Merge branch 'master' into grpc_namespace_completion_queue

.gitignore

@@ -115,6 +115,7 @@ bazel-genfiles
 bazel-grpc
 bazel-out
 bazel-testlogs
+bazel_format_virtual_environment/
 
 # Debug output
 gdb.txt

BUILD

@@ -434,6 +434,7 @@ grpc_cc_library(
         "src/compiler/config.h",
         "src/compiler/cpp_generator.h",
         "src/compiler/cpp_generator_helpers.h",
+        "src/compiler/cpp_plugin.h",
         "src/compiler/csharp_generator.h",
         "src/compiler/csharp_generator_helpers.h",
         "src/compiler/generator_helpers.h",
@@ -579,6 +580,7 @@ grpc_cc_library(
         "src/core/lib/gpr/wrap_memcpy.cc",
         "src/core/lib/gprpp/arena.cc",
         "src/core/lib/gprpp/fork.cc",
+        "src/core/lib/gprpp/global_config_env.cc",
         "src/core/lib/gprpp/thd_posix.cc",
         "src/core/lib/gprpp/thd_windows.cc",
         "src/core/lib/profiling/basic_timers.cc",
@@ -605,6 +607,10 @@ grpc_cc_library(
         "src/core/lib/gprpp/arena.h",
         "src/core/lib/gprpp/atomic.h",
         "src/core/lib/gprpp/fork.h",
+        "src/core/lib/gprpp/global_config_custom.h",
+        "src/core/lib/gprpp/global_config_env.h",
+        "src/core/lib/gprpp/global_config_generic.h",
+        "src/core/lib/gprpp/global_config.h",
         "src/core/lib/gprpp/manual_constructor.h",
         "src/core/lib/gprpp/map.h",
         "src/core/lib/gprpp/memory.h",
@@ -1572,16 +1578,20 @@ grpc_cc_library(
     srcs = [
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc",
     ],
     hdrs = [
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h",
     ],
     external_deps = [
         "cares",

BUILD.gn

@@ -184,6 +184,11 @@ config("grpc_config") {
         "src/core/lib/gprpp/atomic.h",
         "src/core/lib/gprpp/fork.cc",
         "src/core/lib/gprpp/fork.h",
+        "src/core/lib/gprpp/global_config.h",
+        "src/core/lib/gprpp/global_config_custom.h",
+        "src/core/lib/gprpp/global_config_env.cc",
+        "src/core/lib/gprpp/global_config_env.h",
+        "src/core/lib/gprpp/global_config_generic.h",
         "src/core/lib/gprpp/manual_constructor.h",
         "src/core/lib/gprpp/map.h",
         "src/core/lib/gprpp/memory.h",
@@ -310,11 +315,15 @@ config("grpc_config") {
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc",
@@ -1175,6 +1184,10 @@ config("grpc_config") {
         "src/core/lib/gprpp/atomic.h",
         "src/core/lib/gprpp/debug_location.h",
         "src/core/lib/gprpp/fork.h",
+        "src/core/lib/gprpp/global_config.h",
+        "src/core/lib/gprpp/global_config_custom.h",
+        "src/core/lib/gprpp/global_config_env.h",
+        "src/core/lib/gprpp/global_config_generic.h",
         "src/core/lib/gprpp/inlined_vector.h",
         "src/core/lib/gprpp/manual_constructor.h",
         "src/core/lib/gprpp/map.h",

CMakeLists.txt

@@ -629,6 +629,8 @@ add_dependencies(buildtests_cxx error_details_test)
 add_dependencies(buildtests_cxx exception_test)
 add_dependencies(buildtests_cxx filter_end2end_test)
 add_dependencies(buildtests_cxx generic_end2end_test)
+add_dependencies(buildtests_cxx global_config_env_test)
+add_dependencies(buildtests_cxx global_config_test)
 add_dependencies(buildtests_cxx golden_file_test)
 add_dependencies(buildtests_cxx grpc_alts_credentials_options_test)
 add_dependencies(buildtests_cxx grpc_cli)
@@ -873,6 +875,7 @@ add_library(gpr
   src/core/lib/gpr/wrap_memcpy.cc
   src/core/lib/gprpp/arena.cc
   src/core/lib/gprpp/fork.cc
+  src/core/lib/gprpp/global_config_env.cc
   src/core/lib/gprpp/thd_posix.cc
   src/core/lib/gprpp/thd_windows.cc
   src/core/lib/profiling/basic_timers.cc
@@ -1289,10 +1292,13 @@ add_library(grpc
   src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -2682,10 +2688,13 @@ add_library(grpc_unsecure
   src/core/ext/transport/inproc/inproc_transport.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -2896,6 +2905,49 @@ target_link_libraries(test_tcp_server
 )
 
 
+endif (gRPC_BUILD_TESTS)
+if (gRPC_BUILD_TESTS)
+
+add_library(dns_test_util
+  test/cpp/naming/dns_test_util.cc
+)
+
+if(WIN32 AND MSVC)
+  set_target_properties(dns_test_util PROPERTIES COMPILE_PDB_NAME "dns_test_util"
+    COMPILE_PDB_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}"
+  )
+  if (gRPC_INSTALL)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/dns_test_util.pdb
+      DESTINATION ${gRPC_INSTALL_LIBDIR} OPTIONAL
+    )
+  endif()
+endif()
+
+
+target_include_directories(dns_test_util
+  PUBLIC $<INSTALL_INTERFACE:${gRPC_INSTALL_INCLUDEDIR}> $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${_gRPC_SSL_INCLUDE_DIR}
+  PRIVATE ${_gRPC_PROTOBUF_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ZLIB_INCLUDE_DIR}
+  PRIVATE ${_gRPC_BENCHMARK_INCLUDE_DIR}
+  PRIVATE ${_gRPC_CARES_INCLUDE_DIR}
+  PRIVATE ${_gRPC_GFLAGS_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
+  PRIVATE ${_gRPC_NANOPB_INCLUDE_DIR}
+  PRIVATE third_party/googletest/googletest/include
+  PRIVATE third_party/googletest/googletest
+  PRIVATE third_party/googletest/googlemock/include
+  PRIVATE third_party/googletest/googlemock
+  PRIVATE ${_gRPC_PROTO_GENS_DIR}
+)
+target_link_libraries(dns_test_util
+  ${_gRPC_PROTOBUF_LIBRARIES}
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  ${_gRPC_GFLAGS_LIBRARIES}
+)
+
+
 endif (gRPC_BUILD_TESTS)
 
 add_library(grpc++
@@ -13439,6 +13491,80 @@ target_link_libraries(generic_end2end_test
 )
 
