.h
@@ -51,6 +51,8 @@ struct grpc_lb_policy {
   gpr_atm ref_pair;
   /* owned pointer to interested parties in load balancing decisions */
   grpc_pollset_set *interested_parties;
+  /* combiner under which lb_policy actions take place */
+  grpc_combiner *combiner;
 };
 
 /** Extra arguments for an LB pick */
@@ -69,42 +71,44 @@ typedef struct grpc_lb_policy_pick_args {
 
 struct grpc_lb_policy_vtable {
   void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
-  void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+  void (*shutdown_locked)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 
   /** \see grpc_lb_policy_pick */
-  int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-              const grpc_lb_policy_pick_args *pick_args,
-              grpc_connected_subchannel **target, void **user_data,
-              grpc_closure *on_complete);
+  int (*pick_locked)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                     const grpc_lb_policy_pick_args *pick_args,
+                     grpc_connected_subchannel **target, void **user_data,
+                     grpc_closure *on_complete);
 
   /** \see grpc_lb_policy_cancel_pick */
-  void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                      grpc_connected_subchannel **target, grpc_error *error);
+  void (*cancel_pick_locked)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                             grpc_connected_subchannel **target,
+                             grpc_error *error);
 
   /** \see grpc_lb_policy_cancel_picks */
-  void (*cancel_picks)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                       uint32_t initial_metadata_flags_mask,
-                       uint32_t initial_metadata_flags_eq, grpc_error *error);
+  void (*cancel_picks_locked)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                              uint32_t initial_metadata_flags_mask,
+                              uint32_t initial_metadata_flags_eq,
+                              grpc_error *error);
 
   /** \see grpc_lb_policy_ping_one */
-  void (*ping_one)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                   grpc_closure *closure);
+  void (*ping_one_locked)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                          grpc_closure *closure);
 
   /** Try to enter a READY connectivity state */
-  void (*exit_idle)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+  void (*exit_idle_locked)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 
   /** check the current connectivity of the lb_policy */
-  grpc_connectivity_state (*check_connectivity)(
+  grpc_connectivity_state (*check_connectivity_locked)(
       grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
       grpc_error **connectivity_error);
 
   /** call notify when the connectivity state of a channel changes from *state.
       Updates *state with the new state of the policy. Calling with a NULL \a
       state cancels the subscription.  */
-  void (*notify_on_state_change)(grpc_exec_ctx *exec_ctx,
-                                 grpc_lb_policy *policy,
-                                 grpc_connectivity_state *state,
-                                 grpc_closure *closure);
+  void (*notify_on_state_change_locked)(grpc_exec_ctx *exec_ctx,
+                                        grpc_lb_policy *policy,
+                                        grpc_connectivity_state *state,
+                                        grpc_closure *closure);
 };
 
 /*#define GRPC_LB_POLICY_REFCOUNT_DEBUG*/
@@ -144,7 +148,8 @@ void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 
 /** called by concrete implementations to initialize the base struct */
 void grpc_lb_policy_init(grpc_lb_policy *policy,
-                         const grpc_lb_policy_vtable *vtable);
+                         const grpc_lb_policy_vtable *vtable,
+                         grpc_combiner *combiner);
 
 /** Finds an appropriate subchannel for a call, based on \a pick_args.
 
@@ -159,43 +164,45 @@ void grpc_lb_policy_init(grpc_lb_policy *policy,
 
     Any IO should be done under the \a interested_parties \a grpc_pollset_set
     in the \a grpc_lb_policy struct. */
-int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                        const grpc_lb_policy_pick_args *pick_args,
-                        grpc_connected_subchannel **target, void **user_data,
-                        grpc_closure *on_complete);
+int grpc_lb_policy_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                               const grpc_lb_policy_pick_args *pick_args,
+                               grpc_connected_subchannel **target,
+                               void **user_data, grpc_closure *on_complete);
 
 /** Perform a connected subchannel ping (see \a grpc_connected_subchannel_ping)
     against one of the connected subchannels managed by \a policy. */
-void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                             grpc_closure *closure);
+void grpc_lb_policy_ping_one_locked(grpc_exec_ctx *exec_ctx,
+                                    grpc_lb_policy *policy,
+                                    grpc_closure *closure);
 
 /** Cancel picks for \a target.
     The \a on_complete callback of the pending picks will be invoked with \a
     *target set to NULL. */
-void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                                grpc_connected_subchannel **target,
-                                grpc_error *error);
+void grpc_lb_policy_cancel_pick_locked(grpc_exec_ctx *exec_ctx,
+                                       grpc_lb_policy *policy,
+                                       grpc_connected_subchannel **target,
+                                       grpc_error *error);
 
 /** Cancel all pending picks for which their \a initial_metadata_flags (as given
     in the call to \a grpc_lb_policy_pick) matches \a initial_metadata_flags_eq
     when AND'd with \a initial_metadata_flags_mask */
-void grpc_lb_policy_cancel_picks(grpc_exec_ctx *exec_ctx,
-                                 grpc_lb_policy *policy,
-                                 uint32_t initial_metadata_flags_mask,
-                                 uint32_t initial_metadata_flags_eq,
-                                 grpc_error *error);
+void grpc_lb_policy_cancel_picks_locked(grpc_exec_ctx *exec_ctx,
+                                        grpc_lb_policy *policy,
+                                        uint32_t initial_metadata_flags_mask,
+                                        uint32_t initial_metadata_flags_eq,
+                                        grpc_error *error);
 
 /** Try to enter a READY connectivity state */
-void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+void grpc_lb_policy_exit_idle_locked(grpc_exec_ctx *exec_ctx,
+                                     grpc_lb_policy *policy);
 
 /* Call notify when the connectivity state of a channel changes from \a *state.
  * Updates \a *state with the new state of the policy */
-void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
-                                           grpc_lb_policy *policy,
-                                           grpc_connectivity_state *state,
-                                           grpc_closure *closure);
+void grpc_lb_policy_notify_on_state_change_locked(
+    grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+    grpc_connectivity_state *state, grpc_closure *closure);
 
-grpc_connectivity_state grpc_lb_policy_check_connectivity(
+grpc_connectivity_state grpc_lb_policy_check_connectivity_locked(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
     grpc_error **connectivity_error);
 
diff --git a/src/core/ext/client_channel/lb_policy_factory.h b/src/core/ext/client_channel/lb_policy_factory.h
index 9b8b03f982b0b1e9973bc0f8026b8ac9b62708f4..27c12c0d73dd8697ec719605ca5633debb0ac044 100644
--- a/src/core/ext/client_channel/lb_policy_factory.h
+++ b/src/core/ext/client_channel/lb_policy_factory.h
@@ -107,6 +107,7 @@ grpc_arg grpc_lb_addresses_create_channel_arg(
 typedef struct grpc_lb_policy_args {
   grpc_client_channel_factory *client_channel_factory;
   grpc_channel_args *args;
+  grpc_combiner *combiner;
 } grpc_lb_policy_args;
 
 struct grpc_lb_policy_factory_vtable {
diff --git a/src/core/ext/client_channel/subchannel.c b/src/core/ext/client_channel/subchannel.c
index 09c68a91dd8e73182c60f3727f8aa4c9fefa511a..f2da148e495b0551cac2f1559ef078aafc2a8270 100644
--- a/src/core/ext/client_channel/subchannel.c
+++ b/src/core/ext/client_channel/subchannel.c
@@ -438,7 +438,7 @@ static void on_external_state_watcher_done(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_mu_unlock(&w->subchannel->mu);
   GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, w->subchannel, "external_state_watcher");
   gpr_free(w);
-  follow_up->cb(exec_ctx, follow_up->cb_arg, error);
+  grpc_closure_run(exec_ctx, follow_up, GRPC_ERROR_REF(error));
 }
 
 static void on_alarm(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index 8a2af4832839129cbdcf91a4afcc684bed36bace..b5210cb046e085947e51b00068c6d6318ee06d45 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -115,6 +115,7 @@
 #include "src/core/ext/lb_policy/grpclb/grpclb_channel.h"
 #include "src/core/ext/lb_policy/grpclb/load_balancer_api.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/timer.h"
@@ -285,9 +286,6 @@ typedef struct glb_lb_policy {
   /** base policy: must be first */
   grpc_lb_policy base;
 
-  /** mutex protecting remaining members */
-  gpr_mu mu;
-
   /** who the client is trying to communicate with */
   const char *server_name;
   grpc_client_channel_factory *cc_factory;
@@ -557,9 +555,9 @@ static bool pick_from_internal_rr_locked(
     const grpc_lb_policy_pick_args *pick_args,
     grpc_connected_subchannel **target, wrapped_rr_closure_arg *wc_arg) {
   GPR_ASSERT(rr_policy != NULL);
-  const bool pick_done =
-      grpc_lb_policy_pick(exec_ctx, rr_policy, pick_args, target,
-                          (void **)&wc_arg->lb_token, &wc_arg->wrapper_closure);
+  const bool pick_done = grpc_lb_policy_pick_locked(
+      exec_ctx, rr_policy, pick_args, target, (void **)&wc_arg->lb_token,
+      &wc_arg->wrapper_closure);
   if (pick_done) {
     /* synchronous grpc_lb_policy_pick call. Unref the RR policy. */
     if (grpc_lb_glb_trace) {
@@ -590,6 +588,7 @@ static grpc_lb_policy *create_rr_locked(
   grpc_lb_policy_args args;
   memset(&args, 0, sizeof(args));
   args.client_channel_factory = glb_policy->cc_factory;
+  args.combiner = glb_policy->base.combiner;
   grpc_lb_addresses *addresses =
       process_serverlist_locked(exec_ctx, serverlist);
 
@@ -608,8 +607,8 @@ static grpc_lb_policy *create_rr_locked(
   return rr;
 }
 
-static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
-                                        grpc_error *error);
+static void glb_rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx,
+                                               void *arg, grpc_error *error);
 /* glb_policy->rr_policy may be NULL (initial handover) */
 static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
                                glb_lb_policy *glb_policy) {
@@ -633,8 +632,8 @@ static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
 
   grpc_error *new_rr_state_error = NULL;
   const grpc_connectivity_state new_rr_state =
-      grpc_lb_policy_check_connectivity(exec_ctx, new_rr_policy,
-                                        &new_rr_state_error);
+      grpc_lb_policy_check_connectivity_locked(exec_ctx, new_rr_policy,
+                                               &new_rr_state_error);
   /* Connectivity state is a function of the new RR policy just created */
   const bool replace_old_rr = update_lb_connectivity_status_locked(
       exec_ctx, glb_policy, new_rr_state, new_rr_state_error);
@@ -677,17 +676,18 @@ static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
   rr_connectivity_data *rr_connectivity =
       gpr_malloc(sizeof(rr_connectivity_data));
   memset(rr_connectivity, 0, sizeof(rr_connectivity_data));
-  grpc_closure_init(&rr_connectivity->on_change, glb_rr_connectivity_changed,
-                    rr_connectivity, grpc_schedule_on_exec_ctx);
+  grpc_closure_init(&rr_connectivity->on_change,
+                    glb_rr_connectivity_changed_locked, rr_connectivity,
+                    grpc_combiner_scheduler(glb_policy->base.combiner, false));
   rr_connectivity->glb_policy = glb_policy;
   rr_connectivity->state = new_rr_state;
 
   /* Subscribe to changes to the connectivity of the new RR */
   GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "rr_connectivity_cb");
-  grpc_lb_policy_notify_on_state_change(exec_ctx, glb_policy->rr_policy,
-                                        &rr_connectivity->state,
-                                        &rr_connectivity->on_change);
-  grpc_lb_policy_exit_idle(exec_ctx, glb_policy->rr_policy);
+  grpc_lb_policy_notify_on_state_change_locked(exec_ctx, glb_policy->rr_policy,
+                                               &rr_connectivity->state,
+                                               &rr_connectivity->on_change);
+  grpc_lb_policy_exit_idle_locked(exec_ctx, glb_policy->rr_policy);
 
   /* Update picks and pings in wait */
   pending_pick *pp;
@@ -713,17 +713,16 @@ static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
       gpr_log(GPR_INFO, "Pending ping about to PING from 0x%" PRIxPTR "",
               (intptr_t)glb_policy->rr_policy);
     }
-    grpc_lb_policy_ping_one(exec_ctx, glb_policy->rr_policy,
-                            &pping->wrapped_notify_arg.wrapper_closure);
+    grpc_lb_policy_ping_one_locked(exec_ctx, glb_policy->rr_policy,
+                                   &pping->wrapped_notify_arg.wrapper_closure);
   }
 }
 
-static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
-                                        grpc_error *error) {
+static void glb_rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx,
+                                               void *arg, grpc_error *error) {
   rr_connectivity_data *rr_connectivity = arg;
   glb_lb_policy *glb_policy = rr_connectivity->glb_policy;
 
-  gpr_mu_lock(&glb_policy->mu);
   const bool shutting_down = glb_policy->shutting_down;
   bool unref_needed = false;
   GRPC_ERROR_REF(error);
@@ -740,11 +739,10 @@ static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
     update_lb_connectivity_status_locked(exec_ctx, glb_policy,
                                          rr_connectivity->state, error);
     /* Resubscribe. Reuse the "rr_connectivity_cb" weak ref. */
-    grpc_lb_policy_notify_on_state_change(exec_ctx, glb_policy->rr_policy,
-                                          &rr_connectivity->state,
-                                          &rr_connectivity->on_change);
+    grpc_lb_policy_notify_on_state_change_locked(
+        exec_ctx, glb_policy->rr_policy, &rr_connectivity->state,
+        &rr_connectivity->on_change);
   }
-  gpr_mu_unlock(&glb_policy->mu);
   if (unref_needed) {
     GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                               "rr_connectivity_cb");
@@ -899,8 +897,7 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
     gpr_free(glb_policy);
     return NULL;
   }
-  grpc_lb_policy_init(&glb_policy->base, &glb_lb_policy_vtable);
-  gpr_mu_init(&glb_policy->mu);
+  grpc_lb_policy_init(&glb_policy->base, &glb_lb_policy_vtable, args->combiner);
   grpc_connectivity_state_init(&glb_policy->state_tracker, GRPC_CHANNEL_IDLE,
                                "grpclb");
   return &glb_policy->base;
@@ -918,13 +915,11 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   if (glb_policy->serverlist != NULL) {
     grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
   }
-  gpr_mu_destroy(&glb_policy->mu);
   gpr_free(glb_policy);
 }
 
-static void glb_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+static void glb_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
-  gpr_mu_lock(&glb_policy->mu);
   glb_policy->shutting_down = true;
 
   pending_pick *pp = glb_policy->pending_picks;
@@ -941,7 +936,6 @@ static void glb_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
    * while holding glb_policy->mu: lb_on_server_status_received, invoked due to
    * the cancel, needs to acquire that same lock */
   grpc_call *lb_call = glb_policy->lb_call;
-  gpr_mu_unlock(&glb_policy->mu);
 
   /* glb_policy->lb_call and this local lb_call must be consistent at this point
    * because glb_policy->lb_call is only assigned in lb_call_init_locked as part
@@ -967,11 +961,10 @@ static void glb_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   }
 }
 
-static void glb_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                            grpc_connected_subchannel **target,
-                            grpc_error *error) {
+static void glb_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                                   grpc_connected_subchannel **target,
+                                   grpc_error *error) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
-  gpr_mu_lock(&glb_policy->mu);
   pending_pick *pp = glb_policy->pending_picks;
   glb_policy->pending_picks = NULL;
   while (pp != NULL) {
@@ -987,16 +980,15 @@ static void glb_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     pp = next;
   }
-  gpr_mu_unlock(&glb_policy->mu);
   GRPC_ERROR_UNREF(error);
 }
 
-static void glb_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                             uint32_t initial_metadata_flags_mask,
-                             uint32_t initial_metadata_flags_eq,
-                             grpc_error *error) {
+static void glb_cancel_picks_locked(grpc_exec_ctx *exec_ctx,
+                                    grpc_lb_policy *pol,
+                                    uint32_t initial_metadata_flags_mask,
+                                    uint32_t initial_metadata_flags_eq,
+                                    grpc_error *error) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
-  gpr_mu_lock(&glb_policy->mu);
   pending_pick *pp = glb_policy->pending_picks;
   glb_policy->pending_picks = NULL;
   while (pp != NULL) {
@@ -1012,7 +1004,6 @@ static void glb_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     pp = next;
   }
-  gpr_mu_unlock(&glb_policy->mu);
   GRPC_ERROR_UNREF(error);
 }
 
@@ -1025,19 +1016,17 @@ static void start_picking_locked(grpc_exec_ctx *exec_ctx,
   query_for_backends_locked(exec_ctx, glb_policy);
 }
 
-static void glb_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+static void glb_exit_idle_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
-  gpr_mu_lock(&glb_policy->mu);
   if (!glb_policy->started_picking) {
     start_picking_locked(exec_ctx, glb_policy);
   }
-  gpr_mu_unlock(&glb_policy->mu);
 }
 
-static int glb_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                    const grpc_lb_policy_pick_args *pick_args,
-                    grpc_connected_subchannel **target, void **user_data,
-                    grpc_closure *on_complete) {
+static int glb_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                           const grpc_lb_policy_pick_args *pick_args,
+                           grpc_connected_subchannel **target, void **user_data,
+                           grpc_closure *on_complete) {
   if (pick_args->lb_token_mdelem_storage == NULL) {
     *target = NULL;
     grpc_closure_sched(
@@ -1048,7 +1037,6 @@ static int glb_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   }
 
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
-  gpr_mu_lock(&glb_policy->mu);
   glb_policy->deadline = pick_args->deadline;
   bool pick_done;
 
@@ -1087,53 +1075,43 @@ static int glb_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     pick_done = false;
   }
-  gpr_mu_unlock(&glb_policy->mu);
   return pick_done;
 }
 
-static grpc_connectivity_state glb_check_connectivity(
+static grpc_connectivity_state glb_check_connectivity_locked(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     grpc_error **connectivity_error) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
-  grpc_connectivity_state st;
-  gpr_mu_lock(&glb_policy->mu);
-  st = grpc_connectivity_state_get(&glb_policy->state_tracker,
-                                   connectivity_error);
-  gpr_mu_unlock(&glb_policy->mu);
-  return st;
+  return grpc_connectivity_state_get(&glb_policy->state_tracker,
+                                     connectivity_error);
 }
 