 
+endif (gRPC_BUILD_TESTS)
+if (gRPC_BUILD_TESTS)
+
+add_executable(global_config_env_test
+  test/core/gprpp/global_config_env_test.cc
+  third_party/googletest/googletest/src/gtest-all.cc
+  third_party/googletest/googlemock/src/gmock-all.cc
+)
+
+
+target_include_directories(global_config_env_test
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${_gRPC_SSL_INCLUDE_DIR}
+  PRIVATE ${_gRPC_PROTOBUF_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ZLIB_INCLUDE_DIR}
+  PRIVATE ${_gRPC_BENCHMARK_INCLUDE_DIR}
+  PRIVATE ${_gRPC_CARES_INCLUDE_DIR}
+  PRIVATE ${_gRPC_GFLAGS_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
+  PRIVATE ${_gRPC_NANOPB_INCLUDE_DIR}
+  PRIVATE third_party/googletest/googletest/include
+  PRIVATE third_party/googletest/googletest
+  PRIVATE third_party/googletest/googlemock/include
+  PRIVATE third_party/googletest/googlemock
+  PRIVATE ${_gRPC_PROTO_GENS_DIR}
+)
+
+target_link_libraries(global_config_env_test
+  ${_gRPC_PROTOBUF_LIBRARIES}
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  gpr
+  grpc_test_util_unsecure
+  ${_gRPC_GFLAGS_LIBRARIES}
+)
+
+
+endif (gRPC_BUILD_TESTS)
+if (gRPC_BUILD_TESTS)
+
+add_executable(global_config_test
+  test/core/gprpp/global_config_test.cc
+  third_party/googletest/googletest/src/gtest-all.cc
+  third_party/googletest/googlemock/src/gmock-all.cc
+)
+
+
+target_include_directories(global_config_test
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${_gRPC_SSL_INCLUDE_DIR}
+  PRIVATE ${_gRPC_PROTOBUF_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ZLIB_INCLUDE_DIR}
+  PRIVATE ${_gRPC_BENCHMARK_INCLUDE_DIR}
+  PRIVATE ${_gRPC_CARES_INCLUDE_DIR}
+  PRIVATE ${_gRPC_GFLAGS_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
+  PRIVATE ${_gRPC_NANOPB_INCLUDE_DIR}
+  PRIVATE third_party/googletest/googletest/include
+  PRIVATE third_party/googletest/googletest
+  PRIVATE third_party/googletest/googlemock/include
+  PRIVATE third_party/googletest/googlemock
+  PRIVATE ${_gRPC_PROTO_GENS_DIR}
+)
+
+target_link_libraries(global_config_test
+  ${_gRPC_PROTOBUF_LIBRARIES}
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  gpr
+  grpc_test_util_unsecure
+  ${_gRPC_GFLAGS_LIBRARIES}
+)
+
+
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 
@@ -18415,6 +18541,7 @@ target_include_directories(resolver_component_test_unsecure
 target_link_libraries(resolver_component_test_unsecure
   ${_gRPC_PROTOBUF_LIBRARIES}
   ${_gRPC_ALLTARGETS_LIBRARIES}
+  dns_test_util
   grpc++_test_util_unsecure
   grpc_test_util_unsecure
   grpc++_unsecure
@@ -18456,6 +18583,7 @@ target_include_directories(resolver_component_test
 target_link_libraries(resolver_component_test
   ${_gRPC_PROTOBUF_LIBRARIES}
   ${_gRPC_ALLTARGETS_LIBRARIES}
+  dns_test_util
   grpc++_test_util
   grpc_test_util
   grpc++
@@ -18665,6 +18793,7 @@ target_include_directories(cancel_ares_query_test
 target_link_libraries(cancel_ares_query_test
   ${_gRPC_PROTOBUF_LIBRARIES}
   ${_gRPC_ALLTARGETS_LIBRARIES}
+  dns_test_util
   grpc++_test_util
   grpc_test_util
   grpc++

Makefile

@@ -1206,6 +1206,8 @@ error_details_test: $(BINDIR)/$(CONFIG)/error_details_test
 exception_test: $(BINDIR)/$(CONFIG)/exception_test
 filter_end2end_test: $(BINDIR)/$(CONFIG)/filter_end2end_test
 generic_end2end_test: $(BINDIR)/$(CONFIG)/generic_end2end_test
+global_config_env_test: $(BINDIR)/$(CONFIG)/global_config_env_test
+global_config_test: $(BINDIR)/$(CONFIG)/global_config_test
 golden_file_test: $(BINDIR)/$(CONFIG)/golden_file_test
 grpc_alts_credentials_options_test: $(BINDIR)/$(CONFIG)/grpc_alts_credentials_options_test
 grpc_cli: $(BINDIR)/$(CONFIG)/grpc_cli
@@ -1409,9 +1411,9 @@ pc_cxx: $(LIBDIR)/$(CONFIG)/pkgconfig/grpc++.pc
 pc_cxx_unsecure: $(LIBDIR)/$(CONFIG)/pkgconfig/grpc++_unsecure.pc
 
 ifeq ($(EMBED_OPENSSL),true)
-privatelibs_cxx:  $(LIBDIR)/$(CONFIG)/libgrpc++_core_stats.a $(LIBDIR)/$(CONFIG)/libgrpc++_proto_reflection_desc_db.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_cli_libs.a $(LIBDIR)/$(CONFIG)/libhttp2_client_main.a $(LIBDIR)/$(CONFIG)/libinterop_client_helper.a $(LIBDIR)/$(CONFIG)/libinterop_client_main.a $(LIBDIR)/$(CONFIG)/libinterop_server_helper.a $(LIBDIR)/$(CONFIG)/libinterop_server_lib.a $(LIBDIR)/$(CONFIG)/libinterop_server_main.a $(LIBDIR)/$(CONFIG)/libqps.a $(LIBDIR)/$(CONFIG)/libboringssl_test_util.a $(LIBDIR)/$(CONFIG)/libbenchmark.a
+privatelibs_cxx:  $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_core_stats.a $(LIBDIR)/$(CONFIG)/libgrpc++_proto_reflection_desc_db.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_cli_libs.a $(LIBDIR)/$(CONFIG)/libhttp2_client_main.a $(LIBDIR)/$(CONFIG)/libinterop_client_helper.a $(LIBDIR)/$(CONFIG)/libinterop_client_main.a $(LIBDIR)/$(CONFIG)/libinterop_server_helper.a $(LIBDIR)/$(CONFIG)/libinterop_server_lib.a $(LIBDIR)/$(CONFIG)/libinterop_server_main.a $(LIBDIR)/$(CONFIG)/libqps.a $(LIBDIR)/$(CONFIG)/libboringssl_test_util.a $(LIBDIR)/$(CONFIG)/libbenchmark.a
 else
-privatelibs_cxx:  $(LIBDIR)/$(CONFIG)/libgrpc++_core_stats.a $(LIBDIR)/$(CONFIG)/libgrpc++_proto_reflection_desc_db.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_cli_libs.a $(LIBDIR)/$(CONFIG)/libhttp2_client_main.a $(LIBDIR)/$(CONFIG)/libinterop_client_helper.a $(LIBDIR)/$(CONFIG)/libinterop_client_main.a $(LIBDIR)/$(CONFIG)/libinterop_server_helper.a $(LIBDIR)/$(CONFIG)/libinterop_server_lib.a $(LIBDIR)/$(CONFIG)/libinterop_server_main.a $(LIBDIR)/$(CONFIG)/libqps.a $(LIBDIR)/$(CONFIG)/libbenchmark.a
+privatelibs_cxx:  $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_core_stats.a $(LIBDIR)/$(CONFIG)/libgrpc++_proto_reflection_desc_db.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_cli_libs.a $(LIBDIR)/$(CONFIG)/libhttp2_client_main.a $(LIBDIR)/$(CONFIG)/libinterop_client_helper.a $(LIBDIR)/$(CONFIG)/libinterop_client_main.a $(LIBDIR)/$(CONFIG)/libinterop_server_helper.a $(LIBDIR)/$(CONFIG)/libinterop_server_lib.a $(LIBDIR)/$(CONFIG)/libinterop_server_main.a $(LIBDIR)/$(CONFIG)/libqps.a $(LIBDIR)/$(CONFIG)/libbenchmark.a
 endif
 
 
@@ -1682,6 +1684,8 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/exception_test \
   $(BINDIR)/$(CONFIG)/filter_end2end_test \
   $(BINDIR)/$(CONFIG)/generic_end2end_test \
+  $(BINDIR)/$(CONFIG)/global_config_env_test \
+  $(BINDIR)/$(CONFIG)/global_config_test \
   $(BINDIR)/$(CONFIG)/golden_file_test \
   $(BINDIR)/$(CONFIG)/grpc_alts_credentials_options_test \
   $(BINDIR)/$(CONFIG)/grpc_cli \
@@ -1826,6 +1830,8 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/exception_test \
   $(BINDIR)/$(CONFIG)/filter_end2end_test \
   $(BINDIR)/$(CONFIG)/generic_end2end_test \
+  $(BINDIR)/$(CONFIG)/global_config_env_test \
+  $(BINDIR)/$(CONFIG)/global_config_test \
   $(BINDIR)/$(CONFIG)/golden_file_test \
   $(BINDIR)/$(CONFIG)/grpc_alts_credentials_options_test \
   $(BINDIR)/$(CONFIG)/grpc_cli \
@@ -2318,6 +2324,10 @@ test_cxx: buildtests_cxx
 	$(Q) $(BINDIR)/$(CONFIG)/filter_end2end_test || ( echo test filter_end2end_test failed ; exit 1 )
 	$(E) "[RUN]     Testing generic_end2end_test"
 	$(Q) $(BINDIR)/$(CONFIG)/generic_end2end_test || ( echo test generic_end2end_test failed ; exit 1 )
+	$(E) "[RUN]     Testing global_config_env_test"
+	$(Q) $(BINDIR)/$(CONFIG)/global_config_env_test || ( echo test global_config_env_test failed ; exit 1 )
+	$(E) "[RUN]     Testing global_config_test"
+	$(Q) $(BINDIR)/$(CONFIG)/global_config_test || ( echo test global_config_test failed ; exit 1 )
 	$(E) "[RUN]     Testing golden_file_test"
 	$(Q) $(BINDIR)/$(CONFIG)/golden_file_test || ( echo test golden_file_test failed ; exit 1 )
 	$(E) "[RUN]     Testing grpc_alts_credentials_options_test"
@@ -3354,6 +3364,7 @@ LIBGPR_SRC = \
     src/core/lib/gpr/wrap_memcpy.cc \
     src/core/lib/gprpp/arena.cc \
     src/core/lib/gprpp/fork.cc \
+    src/core/lib/gprpp/global_config_env.cc \
     src/core/lib/gprpp/thd_posix.cc \
     src/core/lib/gprpp/thd_windows.cc \
     src/core/lib/profiling/basic_timers.cc \
@@ -3749,10 +3760,13 @@ LIBGRPC_SRC = \
     src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
@@ -5090,10 +5104,13 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/ext/transport/inproc/inproc_transport.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
@@ -5273,6 +5290,55 @@ endif
 endif
 
 
+LIBDNS_TEST_UTIL_SRC = \
+    test/cpp/naming/dns_test_util.cc \
+
+PUBLIC_HEADERS_CXX += \
+
+LIBDNS_TEST_UTIL_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(LIBDNS_TEST_UTIL_SRC))))
+
+
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure libraries if you don't have OpenSSL.
+
+$(LIBDIR)/$(CONFIG)/libdns_test_util.a: openssl_dep_error
+
+
+else
+
+ifeq ($(NO_PROTOBUF),true)
+
+# You can't build a C++ library if you don't have protobuf - a bit overreached, but still okay.
+
+$(LIBDIR)/$(CONFIG)/libdns_test_util.a: protobuf_dep_error
+
+
+else
+
+$(LIBDIR)/$(CONFIG)/libdns_test_util.a: $(ZLIB_DEP) $(OPENSSL_DEP) $(CARES_DEP) $(ADDRESS_SORTING_DEP) $(PROTOBUF_DEP) $(LIBDNS_TEST_UTIL_OBJS) 
+	$(E) "[AR]      Creating $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) rm -f $(LIBDIR)/$(CONFIG)/libdns_test_util.a
+	$(Q) $(AR) $(AROPTS) $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDNS_TEST_UTIL_OBJS) 
+ifeq ($(SYSTEM),Darwin)
+	$(Q) ranlib -no_warning_for_no_symbols $(LIBDIR)/$(CONFIG)/libdns_test_util.a
+endif
+
+
+
+
+endif
+
+endif
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(LIBDNS_TEST_UTIL_OBJS:.o=.dep)
+endif
+endif
+
+
 LIBGRPC++_SRC = \
     src/cpp/client/insecure_credentials.cc \
     src/cpp/client/secure_credentials.cc \
@@ -16407,6 +16473,92 @@ endif
 endif
 
 
+GLOBAL_CONFIG_ENV_TEST_SRC = \
+    test/core/gprpp/global_config_env_test.cc \
+
+GLOBAL_CONFIG_ENV_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(GLOBAL_CONFIG_ENV_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/global_config_env_test: openssl_dep_error
+
+else
+
+
+
+
+ifeq ($(NO_PROTOBUF),true)
+
+# You can't build the protoc plugins or protobuf-enabled targets if you don't have protobuf 3.5.0+.
+
+$(BINDIR)/$(CONFIG)/global_config_env_test: protobuf_dep_error
+
+else
+
+$(BINDIR)/$(CONFIG)/global_config_env_test: $(PROTOBUF_DEP) $(GLOBAL_CONFIG_ENV_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LDXX) $(LDFLAGS) $(GLOBAL_CONFIG_ENV_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/global_config_env_test
+
+endif
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/gprpp/global_config_env_test.o:  $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a
+
+deps_global_config_env_test: $(GLOBAL_CONFIG_ENV_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(GLOBAL_CONFIG_ENV_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
+GLOBAL_CONFIG_TEST_SRC = \
+    test/core/gprpp/global_config_test.cc \
+
+GLOBAL_CONFIG_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(GLOBAL_CONFIG_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/global_config_test: openssl_dep_error
+
+else
+
+
+
+
+ifeq ($(NO_PROTOBUF),true)
+
+# You can't build the protoc plugins or protobuf-enabled targets if you don't have protobuf 3.5.0+.
+
+$(BINDIR)/$(CONFIG)/global_config_test: protobuf_dep_error
+
+else
+
+$(BINDIR)/$(CONFIG)/global_config_test: $(PROTOBUF_DEP) $(GLOBAL_CONFIG_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LDXX) $(LDFLAGS) $(GLOBAL_CONFIG_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/global_config_test
+
+endif
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/gprpp/global_config_test.o:  $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a
+
+deps_global_config_test: $(GLOBAL_CONFIG_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(GLOBAL_CONFIG_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 GOLDEN_FILE_TEST_SRC = \
     $(GENDIR)/src/proto/grpc/testing/compiler_test.pb.cc $(GENDIR)/src/proto/grpc/testing/compiler_test.grpc.pb.cc \
     test/cpp/codegen/golden_file_test.cc \
@@ -21188,16 +21340,16 @@ $(BINDIR)/$(CONFIG)/resolver_component_test_unsecure: protobuf_dep_error
 
 else
 
-$(BINDIR)/$(CONFIG)/resolver_component_test_unsecure: $(PROTOBUF_DEP) $(RESOLVER_COMPONENT_TEST_UNSECURE_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
+$(BINDIR)/$(CONFIG)/resolver_component_test_unsecure: $(PROTOBUF_DEP) $(RESOLVER_COMPONENT_TEST_UNSECURE_OBJS) $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LDXX) $(LDFLAGS) $(RESOLVER_COMPONENT_TEST_UNSECURE_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/resolver_component_test_unsecure
+	$(Q) $(LDXX) $(LDFLAGS) $(RESOLVER_COMPONENT_TEST_UNSECURE_OBJS) $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/resolver_component_test_unsecure
 
 endif
 
 endif
 
-$(OBJDIR)/$(CONFIG)/test/cpp/naming/resolver_component_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
+$(OBJDIR)/$(CONFIG)/test/cpp/naming/resolver_component_test.o:  $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpc_unsecure.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
 
 deps_resolver_component_test_unsecure: $(RESOLVER_COMPONENT_TEST_UNSECURE_OBJS:.o=.dep)
 
@@ -21231,16 +21383,16 @@ $(BINDIR)/$(CONFIG)/resolver_component_test: protobuf_dep_error
 
 else
 
-$(BINDIR)/$(CONFIG)/resolver_component_test: $(PROTOBUF_DEP) $(RESOLVER_COMPONENT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
+$(BINDIR)/$(CONFIG)/resolver_component_test: $(PROTOBUF_DEP) $(RESOLVER_COMPONENT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LDXX) $(LDFLAGS) $(RESOLVER_COMPONENT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/resolver_component_test
+	$(Q) $(LDXX) $(LDFLAGS) $(RESOLVER_COMPONENT_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/resolver_component_test
 
 endif
 
 endif
 
-$(OBJDIR)/$(CONFIG)/test/cpp/naming/resolver_component_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
+$(OBJDIR)/$(CONFIG)/test/cpp/naming/resolver_component_test.o:  $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
 
 deps_resolver_component_test: $(RESOLVER_COMPONENT_TEST_OBJS:.o=.dep)
 
@@ -21446,16 +21598,16 @@ $(BINDIR)/$(CONFIG)/cancel_ares_query_test: protobuf_dep_error
 
 else
 
-$(BINDIR)/$(CONFIG)/cancel_ares_query_test: $(PROTOBUF_DEP) $(CANCEL_ARES_QUERY_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
+$(BINDIR)/$(CONFIG)/cancel_ares_query_test: $(PROTOBUF_DEP) $(CANCEL_ARES_QUERY_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
 	$(E) "[LD]      Linking $@"
 	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LDXX) $(LDFLAGS) $(CANCEL_ARES_QUERY_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/cancel_ares_query_test
+	$(Q) $(LDXX) $(LDFLAGS) $(CANCEL_ARES_QUERY_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/cancel_ares_query_test
 
 endif
 
 endif
 
-$(OBJDIR)/$(CONFIG)/test/cpp/naming/cancel_ares_query_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
+$(OBJDIR)/$(CONFIG)/test/cpp/naming/cancel_ares_query_test.o:  $(LIBDIR)/$(CONFIG)/libdns_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LIBDIR)/$(CONFIG)/libgrpc++_test_config.a
 
 deps_cancel_ares_query_test: $(CANCEL_ARES_QUERY_TEST_OBJS:.o=.dep)
 