-static void glb_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                         grpc_closure *closure) {
+static void glb_ping_one_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                                grpc_closure *closure) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
-  gpr_mu_lock(&glb_policy->mu);
   if (glb_policy->rr_policy) {
-    grpc_lb_policy_ping_one(exec_ctx, glb_policy->rr_policy, closure);
+    grpc_lb_policy_ping_one_locked(exec_ctx, glb_policy->rr_policy, closure);
   } else {
     add_pending_ping(&glb_policy->pending_pings, closure);
     if (!glb_policy->started_picking) {
       start_picking_locked(exec_ctx, glb_policy);
     }
   }
-  gpr_mu_unlock(&glb_policy->mu);
 }
 
-static void glb_notify_on_state_change(grpc_exec_ctx *exec_ctx,
-                                       grpc_lb_policy *pol,
-                                       grpc_connectivity_state *current,
-                                       grpc_closure *notify) {
+static void glb_notify_on_state_change_locked(grpc_exec_ctx *exec_ctx,
+                                              grpc_lb_policy *pol,
+                                              grpc_connectivity_state *current,
+                                              grpc_closure *notify) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
-  gpr_mu_lock(&glb_policy->mu);
   grpc_connectivity_state_notify_on_state_change(
       exec_ctx, &glb_policy->state_tracker, current, notify);
-
-  gpr_mu_unlock(&glb_policy->mu);
 }
 
-static void lb_on_server_status_received(grpc_exec_ctx *exec_ctx, void *arg,
-                                         grpc_error *error);
-static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
-                                    grpc_error *error);
+static void lb_on_server_status_received_locked(grpc_exec_ctx *exec_ctx,
+                                                void *arg, grpc_error *error);
+static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                           grpc_error *error);
 static void lb_call_init_locked(grpc_exec_ctx *exec_ctx,
                                 glb_lb_policy *glb_policy) {
   GPR_ASSERT(glb_policy->server_name != NULL);
@@ -1162,11 +1140,11 @@ static void lb_call_init_locked(grpc_exec_ctx *exec_ctx,
   grpc_grpclb_request_destroy(request);
 
   grpc_closure_init(&glb_policy->lb_on_server_status_received,
-                    lb_on_server_status_received, glb_policy,
-                    grpc_schedule_on_exec_ctx);
+                    lb_on_server_status_received_locked, glb_policy,
+                    grpc_combiner_scheduler(glb_policy->base.combiner, false));
   grpc_closure_init(&glb_policy->lb_on_response_received,
-                    lb_on_response_received, glb_policy,
-                    grpc_schedule_on_exec_ctx);
+                    lb_on_response_received_locked, glb_policy,
+                    grpc_combiner_scheduler(glb_policy->base.combiner, false));
 
   gpr_backoff_init(&glb_policy->lb_call_backoff_state,
                    GRPC_GRPCLB_INITIAL_CONNECT_BACKOFF_SECONDS,
@@ -1261,14 +1239,13 @@ static void query_for_backends_locked(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(GRPC_CALL_OK == call_error);
 }
 
-static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
-                                    grpc_error *error) {
+static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                           grpc_error *error) {
   glb_lb_policy *glb_policy = arg;
 
   grpc_op ops[2];
   memset(ops, 0, sizeof(ops));
   grpc_op *op = ops;
-  gpr_mu_lock(&glb_policy->mu);
   if (glb_policy->lb_response_payload != NULL) {
     gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
     /* Received data from the LB server. Look inside
@@ -1342,20 +1319,17 @@ static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
           &glb_policy->lb_on_response_received); /* loop */
       GPR_ASSERT(GRPC_CALL_OK == call_error);
     }
-    gpr_mu_unlock(&glb_policy->mu);
   } else { /* empty payload: call cancelled. */
            /* dispose of the "lb_on_response_received" weak ref taken in
             * query_for_backends_locked() and reused in every reception loop */
-    gpr_mu_unlock(&glb_policy->mu);
     GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                               "lb_on_response_received_empty_payload");
   }
 }
 
-static void lb_call_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
-                                   grpc_error *error) {
+static void lb_call_on_retry_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                          grpc_error *error) {
   glb_lb_policy *glb_policy = arg;
-  gpr_mu_lock(&glb_policy->mu);
 
   if (!glb_policy->shutting_down) {
     if (grpc_lb_glb_trace) {
@@ -1365,15 +1339,13 @@ static void lb_call_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
     GPR_ASSERT(glb_policy->lb_call == NULL);
     query_for_backends_locked(exec_ctx, glb_policy);
   }
-  gpr_mu_unlock(&glb_policy->mu);
   GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                             "grpclb_on_retry_timer");
 }
 
-static void lb_on_server_status_received(grpc_exec_ctx *exec_ctx, void *arg,
-                                         grpc_error *error) {
+static void lb_on_server_status_received_locked(grpc_exec_ctx *exec_ctx,
+                                                void *arg, grpc_error *error) {
   glb_lb_policy *glb_policy = arg;
-  gpr_mu_lock(&glb_policy->mu);
 
   GPR_ASSERT(glb_policy->lb_call != NULL);
 
@@ -1408,21 +1380,27 @@ static void lb_on_server_status_received(grpc_exec_ctx *exec_ctx, void *arg,
       }
     }
     GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "grpclb_retry_timer");
-    grpc_closure_init(&glb_policy->lb_on_call_retry, lb_call_on_retry_timer,
-                      glb_policy, grpc_schedule_on_exec_ctx);
+    grpc_closure_init(
+        &glb_policy->lb_on_call_retry, lb_call_on_retry_timer_locked,
+        glb_policy, grpc_combiner_scheduler(glb_policy->base.combiner, false));
     grpc_timer_init(exec_ctx, &glb_policy->lb_call_retry_timer, next_try,
                     &glb_policy->lb_on_call_retry, now);
   }
-  gpr_mu_unlock(&glb_policy->mu);
   GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                             "lb_on_server_status_received");
 }
 
 /* Code wiring the policy with the rest of the core */
 static const grpc_lb_policy_vtable glb_lb_policy_vtable = {
-    glb_destroy,     glb_shutdown,           glb_pick,
-    glb_cancel_pick, glb_cancel_picks,       glb_ping_one,
-    glb_exit_idle,   glb_check_connectivity, glb_notify_on_state_change};
+    glb_destroy,
+    glb_shutdown_locked,
+    glb_pick_locked,
+    glb_cancel_pick_locked,
+    glb_cancel_picks_locked,
+    glb_ping_one_locked,
+    glb_exit_idle_locked,
+    glb_check_connectivity_locked,
+    glb_notify_on_state_change_locked};
 
 static void glb_factory_ref(grpc_lb_policy_factory *factory) {}
 
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index 1b965183f6bc186b52c40cb611f25274a14291f4..501cb6d94dff2558b082c2df802d0bc0c82aad97 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -38,6 +38,7 @@
 #include "src/core/ext/client_channel/lb_policy_registry.h"
 #include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
@@ -57,11 +58,11 @@ typedef struct {
 
   grpc_closure connectivity_changed;
 
-  /** the selected channel (a grpc_connected_subchannel) */
-  gpr_atm selected;
+  /** remaining members are protected by the combiner */
+
+  /** the selected channel */
+  grpc_connected_subchannel *selected;
 
-  /** mutex protecting remaining members */
-  gpr_mu mu;
   /** have we started picking? */
   int started_picking;
   /** are we shut down? */
@@ -77,32 +78,24 @@ typedef struct {
   grpc_connectivity_state_tracker state_tracker;
 } pick_first_lb_policy;
 
-#define GET_SELECTED(p) \
-  ((grpc_connected_subchannel *)gpr_atm_acq_load(&(p)->selected))
-
 static void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  grpc_connected_subchannel *selected = GET_SELECTED(p);
   size_t i;
   GPR_ASSERT(p->pending_picks == NULL);
   for (i = 0; i < p->num_subchannels; i++) {
     GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[i], "pick_first");
   }
-  if (selected != NULL) {
-    GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, selected, "picked_first");
+  if (p->selected != NULL) {
+    GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, p->selected, "picked_first");
   }
   grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
   gpr_free(p->subchannels);
-  gpr_mu_destroy(&p->mu);
   gpr_free(p);
 }
 
-static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+static void pf_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   pending_pick *pp;
-  grpc_connected_subchannel *selected;
-  gpr_mu_lock(&p->mu);
-  selected = GET_SELECTED(p);
   p->shutdown = 1;
   pp = p->pending_picks;
   p->pending_picks = NULL;
@@ -110,15 +103,14 @@ static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
       exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN,
       GRPC_ERROR_CREATE("Channel shutdown"), "shutdown");
   /* cancel subscription */
-  if (selected != NULL) {
+  if (p->selected != NULL) {
     grpc_connected_subchannel_notify_on_state_change(
-        exec_ctx, selected, NULL, NULL, &p->connectivity_changed);
+        exec_ctx, p->selected, NULL, NULL, &p->connectivity_changed);
   } else if (p->num_subchannels > 0) {
     grpc_subchannel_notify_on_state_change(
         exec_ctx, p->subchannels[p->checking_subchannel], NULL, NULL,
         &p->connectivity_changed);
   }
-  gpr_mu_unlock(&p->mu);
   while (pp != NULL) {
     pending_pick *next = pp->next;
     *pp->target = NULL;
@@ -128,12 +120,11 @@ static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   }
 }
 
-static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                           grpc_connected_subchannel **target,
-                           grpc_error *error) {
+static void pf_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                                  grpc_connected_subchannel **target,
+                                  grpc_error *error) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   pending_pick *pp;
-  gpr_mu_lock(&p->mu);
   pp = p->pending_picks;
   p->pending_picks = NULL;
   while (pp != NULL) {
@@ -150,17 +141,15 @@ static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     pp = next;
   }
-  gpr_mu_unlock(&p->mu);
   GRPC_ERROR_UNREF(error);
 }
 
-static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                            uint32_t initial_metadata_flags_mask,
-                            uint32_t initial_metadata_flags_eq,
-                            grpc_error *error) {
+static void pf_cancel_picks_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                                   uint32_t initial_metadata_flags_mask,
+                                   uint32_t initial_metadata_flags_eq,
+                                   grpc_error *error) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   pending_pick *pp;
-  gpr_mu_lock(&p->mu);
   pp = p->pending_picks;
   p->pending_picks = NULL;
   while (pp != NULL) {
@@ -177,7 +166,6 @@ static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     pp = next;
   }
-  gpr_mu_unlock(&p->mu);
   GRPC_ERROR_UNREF(error);
 }
 
@@ -192,63 +180,48 @@ static void start_picking(grpc_exec_ctx *exec_ctx, pick_first_lb_policy *p) {
       &p->connectivity_changed);
 }
 
-static void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+static void pf_exit_idle_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  gpr_mu_lock(&p->mu);
   if (!p->started_picking) {
     start_picking(exec_ctx, p);
   }
-  gpr_mu_unlock(&p->mu);
 }
 
-static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                   const grpc_lb_policy_pick_args *pick_args,
-                   grpc_connected_subchannel **target, void **user_data,
-                   grpc_closure *on_complete) {
+static int pf_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                          const grpc_lb_policy_pick_args *pick_args,
+                          grpc_connected_subchannel **target, void **user_data,
+                          grpc_closure *on_complete) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   pending_pick *pp;
 
   /* Check atomically for a selected channel */
-  grpc_connected_subchannel *selected = GET_SELECTED(p);
-  if (selected != NULL) {
-    *target = GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked");
+  if (p->selected != NULL) {
+    *target = GRPC_CONNECTED_SUBCHANNEL_REF(p->selected, "picked");
     return 1;
   }
 
-  /* No subchannel selected yet, so acquire lock and then attempt again */
-  gpr_mu_lock(&p->mu);
-  selected = GET_SELECTED(p);
-  if (selected) {
-    gpr_mu_unlock(&p->mu);
-    *target = GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked");
-    return 1;
-  } else {
-    if (!p->started_picking) {
-      start_picking(exec_ctx, p);
-    }
-    pp = gpr_malloc(sizeof(*pp));
-    pp->next = p->pending_picks;
-    pp->target = target;
-    pp->initial_metadata_flags = pick_args->initial_metadata_flags;
-    pp->on_complete = on_complete;
-    p->pending_picks = pp;
-    gpr_mu_unlock(&p->mu);
-    return 0;
+  /* No subchannel selected yet, so try again */
+  if (!p->started_picking) {
+    start_picking(exec_ctx, p);
   }
+  pp = gpr_malloc(sizeof(*pp));
+  pp->next = p->pending_picks;
+  pp->target = target;
+  pp->initial_metadata_flags = pick_args->initial_metadata_flags;
+  pp->on_complete = on_complete;
+  p->pending_picks = pp;
+  return 0;
 }
 
-static void destroy_subchannels(grpc_exec_ctx *exec_ctx, void *arg,
-                                grpc_error *error) {
-  pick_first_lb_policy *p = arg;
+static void destroy_subchannels_locked(grpc_exec_ctx *exec_ctx,
+                                       pick_first_lb_policy *p) {
   size_t i;
   size_t num_subchannels = p->num_subchannels;
   grpc_subchannel **subchannels;
 
-  gpr_mu_lock(&p->mu);
   subchannels = p->subchannels;
   p->num_subchannels = 0;
   p->subchannels = NULL;
-  gpr_mu_unlock(&p->mu);
   GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "destroy_subchannels");
 
   for (i = 0; i < num_subchannels; i++) {
@@ -258,25 +231,19 @@ static void destroy_subchannels(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_free(subchannels);
 }
 
-static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
-                                    grpc_error *error) {
+static void pf_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                           grpc_error *error) {
   pick_first_lb_policy *p = arg;
   grpc_subchannel *selected_subchannel;
   pending_pick *pp;
-  grpc_connected_subchannel *selected;
 
   GRPC_ERROR_REF(error);
 
-  gpr_mu_lock(&p->mu);
-
-  selected = GET_SELECTED(p);
-
   if (p->shutdown) {
-    gpr_mu_unlock(&p->mu);
     GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
     GRPC_ERROR_UNREF(error);
     return;
-  } else if (selected != NULL) {
+  } else if (p->selected != NULL) {
     if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
       /* if the selected channel goes bad, we're done */
       p->checking_connectivity = GRPC_CHANNEL_SHUTDOWN;
@@ -286,7 +253,7 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                                 "selected_changed");
     if (p->checking_connectivity != GRPC_CHANNEL_SHUTDOWN) {
       grpc_connected_subchannel_notify_on_state_change(
-          exec_ctx, selected, p->base.interested_parties,
+          exec_ctx, p->selected, p->base.interested_parties,
           &p->checking_connectivity, &p->connectivity_changed);
     } else {
       GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
@@ -301,26 +268,21 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                                     GRPC_CHANNEL_READY, GRPC_ERROR_NONE,
                                     "connecting_ready");
         selected_subchannel = p->subchannels[p->checking_subchannel];
-        selected =
-            grpc_subchannel_get_connected_subchannel(selected_subchannel);
-        GPR_ASSERT(selected != NULL);
-        GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked_first");
+        p->selected = GRPC_CONNECTED_SUBCHANNEL_REF(
+            grpc_subchannel_get_connected_subchannel(selected_subchannel),
+            "picked_first");
         /* drop the pick list: we are connected now */
         GRPC_LB_POLICY_WEAK_REF(&p->base, "destroy_subchannels");
-        gpr_atm_rel_store(&p->selected, (gpr_atm)selected);
-        grpc_closure_sched(exec_ctx,
-                           grpc_closure_create(destroy_subchannels, p,
-                                               grpc_schedule_on_exec_ctx),
-                           GRPC_ERROR_NONE);
+        destroy_subchannels_locked(exec_ctx, p);
         /* update any calls that were waiting for a pick */
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
-          *pp->target = GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked");
+          *pp->target = GRPC_CONNECTED_SUBCHANNEL_REF(p->selected, "picked");
           grpc_closure_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
           gpr_free(pp);
         }
         grpc_connected_subchannel_notify_on_state_change(
-            exec_ctx, selected, p->base.interested_parties,
+            exec_ctx, p->selected, p->base.interested_parties,
             &p->checking_connectivity, &p->connectivity_changed);
         break;
       case GRPC_CHANNEL_TRANSIENT_FAILURE:
@@ -387,48 +349,44 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
     }
   }
 
-  gpr_mu_unlock(&p->mu);
-
   GRPC_ERROR_UNREF(error);
 }
 
-static grpc_connectivity_state pf_check_connectivity(grpc_exec_ctx *exec_ctx,
-                                                     grpc_lb_policy *pol,
-                                                     grpc_error **error) {
+static grpc_connectivity_state pf_check_connectivity_locked(
+    grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_error **error) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  grpc_connectivity_state st;
-  gpr_mu_lock(&p->mu);
-  st = grpc_connectivity_state_get(&p->state_tracker, error);
-  gpr_mu_unlock(&p->mu);
-  return st;
+  return grpc_connectivity_state_get(&p->state_tracker, error);
 }
 
-static void pf_notify_on_state_change(grpc_exec_ctx *exec_ctx,
-                                      grpc_lb_policy *pol,
-                                      grpc_connectivity_state *current,
-                                      grpc_closure *notify) {
+static void pf_notify_on_state_change_locked(grpc_exec_ctx *exec_ctx,
+                                             grpc_lb_policy *pol,
+                                             grpc_connectivity_state *current,
+                                             grpc_closure *notify) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  gpr_mu_lock(&p->mu);
   grpc_connectivity_state_notify_on_state_change(exec_ctx, &p->state_tracker,
                                                  current, notify);
-  gpr_mu_unlock(&p->mu);
 }
 
-static void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                        grpc_closure *closure) {
+static void pf_ping_one_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                               grpc_closure *closure) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  grpc_connected_subchannel *selected = GET_SELECTED(p);
-  if (selected) {
-    grpc_connected_subchannel_ping(exec_ctx, selected, closure);
+  if (p->selected) {
+    grpc_connected_subchannel_ping(exec_ctx, p->selected, closure);
   } else {
     grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_CREATE("Not connected"));
   }
 }
 
 static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = {
-    pf_destroy,     pf_shutdown,           pf_pick,
-    pf_cancel_pick, pf_cancel_picks,       pf_ping_one,
-    pf_exit_idle,   pf_check_connectivity, pf_notify_on_state_change};
+    pf_destroy,
+    pf_shutdown_locked,
+    pf_pick_locked,
+    pf_cancel_pick_locked,
+    pf_cancel_picks_locked,
+    pf_ping_one_locked,
+    pf_exit_idle_locked,
+    pf_check_connectivity_locked,
+    pf_notify_on_state_change_locked};
 
 static void pick_first_factory_ref(grpc_lb_policy_factory *factory) {}
 
@@ -489,10 +447,9 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
   }
   p->num_subchannels = subchannel_idx;
 
-  grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable);
-  grpc_closure_init(&p->connectivity_changed, pf_connectivity_changed, p,
-                    grpc_schedule_on_exec_ctx);
-  gpr_mu_init(&p->mu);
+  grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable, args->combiner);
+  grpc_closure_init(&p->connectivity_changed, pf_connectivity_changed_locked, p,
+                    grpc_combiner_scheduler(args->combiner, false));
   return &p->base;
 }
 
diff --git a/src/core/ext/lb_policy/round_robin/round_robin.c b/src/core/ext/lb_policy/round_robin/round_robin.c
index 63e3d033adf5d9104542d5abf7fe8dd6c853fc5b..687df170ad7975d9a44489acd828dd6eac6723ba 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -67,6 +67,7 @@
 #include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/lib/transport/static_metadata.h"
@@ -134,7 +135,6 @@ typedef struct {
 struct round_robin_lb_policy {
   /** base policy: must be first */
   grpc_lb_policy base;
-  gpr_mu mu;
 
   /** total number of addresses received at creation time */
   size_t num_addresses;
@@ -293,7 +293,6 @@ static void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 
   grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
   gpr_free(p->subchannels);
-  gpr_mu_destroy(&p->mu);
 
   elem = p->ready_list.next;
   while (elem != NULL && elem != &p->ready_list) {
@@ -309,12 +308,11 @@ static void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   gpr_free(p);
 }
 
-static void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+static void rr_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   pending_pick *pp;
   size_t i;
 
-  gpr_mu_lock(&p->mu);
   if (grpc_lb_round_robin_trace) {
     gpr_log(GPR_DEBUG, "Shutting down Round Robin policy at %p", (void *)pol);
   }
@@ -335,15 +333,13 @@ static void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     grpc_subchannel_notify_on_state_change(exec_ctx, sd->subchannel, NULL, NULL,
                                            &sd->connectivity_changed_closure);
   }
-  gpr_mu_unlock(&p->mu);
 }
 
-static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                           grpc_connected_subchannel **target,
-                           grpc_error *error) {
+static void rr_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                                  grpc_connected_subchannel **target,
+                                  grpc_error *error) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   pending_pick *pp;
-  gpr_mu_lock(&p->mu);
   pp = p->pending_picks;
   p->pending_picks = NULL;
   while (pp != NULL) {
@@ -360,17 +356,15 @@ static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     pp = next;
   }
-  gpr_mu_unlock(&p->mu);
   GRPC_ERROR_UNREF(error);
 }
 
-static void rr_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                            uint32_t initial_metadata_flags_mask,
-                            uint32_t initial_metadata_flags_eq,
-                            grpc_error *error) {
+static void rr_cancel_picks_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                                   uint32_t initial_metadata_flags_mask,
+                                   uint32_t initial_metadata_flags_eq,
+                                   grpc_error *error) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   pending_pick *pp;
-  gpr_mu_lock(&p->mu);
   pp = p->pending_picks;
   p->pending_picks = NULL;
   while (pp != NULL) {
@@ -388,11 +382,11 @@ static void rr_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     pp = next;
   }
-  gpr_mu_unlock(&p->mu);
   GRPC_ERROR_UNREF(error);
 }
 
-static void start_picking(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) {
+static void start_picking_locked(grpc_exec_ctx *exec_ctx,
+                                 round_robin_lb_policy *p) {
   size_t i;
   p->started_picking = 1;
 
@@ -411,23 +405,20 @@ static void start_picking(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) {
   }
 }
 
-static void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+static void rr_exit_idle_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  gpr_mu_lock(&p->mu);
   if (!p->started_picking) {
-    start_picking(exec_ctx, p);
+    start_picking_locked(exec_ctx, p);
   }
-  gpr_mu_unlock(&p->mu);
 }
 
-static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                   const grpc_lb_policy_pick_args *pick_args,
-                   grpc_connected_subchannel **target, void **user_data,
-                   grpc_closure *on_complete) {
+static int rr_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                          const grpc_lb_policy_pick_args *pick_args,
+                          grpc_connected_subchannel **target, void **user_data,
+                          grpc_closure *on_complete) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   pending_pick *pp;
   ready_list *selected;
-  gpr_mu_lock(&p->mu);
 
   if (grpc_lb_round_robin_trace) {
     gpr_log(GPR_INFO, "Round Robin %p trying to pick", (void *)pol);
@@ -449,12 +440,11 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     /* only advance the last picked pointer if the selection was used */
     advance_last_picked_locked(p);
-    gpr_mu_unlock(&p->mu);
     return 1;
   } else {
     /* no pick currently available. Save for later in list of pending picks */
     if (!p->started_picking) {
-      start_picking(exec_ctx, p);
+      start_picking_locked(exec_ctx, p);
     }
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
@@ -463,7 +453,6 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pp->initial_metadata_flags = pick_args->initial_metadata_flags;
     pp->user_data = user_data;
     p->pending_picks = pp;
-    gpr_mu_unlock(&p->mu);
     return 0;
   }
 }
@@ -538,17 +527,15 @@ static grpc_connectivity_state update_lb_connectivity_status(
   return sd->curr_connectivity_state;
 }
 
-static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
-                                    grpc_error *error) {
+static void rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                           grpc_error *error) {
   subchannel_data *sd = arg;
   round_robin_lb_policy *p = sd->policy;
   pending_pick *pp;
 
   GRPC_ERROR_REF(error);
-  gpr_mu_lock(&p->mu);
 
   if (p->shutdown) {
-    gpr_mu_unlock(&p->mu);
     GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "rr_connectivity");
     GRPC_ERROR_UNREF(error);
     return;
@@ -645,56 +632,51 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
       GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "rr_connectivity");
       break;
   }
-  gpr_mu_unlock(&p->mu);
   GRPC_ERROR_UNREF(error);
 }
 
-static grpc_connectivity_state rr_check_connectivity(grpc_exec_ctx *exec_ctx,
-                                                     grpc_lb_policy *pol,
-                                                     grpc_error **error) {
+static grpc_connectivity_state rr_check_connectivity_locked(
+    grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_error **error) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  grpc_connectivity_state st;
-  gpr_mu_lock(&p->mu);
-  st = grpc_connectivity_state_get(&p->state_tracker, error);
-  gpr_mu_unlock(&p->mu);
-  return st;
+  return grpc_connectivity_state_get(&p->state_tracker, error);
 }
 
-static void rr_notify_on_state_change(grpc_exec_ctx *exec_ctx,
-                                      grpc_lb_policy *pol,
-                                      grpc_connectivity_state *current,
-                                      grpc_closure *notify) {
+static void rr_notify_on_state_change_locked(grpc_exec_ctx *exec_ctx,
+                                             grpc_lb_policy *pol,
+                                             grpc_connectivity_state *current,
+                                             grpc_closure *notify) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  gpr_mu_lock(&p->mu);
   grpc_connectivity_state_notify_on_state_change(exec_ctx, &p->state_tracker,
                                                  current, notify);
-  gpr_mu_unlock(&p->mu);
 }
 
-static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                        grpc_closure *closure) {
+static void rr_ping_one_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                               grpc_closure *closure) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
   ready_list *selected;
   grpc_connected_subchannel *target;
-  gpr_mu_lock(&p->mu);
   if ((selected = peek_next_connected_locked(p))) {
-    gpr_mu_unlock(&p->mu);
     target = GRPC_CONNECTED_SUBCHANNEL_REF(
         grpc_subchannel_get_connected_subchannel(selected->subchannel),
         "rr_picked");
     grpc_connected_subchannel_ping(exec_ctx, target, closure);
     GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, target, "rr_picked");
   } else {
-    gpr_mu_unlock(&p->mu);
     grpc_closure_sched(exec_ctx, closure,
                        GRPC_ERROR_CREATE("Round Robin not connected"));
   }
 }
 
 static const grpc_lb_policy_vtable round_robin_lb_policy_vtable = {
-    rr_destroy,     rr_shutdown,           rr_pick,
-    rr_cancel_pick, rr_cancel_picks,       rr_ping_one,
-    rr_exit_idle,   rr_check_connectivity, rr_notify_on_state_change};
+    rr_destroy,
+    rr_shutdown_locked,
+    rr_pick_locked,
+    rr_cancel_pick_locked,
+    rr_cancel_picks_locked,
+    rr_ping_one_locked,
+    rr_exit_idle_locked,
+    rr_check_connectivity_locked,
+    rr_notify_on_state_change_locked};
 
 static void round_robin_factory_ref(grpc_lb_policy_factory *factory) {}
 
@@ -762,7 +744,8 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
       }
       ++subchannel_idx;
       grpc_closure_init(&sd->connectivity_changed_closure,
-                        rr_connectivity_changed, sd, grpc_schedule_on_exec_ctx);
+                        rr_connectivity_changed_locked, sd,
+                        grpc_combiner_scheduler(args->combiner, false));
     }
   }
   if (subchannel_idx == 0) {
@@ -779,7 +762,7 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
   p->ready_list.next = NULL;
   p->ready_list_last_pick = &p->ready_list;
 
-  grpc_lb_policy_init(&p->base, &round_robin_lb_policy_vtable);
+  grpc_lb_policy_init(&p->base, &round_robin_lb_policy_vtable, args->combiner);
   grpc_connectivity_state_init(&p->state_tracker, GRPC_CHANNEL_IDLE,
                                "round_robin");
 
@@ -787,7 +770,6 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
     gpr_log(GPR_DEBUG, "Created RR policy at %p with %lu subchannels",
             (void *)p, (unsigned long)p->num_subchannels);
   }
-  gpr_mu_init(&p->mu);
   return &p->base;
 }
 
diff --git a/src/core/lib/channel/http_server_filter.c b/src/core/lib/channel/http_server_filter.c
index a6946ef9f3aae24457d718c2ac94117cb07eceb8..ce519f9c9291b75e9d4174989a1ea4606d287b7b 100644
--- a/src/core/lib/channel/http_server_filter.c
+++ b/src/core/lib/channel/http_server_filter.c
@@ -252,12 +252,11 @@ static void hs_on_complete(grpc_exec_ctx *exec_ctx, void *user_data,
     *calld->pp_recv_message = calld->payload_bin_delivered
                                   ? NULL
                                   : (grpc_byte_stream *)&calld->read_stream;
-    calld->recv_message_ready->cb(exec_ctx, calld->recv_message_ready->cb_arg,
-                                  err);
+    grpc_closure_run(exec_ctx, calld->recv_message_ready, GRPC_ERROR_REF(err));
     calld->recv_message_ready = NULL;
     calld->payload_bin_delivered = true;
   }
-  calld->on_complete->cb(exec_ctx, calld->on_complete->cb_arg, err);
+  grpc_closure_run(exec_ctx, calld->on_complete, GRPC_ERROR_REF(err));
 }
 
 static void hs_recv_message_ready(grpc_exec_ctx *exec_ctx, void *user_data,
@@ -268,8 +267,7 @@ static void hs_recv_message_ready(grpc_exec_ctx *exec_ctx, void *user_data,
     /* do nothing. This is probably a GET request, and payload will be returned
     in hs_on_complete callback. */
   } else {
-    calld->recv_message_ready->cb(exec_ctx, calld->recv_message_ready->cb_arg,
-                                  err);
+    grpc_closure_run(exec_ctx, calld->recv_message_ready, GRPC_ERROR_REF(err));
   }
 }
 
diff --git a/src/core/lib/iomgr/error.h b/src/core/lib/iomgr/error.h
index ffacdac3934b2f8f2b2e63487c1096e6f056ec6e..2613512acbeedd5970d64bb10a07e4cf1bb56c45 100644
--- a/src/core/lib/iomgr/error.h
+++ b/src/core/lib/iomgr/error.h
@@ -137,8 +137,8 @@ typedef enum {
 } grpc_error_times;
 
 /// The following "special" errors can be propagated without allocating memory.
-/// They are always even so that other code (particularly combiner locks) can
-/// safely use the lower bit for themselves.
+/// They are always even so that other code (particularly combiner locks,
+/// polling engines) can safely use the lower bit for themselves.
 
 #define GRPC_ERROR_NONE ((grpc_error *)NULL)
 #define GRPC_ERROR_OOM ((grpc_error *)2)
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index fac3705142b974534e7948212ebcadb79414d2bf..11208b9ad13d5033355ac9902a306ecaf9f2c5a2 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -68,7 +68,7 @@ static int grpc_polling_trace = 0; /* Disabled by default */
     gpr_log(GPR_INFO, (fmt), __VA_ARGS__); \
   }
 
-/* Uncomment the following enable extra checks on poll_object operations */
+/* Uncomment the following to enable extra checks on poll_object operations */
 /* #define PO_DEBUG */
 
 static int grpc_wakeup_signal = -1;
@@ -140,24 +140,61 @@ struct grpc_fd {
      Ref/Unref by two to avoid altering the orphaned bit */
   gpr_atm refst;
 
-  /* 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 */
+  /* Internally stores data of type (grpc_error *). If the FD is shutdown, this
+     contains reason for shutdown (i.e a pointer to grpc_error) ORed with
+     FD_SHUTDOWN_BIT. Since address allocations are word-aligned, the lower bit
+     of (grpc_error *) addresses is guaranteed to be zero. Even if the
+     (grpc_error *), is of special types like GRPC_ERROR_NONE, GRPC_ERROR_OOM
+     etc, the lower bit is guaranteed to be zero.
 
-  /* 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 */
+     Once an fd is shutdown, any pending or future read/write closures on the
+     fd should fail */
+  gpr_atm shutdown_error;
+
+  /* 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 */
   bool orphaned;
 
-  /* TODO: sreek - Move this to a lockfree implementation */
-  grpc_closure *read_closure;
-  grpc_closure *write_closure;
+  /* Closures to call when the fd is readable or writable respectively. These
+     fields contain one of the following values:
+       CLOSURE_READY     : The fd has an I/O event of interest but there is no
+                           closure yet to execute
+
+       CLOSURE_NOT_READY : The fd has no I/O event of interest
+
+       closure ptr       : The closure to be executed when the fd has an I/O
+                           event of interest
+
+       shutdown_error | FD_SHUTDOWN_BIT :
+                          'shutdown_error' field ORed with FD_SHUTDOWN_BIT.
+                           This indicates that the fd is shutdown. Since all
+                           memory allocations are word-aligned, the lower two
+                           bits of the shutdown_error pointer are always 0. So
+                           it is safe to OR these with FD_SHUTDOWN_BIT
+
+     Valid state transitions:
+
+       <closure ptr> <-----3------ CLOSURE_NOT_READY ----1---->  CLOSURE_READY
+         |  |                         ^   |    ^                         |  |
+         |  |                         |   |    |                         |  |
+         |  +--------------4----------+   6    +---------2---------------+  |
+         |                                |                                 |
+         |                                v                                 |
+         +-----5------->  [shutdown_error | FD_SHUTDOWN_BIT] <----7---------+
+
+      For 1, 4 : See set_ready() function
+      For 2, 3 : See notify_on() function
+      For 5,6,7: See set_shutdown() function */
+  gpr_atm read_closure;
+  gpr_atm write_closure;
 
   struct grpc_fd *freelist_next;
   grpc_closure *on_done_closure;
 
-  /* The pollset that last noticed that the fd is readable */
-  grpc_pollset *read_notifier_pollset;
+  /* The pollset that last noticed that the fd is readable. The actual type
+   * stored in this is (grpc_pollset *) */
+  gpr_atm read_notifier_pollset;
 
   grpc_iomgr_object iomgr_object;
 };
@@ -180,8 +217,10 @@ static void fd_unref(grpc_fd *fd);
 static void fd_global_init(void);
 static void fd_global_shutdown(void);
 
-#define CLOSURE_NOT_READY ((grpc_closure *)0)
-#define CLOSURE_READY ((grpc_closure *)1)
+#define CLOSURE_NOT_READY ((gpr_atm)0)
+#define CLOSURE_READY ((gpr_atm)2)
+
+#define FD_SHUTDOWN_BIT 1
 
 /*******************************************************************************
  * Polling island Declarations
@@ -908,7 +947,11 @@ 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);
+
+    grpc_error *err = (grpc_error *)gpr_atm_acq_load(&fd->shutdown_error);
+    /* Clear the least significant bit if it set (in case fd was shutdown) */
+    err = (grpc_error *)((intptr_t)err & ~FD_SHUTDOWN_BIT);
+    GRPC_ERROR_UNREF(err);
 
     gpr_mu_unlock(&fd_freelist_mu);
   } else {
@@ -972,13 +1015,14 @@ static grpc_fd *fd_create(int fd, const char *name) {
 
   gpr_atm_rel_store(&new_fd->refst, (gpr_atm)1);
   new_fd->fd = fd;
-  new_fd->shutdown = false;
+  gpr_atm_no_barrier_store(&new_fd->shutdown_error, (gpr_atm)GRPC_ERROR_NONE);
   new_fd->orphaned = false;
-  new_fd->read_closure = CLOSURE_NOT_READY;
-  new_fd->write_closure = CLOSURE_NOT_READY;
+  gpr_atm_no_barrier_store(&new_fd->read_closure, CLOSURE_NOT_READY);
+  gpr_atm_no_barrier_store(&new_fd->write_closure, CLOSURE_NOT_READY);
+  gpr_atm_no_barrier_store(&new_fd->read_notifier_pollset, (gpr_atm)NULL);
+
   new_fd->freelist_next = NULL;
   new_fd->on_done_closure = NULL;
-  new_fd->read_notifier_pollset = NULL;
 
   gpr_mu_unlock(&new_fd->po.mu);
 
@@ -1060,101 +1104,206 @@ static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   GRPC_ERROR_UNREF(error);
 }
 