@@ -22085,6 +22237,7 @@ test/cpp/interop/interop_server.cc: $(OPENSSL_DEP)
 test/cpp/interop/interop_server_bootstrap.cc: $(OPENSSL_DEP)
 test/cpp/interop/server_helper.cc: $(OPENSSL_DEP)
 test/cpp/microbenchmarks/helpers.cc: $(OPENSSL_DEP)
+test/cpp/naming/dns_test_util.cc: $(OPENSSL_DEP)
 test/cpp/qps/benchmark_config.cc: $(OPENSSL_DEP)
 test/cpp/qps/client_async.cc: $(OPENSSL_DEP)
 test/cpp/qps/client_callback.cc: $(OPENSSL_DEP)

WORKSPACE

@@ -18,13 +18,6 @@ register_toolchains(
     "//third_party/toolchains/bazel_0.23.2_rbe_windows:cc-toolchain-x64_windows",
 )
 
-# TODO(https://github.com/grpc/grpc/issues/18331): Move off of this dependency.
-git_repository(
-    name = "org_pubref_rules_protobuf",
-    remote = "https://github.com/ghostwriternr/rules_protobuf",
-    tag = "v0.8.2.1-alpha",
-)
-
 git_repository(
     name = "io_bazel_rules_python",
     commit = "8b5d0683a7d878b28fffe464779c8a53659fc645",

bazel/BUILD

@@ -17,15 +17,3 @@ licenses(["notice"])  # Apache v2
 package(default_visibility = ["//:__subpackages__"])
 
 load(":cc_grpc_library.bzl", "cc_grpc_library")
-
-proto_library(
-    name = "well_known_protos_list",
-    srcs = ["@com_google_protobuf//:well_known_protos"],
-)
-
-cc_grpc_library(
-    name = "well_known_protos",
-    srcs = "well_known_protos_list",
-    proto_only = True,
-    deps = [],
-)

bazel/cc_grpc_library.bzl

@@ -1,71 +1,105 @@
 """Generates and compiles C++ grpc stubs from proto_library rules."""
 
 load("//bazel:generate_cc.bzl", "generate_cc")
+load("//bazel:protobuf.bzl", "well_known_proto_libs")
 
-def cc_grpc_library(name, srcs, deps, proto_only, well_known_protos, generate_mocks = False, use_external = False, **kwargs):
-  """Generates C++ grpc classes from a .proto file.
+def cc_grpc_library(
+        name,
+        srcs,
+        deps,
+        proto_only = False,
+        well_known_protos = False,
+        generate_mocks = False,
+        use_external = False,
+        grpc_only = False,
+        **kwargs):
+    """Generates C++ grpc classes for services defined in a proto file.
 
-  Assumes the generated classes will be used in cc_api_version = 2.
+    If grpc_only is True, this rule is compatible with proto_library and
+    cc_proto_library native rules such that it expects proto_library target
+    as srcs argument and generates only grpc library classes, expecting
+    protobuf messages classes library (cc_proto_library target) to be passed in
+    deps argument. By default grpc_only is False which makes this rule to behave
+    in a backwards-compatible mode (trying to generate both proto and grpc
+    classes).
 
-  Arguments:
-      name: name of rule.
-      srcs: a single proto_library, which wraps the .proto files with services.
-      deps: a list of C++ proto_library (or cc_proto_library) which provides
-        the compiled code of any message that the services depend on.
-      well_known_protos: Should this library additionally depend on well known
-        protos
-      use_external: When True the grpc deps are prefixed with //external. This
-        allows grpc to be used as a dependency in other bazel projects.
-      generate_mocks: When True, Google Mock code for client stub is generated.
-      **kwargs: rest of arguments, e.g., compatible_with and visibility.
-  """
-  if len(srcs) > 1:
-    fail("Only one srcs value supported", "srcs")
+    Assumes the generated classes will be used in cc_api_version = 2.
 
-  proto_target = "_" + name + "_only"
-  codegen_target = "_" + name + "_codegen"
-  codegen_grpc_target = "_" + name + "_grpc_codegen"
-  proto_deps = ["_" + dep + "_only" for dep in deps if dep.find(':') == -1]
-  proto_deps += [dep.split(':')[0] + ':' + "_" + dep.split(':')[1] + "_only" for dep in deps if dep.find(':') != -1]
+    Args:
+        name (str): Name of rule.
+        srcs (list): A single .proto file which contains services definitions,
+          or if grpc_only parameter is True, a single proto_library which
+          contains services descriptors.
+        deps (list): A list of C++ proto_library (or cc_proto_library) which
+          provides the compiled code of any message that the services depend on.
+        proto_only (bool): If True, create only C++ proto classes library,
+          avoid creating C++ grpc classes library (expect it in deps).
+          Deprecated, use native cc_proto_library instead. False by default.
+        well_known_protos (bool): Should this library additionally depend on
+          well known protos. Deprecated, the well known protos should be
+          specified as explicit dependencies of the proto_library target
+          (passed in srcs parameter) instead. False by default.
+        generate_mocks (bool): when True, Google Mock code for client stub is
+          generated. False by default.
+        use_external (bool): Not used.
+        grpc_only (bool): if True, generate only grpc library, expecting
+          protobuf messages library (cc_proto_library target) to be passed as
+          deps. False by default (will become True by default eventually).
+        **kwargs: rest of arguments, e.g., compatible_with and visibility
+    """
+    if len(srcs) > 1:
+        fail("Only one srcs value supported", "srcs")
+    if grpc_only and proto_only:
+        fail("A mutualy exclusive configuration is specified: grpc_only = True and proto_only = True")
 
-  native.proto_library(
-      name = proto_target,
-      srcs = srcs,
-      deps = proto_deps,
-      **kwargs
-  )
+    extra_deps = []
+    proto_targets = []
 
-  generate_cc(
-      name = codegen_target,
-      srcs = [proto_target],
-      well_known_protos = well_known_protos,
-      **kwargs
-  )
+    if not grpc_only:
+        proto_target = "_" + name + "_only"
+        cc_proto_target = name if proto_only else "_" + name + "_cc_proto"
 
-  if not proto_only:
-    plugin = "@com_github_grpc_grpc//:grpc_cpp_plugin"
-    generate_cc(
-        name = codegen_grpc_target,
-        srcs = [proto_target],
-        plugin = plugin,
-        well_known_protos = well_known_protos,
-        generate_mocks = generate_mocks,
-        **kwargs
-    )
-    grpc_deps  = ["@com_github_grpc_grpc//:grpc++_codegen_proto",
-                  "//external:protobuf"]
-    native.cc_library(
-        name = name,
-        srcs = [":" + codegen_grpc_target, ":" + codegen_target],
-        hdrs = [":" + codegen_grpc_target, ":" + codegen_target],
-        deps = deps + grpc_deps,
-        **kwargs
-    )
-  else:
-    native.cc_library(
-        name = name,
-        srcs = [":" + codegen_target],
-        hdrs = [":" + codegen_target],
-        deps = deps + ["//external:protobuf"],
-        **kwargs
-    )
+        proto_deps = ["_" + dep + "_only" for dep in deps if dep.find(":") == -1]
+        proto_deps += [dep.split(":")[0] + ":" + "_" + dep.split(":")[1] + "_only" for dep in deps if dep.find(":") != -1]
+        if well_known_protos:
+            proto_deps += well_known_proto_libs()
+
+        native.proto_library(
+            name = proto_target,
+            srcs = srcs,
+            deps = proto_deps,
+            **kwargs
+        )
+
+        native.cc_proto_library(
+            name = cc_proto_target,
+            deps = [":" + proto_target],
+            **kwargs
+        )
+        extra_deps.append(":" + cc_proto_target)
+        proto_targets.append(proto_target)
+    else:
+        if not srcs:
+            fail("srcs cannot be empty", "srcs")
+        proto_targets += srcs
+
+    if not proto_only:
+        codegen_grpc_target = "_" + name + "_grpc_codegen"
+        generate_cc(
+            name = codegen_grpc_target,
+            srcs = proto_targets,
+            plugin = "@com_github_grpc_grpc//:grpc_cpp_plugin",
+            well_known_protos = well_known_protos,
+            generate_mocks = generate_mocks,
+            **kwargs
+        )
+
+        native.cc_library(
+            name = name,
+            srcs = [":" + codegen_grpc_target],
+            hdrs = [":" + codegen_grpc_target],
+            deps = deps +
+                   extra_deps +
+                   ["@com_github_grpc_grpc//:grpc++_codegen_proto"],
+            **kwargs
+        )

bazel/generate_cc.bzl

@@ -4,81 +4,142 @@ This is an internal rule used by cc_grpc_library, and shouldn't be used
 directly.
 """
 
+load(
+    "//bazel:protobuf.bzl",
+    "get_include_protoc_args",
+    "get_plugin_args",
+    "get_proto_root",
+    "proto_path_to_generated_filename",
+)
+
+_GRPC_PROTO_HEADER_FMT = "{}.grpc.pb.h"
+_GRPC_PROTO_SRC_FMT = "{}.grpc.pb.cc"
+_GRPC_PROTO_MOCK_HEADER_FMT = "{}_mock.grpc.pb.h"
+_PROTO_HEADER_FMT = "{}.pb.h"
+_PROTO_SRC_FMT = "{}.pb.cc"
+
+def _strip_package_from_path(label_package, file):
+    prefix_len = 0
+    if not file.is_source and file.path.startswith(file.root.path):
+        prefix_len = len(file.root.path) + 1
+
+    path = file.path
+    if len(label_package) == 0:
+        return path
+    if not path.startswith(label_package + "/", prefix_len):
+        fail("'{}' does not lie within '{}'.".format(path, label_package))
+    return path[prefix_len + len(label_package + "/"):]
+
+def _get_srcs_file_path(file):
+    if not file.is_source and file.path.startswith(file.root.path):
+        return file.path[len(file.root.path) + 1:]
+    return file.path
+
+def _join_directories(directories):
+    massaged_directories = [directory for directory in directories if len(directory) != 0]
+    return "/".join(massaged_directories)
+
 def generate_cc_impl(ctx):
-  """Implementation of the generate_cc rule."""
-  protos = [f for src in ctx.attr.srcs for f in src.proto.direct_sources]
-  includes = [f for src in ctx.attr.srcs for f in src.proto.transitive_imports]
-  outs = []
-  # label_len is length of the path from WORKSPACE root to the location of this build file
-  label_len = 0
-  # proto_root is the directory relative to which generated include paths should be
-  proto_root = ""
-  if ctx.label.package:
-    # The +1 is for the trailing slash.
-    label_len += len(ctx.label.package) + 1
-  if ctx.label.workspace_root:
-    label_len += len(ctx.label.workspace_root) + 1
-    proto_root = "/" + ctx.label.workspace_root
-
-  if ctx.executable.plugin:
-    outs += [proto.path[label_len:-len(".proto")] + ".grpc.pb.h" for proto in protos]
-    outs += [proto.path[label_len:-len(".proto")] + ".grpc.pb.cc" for proto in protos]
-    if ctx.attr.generate_mocks:
-      outs += [proto.path[label_len:-len(".proto")] + "_mock.grpc.pb.h" for proto in protos]
-  else:
-    outs += [proto.path[label_len:-len(".proto")] + ".pb.h" for proto in protos]
-    outs += [proto.path[label_len:-len(".proto")] + ".pb.cc" for proto in protos]
-  out_files = [ctx.actions.declare_file(out) for out in outs]
-  dir_out = str(ctx.genfiles_dir.path + proto_root)
-
-  arguments = []
-  if ctx.executable.plugin:
-    arguments += ["--plugin=protoc-gen-PLUGIN=" + ctx.executable.plugin.path]
-    flags = list(ctx.attr.flags)
-    if ctx.attr.generate_mocks:
-      flags.append("generate_mock_code=true")
-    arguments += ["--PLUGIN_out=" + ",".join(flags) + ":" + dir_out]
-    tools = [ctx.executable.plugin]
-  else:
-    arguments += ["--cpp_out=" + ",".join(ctx.attr.flags) + ":" + dir_out]
-    tools = []
-
-  # Import protos relative to their workspace root so that protoc prints the
-  # right include paths.
-  for include in includes:
-    directory = include.path
-    if directory.startswith("external"):
-      external_sep = directory.find("/")
-      repository_sep = directory.find("/", external_sep + 1)
-      arguments += ["--proto_path=" + directory[:repository_sep]]
+    """Implementation of the generate_cc rule."""
+    protos = [f for src in ctx.attr.srcs for f in src.proto.check_deps_sources]
+    includes = [
+        f
+        for src in ctx.attr.srcs
+        for f in src.proto.transitive_imports
+    ]
+    outs = []
+    proto_root = get_proto_root(
+        ctx.label.workspace_root,
+    )
+
+    label_package = _join_directories([ctx.label.workspace_root, ctx.label.package])
+    if ctx.executable.plugin:
+        outs += [
+            proto_path_to_generated_filename(
+                _strip_package_from_path(label_package, proto),
+                _GRPC_PROTO_HEADER_FMT,
+            )
+            for proto in protos
+        ]
+        outs += [
+            proto_path_to_generated_filename(
+                _strip_package_from_path(label_package, proto),
+                _GRPC_PROTO_SRC_FMT,
+            )
+            for proto in protos
+        ]
+        if ctx.attr.generate_mocks:
+            outs += [
+                proto_path_to_generated_filename(
+                    _strip_package_from_path(label_package, proto),
+                    _GRPC_PROTO_MOCK_HEADER_FMT,
+                )
+                for proto in protos
+            ]
     else:
-      arguments += ["--proto_path=."]
-  # Include the output directory so that protoc puts the generated code in the
-  # right directory.
-  arguments += ["--proto_path={0}{1}".format(dir_out, proto_root)]
-  arguments += [proto.path for proto in protos]
-
-  # create a list of well known proto files if the argument is non-None
-  well_known_proto_files = []
-  if ctx.attr.well_known_protos:
-    f = ctx.attr.well_known_protos.files.to_list()[0].dirname
-    if f != "external/com_google_protobuf/src/google/protobuf":
-      print("Error: Only @com_google_protobuf//:well_known_protos is supported")
+        outs += [
+            proto_path_to_generated_filename(
+                _strip_package_from_path(label_package, proto),
+                _PROTO_HEADER_FMT,
+            )
+            for proto in protos
+        ]
+        outs += [
+            proto_path_to_generated_filename(
+                _strip_package_from_path(label_package, proto),
+                _PROTO_SRC_FMT,
+            )
+            for proto in protos
+        ]
+    out_files = [ctx.actions.declare_file(out) for out in outs]
+    dir_out = str(ctx.genfiles_dir.path + proto_root)
+
+    arguments = []
+    if ctx.executable.plugin:
+        arguments += get_plugin_args(
+            ctx.executable.plugin,
+            ctx.attr.flags,
+            dir_out,
+            ctx.attr.generate_mocks,
+        )
+        tools = [ctx.executable.plugin]
     else:
-      # f points to "external/com_google_protobuf/src/google/protobuf"
-      # add -I argument to protoc so it knows where to look for the proto files.
-      arguments += ["-I{0}".format(f + "/../..")]
-      well_known_proto_files = [f for f in ctx.attr.well_known_protos.files]
+        arguments += ["--cpp_out=" + ",".join(ctx.attr.flags) + ":" + dir_out]
+        tools = []
+
+    arguments += get_include_protoc_args(includes)
+
+    # Include the output directory so that protoc puts the generated code in the
+    # right directory.
+    arguments += ["--proto_path={0}{1}".format(dir_out, proto_root)]
+    arguments += [_get_srcs_file_path(proto) for proto in protos]
+
+    # create a list of well known proto files if the argument is non-None
+    well_known_proto_files = []
+    if ctx.attr.well_known_protos:
+        f = ctx.attr.well_known_protos.files.to_list()[0].dirname
+        if f != "external/com_google_protobuf/src/google/protobuf":
+            print(
+                "Error: Only @com_google_protobuf//:well_known_protos is supported",
+            )
+        else:
+            # f points to "external/com_google_protobuf/src/google/protobuf"
+            # add -I argument to protoc so it knows where to look for the proto files.
+            arguments += ["-I{0}".format(f + "/../..")]
+            well_known_proto_files = [
+                f
+                for f in ctx.attr.well_known_protos.files
+            ]
 