-static grpc_error *fd_shutdown_error(grpc_fd *fd) {
-  if (!fd->shutdown) {
-    return GRPC_ERROR_NONE;
-  } else {
-    return GRPC_ERROR_CREATE_REFERENCING("FD shutdown", &fd->shutdown_error, 1);
+static void notify_on(grpc_exec_ctx *exec_ctx, grpc_fd *fd, gpr_atm *state,
+                      grpc_closure *closure) {
+  while (true) {
+    /* Fast-path: CLOSURE_NOT_READY -> <closure>.
+       The 'release' cas here matches the 'acquire' load in set_ready and
+       set_shutdown ensuring that the closure (scheduled by set_ready or
+       set_shutdown) happens-after the I/O event on the fd */
+    if (gpr_atm_rel_cas(state, CLOSURE_NOT_READY, (gpr_atm)closure)) {
+      return; /* Fast-path successful. Return */
+    }
+
+    /* Slowpath. The 'acquire' load matches the 'release' cas in set_ready and
+       set_shutdown */
+    gpr_atm curr = gpr_atm_acq_load(state);
+    switch (curr) {
+      case CLOSURE_NOT_READY: {
+        break; /* retry */
+      }
+
+      case CLOSURE_READY: {
+        /* Change the state to CLOSURE_NOT_READY. Schedule the closure if
+           successful. If not, the state most likely transitioned to shutdown.
+           We should retry.
+
+           This can be a no-barrier cas since the state is being transitioned to
+           CLOSURE_NOT_READY; set_ready and set_shutdown do not schedule any
+           closure when transitioning out of CLOSURE_NO_READY state (i.e there
+           is no other code that needs to 'happen-after' this) */
+        if (gpr_atm_no_barrier_cas(state, CLOSURE_READY, CLOSURE_NOT_READY)) {
+          grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_NONE);
+          return; /* Slow-path successful. Return */
+        }
+
+        break; /* retry */
+      }
+
+      default: {
+        /* 'curr' is either a closure or the fd is shutdown(in which case 'curr'
+           contains a pointer to the shutdown-error). If the fd is shutdown,
+           schedule the closure with the shutdown error */
+        if ((curr & FD_SHUTDOWN_BIT) > 0) {
+          grpc_error *shutdown_err = (grpc_error *)(curr & ~FD_SHUTDOWN_BIT);
+          grpc_closure_sched(
+              exec_ctx, closure,
+              GRPC_ERROR_CREATE_REFERENCING("FD Shutdown", &shutdown_err, 1));
+          return;
+        }
+
+        /* There is already a closure!. This indicates a bug in the code */
+        gpr_log(GPR_ERROR,
+                "notify_on called with a previous callback still pending");
+        abort();
+      }
+    }
   }
+
+  GPR_UNREACHABLE_CODE(return );
 }
 
-static void notify_on_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                             grpc_closure **st, grpc_closure *closure) {
-  if (fd->shutdown) {
-    grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_CREATE("FD shutdown"));
-  } else if (*st == CLOSURE_NOT_READY) {
-    /* not ready ==> switch to a waiting state by setting the closure */
-    *st = closure;
-  } 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));
-  } else {
-    /* upcallptr was set to a different closure.  This is an error! */
-    gpr_log(GPR_ERROR,
-            "User called a notify_on function with a previous callback still "
-            "pending");
-    abort();
+static void set_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, gpr_atm *state,
+                         grpc_error *shutdown_err) {
+  /* Try the fast-path first (i.e expect the current value to be
+     CLOSURE_NOT_READY */
+  gpr_atm curr = CLOSURE_NOT_READY;
+  gpr_atm new_state = (gpr_atm)shutdown_err | FD_SHUTDOWN_BIT;
+
+  while (true) {
+    /* The 'release' cas here matches the 'acquire' load in notify_on to ensure
+       that the closure it schedules 'happens-after' the set_shutdown is called
+       on the fd */
+    if (gpr_atm_rel_cas(state, curr, new_state)) {
+      return; /* Fast-path successful. Return */
+    }
+
+    /* Fallback to slowpath. This 'acquire' load matches the 'release' cas in
+       notify_on and set_ready */
+    curr = gpr_atm_acq_load(state);
+    switch (curr) {
+      case CLOSURE_READY: {
+        break; /* retry */
+      }
+
+      case CLOSURE_NOT_READY: {
+        break; /* retry */
+      }
+
+      default: {
+        /* 'curr' is either a closure or the fd is already shutdown */
+
+        /* If fd is already shutdown, we are done */
+        if ((curr & FD_SHUTDOWN_BIT) > 0) {
+          return;
+        }
+
+        /* Fd is not shutdown. Schedule the closure and move the state to
+           shutdown state. The 'release' cas here matches the 'acquire' load in
+           notify_on to ensure that the closure it schedules 'happens-after'
+           the set_shutdown is called on the fd */
+        if (gpr_atm_rel_cas(state, curr, new_state)) {
+          grpc_closure_sched(
+              exec_ctx, (grpc_closure *)curr,
+              GRPC_ERROR_CREATE_REFERENCING("FD Shutdown", &shutdown_err, 1));
+          return;
+        }
+
+        /* 'curr' was a closure but now changed to a different state. We will
+          have to retry */
+        break;
+      }
+    }
   }
+
+  GPR_UNREACHABLE_CODE(return );
 }
 
-/* returns 1 if state becomes not ready */
-static int set_ready_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                            grpc_closure **st) {
-  if (*st == CLOSURE_READY) {
-    /* duplicate ready ==> ignore */
-    return 0;
-  } else if (*st == CLOSURE_NOT_READY) {
-    /* not ready, and not waiting ==> flag ready */
-    *st = CLOSURE_READY;
-    return 0;
-  } else {
-    /* waiting ==> queue closure */
-    grpc_closure_sched(exec_ctx, *st, fd_shutdown_error(fd));
-    *st = CLOSURE_NOT_READY;
-    return 1;
+static void set_ready(grpc_exec_ctx *exec_ctx, grpc_fd *fd, gpr_atm *state) {
+  /* Try an optimistic case first (i.e assume current state is
+     CLOSURE_NOT_READY).
+
+     This 'release' cas matches the 'acquire' load in notify_on ensuring that
+     any closure (scheduled by notify_on) 'happens-after' the return from
+     epoll_pwait */
+  if (gpr_atm_rel_cas(state, CLOSURE_NOT_READY, CLOSURE_READY)) {
+    return; /* early out */
+  }
+
+  /* The 'acquire' load here matches the 'release' cas in notify_on and
+     set_shutdown */
+  gpr_atm curr = gpr_atm_acq_load(state);
+  switch (curr) {
+    case CLOSURE_READY: {
+      /* Already ready. We are done here */
+      break;
+    }
+
+    case CLOSURE_NOT_READY: {
+      /* The state was not CLOSURE_NOT_READY when we checked initially at the
+         beginning of this function but now it is CLOSURE_NOT_READY again.
+         This is only possible if the state transitioned out of
+         CLOSURE_NOT_READY to either CLOSURE_READY or <some closure> and then
+         back to CLOSURE_NOT_READY again (i.e after we entered this function,
+         the fd became "ready" and the necessary actions were already done).
+         So there is no need to make the state CLOSURE_READY now */
+      break;
+    }
+
+    default: {
+      /* 'curr' is either a closure or the fd is shutdown */
+      if ((curr & FD_SHUTDOWN_BIT) > 0) {
+        /* The fd is shutdown. Do nothing */
+      } else if (gpr_atm_no_barrier_cas(state, curr, CLOSURE_NOT_READY)) {
+        /* The cas above was no-barrier since the state is being transitioned to
+           CLOSURE_NOT_READY; notify_on and set_shutdown do not schedule any
+           closures when transitioning out of CLOSURE_NO_READY state (i.e there
+           is no other code that needs to 'happen-after' this) */
+
+        grpc_closure_sched(exec_ctx, (grpc_closure *)curr, GRPC_ERROR_NONE);
+      }
+      /* else the state changed again (only possible by either a racing
+         set_ready or set_shutdown functions. In both these cases, the closure
+         would have been scheduled for execution. So we are done here */
+      break;
+    }
   }
 }
 
 static grpc_pollset *fd_get_read_notifier_pollset(grpc_exec_ctx *exec_ctx,
                                                   grpc_fd *fd) {
-  grpc_pollset *notifier = NULL;
-
-  gpr_mu_lock(&fd->po.mu);
-  notifier = fd->read_notifier_pollset;
-  gpr_mu_unlock(&fd->po.mu);
-
-  return notifier;
+  gpr_atm notifier = gpr_atm_acq_load(&fd->read_notifier_pollset);
+  return (grpc_pollset *)notifier;
 }
 
 static bool fd_is_shutdown(grpc_fd *fd) {
-  gpr_mu_lock(&fd->po.mu);
-  const bool r = fd->shutdown;
-  gpr_mu_unlock(&fd->po.mu);
-  return r;
+  grpc_error *err = (grpc_error *)gpr_atm_acq_load(&fd->shutdown_error);
+  return (((intptr_t)err & FD_SHUTDOWN_BIT) > 0);
 }
 
 /* Might be called multiple times */
 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;
-
+  /* Store the shutdown error ORed with FD_SHUTDOWN_BIT in fd->shutdown_error */
+  if (gpr_atm_rel_cas(&fd->shutdown_error, (gpr_atm)GRPC_ERROR_NONE,
+                      (gpr_atm)why | FD_SHUTDOWN_BIT)) {
     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);
+
+    set_shutdown(exec_ctx, fd, &fd->read_closure, why);
+    set_shutdown(exec_ctx, fd, &fd->write_closure, why);
   } else {
+    /* Shutdown already called */
     GRPC_ERROR_UNREF(why);
   }
-  gpr_mu_unlock(&fd->po.mu);
 }
 
 static void fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
                               grpc_closure *closure) {
-  gpr_mu_lock(&fd->po.mu);
-  notify_on_locked(exec_ctx, fd, &fd->read_closure, closure);
-  gpr_mu_unlock(&fd->po.mu);
+  notify_on(exec_ctx, fd, &fd->read_closure, closure);
 }
 
 static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
                                grpc_closure *closure) {
-  gpr_mu_lock(&fd->po.mu);
-  notify_on_locked(exec_ctx, fd, &fd->write_closure, closure);
-  gpr_mu_unlock(&fd->po.mu);
+  notify_on(exec_ctx, fd, &fd->write_closure, closure);
 }
 
 static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) {
@@ -1343,18 +1492,19 @@ static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
 
 static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
                                grpc_pollset *notifier) {
-  /* Need the fd->po.mu since we might be racing with fd_notify_on_read */
-  gpr_mu_lock(&fd->po.mu);
-  set_ready_locked(exec_ctx, fd, &fd->read_closure);
-  fd->read_notifier_pollset = notifier;
-  gpr_mu_unlock(&fd->po.mu);
+  set_ready(exec_ctx, fd, &fd->read_closure);
+
+  /* Note, it is possible that fd_become_readable might be called twice with
+     different 'notifier's when an fd becomes readable and it is in two epoll
+     sets (This can happen briefly during polling island merges). In such cases
+     it does not really matter which notifer is set as the read_notifier_pollset
+     (They would both point to the same polling island anyway) */
+  /* Use release store to match with acquire load in fd_get_read_notifier */
+  gpr_atm_rel_store(&fd->read_notifier_pollset, (gpr_atm)notifier);
 }
 
 static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  /* Need the fd->po.mu since we might be racing with fd_notify_on_write */
-  gpr_mu_lock(&fd->po.mu);
-  set_ready_locked(exec_ctx, fd, &fd->write_closure);
-  gpr_mu_unlock(&fd->po.mu);
+  set_ready(exec_ctx, fd, &fd->write_closure);
 }
 
 static void pollset_release_polling_island(grpc_exec_ctx *exec_ctx,
@@ -1737,7 +1887,7 @@ retry:
               (void *)pi_new, FD_FROM_PO(item)->fd, poll_obj_string(bag_type),
               (void *)bag);
           /* No need to lock 'pi_new' here since this is a new polling island
-            * and no one has a reference to it yet */
+             and no one has a reference to it yet */
           polling_island_remove_all_fds_locked(pi_new, true, &error);
 
           /* Ref and unref so that the polling island gets deleted during unref
diff --git a/src/core/lib/iomgr/resolve_address_uv.c b/src/core/lib/iomgr/resolve_address_uv.c
index 9b5f3209f05cf131cfe3247e643b03ba61525660..79ff91073899e47b6c47afb50fb322780c5f636c 100644
--- a/src/core/lib/iomgr/resolve_address_uv.c
+++ b/src/core/lib/iomgr/resolve_address_uv.c
@@ -113,14 +113,15 @@ static grpc_error *try_split_host_port(const char *name,
   /* parse name, splitting it into host and port parts */
   grpc_error *error;
   gpr_split_host_port(name, host, port);
-  if (host == NULL) {
+  if (*host == NULL) {
     char *msg;
     gpr_asprintf(&msg, "unparseable host:port: '%s'", name);
     error = GRPC_ERROR_CREATE(msg);
     gpr_free(msg);
     return error;
   }
-  if (port == NULL) {
+  if (*port == NULL) {
+    // TODO(murgatroid99): add tests for this case
     if (default_port == NULL) {
       char *msg;
       gpr_asprintf(&msg, "no port in name '%s'", name);
diff --git a/src/core/lib/iomgr/socket_utils_windows.c b/src/core/lib/iomgr/socket_utils_windows.c
index 628ad4a45be265ac0623dcf6aff412c7b598fb64..5bbe8fa34c96f3c2444ce795ad4a7b746995fd4e 100644
--- a/src/core/lib/iomgr/socket_utils_windows.c
+++ b/src/core/lib/iomgr/socket_utils_windows.c
@@ -41,8 +41,12 @@
 #include <grpc/support/log.h>
 
 const char *grpc_inet_ntop(int af, const void *src, char *dst, size_t size) {
+#ifdef GPR_WIN_INET_NTOP
+  return inet_ntop(af, src, dst, size);
+#else
   /* Windows InetNtopA wants a mutable ip pointer */
   return InetNtopA(af, (void *)src, dst, size);
+#endif /* GPR_WIN_INET_NTOP */
 }
 
 #endif /* GRPC_WINDOWS_SOCKETUTILS */
diff --git a/src/core/lib/iomgr/tcp_client_uv.c b/src/core/lib/iomgr/tcp_client_uv.c
index 5225a5402b2c99dbcb76eb1d832f1edfcc457c08..3de0795187b4fc48604768f426a1b7518a9ae738 100644
--- a/src/core/lib/iomgr/tcp_client_uv.c
+++ b/src/core/lib/iomgr/tcp_client_uv.c
@@ -46,6 +46,8 @@
 #include "src/core/lib/iomgr/tcp_uv.h"
 #include "src/core/lib/iomgr/timer.h"
 
+extern int grpc_tcp_trace;
+
 typedef struct grpc_uv_tcp_connect {
   uv_connect_t connect_req;
   grpc_timer alarm;
@@ -70,6 +72,12 @@ static void uv_tc_on_alarm(grpc_exec_ctx *exec_ctx, void *acp,
                            grpc_error *error) {
   int done;
   grpc_uv_tcp_connect *connect = acp;
+  if (grpc_tcp_trace) {
+    const char *str = grpc_error_string(error);
+    gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %s: on_alarm: error=%s",
+            connect->addr_name, str);
+    grpc_error_free_string(str);
+  }
   if (error == GRPC_ERROR_NONE) {
     /* error == NONE implies that the timer ran out, and wasn't cancelled. If
        it was cancelled, then the handler that cancelled it also should close
@@ -145,6 +153,12 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
   connect->resource_quota = resource_quota;
   uv_tcp_init(uv_default_loop(), connect->tcp_handle);
   connect->connect_req.data = connect;
+
+  if (grpc_tcp_trace) {
+    gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %s: asynchronously connecting",
+            connect->addr_name);
+  }
+
   // TODO(murgatroid99): figure out what the return value here means
   uv_tcp_connect(&connect->connect_req, connect->tcp_handle,
                  (const struct sockaddr *)resolved_addr->addr,
diff --git a/src/core/plugin_registry/grpc_cronet_plugin_registry.c b/src/core/plugin_registry/grpc_cronet_plugin_registry.c
index d339ed327fdc3a3ae7f35c176b9212275b52ed69..c97f47b397a3cfd296068251ad644189c75b7074 100644
--- a/src/core/plugin_registry/grpc_cronet_plugin_registry.c
+++ b/src/core/plugin_registry/grpc_cronet_plugin_registry.c
@@ -37,10 +37,14 @@ extern void grpc_chttp2_plugin_init(void);
 extern void grpc_chttp2_plugin_shutdown(void);
 extern void grpc_client_channel_init(void);
 extern void grpc_client_channel_shutdown(void);
+extern void grpc_load_reporting_plugin_init(void);
+extern void grpc_load_reporting_plugin_shutdown(void);
 
 void grpc_register_built_in_plugins(void) {
   grpc_register_plugin(grpc_chttp2_plugin_init,
                        grpc_chttp2_plugin_shutdown);
   grpc_register_plugin(grpc_client_channel_init,
                        grpc_client_channel_shutdown);
+  grpc_register_plugin(grpc_load_reporting_plugin_init,
+                       grpc_load_reporting_plugin_shutdown);
 }
diff --git a/src/cpp/server/server_cc.cc b/src/cpp/server/server_cc.cc
index 150c5a5faf2ec59568e327cea1a51c40fcfb4575..9e11a8a9e07a41420694f406d15a88fc49f4d4b5 100644
--- a/src/cpp/server/server_cc.cc
+++ b/src/cpp/server/server_cc.cc
@@ -189,8 +189,7 @@ class Server::SyncRequest final : public CompletionQueueTag {
     explicit CallData(Server* server, SyncRequest* mrd)
         : cq_(mrd->cq_),
           call_(mrd->call_, server, &cq_, server->max_receive_message_size()),
-          ctx_(mrd->deadline_, mrd->request_metadata_.metadata,
-               mrd->request_metadata_.count),
+          ctx_(mrd->deadline_, &mrd->request_metadata_),
           has_request_payload_(mrd->has_request_payload_),
           request_payload_(mrd->request_payload_),
           method_(mrd->method_) {
diff --git a/src/cpp/server/server_context.cc b/src/cpp/server/server_context.cc
index 6edbc9092773c7afa2cfbef2400bf214c46e5d98..05c05c86953404223dcc28be79f046385bd639ea 100644
--- a/src/cpp/server/server_context.cc
+++ b/src/cpp/server/server_context.cc
@@ -33,7 +33,9 @@
 
 #include <grpc++/server_context.h>
 
+#include <algorithm>
 #include <mutex>
+#include <utility>
 
 #include <grpc++/completion_queue.h>
 #include <grpc++/impl/call.h>
@@ -133,8 +135,7 @@ ServerContext::ServerContext()
       sent_initial_metadata_(false),
       compression_level_set_(false) {}
 
-ServerContext::ServerContext(gpr_timespec deadline, grpc_metadata* metadata,
-                             size_t metadata_count)
+ServerContext::ServerContext(gpr_timespec deadline, grpc_metadata_array* arr)
     : completion_op_(nullptr),
       has_notify_when_done_tag_(false),
       async_notify_when_done_tag_(nullptr),
@@ -143,12 +144,8 @@ ServerContext::ServerContext(gpr_timespec deadline, grpc_metadata* metadata,
       cq_(nullptr),
       sent_initial_metadata_(false),
       compression_level_set_(false) {
-  for (size_t i = 0; i < metadata_count; i++) {
-    client_metadata_.map()->insert(
-        std::pair<grpc::string_ref, grpc::string_ref>(
-            StringRefFromSlice(&metadata[i].key),
-            StringRefFromSlice(&metadata[i].value)));
-  }
+  std::swap(*client_metadata_.arr(), *arr);
+  client_metadata_.FillMap();
 }
 
 ServerContext::~ServerContext() {
diff --git a/src/csharp/README.md b/src/csharp/README.md
index 8468eb991ec47b4290a5e177e3231b943bf3d3d0..a21b72f2253083a081997ee1bd60dd6c9bb92648 100644
--- a/src/csharp/README.md
+++ b/src/csharp/README.md
@@ -7,19 +7,19 @@ A C# implementation of gRPC.
 SUPPORTED PLATFORMS
 ------------------
 
+- [.NET Core](https://dotnet.github.io/) on Linux, Windows and Mac OS X 
 - .NET Framework 4.5+ (Windows)
-- [.NET Core](https://dotnet.github.io/) on Linux, Windows and Mac OS X (starting from version 1.0.1)
 - Mono 4+ on Linux, Windows and Mac OS X
 
-
 PREREQUISITES
 --------------
 
+When using gRPC C# under .NET Core you only need to [install .NET Core](https://www.microsoft.com/net/core).
+
 - Windows: .NET Framework 4.5+, Visual Studio 2013 or 2015
 - Linux: Mono 4+, MonoDevelop 5.9+ (with NuGet add-in installed)
 - Mac OS X: Xamarin Studio 5.9+
 
-
 HOW TO USE
 --------------
 
@@ -27,7 +27,7 @@ HOW TO USE
 
 - Open Visual Studio / MonoDevelop / Xamarin Studio and start a new project/solution.
 