-  ctx.actions.run(
-      inputs = protos + includes + well_known_proto_files,
-      tools = tools,
-      outputs = out_files,
-      executable = ctx.executable._protoc,
-      arguments = arguments,
-  )
+    ctx.actions.run(
+        inputs = protos + includes + well_known_proto_files,
+        tools = tools,
+        outputs = out_files,
+        executable = ctx.executable._protoc,
+        arguments = arguments,
+    )
 
-  return struct(files=depset(out_files))
+    return struct(files = depset(out_files))
 
 _generate_cc = rule(
     attrs = {
@@ -96,10 +157,8 @@ _generate_cc = rule(
             mandatory = False,
             allow_empty = True,
         ),
-        "well_known_protos" : attr.label(
-            mandatory = False,
-        ),
-        "generate_mocks" : attr.bool(
+        "well_known_protos": attr.label(mandatory = False),
+        "generate_mocks": attr.bool(
             default = False,
             mandatory = False,
         ),
@@ -115,7 +174,10 @@ _generate_cc = rule(
 )
 
 def generate_cc(well_known_protos, **kwargs):
-  if well_known_protos:
-    _generate_cc(well_known_protos="@com_google_protobuf//:well_known_protos", **kwargs)
-  else:
-    _generate_cc(**kwargs)
+    if well_known_protos:
+        _generate_cc(
+            well_known_protos = "@com_google_protobuf//:well_known_protos",
+            **kwargs
+        )
+    else:
+        _generate_cc(**kwargs)

bazel/grpc_python_deps.bzl

@@ -1,16 +1,8 @@
 load("//third_party/py:python_configure.bzl", "python_configure")
 load("@io_bazel_rules_python//python:pip.bzl", "pip_repositories")
 load("@grpc_python_dependencies//:requirements.bzl", "pip_install")
-load("@org_pubref_rules_protobuf//python:rules.bzl", "py_proto_repositories")
 
 def grpc_python_deps():
-    # TODO(https://github.com/grpc/grpc/issues/18256): Remove conditional.
-    if hasattr(native, "http_archive"):
-        python_configure(name = "local_config_python")
-        pip_repositories()
-        pip_install()
-        py_proto_repositories()
-    else:
-        print("Building Python gRPC with bazel 23.0+ is disabled pending " +
-              "resolution of https://github.com/grpc/grpc/issues/18256.")
-
+    python_configure(name = "local_config_python")
+    pip_repositories()
+    pip_install()

bazel/protobuf.bzl

@@ -0,0 +1,104 @@
+"""Utility functions for generating protobuf code."""
+
+_PROTO_EXTENSION = ".proto"
+
+def well_known_proto_libs():
+    return [
+        "@com_google_protobuf//:any_proto",
+        "@com_google_protobuf//:api_proto",
+        "@com_google_protobuf//:compiler_plugin_proto",
+        "@com_google_protobuf//:descriptor_proto",
+        "@com_google_protobuf//:duration_proto",
+        "@com_google_protobuf//:empty_proto",
+        "@com_google_protobuf//:field_mask_proto",
+        "@com_google_protobuf//:source_context_proto",
+        "@com_google_protobuf//:struct_proto",
+        "@com_google_protobuf//:timestamp_proto",
+        "@com_google_protobuf//:type_proto",
+        "@com_google_protobuf//:wrappers_proto",
+    ]
+
+def get_proto_root(workspace_root):
+    """Gets the root protobuf directory.
+
+    Args:
+      workspace_root: context.label.workspace_root
+
+    Returns:
+      The directory relative to which generated include paths should be.
+    """
+    if workspace_root:
+        return "/{}".format(workspace_root)
+    else:
+        return ""
+
+def _strip_proto_extension(proto_filename):
+    if not proto_filename.endswith(_PROTO_EXTENSION):
+        fail('"{}" does not end with "{}"'.format(
+            proto_filename,
+            _PROTO_EXTENSION,
+        ))
+    return proto_filename[:-len(_PROTO_EXTENSION)]
+
+def proto_path_to_generated_filename(proto_path, fmt_str):
+    """Calculates the name of a generated file for a protobuf path.
+
+    For example, "examples/protos/helloworld.proto" might map to
+      "helloworld.pb.h".
+
+    Args:
+      proto_path: The path to the .proto file.
+      fmt_str: A format string used to calculate the generated filename. For
+        example, "{}.pb.h" might be used to calculate a C++ header filename.
+
+    Returns:
+      The generated filename.
+    """
+    return fmt_str.format(_strip_proto_extension(proto_path))
+
+def _get_include_directory(include):
+    directory = include.path
+    prefix_len = 0
+    if not include.is_source and directory.startswith(include.root.path):
+        prefix_len = len(include.root.path) + 1
+
+    if directory.startswith("external", prefix_len):
+        external_separator = directory.find("/", prefix_len)
+        repository_separator = directory.find("/", external_separator + 1)
+        return directory[:repository_separator]
+    else:
+        return include.root.path if include.root.path else "."
+
+def get_include_protoc_args(includes):
+    """Returns protoc args that imports protos relative to their import root.
+
+    Args:
+      includes: A list of included proto files.
+
+    Returns:
+      A list of arguments to be passed to protoc. For example, ["--proto_path=."].
+    """
+    return [
+        "--proto_path={}".format(_get_include_directory(include))
+        for include in includes
+    ]
+
+def get_plugin_args(plugin, flags, dir_out, generate_mocks):
+    """Returns arguments configuring protoc to use a plugin for a language.
+
+    Args:
+      plugin: An executable file to run as the protoc plugin.
+      flags: The plugin flags to be passed to protoc.
+      dir_out: The output directory for the plugin.
+      generate_mocks: A bool indicating whether to generate mocks.
+
+    Returns:
+      A list of protoc arguments configuring the plugin.
+    """
+    augmented_flags = list(flags)
+    if generate_mocks:
+        augmented_flags.append("generate_mock_code=true")
+    return [
+        "--plugin=protoc-gen-PLUGIN=" + plugin.path,
+        "--PLUGIN_out=" + ",".join(augmented_flags) + ":" + dir_out,
+    ]

bazel/python_rules.bzl

@@ -0,0 +1,186 @@
+"""Generates and compiles Python gRPC stubs from proto_library rules."""
+
+load("@grpc_python_dependencies//:requirements.bzl", "requirement")
+load(
+    "//bazel:protobuf.bzl",
+    "get_include_protoc_args",
+    "get_plugin_args",
+    "get_proto_root",
+    "proto_path_to_generated_filename",
+)
+
+_GENERATED_PROTO_FORMAT = "{}_pb2.py"
+_GENERATED_GRPC_PROTO_FORMAT = "{}_pb2_grpc.py"
+
+def _get_staged_proto_file(context, source_file):
+    if source_file.dirname == context.label.package:
+        return source_file
+    else:
+        copied_proto = context.actions.declare_file(source_file.basename)
+        context.actions.run_shell(
+            inputs = [source_file],
+            outputs = [copied_proto],
+            command = "cp {} {}".format(source_file.path, copied_proto.path),
+            mnemonic = "CopySourceProto",
+        )
+        return copied_proto
+
+def _generate_py_impl(context):
+    protos = []
+    for src in context.attr.deps:
+        for file in src.proto.direct_sources:
+            protos.append(_get_staged_proto_file(context, file))
+    includes = [
+        file
+        for src in context.attr.deps
+        for file in src.proto.transitive_imports
+    ]
+    proto_root = get_proto_root(context.label.workspace_root)
+    format_str = (_GENERATED_GRPC_PROTO_FORMAT if context.executable.plugin else _GENERATED_PROTO_FORMAT)
+    out_files = [
+        context.actions.declare_file(
+            proto_path_to_generated_filename(
+                proto.basename,
+                format_str,
+            ),
+        )
+        for proto in protos
+    ]
+
+    arguments = []
+    tools = [context.executable._protoc]
+    if context.executable.plugin:
+        arguments += get_plugin_args(
+            context.executable.plugin,
+            context.attr.flags,
+            context.genfiles_dir.path,
+            False,
+        )
+        tools += [context.executable.plugin]
+    else:
+        arguments += [
+            "--python_out={}:{}".format(
+                ",".join(context.attr.flags),
+                context.genfiles_dir.path,
+            ),
+        ]
+
+    arguments += get_include_protoc_args(includes)
+    arguments += [
+        "--proto_path={}".format(context.genfiles_dir.path)
+        for proto in protos
+    ]
+    for proto in protos:
+        massaged_path = proto.path
+        if massaged_path.startswith(context.genfiles_dir.path):
+            massaged_path = proto.path[len(context.genfiles_dir.path) + 1:]
+        arguments.append(massaged_path)
+
+    well_known_proto_files = []
+    if context.attr.well_known_protos:
+        well_known_proto_directory = context.attr.well_known_protos.files.to_list(
+        )[0].dirname
+
+        arguments += ["-I{}".format(well_known_proto_directory + "/../..")]
+        well_known_proto_files = context.attr.well_known_protos.files.to_list()
+
+    context.actions.run(
+        inputs = protos + includes + well_known_proto_files,
+        tools = tools,
+        outputs = out_files,
+        executable = context.executable._protoc,
+        arguments = arguments,
+        mnemonic = "ProtocInvocation",
+    )
+    return struct(files = depset(out_files))
+
+__generate_py = rule(
+    attrs = {
+        "deps": attr.label_list(
+            mandatory = True,
+            allow_empty = False,
+            providers = ["proto"],
+        ),
+        "plugin": attr.label(
+            executable = True,
+            providers = ["files_to_run"],
+            cfg = "host",
+        ),
+        "flags": attr.string_list(
+            mandatory = False,
+            allow_empty = True,
+        ),
+        "well_known_protos": attr.label(mandatory = False),
+        "_protoc": attr.label(
+            default = Label("//external:protocol_compiler"),
+            executable = True,
+            cfg = "host",
+        ),
+    },
+    output_to_genfiles = True,
+    implementation = _generate_py_impl,
+)
+
+def _generate_py(well_known_protos, **kwargs):
+    if well_known_protos:
+        __generate_py(
+            well_known_protos = "@com_google_protobuf//:well_known_protos",
+            **kwargs
+        )
+    else:
+        __generate_py(**kwargs)
+
+def py_proto_library(
+        name,
+        deps,
+        well_known_protos = True,
+        proto_only = False,
+        **kwargs):
+    """Generate python code for a protobuf.
+
+    Args:
+      name: The name of the target.
+      deps: A list of dependencies. Must contain a single element.
+      well_known_protos: A bool indicating whether or not to include well-known
+        protos.
+      proto_only: A bool indicating whether to generate vanilla protobuf code
+        or to also generate gRPC code.
+    """
+    if len(deps) > 1:
+        fail("The supported length of 'deps' is 1.")
+
+    codegen_target = "_{}_codegen".format(name)
+    codegen_grpc_target = "_{}_grpc_codegen".format(name)
+
+    _generate_py(
+        name = codegen_target,
+        deps = deps,
+        well_known_protos = well_known_protos,
+        **kwargs
+    )
+
+    if not proto_only:
+        _generate_py(
+            name = codegen_grpc_target,
+            deps = deps,
+            plugin = "//:grpc_python_plugin",
+            well_known_protos = well_known_protos,
+            **kwargs
+        )
+
+        native.py_library(
+            name = name,
+            srcs = [
+                ":{}".format(codegen_grpc_target),
+                ":{}".format(codegen_target),
+            ],
+            deps = [requirement("protobuf")],
+            **kwargs
+        )
+    else:
+        native.py_library(
+            name = name,
+            srcs = [":{}".format(codegen_target), ":{}".format(codegen_target)],
+            deps = [requirement("protobuf")],
+            **kwargs
+        )

build.yaml

@@ -148,6 +148,7 @@ filegroups:
   - src/core/lib/gpr/wrap_memcpy.cc
   - src/core/lib/gprpp/arena.cc
   - src/core/lib/gprpp/fork.cc
+  - src/core/lib/gprpp/global_config_env.cc
   - src/core/lib/gprpp/thd_posix.cc
   - src/core/lib/gprpp/thd_windows.cc
   - src/core/lib/profiling/basic_timers.cc
@@ -194,6 +195,10 @@ filegroups:
   - src/core/lib/gprpp/arena.h
   - src/core/lib/gprpp/atomic.h
   - src/core/lib/gprpp/fork.h
+  - src/core/lib/gprpp/global_config.h
+  - src/core/lib/gprpp/global_config_custom.h
+  - src/core/lib/gprpp/global_config_env.h
+  - src/core/lib/gprpp/global_config_generic.h
   - src/core/lib/gprpp/manual_constructor.h
   - src/core/lib/gprpp/map.h
   - src/core/lib/gprpp/memory.h
@@ -775,13 +780,17 @@ filegroups:
   headers:
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h
   src:
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
   plugin: grpc_resolver_dns_ares
@@ -1670,6 +1679,13 @@ libs:
   - grpc_test_util
   - grpc
   - gpr
+- name: dns_test_util
+  build: private
+  language: c++
+  headers:
+  - test/cpp/naming/dns_test_util.h
+  src:
+  - test/cpp/naming/dns_test_util.cc
 - name: grpc++
   build: all
   language: c++
@@ -4727,6 +4743,24 @@ targets:
   - grpc++
   - grpc
   - gpr
+- name: global_config_env_test
+  build: test
+  language: c++
+  src:
+  - test/core/gprpp/global_config_env_test.cc
+  deps:
+  - gpr
+  - grpc_test_util_unsecure
+  uses_polling: false
+- name: global_config_test
+  build: test
+  language: c++
+  src:
+  - test/core/gprpp/global_config_test.cc
+  deps:
+  - gpr
+  - grpc_test_util_unsecure
+  uses_polling: false
 - name: golden_file_test
   gtest: true
   build: test

config.m4

@@ -79,6 +79,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/gpr/wrap_memcpy.cc \
     src/core/lib/gprpp/arena.cc \
     src/core/lib/gprpp/fork.cc \
+    src/core/lib/gprpp/global_config_env.cc \
     src/core/lib/gprpp/thd_posix.cc \
     src/core/lib/gprpp/thd_windows.cc \
     src/core/lib/profiling/basic_timers.cc \
@@ -402,10 +403,13 @@ if test "$PHP_GRPC" != "no"; then
     src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \

config.w32

@@ -54,6 +54,7 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\gpr\\wrap_memcpy.cc " +
     "src\\core\\lib\\gprpp\\arena.cc " +
     "src\\core\\lib\\gprpp\\fork.cc " +
+    "src\\core\\lib\\gprpp\\global_config_env.cc " +
     "src\\core\\lib\\gprpp\\thd_posix.cc " +
     "src\\core\\lib\\gprpp\\thd_windows.cc " +
     "src\\core\\lib\\profiling\\basic_timers.cc " +
@@ -377,10 +378,13 @@ if (PHP_GRPC != "no") {
     "src\\core\\ext\\filters\\client_channel\\lb_policy\\round_robin\\round_robin.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\dns_resolver_ares.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver.cc " +
+    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver_libuv.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver_posix.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver_windows.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_fallback.cc " +
+    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_libuv.cc " +
+    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_libuv_windows.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_posix.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_windows.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\native\\dns_resolver.cc " +

doc/statuscodes.md

@@ -20,7 +20,7 @@ statuses are defined as such:
 | OUT_OF_RANGE | 11 | The operation was attempted past the valid range. E.g., seeking or reading past end-of-file. Unlike `INVALID_ARGUMENT`, this error indicates a problem that may be fixed if the system state changes. For example, a 32-bit file system will generate `INVALID_ARGUMENT` if asked to read at an offset that is not in the range [0,2^32-1], but it will generate `OUT_OF_RANGE` if asked to read from an offset past the current file size. There is a fair bit of overlap between `FAILED_PRECONDITION` and `OUT_OF_RANGE`. We recommend using `OUT_OF_RANGE` (the more specific error) when it applies so that callers who are iterating through a space can easily look for an `OUT_OF_RANGE` error to detect when they are done. | 400 Bad Request |
 | UNIMPLEMENTED | 12 | The operation is not implemented or is not supported/enabled in this service. | 501 Not Implemented |
 | INTERNAL | 13 | Internal errors. This means that some invariants expected by the underlying system have been broken. This error code is reserved for serious errors. | 500 Internal Server Error |
-| UNAVAILABLE | 14 | The service is currently unavailable. This is most likely a transient condition, which can be corrected by retrying with a backoff. | 503 Service Unavailable |
+| UNAVAILABLE | 14 | The service is currently unavailable. This is most likely a transient condition, which can be corrected by retrying with a backoff. Note that it is not always safe to retry non-idempotent operations. | 503 Service Unavailable |
 | DATA_LOSS | 15 | Unrecoverable data loss or corruption. | 500 Internal Server Error |
 