-- Add the [Grpc](https://www.nuget.org/packages/Grpc/) NuGet package as a dependency (Project options -> Manage NuGet Packages).
+- Add the [Grpc](https://www.nuget.org/packages/Grpc/) NuGet package as a dependency (Project options -> Manage NuGet Packages). 
 
 - To be able to generate code from Protocol Buffer (`.proto`) file definitions, add the [Grpc.Tools](https://www.nuget.org/packages/Grpc.Tools/) NuGet package that contains Protocol Buffers compiler (_protoc_) and the gRPC _protoc_ plugin.
 
@@ -71,23 +71,10 @@ DOCUMENTATION
 - [Helloworld Example][]
 - [RouteGuide Tutorial][]
 
-CONTENTS
---------
-
-- ext:
-  The extension library that wraps C API to be more digestible by C#.
-- Grpc.Auth:
-  gRPC OAuth2/JWT support.
-- Grpc.Core:
-  The main gRPC C# library.
-- Grpc.Examples:
-  API examples for math.proto
-- Grpc.Examples.MathClient:
-  An example client that sends requests to math server.
-- Grpc.Examples.MathServer:
-  An example server that implements a simple math service.
-- Grpc.IntegrationTesting:
-  Cross-language gRPC implementation testing (interop testing).
+PERFORMANCE
+-----------
+
+For best gRPC C# performance, use [.NET Core](https://dotnet.github.io/) and the Server GC mode `"System.GC.Server": true` for your applications.
 
 THE NATIVE DEPENDENCY
 ---------------
diff --git a/src/node/ext/completion_queue_threadpool.cc b/src/node/ext/completion_queue_threadpool.cc
index 6302e7a103b112378b36d87fbacf0c67b5d56b8b..4881542f2d07668a2699c9853234060ecaf4fe02 100644
--- a/src/node/ext/completion_queue_threadpool.cc
+++ b/src/node/ext/completion_queue_threadpool.cc
@@ -78,6 +78,8 @@ class CompletionQueueAsyncWorker : public Nan::AsyncWorker {
   void HandleErrorCallback();
 
  private:
+  static void TryAddWorker();
+
   grpc_event result;
 
   static grpc_completion_queue *queue;
@@ -118,20 +120,21 @@ void CompletionQueueAsyncWorker::Execute() {
 
 grpc_completion_queue *CompletionQueueAsyncWorker::GetQueue() { return queue; }
 
-void CompletionQueueAsyncWorker::Next() {
-#ifndef GRPC_UV
-  Nan::HandleScope scope;
-  if (current_threads < max_queue_threads) {
+void CompletionQueueAsyncWorker::TryAddWorker() {
+  if (current_threads < max_queue_threads && waiting_next_calls > 0) {
     current_threads += 1;
+    waiting_next_calls -= 1;
     CompletionQueueAsyncWorker *worker = new CompletionQueueAsyncWorker();
     Nan::AsyncQueueWorker(worker);
-  } else {
-    waiting_next_calls += 1;
   }
   GPR_ASSERT(current_threads <= max_queue_threads);
   GPR_ASSERT((current_threads == max_queue_threads) ||
              (waiting_next_calls == 0));
-#endif
+}
+
+void CompletionQueueAsyncWorker::Next() {
+  waiting_next_calls += 1;
+  TryAddWorker();
 }
 
 void CompletionQueueAsyncWorker::Init(Local<Object> exports) {
@@ -143,17 +146,8 @@ void CompletionQueueAsyncWorker::Init(Local<Object> exports) {
 
 void CompletionQueueAsyncWorker::HandleOKCallback() {
   Nan::HandleScope scope;
-  if (waiting_next_calls > 0) {
-    waiting_next_calls -= 1;
-    // Old worker removed, new worker added. current_threads += 0
-    CompletionQueueAsyncWorker *worker = new CompletionQueueAsyncWorker();
-    Nan::AsyncQueueWorker(worker);
-  } else {
-    current_threads -= 1;
-  }
-  GPR_ASSERT(current_threads <= max_queue_threads);
-  GPR_ASSERT((current_threads == max_queue_threads) ||
-             (waiting_next_calls == 0));
+  current_threads -= 1;
+  TryAddWorker();
   Nan::Callback *callback = GetTagCallback(result.tag);
   Local<Value> argv[] = {Nan::Null(), GetTagNodeValue(result.tag)};
   callback->Call(2, argv);
@@ -162,18 +156,9 @@ void CompletionQueueAsyncWorker::HandleOKCallback() {
 }
 
 void CompletionQueueAsyncWorker::HandleErrorCallback() {
-  if (waiting_next_calls > 0) {
-    waiting_next_calls -= 1;
-    // Old worker removed, new worker added. current_threads += 0
-    CompletionQueueAsyncWorker *worker = new CompletionQueueAsyncWorker();
-    Nan::AsyncQueueWorker(worker);
-  } else {
-    current_threads -= 1;
-  }
-  GPR_ASSERT(current_threads <= max_queue_threads);
-  GPR_ASSERT((current_threads == max_queue_threads) ||
-             (waiting_next_calls == 0));
   Nan::HandleScope scope;
+  current_threads -= 1;
+  TryAddWorker();
   Nan::Callback *callback = GetTagCallback(result.tag);
   Local<Value> argv[] = {Nan::Error(ErrorMessage())};
 
@@ -189,6 +174,7 @@ grpc_completion_queue *GetCompletionQueue() {
 }
 
 void CompletionQueueNext() {
+  gpr_log(GPR_DEBUG, "Called CompletionQueueNext");
   CompletionQueueAsyncWorker::Next();
 }
 
diff --git a/src/node/src/client.js b/src/node/src/client.js
index 134ef239c2560e10ffaf382bcb5e4897c8c355ce..44081a3a6cd42965d0364d3e3c09fa438be3d6ab 100644
--- a/src/node/src/client.js
+++ b/src/node/src/client.js
@@ -108,7 +108,7 @@ function _write(chunk, encoding, callback) {
        but passing an object that causes a serialization failure is a misuse
        of the API anyway, so that's OK. The primary purpose here is to give the
        programmer a useful error and to stop the stream properly */
-    this.call.cancelWithStatus(grpc.status.INTERNAL, "Serialization failure");
+    this.call.cancelWithStatus(grpc.status.INTERNAL, 'Serialization failure');
     callback(e);
   }
   if (_.isFinite(encoding)) {
@@ -831,13 +831,12 @@ exports.waitForClientReady = function(client, deadline, callback) {
  */
 exports.makeProtobufClientConstructor =  function(service, options) {
   var method_attrs = common.getProtobufServiceAttrs(service, options);
-  var deprecatedArgumentOrder = false;
-  if (options) {
-    deprecatedArgumentOrder = options.deprecatedArgumentOrder;
+  if (!options) {
+    options = {deprecatedArgumentOrder: false};
   }
   var Client = exports.makeClientConstructor(
       method_attrs, common.fullyQualifiedName(service),
-      deprecatedArgumentOrder);
+      options);
   Client.service = service;
   Client.service.grpc_options = options;
   return Client;
diff --git a/src/node/src/server.js b/src/node/src/server.js
index da9c6b2d7ff0983f09f1000e609f9f3d5275bc1a..8a7eff507d03a691a8cd412475ca56928f7a02c8 100644
--- a/src/node/src/server.js
+++ b/src/node/src/server.js
@@ -121,20 +121,20 @@ function sendUnaryResponse(call, value, serialize, metadata, flags) {
   if (metadata) {
     statusMetadata = metadata;
   }
-  status.metadata = statusMetadata._getCoreRepresentation();
-  if (!call.metadataSent) {
-    end_batch[grpc.opType.SEND_INITIAL_METADATA] =
-        (new Metadata())._getCoreRepresentation();
-    call.metadataSent = true;
-  }
   var message;
   try {
     message = serialize(value);
   } catch (e) {
     e.code = grpc.status.INTERNAL;
-    handleError(e);
+    handleError(call, e);
     return;
   }
+  status.metadata = statusMetadata._getCoreRepresentation();
+  if (!call.metadataSent) {
+    end_batch[grpc.opType.SEND_INITIAL_METADATA] =
+        (new Metadata())._getCoreRepresentation();
+    call.metadataSent = true;
+  }
   message.grpcWriteFlags = flags;
   end_batch[grpc.opType.SEND_MESSAGE] = message;
   end_batch[grpc.opType.SEND_STATUS_FROM_SERVER] = status;
@@ -280,11 +280,6 @@ function _write(chunk, encoding, callback) {
   /* jshint validthis: true */
   var batch = {};
   var self = this;
-  if (!this.call.metadataSent) {
-    batch[grpc.opType.SEND_INITIAL_METADATA] =
-        (new Metadata())._getCoreRepresentation();
-    this.call.metadataSent = true;
-  }
   var message;
   try {
     message = this.serialize(chunk);
@@ -293,6 +288,11 @@ function _write(chunk, encoding, callback) {
     callback(e);
     return;
   }
+  if (!this.call.metadataSent) {
+    batch[grpc.opType.SEND_INITIAL_METADATA] =
+        (new Metadata())._getCoreRepresentation();
+    this.call.metadataSent = true;
+  }
   if (_.isFinite(encoding)) {
     /* Attach the encoding if it is a finite number. This is the closest we
      * can get to checking that it is valid flags */
@@ -728,11 +728,17 @@ var defaultHandler = {
  *     method implementation for the provided service.
  */
 Server.prototype.addService = function(service, implementation) {
+  if (!_.isObjectLike(service) || !_.isObjectLike(implementation)) {
+    throw new Error('addService requires two objects as arguments');
+  }
+  if (_.keys(service).length === 0) {
+    throw new Error('Cannot add an empty service to a server');
+  }
   if (this.started) {
     throw new Error('Can\'t add a service to a started server.');
   }
   var self = this;
-  _.each(service, function(attrs, name) {
+  _.forOwn(service, function(attrs, name) {
     var method_type;
     if (attrs.requestStream) {
       if (attrs.responseStream) {
diff --git a/src/node/test/surface_test.js b/src/node/test/surface_test.js
index e429a3648ba1d60023f2fdb057b5c0caba561bd1..2636ea85ac8e81113dc2e7c6db5c9c484d4b057f 100644
--- a/src/node/test/surface_test.js
+++ b/src/node/test/surface_test.js
@@ -607,6 +607,113 @@ describe('Client malformed response handling', function() {
     call.end();
   });
 });
+describe('Server serialization failure handling', function() {
+  function serializeFail(obj) {
+    throw new Error('Serialization failed');
+  }
+  var client;
+  var server;
+  before(function() {
+    var test_proto = ProtoBuf.loadProtoFile(__dirname + '/test_service.proto');
+    var test_service = test_proto.lookup('TestService');
+    var malformed_test_service = {
+      unary: {
+        path: '/TestService/Unary',
+        requestStream: false,
+        responseStream: false,
+        requestDeserialize: _.identity,
+        responseSerialize: serializeFail
+      },
+      clientStream: {
+        path: '/TestService/ClientStream',
+        requestStream: true,
+        responseStream: false,
+        requestDeserialize: _.identity,
+        responseSerialize: serializeFail
+      },
+      serverStream: {
+        path: '/TestService/ServerStream',
+        requestStream: false,
+        responseStream: true,
+        requestDeserialize: _.identity,
+        responseSerialize: serializeFail
+      },
+      bidiStream: {
+        path: '/TestService/BidiStream',
+        requestStream: true,
+        responseStream: true,
+        requestDeserialize: _.identity,
+        responseSerialize: serializeFail
+      }
+    };
+    server = new grpc.Server();
+    server.addService(malformed_test_service, {
+      unary: function(call, cb) {
+        cb(null, {});
+      },
+      clientStream: function(stream, cb) {
+        stream.on('data', function() {/* Ignore requests */});
+        stream.on('end', function() {
+          cb(null, {});
+        });
+      },
+      serverStream: function(stream) {
+        stream.write({});
+        stream.end();
+      },
+      bidiStream: function(stream) {
+        stream.on('data', function() {
+          // Ignore requests
+          stream.write({});
+        });
+        stream.on('end', function() {
+          stream.end();
+        });
+      }
+    });
+    var port = server.bind('localhost:0', server_insecure_creds);
+    var Client = surface_client.makeProtobufClientConstructor(test_service);
+    client = new Client('localhost:' + port, grpc.credentials.createInsecure());
+    server.start();
+  });
+  after(function() {
+    server.forceShutdown();
+  });
+  it('should get an INTERNAL status with a unary call', function(done) {
+    client.unary({}, function(err, data) {
+      assert(err);
+      assert.strictEqual(err.code, grpc.status.INTERNAL);
+      done();
+    });
+  });
+  it('should get an INTERNAL status with a client stream call', function(done) {
+    var call = client.clientStream(function(err, data) {
+      assert(err);
+      assert.strictEqual(err.code, grpc.status.INTERNAL);
+      done();
+    });
+    call.write({});
+    call.end();
+  });
+  it('should get an INTERNAL status with a server stream call', function(done) {
+    var call = client.serverStream({});
+    call.on('data', function(){});
+    call.on('error', function(err) {
+      assert.strictEqual(err.code, grpc.status.INTERNAL);
+      done();
+    });
+  });
+  it('should get an INTERNAL status with a bidi stream call', function(done) {
+    var call = client.bidiStream();
+    call.on('data', function(){});
+    call.on('error', function(err) {
+      assert.strictEqual(err.code, grpc.status.INTERNAL);
+      done();
+    });
+    call.write({});
+    call.end();
+  });
+});
 describe('Other conditions', function() {
   var test_service;
   var Client;
diff --git a/src/proto/grpc/reflection/v1alpha/BUILD b/src/proto/grpc/reflection/v1alpha/BUILD
new file mode 100644
index 0000000000000000000000000000000000000000..92dd3d7f68660a424dc8cf51707b6c084095eb77
--- /dev/null
+++ b/src/proto/grpc/reflection/v1alpha/BUILD
@@ -0,0 +1,39 @@
+# Copyright 2017, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+licenses(["notice"])  # 3-clause BSD
+
+package(default_visibility = ["//visibility:public"])
+
+load("//bazel:grpc_build_system.bzl", "grpc_proto_library")
+
+grpc_proto_library(
+    name = "reflection_proto",
+    srcs = ["reflection.proto"],
+)
diff --git a/src/python/grpcio/grpc/_channel.py b/src/python/grpcio/grpc/_channel.py
index e602f39aeb09d61eb5dc68b7ff4b420fa25421f3..af86f5eabe3aa12385742ed017ddf91149bac587 100644
--- a/src/python/grpcio/grpc/_channel.py
+++ b/src/python/grpcio/grpc/_channel.py
@@ -39,7 +39,7 @@ from grpc import _grpcio_metadata
 from grpc._cython import cygrpc
 from grpc.framework.foundation import callable_util
 
-_USER_AGENT = 'Python-gRPC-{}'.format(_grpcio_metadata.__version__)
+_USER_AGENT = 'grpc-python/{}'.format(_grpcio_metadata.__version__)
 
 _EMPTY_FLAGS = 0
 _INFINITE_FUTURE = cygrpc.Timespec(float('+inf'))
diff --git a/src/python/grpcio_tests/tests/unit/_metadata_test.py b/src/python/grpcio_tests/tests/unit/_metadata_test.py
index 53fe7ba8aa57ddda6ab57b6338b5408e0f6c591f..035d87e3cf48fd420ab20a2aea7a5f619367ae44 100644
--- a/src/python/grpcio_tests/tests/unit/_metadata_test.py
+++ b/src/python/grpcio_tests/tests/unit/_metadata_test.py
@@ -32,7 +32,7 @@ import unittest
 import weakref
 
 import grpc
-from grpc import _grpcio_metadata
+from grpc import _channel
 from grpc.framework.foundation import logging_pool
 
 from tests.unit import test_common
@@ -49,8 +49,6 @@ _UNARY_STREAM = '/test/UnaryStream'
 _STREAM_UNARY = '/test/StreamUnary'
 _STREAM_STREAM = '/test/StreamStream'
 
-_USER_AGENT = 'Python-gRPC-{}'.format(_grpcio_metadata.__version__)
-
 _CLIENT_METADATA = (('client-md-key', 'client-md-key'),
                     ('client-md-key-bin', b'\x00\x01'))
 
@@ -76,7 +74,7 @@ def validate_client_metadata(test, servicer_context):
             _CLIENT_METADATA, servicer_context.invocation_metadata()))
     test.assertTrue(
         user_agent(servicer_context.invocation_metadata())
-        .startswith('primary-agent ' + _USER_AGENT))
+        .startswith('primary-agent ' + _channel._USER_AGENT))
     test.assertTrue(
         user_agent(servicer_context.invocation_metadata())
         .endswith('secondary-agent'))
diff --git a/src/ruby/ext/grpc/extconf.rb b/src/ruby/ext/grpc/extconf.rb
index 66c54aa3e0ec35515a9c00e472bdb575fbbf17ef..b379664bab8d39e866ec320c6f9dd3389b9af6c5 100644
--- a/src/ruby/ext/grpc/extconf.rb
+++ b/src/ruby/ext/grpc/extconf.rb
@@ -102,7 +102,6 @@ $CFLAGS << ' -std=c99 '
 $CFLAGS << ' -Wall '
 $CFLAGS << ' -Wextra '
 $CFLAGS << ' -pedantic '
-$CFLAGS << ' -Werror '
 $CFLAGS << ' -Wno-format '
 
 output = File.join('grpc', 'grpc_c')
diff --git a/templates/Makefile.template b/templates/Makefile.template
index 10d7861f03d1e2fd6fc1a62eab3e6fd447f14d45..f81d64399136940fea355eabcc2ad6a77fd623e6 100644
--- a/templates/Makefile.template
+++ b/templates/Makefile.template
@@ -1492,7 +1492,7 @@
     out_mingbase = '$(LIBDIR)/$(CONFIG)/' + lib.name + '$(SHARED_VERSION_' + lang_to_var[lib.language] + ')'
     out_libbase = '$(LIBDIR)/$(CONFIG)/lib' + lib.name + '$(SHARED_VERSION_' + lang_to_var[lib.language] + ')'
 
-    common = '$(LIB' + lib.name.upper() + '_OBJS) $(LDLIBS)'
+    common = '$(LIB' + lib.name.upper() + '_OBJS)'
 
     link_libs = ''
     lib_deps = ' $(ZLIB_DEP)'
@@ -1542,6 +1542,8 @@
     ldflags = '$(LDFLAGS)'
     if lib.get('LDFLAGS', None):
       ldflags += ' ' + lib['LDFLAGS']
+
+    common = common + ' $(LDLIBS)'
   %>
 
   % if lib.build == "all":
diff --git a/templates/binding.gyp.template b/templates/binding.gyp.template
index 851effc4f3dab98edf493cdb823f9babe4c22f32..4b2f6ac12bec7fded063fa707ba220cdaa8303ce 100644
--- a/templates/binding.gyp.template
+++ b/templates/binding.gyp.template
@@ -53,7 +53,9 @@
       'conditions': [
         ['runtime=="node"', {
           'defines': [
-            'GRPC_UV'
+            # Disabling this while bugs are ironed out. Uncomment this to
+            # re-enable libuv integration in C core.
+            # 'GRPC_UV'
           ]
         }],
         ['OS!="win" and runtime=="electron"', {
diff --git a/templates/grpc.gemspec.template b/templates/grpc.gemspec.template
index 82fbb69008853f1c19515182af266b6433a839a5..462ea52614069e651fab784b922a44c764d7019d 100644
--- a/templates/grpc.gemspec.template
+++ b/templates/grpc.gemspec.template
@@ -29,7 +29,7 @@
     s.require_paths = %w( src/ruby/bin src/ruby/lib src/ruby/pb )
     s.platform      = Gem::Platform::RUBY
 
-    s.add_dependency 'google-protobuf', '~> 3.1.0'
+    s.add_dependency 'google-protobuf', '~> 3.1'
     s.add_dependency 'googleauth',      '~> 0.5.1'
 
     s.add_development_dependency 'bundler',            '~> 1.9'
@@ -37,7 +37,7 @@
     s.add_development_dependency 'logging',            '~> 2.0'
     s.add_development_dependency 'simplecov',          '~> 0.9'
     s.add_development_dependency 'rake',               '~> 10.4'
-    s.add_development_dependency 'rake-compiler',      '~> 0.9'
+    s.add_development_dependency 'rake-compiler',      '~> 1.0'
     s.add_development_dependency 'rake-compiler-dock', '~> 0.5.1'
     s.add_development_dependency 'rspec',              '~> 3.2'
     s.add_development_dependency 'rubocop',            '~> 0.30.0'
diff --git a/templates/tools/run_tests/generated/tests.json.template b/templates/tools/run_tests/generated/tests.json.template
index 2815dbb9b3877c19dba6509e8fabe65fa2718df7..10ab2e445a4ec80664ce0ec6590aecc2c4154022 100644
--- a/templates/tools/run_tests/generated/tests.json.template
+++ b/templates/tools/run_tests/generated/tests.json.template
@@ -2,18 +2,28 @@
 --- |
   <%!
   import json
+
+  def gen_one_target(tgt):
+    out = {"name": tgt.name,
+           "language": tgt.language,
+           "platforms": tgt.platforms,
+           "ci_platforms": tgt.ci_platforms,
+           "gtest": tgt.gtest,
+           "exclude_configs": tgt.get("exclude_configs", []),
+           "exclude_iomgrs": tgt.get("exclude_iomgrs", []),
+           "args": tgt.get("args", []),
+           "flaky": tgt.flaky,
+           "cpu_cost": tgt.get("cpu_cost", 1.0)}
+    timeout_seconds = tgt.get("timeout_seconds", None)
+    if timeout_seconds:
+      out['timeout_seconds'] = timeout_seconds
+    excluded_poll_engines = tgt.get("excluded_poll_engines", None)
+    if excluded_poll_engines:
+      out['excluded_poll_engines'] = excluded_poll_engines
+    return out
   %>
 
-  ${json.dumps([{"name": tgt.name,
-                 "language": tgt.language,
-                 "platforms": tgt.platforms,
-                 "ci_platforms": tgt.ci_platforms,
-                 "gtest": tgt.gtest,
-                 "exclude_configs": tgt.get("exclude_configs", []),
-                 "exclude_iomgrs": tgt.get("exclude_iomgrs", []),
-                 "args": tgt.get("args", []),
-                 "flaky": tgt.flaky,
-                 "cpu_cost": tgt.get("cpu_cost", 1.0)}
+  ${json.dumps([gen_one_target(tgt)
                 for tgt in targets
                 if tgt.get('run', True) and tgt.build == 'test'] +
                 tests,
diff --git a/test/core/surface/BUILD b/test/core/surface/BUILD
new file mode 100644
index 0000000000000000000000000000000000000000..c1584131229590db92908daa6c99126d1ccc3f95
--- /dev/null
+++ b/test/core/surface/BUILD
@@ -0,0 +1,186 @@
+# Copyright 2017, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+cc_test(
+    name = "alarm_test",
+    srcs = ["alarm_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "grpc_byte_buffer_reader_test",
+    srcs = ["byte_buffer_reader_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "channel_create_test",
+    srcs = ["channel_create_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "grpc_completion_queue_test",
+    srcs = ["completion_queue_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "concurrent_connectivity_test",
+    srcs = ["concurrent_connectivity_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "init_test",
+    srcs = ["init_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "grpc_invalid_channel_args_test",
+    srcs = ["invalid_channel_args_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "lame_client_test",
+    srcs = ["lame_client_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/end2end:cq_verifier",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "public_headers_must_be_c89",
+    srcs = ["public_headers_must_be_c89.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "secure_channel_create_test",
+    srcs = ["secure_channel_create_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "sequential_connectivity_test",
+    srcs = ["sequential_connectivity_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/end2end:ssl_test_data",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "server_chttp2_test",
+    srcs = ["server_chttp2_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+cc_test(
+    name = "server_test",
+    srcs = ["server_test.c"],
+    copts = ["-std=c99"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
diff --git a/test/cpp/end2end/BUILD b/test/cpp/end2end/BUILD
new file mode 100644
index 0000000000000000000000000000000000000000..0bf7948fcfe72ca2c999b76e4d387f1e6299e1a9
--- /dev/null
+++ b/test/cpp/end2end/BUILD
@@ -0,0 +1,323 @@
+# Copyright 2017, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+licenses(["notice"])  # 3-clause BSD
+
+cc_library(
+    name = "test_service_impl",
+    srcs = ["test_service_impl.cc"],
+    hdrs = ["test_service_impl.h"],
+    deps = [
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_proto",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "async_end2end_test",
+    srcs = ["async_end2end_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "client_crash_test",
+    srcs = ["client_crash_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "client_crash_test_server",
+    srcs = ["client_crash_test_server.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gflags",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "end2end_test",
+    srcs = ["end2end_test.cc"],
+    deps = [
+        ":test_service_impl",
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "filter_end2end_test",
+    srcs = ["filter_end2end_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "generic_end2end_test",
+    srcs = ["generic_end2end_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "hybrid_end2end_test",
+    srcs = ["hybrid_end2end_test.cc"],
+    deps = [
+        ":test_service_impl",
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "mock_test",
+    srcs = ["mock_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "round_robin_end2end_test",
+    srcs = ["round_robin_end2end_test.cc"],
+    deps = [
+        ":test_service_impl",
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "proto_server_reflection_test",
+    srcs = ["proto_server_reflection_test.cc"],
+    deps = [
+        ":test_service_impl",
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//:grpc++_reflection",
+        "//external:gflags",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:grpc++_proto_reflection_desc_db",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "server_builder_plugin_test",
+    srcs = ["server_builder_plugin_test.cc"],
+    deps = [
+        ":test_service_impl",
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "server_crash_test",
+    srcs = ["server_crash_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "server_crash_test_client",
+    srcs = ["server_crash_test_client.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gflags",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "shutdown_test",
+    srcs = ["shutdown_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "streaming_throughput_test",
+    srcs = ["streaming_throughput_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
+
+cc_test(
+    name = "thread_stress_test",
+    srcs = ["thread_stress_test.cc"],
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//:grpc++",
+        "//external:gtest",
+        "//src/proto/grpc/testing:echo_messages_proto",
+        "//src/proto/grpc/testing:echo_proto",
+        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+        "//test/cpp/util:test_util",
+    ],
+)
diff --git a/test/cpp/util/BUILD b/test/cpp/util/BUILD
index f3cdc58986a358c65e43049793c99d94d5bd7356..dc90a4e172cc8411daa56a2d9bb91ade0adbf8d3 100644
--- a/test/cpp/util/BUILD
+++ b/test/cpp/util/BUILD
@@ -44,6 +44,21 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "grpc++_proto_reflection_desc_db",
+    srcs = [
+        "proto_reflection_descriptor_database.cc",
+    ],
+    hdrs = [
+        "proto_reflection_descriptor_database.h",
+    ],
+    visibility = ["//test:__subpackages__"],
+    deps = [
+        "//:grpc++_config_proto",
+        "//src/proto/grpc/reflection/v1alpha:reflection_proto",
+    ],
+)
+
 cc_library(
     name = "test_util",
     srcs = [
diff --git a/third_party/gflags b/third_party/gflags
index 30dbc81fb5ffdc98ea9b14b1918bfe4e8779b26e..f8a0efe03aa69b3336d8e228b37d4ccb17324b88 160000
--- a/third_party/gflags
+++ b/third_party/gflags
@@ -1 +1 @@
-Subproject commit 30dbc81fb5ffdc98ea9b14b1918bfe4e8779b26e
+Subproject commit f8a0efe03aa69b3336d8e228b37d4ccb17324b88
diff --git a/third_party/gtest.BUILD b/third_party/gtest.BUILD
index bf980754ca28877adcc189b300e1c60437769b85..a07db65b91b2732eeecdb6e0682ee1b2e2b910da 100644
--- a/third_party/gtest.BUILD
+++ b/third_party/gtest.BUILD
@@ -5,7 +5,7 @@ cc_library(
     ],
     hdrs = glob(["include/**/*.h", "src/*.cc", "src/*.h"]),
     includes = [
-        "include", "."
+        "include",
     ],
     linkstatic = 1,
     visibility = [
diff --git a/third_party/rake-compiler-dock/Dockerfile b/third_party/rake-compiler-dock/Dockerfile
index c7a6657246c829c1ceed128d2c5b6362a6ca023c..475c6a8d3dbd7b26785c69dba539373248673b3e 100644
--- a/third_party/rake-compiler-dock/Dockerfile
+++ b/third_party/rake-compiler-dock/Dockerfile
@@ -26,76 +26,77 @@ RUN gpg --keyserver hkp://keys.gnupg.net --recv-keys D39DC0E3 && \
         rvmsudo rvm cleanup all "
 
 # Regenerate the following using build.sh if the build folder changes.
-RUN echo \
-H4sIAJSZulYAA+07a1fbSLL5evUragxnbAdLtvwEApnJAMmwN68DJHPvGbLattSyNZYlbXfLhpuw\
-v/1WtSS/gBB2EnZn1n3AbvWjqrqqurqq1O6nQejVH33T0sDS63Xo2+51GovfRXlkN7uddrPd67a7\
-jxq23Wy2HkHn25KVlVQqJgAeJcEFDz8z7q7+P2jpa/nLYOBPLfcb4SABd7vt2+Rvd5ur8m92Gp1H\
-0PhG9CyV/3D51x8b8BjOhoGERMQDwcYwZJEXcgmnxy+OX58BPoEfiykTnoRAgYqxKVZDLmiGy6W0\
-CMSxAoQRRIpHHvdoVJ+DSCNgEt4eH4JNo2jgYeyOcC6xXckCBKKbBmoIJS/rxYmlpZnwJoKXQZRe\
-1ABRg8d9loYKUHEjFuYkC6IzmwLYHguEyqLLfFBG5hnSzXEYhwMlQvMA2IgVKyX69TQPEgSW46Bp\
-dcPYCCI3TD0Oexk4a/h0se1S1tVlwuX15ikLFLUayBtIAg/2ofHEMCZx4BkZ3Q5CpM4KfRD0dFw1\
-PhoAgV/BCVWsAYyCMKSnWk5t9YlxlcEcsyDSU5kYuDVwh6jPj7E++fVDlaBIJVJXA2auCuIIIj51\
-suoTQkJIFVOpRMpMG0kDqD+GU64gTTSzMwAp8gylKhPuBv6l7kBAkAGyiEewANmSzCmksg9L6ySk\
-WOPjRF1KxFL5fnnamMlR9ck1aH7IBjJnHiysppLxowYLYGpQIf4+rjaqenTGdhT7qKIh54z9qDlL\
-Aqp8n7FA9wIIjsuN4Jej/zk+Oz17dvbutLLQf8VDybO5M8bxC+5Okopmu/0BiclrOUDUJxGLSomG\
-lZaRZCA0XJToQ+//zP4nTLlDLr+RH3D/8x8fmuvz/yHKsvxF2r80bWvb6plJq9f+Svpwf/m3e73e\
-Wv4PUT4v/yhOLN33u3Dc4f817Ia9Iv9ut9Fe+38PUbzA98E0B+jYsbobR34woIO+P6+jj+HxC+h0\
-7E6P+ZbV7bYavM/Axk3d6Tz4gbUuX7XcsP+bVstqfE1X4J+w/82evbb/D1FulX8UOxJDOT8I+e89\
-Au6y/+1ua0X+vW6jubb/D1G+2P7zPm95265lsVar2++1CvtvmubiTGNra2tp9o8/YlC5vdNu1Xqw\
-lVW6gI1eDLsUBjHX8SPHdVD/3JHjp5ELpc2Xx6+PXr8pQalQQaziQHeiB8wUs2RgJAeKSwWli82b\
-BmBkdnHJ5RMKV6MMocsUPH1KBGKAj/E67O05zw6O3jw3zA1sCSIOPz97f+ScHr0+fH788ghsA/IB\
-YIAf/LlOvBv9vx2r9S+2/63G2v4/SLlV/g9n/+2m3b5u/9f53wcpX2z/t3e2e60G2n/X591m5372\
-v93d6Wj7n1ewkVK1ZPvJ4AcR+OPY0znOZKATcm39SXk7ytqBTNg0moC8lC4LQ3CcouYORRwrGHAD\
-/gt0kVxJnKZ4GHqBwEc+om/fHRIKN5ZDkEE0BMXwI4wHTRBxGnnniwBSBIBfA/zyGB/HET6F3FVO\
-yMSAO75HeUv850hTGmWVcwOWy3ikgjEH+hiMYTCmiiPADWM86AZc6d78O/Y9dglJjCtK6PPcMJeB\
-JYIzoinbkSCHqfLiaaTzoKFCHXZH4IVOoLhgijvJ0BPG1o0gvmTm/HSWDgppwsT+3zaxzt1hvHQS\
-b+YiLMEnoAFKOHL4N+OOU30+q7Q5w1D6cx2sf5DyGfv/NVI/uvwT+R+70V3b/4co6/zPf3ZZ2f9s\
-xE03Hid4xgizgYag8xUCgS/1/7sd9A8aPdr/jfY6//8g5W7503v5OFUmv1DSInNxbxx32f9es7ls\
-/5t2q7fO/zxIWbL/ismRrPeDqO6KWEqT3AGLdALPg1v78vOhy1x32+7i+cBYk7V36Hzottt5fHD7\
-7CxeuL1fxw+tTm0bo4dWETuQC1za+Pju9OjE+fnNq6OrutZjWd/4+Or49YtfsPH07AqfTt799L/O\
-wYHz/ujk9PjN66v6K4SZZ4aewq85jMxzL5mmhrKfT/vp3fHLw6tSLestmyaPWD/kphwywb3yvN0L\
-pO4IItSlMDS92MVeM+8t9o8a3dTohuXMT88baZvtlwn0B7q4ABvwPBYuh18QOMYNTR03nSB3wLa2\
-a/ixU9xTkXQ7I1D3PJDv3v/0yFRGXD/VNzruaQZu2P9YaT0qvL9Oq7ts/5vNnt37N9v/2cWkh6Do\
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-BGYXXjIh4b9ZFEjYw0hZ/jgQPPg/Ez8i6cXCtzz+1DjEKHMXTpmqQasBf2ERQrC70Njepb8ebKFG\
-NIzTtP8bBty78OvbZ2cHP3+AgyGLBlxfO/LJIo0xFiVM4/yqWaamAe7D7CZZoaqGcYZTMPadBHEq\
-V+dOYzHiHuB2GsbxKIgGEEcID7EYJcH/ngboC5dFP3OGyyWgnINl6Oty2Y05xDdGtC6S4LJU8gKv\
-vgknIhx+CTkgCQWgGo5SGGNzGZWVQTQg+UJwhYODCJim0gMeTQIRR2MeKcs4VlkO22dBqLd6GGM0\
-P+BjfBgyuvzFgYUyhoQJBbGf39xikceEB2HQF0xc1rCCNvU3iXKke30CtTpfDtKnjQjiD6RMkVoa\
-CkOlErlbr+MBMUz7FnJ52UismAzaJfVsfn07Y/0KxxFVFE/plhqKU98TJM7P2A5zto9Hop+zvGZM\
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-FiLKFSNZBctXwHzJzJzswpWfy+Sah35dXLXV7Pht5VZ1q60m678IQr6k0oclBsZJdhtaL4X2ln6a\
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-SyhX74aU/wLg9wLS/uS5VU0EBh0VKDL3Wg3PK1K4dMYEF+fVGfAkVTLj0pKISbBT9IFWW7N9kyNe\
-7VQijVDleQWrPAyXqOWLsBYedHVuQu9lkm41ojOTtLqR7m1/7jIqN9ihgjlLS1+sar+gvaMTWe3t\
-bs2+r1tAjCq5LEIfP4v9ZIoRkWYD+qUotlazji5SHE5KFPZEefSS7xYMARnFL3G0BPCUZ1Hj7k2B\
-nvpNusMUA7qVGI9PzH58UYR5nTm8ecSs6SjPGXU9lp5bU1TpkKFL80ZH/IvMFXwcT8iniaSC3ZP+\
-gZ66qGArI2gfv3357Oz5m5NXdwy7YbvfMOrw6PTg5PjtGY4kK5I5Wd4PldVO3EgmGE2rYzUs2kHx\
-VFq28Qd4OZb//jP1Ytxf3wjHXfn/ZqN77fc/rca/Wf7vT5r/PyySxzNbNXFGnCewtQ8lsglOIuKL\
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-7382Ouv3fw9SNr6rp1LoN290mY18HMNAv4AUInMu0C2hmCZEpyz0dGJbKrpIppOJ7wNByVN0ByB7\
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-u1S4TAhs5VlWJOjjJ1WLP1EUiODgyjDSCHskXYNEnlRAE1SDxwVY8r35Bfp9drOnEbqxxxHZ5g8W\
-NWe/NM6ZYXGG7qN2lYnGWAR63fPliLFuXF1isbpsSrYsjZNwrQ35H61k9h9DOPatvL+77/+026v3\
-/5qtxtr/e5CC9p9sP9rMoWEM0FQn9HrBHEBp88XxIV3QfXHy5t3bkjHWt6jNBOpoAerDeMyNVHKx\
-PNpMsfZO116AmIxrFFjQpBK29OdTwRzTwNOjE7TNdIFjf7NCJMDe3h6U9C3jf2TdVSOMwJSgTyl9\
-Di1HowiG5pfq1lIzngoac1qgwRhZcmVq5NlN7Z+enf7sHL1+v1/nytU3X4kC4ebdGM+VNn9cu6br\
-si7rsi7r8qcs/w8AInVFAFAAAA==\
+RUN echo \\
+H4sIANslcFgAA+08a3fbxo75uvwVqOxTSbFIidTDVhKnTW0n8d28ju2ku6fO5R2RQ4kVRXJnSMve\
+OPe3LzAk9fIrvk3UuylxUnk0DwADYDADzKiD1A/c5oNvCi2E7W7rgdlpdbe3Tfxumj2zpepzeGC2\
+W+1Oy7TaZvcBNpvYHbrflq0MUpkwAfCAxVHgXIQ39uPhcB3srBsGSv8ydSMu5DeiQQrudW7Wv9Xq\
+rejf6nZ7D6D1jfhZgr+4/ve5x9IgkZADD8/sMecxbO1CZZQksR2L6PwCqCjzsjerPdrbt1++PT6x\
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 | base64 -d | tar xzC /tmp
 
 # Import patch files for ruby and gems
@@ -105,8 +106,10 @@ ENV BASH_ENV /etc/rubybashrc
 # install rubies and fix permissions on
 RUN bash -c " \
     export CFLAGS='-s -O3 -fno-fast-math -fPIC' && \
-    for v in 2.3.0 ; do \
-        rvm install \$v --patch \$(echo ~/patches/ruby-\$v/* | tr ' ' ','); \
+    echo 'about to install patches for ruby 2.4.0 from:' && \
+    ls -r ~/patches && \
+    for v in 2.4.0 ; do \
+	rvm install \$v --patch \$(echo ~/patches/ruby-\$v/* | tr ' ' ','); \
     done && \
     rvm cleanup all && \
     find /usr/local/rvm -type d -print0 | sudo xargs -0 chmod g+sw "
@@ -116,20 +119,26 @@ RUN bash -c " \
 RUN echo "gem: --no-ri --no-rdoc" >> ~/.gemrc && \
     bash -c " \
         rvm all do gem install bundler rake-compiler hoe mini_portile rubygems-tasks && \
-        rvm 2.3.0 do gem install mini_portile2 && \
+        rvm 2.4.0 do gem install mini_portile2 && \
         find /usr/local/rvm -type d -print0 | sudo xargs -0 chmod g+sw "
 
+RUN bash -c "gem env"
+RUN bash -c "gem list rake-compiler"
+
 # Install rake-compiler's cross rubies in global dir instead of /root
 RUN sudo mkdir -p /usr/local/rake-compiler && \
     sudo chown rvm.rvm /usr/local/rake-compiler && \
     ln -s /usr/local/rake-compiler ~/.rake-compiler
 
 # Patch rake-compiler to avoid build of ruby extensions
-RUN cd /usr/local/rvm/gems/ruby-2.3.0/gems/rake-compiler-0.9.5 && git apply /home/rvm/patches/rake-compiler-0.9.5/*.diff ; \
+RUN cd /usr/local/rvm/gems/ruby-2.4.0/gems/rake-compiler-0.9.5 && git apply /home/rvm/patches/rake-compiler-0.9.5/*.diff ; \
     true
 
-RUN bash -c "rvm use 2.3.0 --default && \
+RUN bash -c "rvm use 2.4.0 --default && \
     export MAKE=\"make -j`nproc`\" CFLAGS='-s -O1 -fno-omit-frame-pointer -fno-fast-math' && \
+    rake-compiler cross-ruby VERSION=2.4.0 HOST=i686-w64-mingw32 && \
+    rake-compiler cross-ruby VERSION=2.4.0 HOST=x86_64-w64-mingw32 && \
+    rake-compiler cross-ruby VERSION=2.4.0 HOST=x86_64-linux-gnu && \
     rake-compiler cross-ruby VERSION=2.3.0 HOST=i686-w64-mingw32 && \
     rake-compiler cross-ruby VERSION=2.3.0 HOST=x86_64-w64-mingw32 && \
     rake-compiler cross-ruby VERSION=2.3.0 HOST=x86_64-linux-gnu && \
@@ -145,8 +154,9 @@ RUN bash -c "rvm use 2.3.0 --default && \
     rm -rf ~/.rake-compiler/tmp/builds ~/.rake-compiler/sources && \
     find /usr/local/rvm -type d -print0 | sudo xargs -0 chmod g+sw "
 
-RUN bash -c "rvm use 2.3.0 --default && \
+RUN bash -c "rvm use 2.4.0 --default && \
     export MAKE=\"make -j`nproc`\" CFLAGS='-m32 -s -O1 -fno-omit-frame-pointer -fno-fast-math' LDFLAGS='-m32' && \
+    rake-compiler cross-ruby VERSION=2.4.0 HOST=i686-linux-gnu && \
     rake-compiler cross-ruby VERSION=2.3.0 HOST=i686-linux-gnu && \
     rake-compiler cross-ruby VERSION=2.2.2 HOST=i686-linux-gnu && \
     rake-compiler cross-ruby VERSION=2.1.5 HOST=i686-linux-gnu && \
@@ -155,7 +165,7 @@ RUN bash -c "rvm use 2.3.0 --default && \
     find /usr/local/rvm -type d -print0 | sudo xargs -0 chmod g+sw "
 
 RUN bash -c " \
-    rvm alias create 2.3 2.3.0 "
+    rvm alias create 2.4 2.4.0 "
 
 USER root
 
@@ -167,6 +177,7 @@ RUN sed -i -- "s:/root/.rake-compiler:/usr/local/rake-compiler:g" /usr/local/rak
 
 # Install wrappers for strip commands as a workaround for "Protocol error" in boot2docker.
 RUN cp /tmp/build/strip_wrapper /root/
+RUN sudo chmod +rx /root/strip_wrapper
 RUN mv /opt/mingw/mingw32/bin/i686-w64-mingw32-strip /opt/mingw/mingw32/bin/i686-w64-mingw32-strip.bin && \
     mv /opt/mingw/mingw64/bin/x86_64-w64-mingw32-strip /opt/mingw/mingw64/bin/x86_64-w64-mingw32-strip.bin && \
     mv /usr/bin/i686-w64-mingw32-strip /usr/bin/i686-w64-mingw32-strip.bin && \
@@ -196,6 +207,10 @@ RUN cp /tmp/build/runas /usr/local/bin/
 # Install sudoers configuration
 RUN cp /tmp/build/sudoers /etc/sudoers.d/rake-compiler-dock
 
-ENV RUBY_CC_VERSION 2.3.0:2.2.2:2.1.5:2.0.0
+# Fixup Ruby 2.4 'static' compilation issue.
+RUN echo '!<arch>' > /usr/local/rake-compiler/ruby/x86_64-linux-gnu/ruby-2.4.0/lib/libruby.a
+RUN echo '!<arch>' > /usr/local/rake-compiler/ruby/i686-linux-gnu/ruby-2.4.0/lib/libruby.a
+
+ENV RUBY_CC_VERSION 2.4.0:2.3.0:2.2.2:2.1.5:2.0.0
 
 CMD bash
diff --git a/third_party/rake-compiler-dock/build/patches/ruby-2.4.0/no_sendfile.patch b/third_party/rake-compiler-dock/build/patches/ruby-2.4.0/no_sendfile.patch
new file mode 100644
index 0000000000000000000000000000000000000000..915fc7b790f8b0441102951da53dc3c59dbc8354
--- /dev/null
+++ b/third_party/rake-compiler-dock/build/patches/ruby-2.4.0/no_sendfile.patch
@@ -0,0 +1,12 @@
+diff --git a/configure b/configure
+index ebe3d8c..a336b73 100755
+--- a/configure
++++ b/configure
+@@ -18943,7 +18943,6 @@ do :
+   ac_fn_c_check_func "$LINENO" "sendfile" "ac_cv_func_sendfile"
+ if test "x$ac_cv_func_sendfile" = xyes; then :
+   cat >>confdefs.h <<_ACEOF
+-#define HAVE_SENDFILE 1
+ _ACEOF
+ 
+ fi
diff --git a/tools/distrib/build_ruby_environment_macos.sh b/tools/distrib/build_ruby_environment_macos.sh
index 64fad7c606add5fe64b97ef83b599c014788e11f..0ae589cb0b60b56b1105a6a60e5a4077b5f5312d 100644
--- a/tools/distrib/build_ruby_environment_macos.sh
+++ b/tools/distrib/build_ruby_environment_macos.sh
@@ -34,7 +34,7 @@ rm -rf ~/.rake-compiler
 
 CROSS_RUBY=`mktemp tmpfile.XXXXXXXX`
 
-curl https://raw.githubusercontent.com/rake-compiler/rake-compiler/v0.9.5/tasks/bin/cross-ruby.rake > $CROSS_RUBY
+curl https://raw.githubusercontent.com/rake-compiler/rake-compiler/v1.0.3/tasks/bin/cross-ruby.rake > $CROSS_RUBY
 
 patch $CROSS_RUBY << EOF
 --- cross-ruby.rake	2016-02-05 16:26:53.000000000 -0800
@@ -53,7 +53,8 @@ EOF
 
 MAKE="make -j8"
 
-for v in 2.3.0 2.2.2 2.1.5 2.0.0-p645 ; do
+for v in 2.4.0 2.3.0 2.2.2 2.1.5 2.0.0-p645 ; do
+  ccache -c
   rake -f $CROSS_RUBY cross-ruby VERSION=$v HOST=x86_64-darwin11
 done
 
diff --git a/tools/dockerfile/push_testing_images.sh b/tools/dockerfile/push_testing_images.sh
index f1ee8d59dd7e2db4651df7748c079fea96f26bae..9dceb29a8774ee34a64e261d0303cecb886cd289 100755
--- a/tools/dockerfile/push_testing_images.sh
+++ b/tools/dockerfile/push_testing_images.sh
@@ -44,7 +44,7 @@ cd -
 
 DOCKERHUB_ORGANIZATION=grpctesting
 
-for DOCKERFILE_DIR in tools/dockerfile/test/fuzzer
+for DOCKERFILE_DIR in tools/dockerfile/test/fuzzer tools/dockerfile/test/sanity
 do
   # Generate image name based on Dockerfile checksum. That works well as long
   # as can count on dockerfiles being written in a way that changing the logical 
diff --git a/tools/internal_ci/linux/grpc_fuzzer_api.sh b/tools/internal_ci/linux/grpc_fuzzer_api.sh
index b1f792e7657bf7fb8044b60fb8010c368662f6cb..edf884338fc0ca7a1256f8ca4392e0bead623996 100755
--- a/tools/internal_ci/linux/grpc_fuzzer_api.sh
+++ b/tools/internal_ci/linux/grpc_fuzzer_api.sh
@@ -38,4 +38,4 @@ git submodule update --init
 # download fuzzer docker image from dockerhub
 export DOCKERHUB_ORGANIZATION=grpctesting
 # runtime 23 * 60 mins
-config=asan-trace-cmp runtime=86400 tools/jenkins/run_fuzzer.sh api_fuzzer
+config=asan-trace-cmp runtime=82800 tools/jenkins/run_fuzzer.sh api_fuzzer
diff --git a/tools/internal_ci/linux/grpc_fuzzer_hpack_parser.sh b/tools/internal_ci/linux/grpc_fuzzer_hpack_parser.sh
index 40179aa5470ff5d2e518ae4adf74d859902ff0c8..43933e6d82e1ba461ab920fb2fed051ed33ea1e9 100755
--- a/tools/internal_ci/linux/grpc_fuzzer_hpack_parser.sh
+++ b/tools/internal_ci/linux/grpc_fuzzer_hpack_parser.sh
@@ -37,6 +37,5 @@ git submodule update --init
 
 # download fuzzer docker image from dockerhub
 export DOCKERHUB_ORGANIZATION=grpctesting
-# runtime 23 * 60 mins
 config=asan-trace-cmp tools/jenkins/run_fuzzer.sh hpack_parser_fuzzer_test
 
diff --git a/tools/internal_ci/linux/grpc_fuzzer_http_request.sh b/tools/internal_ci/linux/grpc_fuzzer_http_request.sh
index 6dac4ed9abbd4267b9b39f33ea44bf99d6428131..ef975d327a00e7ab66b84b5fa9ccf288036dc0d2 100755
--- a/tools/internal_ci/linux/grpc_fuzzer_http_request.sh
+++ b/tools/internal_ci/linux/grpc_fuzzer_http_request.sh
@@ -37,6 +37,5 @@ git submodule update --init
 
 # download fuzzer docker image from dockerhub
 export DOCKERHUB_ORGANIZATION=grpctesting
-# runtime 23 * 60 mins
 config=asan-trace-cmp tools/jenkins/run_fuzzer.sh http_request_fuzzer_test
 
diff --git a/tools/internal_ci/linux/grpc_fuzzer_json.sh b/tools/internal_ci/linux/grpc_fuzzer_json.sh
index b002ecb26258e82885c6a7aecb470146935d4cde..1e64a026b689b211b55ab5a958fbd4f37d4f04f0 100755
--- a/tools/internal_ci/linux/grpc_fuzzer_json.sh
+++ b/tools/internal_ci/linux/grpc_fuzzer_json.sh
@@ -37,6 +37,5 @@ git submodule update --init
 
 # download fuzzer docker image from dockerhub
 export DOCKERHUB_ORGANIZATION=grpctesting
-# runtime 23 * 60 mins
 config=asan-trace-cmp tools/jenkins/run_fuzzer.sh json_fuzzer_test
 
diff --git a/tools/internal_ci/linux/grpc_fuzzer_nanopb_response.sh b/tools/internal_ci/linux/grpc_fuzzer_nanopb_response.sh
index 51a8eb58bbfcceae947911f9b3c0a1caea6c5167..6e7f4b7f291bb2ff4ba7db293d968f0af6e67a4e 100755
--- a/tools/internal_ci/linux/grpc_fuzzer_nanopb_response.sh
+++ b/tools/internal_ci/linux/grpc_fuzzer_nanopb_response.sh
@@ -37,5 +37,4 @@ git submodule update --init
 
 # download fuzzer docker image from dockerhub
 export DOCKERHUB_ORGANIZATION=grpctesting
-# runtime 23 * 60 mins
 config=asan-trace-cmp tools/jenkins/run_fuzzer.sh nanopb_fuzzer_response_test
diff --git a/tools/internal_ci/linux/grpc_fuzzer_server.sh b/tools/internal_ci/linux/grpc_fuzzer_server.sh
index b6648db34d11b9c96abf854c33584238cd4e53ef..82b24b0f20d733c028443d4544f1a6815e225394 100755
--- a/tools/internal_ci/linux/grpc_fuzzer_server.sh
+++ b/tools/internal_ci/linux/grpc_fuzzer_server.sh
@@ -38,4 +38,4 @@ git submodule update --init
 # download fuzzer docker image from dockerhub
 export DOCKERHUB_ORGANIZATION=grpctesting
 # runtime 23 * 60 mins
-config=asan-trace-cmp runtime=86400 tools/jenkins/run_fuzzer.sh server_fuzzer
+config=asan-trace-cmp runtime=82800 tools/jenkins/run_fuzzer.sh server_fuzzer
diff --git a/tools/internal_ci/linux/grpc_fuzzer_uri.sh b/tools/internal_ci/linux/grpc_fuzzer_uri.sh
index e3e46515e27bdfd2c43a42582487fc56e5863898..67039f38807ebc992edb4f4d6ba15bc77dfa6620 100755
--- a/tools/internal_ci/linux/grpc_fuzzer_uri.sh
+++ b/tools/internal_ci/linux/grpc_fuzzer_uri.sh
@@ -37,5 +37,4 @@ git submodule update --init
 
 # download fuzzer docker image from dockerhub
 export DOCKERHUB_ORGANIZATION=grpctesting
-# runtime 23 * 60 mins
 config=asan-trace-cmp tools/jenkins/run_fuzzer.sh uri_fuzzer_test
diff --git a/tools/internal_ci/linux/grpc_master.sh b/tools/internal_ci/linux/grpc_master.sh
index 397e1bd713c1bf15dc7e8fd65fd8a605b1ce6d3c..d01d6375e9a7fff8d8c571dcf252b5935cef2526 100755
--- a/tools/internal_ci/linux/grpc_master.sh
+++ b/tools/internal_ci/linux/grpc_master.sh
@@ -40,6 +40,9 @@ gcc --version || true
 clang --version || true
 docker --version || true
 
+# Need to increase open files limit for c tests
+ulimit -n 2000
+
 git submodule update --init
 
 tools/run_tests/run_tests.py -l c -t -x sponge_log.xml || FAILED="true"
diff --git a/tools/internal_ci/linux/grpc_pull_request_sanity.cfg b/tools/internal_ci/linux/grpc_pull_request_sanity.cfg
new file mode 100644
index 0000000000000000000000000000000000000000..511f2d6b35b3106048772c88e914a43c7bc100af
--- /dev/null
+++ b/tools/internal_ci/linux/grpc_pull_request_sanity.cfg
@@ -0,0 +1,39 @@
+# Copyright 2017, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Config file for the internal CI (in protobuf text format)
+
+# Location of the continuous shell script in repository.
+build_file: "grpc/tools/internal_ci/linux/grpc_sanity.sh"
+timeout_mins: 30
+action {
+  define_artifacts {
+    regex: "**/sponge_log.xml"
+  }
+}
diff --git a/tools/internal_ci/linux/grpc_sanity.sh b/tools/internal_ci/linux/grpc_sanity.sh
new file mode 100755
index 0000000000000000000000000000000000000000..fac25c75315d2369e03311edefdfc8a1bc23b569
--- /dev/null
+++ b/tools/internal_ci/linux/grpc_sanity.sh
@@ -0,0 +1,40 @@
+#!/bin/bash
+# Copyright 2017, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set -ex
+
+# change to grpc repo root
+cd $(dirname $0)/../../..
+
+git submodule update --init
+
+# download base docker image from dockerhub
+export DOCKERHUB_ORGANIZATION=grpctesting
+tools/run_tests/run_tests.py -l sanity -c opt -t -x sponge_log.xml --use_docker --report_suite_name sanity_linux_opt
diff --git a/tools/jenkins/run_interop.sh b/tools/jenkins/run_interop.sh
index 176ee1815a9bb5c7698ce5db6c60e378b3edfe23..2a9fc662a9efc6e4d568387bac5ac0f3d85f761a 100755
--- a/tools/jenkins/run_interop.sh
+++ b/tools/jenkins/run_interop.sh
@@ -36,6 +36,4 @@ export LANG=en_US.UTF-8
 # Enter the gRPC repo root
 cd $(dirname $0)/../..
 
-tools/run_tests/run_interop_tests.py -l all -s all --cloud_to_prod --cloud_to_prod_auth --use_docker --http2_interop -t -j 12 $@ || true
-tools/run_tests/run_interop_tests.py -l java --use_docker --http2_badserver_interop $@ || true
-tools/run_tests/run_interop_tests.py -l python --use_docker --http2_badserver_interop $@ || true
+tools/run_tests/run_interop_tests.py -l all -s all --cloud_to_prod --cloud_to_prod_auth --use_docker --http2_interop --http2_badserver_interop -t -j 12 $@ || true
diff --git a/tools/run_tests/artifacts/build_artifact_ruby.sh b/tools/run_tests/artifacts/build_artifact_ruby.sh
index 019efb01fddb24edd749a3f74746f811a553daaf..ca461ba561eb0703b7516f96e94a5c776c4120c8 100755
--- a/tools/run_tests/artifacts/build_artifact_ruby.sh
+++ b/tools/run_tests/artifacts/build_artifact_ruby.sh
@@ -52,7 +52,9 @@ fi
 set +ex
 rvm use default
 gem install bundler --update
-bundle install
+
+tools/run_tests/helper_scripts/bundle_install_wrapper.sh
+
 set -ex
 
 rake gem:native
diff --git a/tools/run_tests/dockerize/build_docker_and_run_tests.sh b/tools/run_tests/dockerize/build_docker_and_run_tests.sh
index b68ac89121cb96948ec695f597cae04da860be97..f10916d19235f1284287e9f5111ec76fcc419072 100755
--- a/tools/run_tests/dockerize/build_docker_and_run_tests.sh
+++ b/tools/run_tests/dockerize/build_docker_and_run_tests.sh
@@ -47,12 +47,19 @@ mkdir -p /tmp/xdg-cache-home
 # Inputs
 # DOCKERFILE_DIR - Directory in which Dockerfile file is located.
 # DOCKER_RUN_SCRIPT - Script to run under docker (relative to grpc repo root)
+# DOCKERHUB_ORGANIZATION - If set, pull a prebuilt image from given dockerhub org.
 
 # Use image name based on Dockerfile location checksum
 DOCKER_IMAGE_NAME=$(basename $DOCKERFILE_DIR)_$(sha1sum $DOCKERFILE_DIR/Dockerfile | cut -f1 -d\ )
 
-# Make sure docker image has been built. Should be instantaneous if so.
-docker build -t $DOCKER_IMAGE_NAME $DOCKERFILE_DIR
+if [ "$DOCKERHUB_ORGANIZATION" != "" ]
+then
+  DOCKER_IMAGE_NAME=$DOCKERHUB_ORGANIZATION/$DOCKER_IMAGE_NAME
+  docker pull $DOCKER_IMAGE_NAME
+else
+  # Make sure docker image has been built. Should be instantaneous if so.
+  docker build -t $DOCKER_IMAGE_NAME $DOCKERFILE_DIR
+fi
 
 # Choose random name for docker container
 CONTAINER_NAME="run_tests_$(uuidgen)"
diff --git a/tools/run_tests/dockerize/docker_run_tests.sh b/tools/run_tests/dockerize/docker_run_tests.sh
index eb220ae416fea16d82a26ffcba5c3e38cc9c21fd..0d260ffecaa31dd3606f22e4ff3de13f5a9ca322 100755
--- a/tools/run_tests/dockerize/docker_run_tests.sh
+++ b/tools/run_tests/dockerize/docker_run_tests.sh
@@ -68,6 +68,7 @@ cd ..
 
 zip -r reports.zip reports
 find . -name report.xml | xargs -r zip reports.zip
+find . -name sponge_log.xml | xargs -r zip reports.zip
 find . -name 'report_*.xml' | xargs -r zip reports.zip
 
 exit $exit_code
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index 8403f0664bd82a32820c6cffe3690eb8371502fd..8cf282a389b05c744e0d674dce67d252b524ad8b 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -5326,6 +5326,7 @@
     "deps": [
       "gpr", 
       "grpc_base", 
+      "grpc_load_reporting", 
       "grpc_transport_chttp2_client_secure", 
       "grpc_transport_cronet_client_secure"
     ], 
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index 65707a4623b22c426ffc0979725d0102c7f8dcf9..8e843d07c053057499bb8720829ffe57dda54007 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -2569,6 +2569,10 @@
     "cpu_cost": 1.0, 
     "exclude_configs": [], 
     "exclude_iomgrs": [], 
+    "excluded_poll_engines": [
+      "poll", 
+      "poll-cv"
+    ], 
     "flaky": false, 
     "gtest": false, 
     "language": "c++", 
@@ -2577,7 +2581,8 @@
       "linux", 
       "mac", 
       "posix"
-    ]
+    ], 
+    "timeout_seconds": 1200
   }, 
   {
     "args": [
diff --git a/tools/run_tests/helper_scripts/bundle_install_wrapper.sh b/tools/run_tests/helper_scripts/bundle_install_wrapper.sh
new file mode 100755
index 0000000000000000000000000000000000000000..d56afad89314baf202a102ab34def061e5a8701a
--- /dev/null
+++ b/tools/run_tests/helper_scripts/bundle_install_wrapper.sh
@@ -0,0 +1,46 @@
+#!/bin/bash
+
+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set -ex
+
+# change to grpc repo root
+cd $(dirname $0)/../../..
+
+SYSTEM=`uname | cut -f 1 -d_`
+
+if [ "$SYSTEM" == "Darwin" ] ; then
+  # Workaround for crash during bundle install
+  # See suggestion in https://github.com/bundler/bundler/issues/3692
+  BUNDLE_SPECIFIC_PLATFORM=true bundle install
+else
+  bundle install
+fi
+
diff --git a/tools/run_tests/helper_scripts/pre_build_ruby.sh b/tools/run_tests/helper_scripts/pre_build_ruby.sh
index 56b58df5441bed4b4f7e919ffdce4e5326d59fb2..83647b5ea799384570c579e5580f1553c51bbca8 100755
--- a/tools/run_tests/helper_scripts/pre_build_ruby.sh
+++ b/tools/run_tests/helper_scripts/pre_build_ruby.sh
@@ -36,4 +36,4 @@ export GRPC_CONFIG=${CONFIG:-opt}
 # change to grpc repo root
 cd $(dirname $0)/../../..
 
-bundle install
+tools/run_tests/helper_scripts/bundle_install_wrapper.sh
diff --git a/tools/run_tests/helper_scripts/run_node_electron.sh b/tools/run_tests/helper_scripts/run_node_electron.sh
index 1999ffb0fa8803b64376db44cf889b5c58606372..3ce57e04153a9e4ef500aa4a093a9e1b2a927031 100755
--- a/tools/run_tests/helper_scripts/run_node_electron.sh
+++ b/tools/run_tests/helper_scripts/run_node_electron.sh
@@ -34,7 +34,7 @@ nvm use 6
 set -ex
 
 # change to grpc repo root
-cd $(dirname $0)/../..
+cd $(dirname $0)/../../..
 
 test_directory='src/node/test'
 timeout=8000
diff --git a/tools/run_tests/interop/interop_html_report.template b/tools/run_tests/interop/interop_html_report.template
index 46cce426b7af3e05adfe568a59e150a997a304f5..88ecd4e4db16fe25cc29658226ddba569b6de8e5 100644
--- a/tools/run_tests/interop/interop_html_report.template
+++ b/tools/run_tests/interop/interop_html_report.template
@@ -106,6 +106,30 @@
   % endfor
 % endif
 
+% if http2_badserver_cases:
+  <h2>HTTP/2 Bad Server Tests</h2>
+  ## Each column header is the client language.
+  <table style="width:100%" border="1">
+  <tr bgcolor="#00BFFF">
+  <th>Client languages &#9658;<br/>Test Cases &#9660;</th>
+  % for client_lang in client_langs_http2_badserver_cases:
+    <th>${client_lang}</th>
+  % endfor
+  </tr>
+  % for test_case in http2_badserver_cases:
+    <tr><td><b>${test_case}</b></td>
+    % for client_lang in client_langs_http2_badserver_cases:
+      <% 
+        shortname = 'cloud_to_cloud:%s:http2_server:%s' % (client_lang, 
+                                                           test_case)
+      %>
+      ${fill_one_test_result(shortname, resultset)}
+    % endfor
+    </tr> 
+  % endfor
+  </table>
+% endif
+
 % if http2_interop:
   ## Each column header is the server language.
   <h2>HTTP/2 Interop</h2> 
diff --git a/tools/run_tests/python_utils/report_utils.py b/tools/run_tests/python_utils/report_utils.py
index 352cf7abe76b260c3020aa62db5dc04208bd2e68..9dad60408f293b8eee552b314d6ba4abe724a5ab 100644
--- a/tools/run_tests/python_utils/report_utils.py
+++ b/tools/run_tests/python_utils/report_utils.py
@@ -82,7 +82,8 @@ def render_junit_xml_report(resultset, xml_report, suite_package='grpc',
 
 def render_interop_html_report(
   client_langs, server_langs, test_cases, auth_test_cases, http2_cases,
-  resultset, num_failures, cloud_to_prod, prod_servers, http2_interop):
+  http2_badserver_cases, client_langs_http2_badserver_cases, resultset, 
+  num_failures, cloud_to_prod, prod_servers, http2_interop):
   """Generate HTML report for interop tests."""
   template_file = 'tools/run_tests/interop/interop_html_report.template'
   try:
@@ -97,6 +98,9 @@ def render_interop_html_report(
   sorted_test_cases = sorted(test_cases)
   sorted_auth_test_cases = sorted(auth_test_cases)
   sorted_http2_cases = sorted(http2_cases)
+  sorted_http2_badserver_cases = sorted(http2_badserver_cases)
+  sorted_client_langs_http2_badserver_cases = sorted(
+      client_langs_http2_badserver_cases)
   sorted_client_langs = sorted(client_langs)
   sorted_server_langs = sorted(server_langs)
   sorted_prod_servers = sorted(prod_servers)
@@ -106,6 +110,9 @@ def render_interop_html_report(
           'test_cases': sorted_test_cases,
           'auth_test_cases': sorted_auth_test_cases,
           'http2_cases': sorted_http2_cases,
+          'http2_badserver_cases': sorted_http2_badserver_cases,
+          'client_langs_http2_badserver_cases': (
+              sorted_client_langs_http2_badserver_cases),
           'resultset': resultset,
           'num_failures': num_failures,
           'cloud_to_prod': cloud_to_prod,
diff --git a/tools/run_tests/run_interop_tests.py b/tools/run_tests/run_interop_tests.py
index 53df3347a0c977ab7f802cd0b30f886c19a48a3a..b47dc1e8f229f9582bed36e8375ebadc35df3af0 100755
--- a/tools/run_tests/run_interop_tests.py
+++ b/tools/run_tests/run_interop_tests.py
@@ -468,6 +468,9 @@ _HTTP2_TEST_CASES = ['tls', 'framing']
 _HTTP2_BADSERVER_TEST_CASES = ['rst_after_header', 'rst_after_data', 'rst_during_data',
                      'goaway', 'ping', 'max_streams']
 
+# TODO: Add python once the tests are fixed.
+_LANGUAGES_FOR_HTTP2_BADSERVER_TESTS = ['java']
+
 DOCKER_WORKDIR_ROOT = '/var/local/git/grpc'
 
 def docker_run_cmdline(cmdline, image, docker_args=[], cwd=None, environ=None):
@@ -830,8 +833,13 @@ if not args.use_docker and servers:
 
 languages = set(_LANGUAGES[l]
                 for l in itertools.chain.from_iterable(
-                      _LANGUAGES.iterkeys() if x == 'all' else [x]
-                      for x in args.language))
+                    _LANGUAGES.iterkeys() if x == 'all' else [x]
+                    for x in args.language))
+
+languages_http2_badserver_interop = set()
+if args.http2_badserver_interop:
+  languages_http2_badserver_interop = set(
+      _LANGUAGES[l] for l in _LANGUAGES_FOR_HTTP2_BADSERVER_TESTS)
 
 http2Interop = Http2Client() if args.http2_interop else None
 http2InteropServer = Http2Server() if args.http2_badserver_interop else None
@@ -839,8 +847,10 @@ http2InteropServer = Http2Server() if args.http2_badserver_interop else None
 docker_images={}
 if args.use_docker:
   # languages for which to build docker images
-  languages_to_build = set(_LANGUAGES[k] for k in set([str(l) for l in languages] +
-                                                    [s for s in servers]))
+  languages_to_build = set(
+      _LANGUAGES[k] for k in set([str(l) for l in languages] + [s for s in servers]))
+  languages_to_build = languages_to_build | languages_http2_badserver_interop
+
   if args.http2_interop:
     languages_to_build.add(http2Interop)
 
@@ -885,7 +895,6 @@ try:
     spec = server_jobspec(http2InteropServer, docker_images.get(lang))
     job = dockerjob.DockerJob(spec)
     server_jobs[lang] = job
-    server_addresses[lang] = ('localhost', _DEFAULT_SERVER_PORT)
 
   jobs = []
   if args.cloud_to_prod:
@@ -934,19 +943,18 @@ try:
     skip_server = []  # test cases unimplemented by server
     if server_language:
       skip_server = server_language.unimplemented_test_cases_server()
-    if not args.http2_badserver_interop:
-      for language in languages:
-        for test_case in _TEST_CASES:
-          if not test_case in language.unimplemented_test_cases():
-            if not test_case in skip_server:
-              test_job = cloud_to_cloud_jobspec(language,
-                                                test_case,
-                                                server_name,
-                                                server_host,
-                                                server_port,
-                                                docker_image=docker_images.get(str(language)),
-                                                insecure=args.insecure)
-              jobs.append(test_job)
+    for language in languages:
+      for test_case in _TEST_CASES:
+        if not test_case in language.unimplemented_test_cases():
+          if not test_case in skip_server:
+            test_job = cloud_to_cloud_jobspec(language,
+                                              test_case,
+                                              server_name,
+                                              server_host,
+                                              server_port,
+                                              docker_image=docker_images.get(str(language)),
+                                              insecure=args.insecure)
+            jobs.append(test_job)
 
     if args.http2_interop:
       for test_case in _HTTP2_TEST_CASES:
@@ -962,16 +970,16 @@ try:
                                           insecure=args.insecure)
         jobs.append(test_job)
 
-    if args.http2_badserver_interop:
-      for language in languages:
-        for test_case in _HTTP2_BADSERVER_TEST_CASES:
-          test_job = cloud_to_cloud_jobspec(language,
-                                            test_case,
-                                            server_name,
-                                            server_host,
-                                            server_port,
-                                            docker_image=docker_images.get(str(language)))
-          jobs.append(test_job)
+  if args.http2_badserver_interop:
+    for language in languages_http2_badserver_interop:
+      for test_case in _HTTP2_BADSERVER_TEST_CASES:
+        test_job = cloud_to_cloud_jobspec(language,
+                                          test_case,
+                                          str(http2InteropServer),
+                                          'localhost',
+                                          _DEFAULT_SERVER_PORT,
+                                          docker_image=docker_images.get(str(language)))
+        jobs.append(test_job)
 
   if not jobs:
     print('No jobs to run.')
@@ -992,9 +1000,13 @@ try:
     if "http2" in name:
       job[0].http2results = aggregate_http2_results(job[0].message)
 
+  http2_badserver_test_cases = (
+      _HTTP2_BADSERVER_TEST_CASES if args.http2_badserver_interop else [])
+
   report_utils.render_interop_html_report(
       set([str(l) for l in languages]), servers, _TEST_CASES, _AUTH_TEST_CASES,
-      _HTTP2_TEST_CASES, resultset, num_failures,
+      _HTTP2_TEST_CASES, http2_badserver_test_cases,
+      _LANGUAGES_FOR_HTTP2_BADSERVER_TESTS, resultset, num_failures,
       args.cloud_to_prod_auth or args.cloud_to_prod, args.prod_servers,
       args.http2_interop)
 
diff --git a/tools/run_tests/run_microbenchmark.py b/tools/run_tests/run_microbenchmark.py
index 7f871bf0adf0db4d1be88e948cedce4aecbd44cc..4307906a7e4a5f1b6a035a6494187ea4a8c895ea 100755
--- a/tools/run_tests/run_microbenchmark.py
+++ b/tools/run_tests/run_microbenchmark.py
@@ -206,7 +206,6 @@ argp.add_argument('-b', '--benchmarks',
                            'bm_error',
                            'bm_chttp2_hpack',
                            'bm_metadata'],
->>>>>>> b325a1dd4af3f3d3443da3e0ac0f007162c63772
                   nargs='+',
                   type=str,
                   help='Which microbenchmarks should be run')