 All RPCs started at a client return a `status` object composed of an integer

etc/roots.pem

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+MpXRAJi70/33MvJJrsZ64Ee+bs7Lo3I6LWldy8joRTnU+kLBEUx3XZL7av9YROXr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+-----END CERTIFICATE-----

examples/BUILD

@@ -16,9 +16,9 @@ licenses(["notice"])  # 3-clause BSD
 
 package(default_visibility = ["//visibility:public"])
 
-load("@grpc_python_dependencies//:requirements.bzl", "requirement")
 load("//bazel:grpc_build_system.bzl", "grpc_proto_library")
-load("@org_pubref_rules_protobuf//python:rules.bzl", "py_proto_library")
+load("//bazel:cc_grpc_library.bzl", "cc_grpc_library")
+load("//bazel:python_rules.bzl", "py_proto_library")
 
 grpc_proto_library(
     name = "auth_sample",
@@ -30,11 +30,25 @@ grpc_proto_library(
     srcs = ["protos/hellostreamingworld.proto"],
 )
 
-grpc_proto_library(
-    name = "helloworld",
+# The following three rules demonstrate the usage of the cc_grpc_library rule in
+# in a mode compatible with the native proto_library and cc_proto_library rules.
+proto_library(
+    name = "helloworld_proto",
     srcs = ["protos/helloworld.proto"],
 )
 
+cc_proto_library(
+    name = "helloworld_cc_proto",
+    deps = [":helloworld_proto"],
+)
+
+cc_grpc_library(
+    name = "helloworld_cc_grpc",
+    srcs = [":helloworld_proto"],
+    grpc_only = True,
+    deps = [":helloworld_cc_proto"],
+)
+
 grpc_proto_library(
     name = "route_guide",
     srcs = ["protos/route_guide.proto"],
@@ -45,11 +59,14 @@ grpc_proto_library(
     srcs = ["protos/keyvaluestore.proto"],
 )
 
+proto_library(
+    name = "helloworld_proto_descriptor",
+    srcs = ["protos/helloworld.proto"],
+)
+
 py_proto_library(
     name = "py_helloworld",
-    protos = ["protos/helloworld.proto"],
-    with_grpc = True,
-    deps = [requirement('protobuf'),],
+    deps = [":helloworld_proto_descriptor"],
 )
 
 cc_binary(
@@ -57,7 +74,7 @@ cc_binary(
     srcs = ["cpp/helloworld/greeter_client.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -67,7 +84,7 @@ cc_binary(
     srcs = ["cpp/helloworld/greeter_async_client.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -77,7 +94,7 @@ cc_binary(
     srcs = ["cpp/helloworld/greeter_async_client2.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -87,7 +104,7 @@ cc_binary(
     srcs = ["cpp/helloworld/greeter_server.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -97,7 +114,7 @@ cc_binary(
     srcs = ["cpp/helloworld/greeter_async_server.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -107,7 +124,7 @@ cc_binary(
     srcs = ["cpp/metadata/greeter_client.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -117,7 +134,7 @@ cc_binary(
     srcs = ["cpp/metadata/greeter_server.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -127,7 +144,7 @@ cc_binary(
     srcs = ["cpp/load_balancing/greeter_client.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -137,7 +154,7 @@ cc_binary(
     srcs = ["cpp/load_balancing/greeter_server.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -147,7 +164,7 @@ cc_binary(
     srcs = ["cpp/compression/greeter_client.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
@@ -157,15 +174,17 @@ cc_binary(
     srcs = ["cpp/compression/greeter_server.cc"],
     defines = ["BAZEL_BUILD"],
     deps = [
-        ":helloworld",
+        ":helloworld_cc_grpc",
         "//:grpc++",
     ],
 )
 
 cc_binary(
     name = "keyvaluestore_client",
-    srcs = ["cpp/keyvaluestore/caching_interceptor.h",
-            "cpp/keyvaluestore/client.cc"],    
+    srcs = [
+        "cpp/keyvaluestore/caching_interceptor.h",
+        "cpp/keyvaluestore/client.cc",
+    ],
     defines = ["BAZEL_BUILD"],
     deps = [
         ":keyvaluestore",

examples/python/errors/client.py

@@ -20,8 +20,8 @@ import grpc
 from grpc_status import rpc_status
 from google.rpc import error_details_pb2
 
-from examples.protos import helloworld_pb2
-from examples.protos import helloworld_pb2_grpc
+from examples import helloworld_pb2
+from examples import helloworld_pb2_grpc
 
 _LOGGER = logging.getLogger(__name__)
 

examples/python/errors/server.py

@@ -24,8 +24,8 @@ from grpc_status import rpc_status
 from google.protobuf import any_pb2
 from google.rpc import code_pb2, status_pb2, error_details_pb2
 
-from examples.protos import helloworld_pb2
-from examples.protos import helloworld_pb2_grpc
+from examples import helloworld_pb2
+from examples import helloworld_pb2_grpc
 
 _ONE_DAY_IN_SECONDS = 60 * 60 * 24
 

examples/python/errors/test/_error_handling_example_test.py

@@ -26,7 +26,7 @@ import logging
 
 import grpc
 
-from examples.protos import helloworld_pb2_grpc
+from examples import helloworld_pb2_grpc
 from examples.python.errors import client as error_handling_client
 from examples.python.errors import server as error_handling_server
 

examples/python/multiprocessing/BUILD

@@ -15,12 +15,17 @@
 # limitations under the License.
 
 load("@grpc_python_dependencies//:requirements.bzl", "requirement")
-load("@org_pubref_rules_protobuf//python:rules.bzl", "py_proto_library")
+load("//bazel:python_rules.bzl", "py_proto_library")
 
-py_proto_library(
+proto_library(
     name = "prime_proto",
-    protos = ["prime.proto",],
-    deps = [requirement("protobuf")],
+    srcs = ["prime.proto"]
+)
+
+py_proto_library(
+    name = "prime_proto_pb2",
+    deps = [":prime_proto"],
+    well_known_protos = False,
 )
 
 py_binary(
@@ -29,7 +34,7 @@ py_binary(
     srcs = ["client.py"],
     deps = [
         "//src/python/grpcio/grpc:grpcio",
-        ":prime_proto",
+        ":prime_proto_pb2",
     ],
     default_python_version = "PY3",
 )
@@ -40,7 +45,7 @@ py_binary(
     srcs = ["server.py"],
     deps = [
         "//src/python/grpcio/grpc:grpcio",
-        ":prime_proto"
+        ":prime_proto_pb2"
     ] + select({
         "//conditions:default": [requirement("futures")],
         "//:python3": [],

examples/python/wait_for_ready/wait_for_ready_example.py

@@ -22,8 +22,8 @@ import threading
 
 import grpc
 
-from examples.protos import helloworld_pb2
-from examples.protos import helloworld_pb2_grpc
+from examples import helloworld_pb2
+from examples import helloworld_pb2_grpc
 
 _LOGGER = logging.getLogger(__name__)
 _LOGGER.setLevel(logging.INFO)
@@ -33,10 +33,13 @@ _ONE_DAY_IN_SECONDS = 60 * 60 * 24
 
 @contextmanager
 def get_free_loopback_tcp_port():
-    tcp_socket = socket.socket(socket.AF_INET6)
+    if socket.has_ipv6:
+        tcp_socket = socket.socket(socket.AF_INET6)
+    else:
+        tcp_socket = socket.socket(socket.AF_INET)
     tcp_socket.bind(('', 0))
     address_tuple = tcp_socket.getsockname()
-    yield "[::1]:%s" % (address_tuple[1])
+    yield "localhost:%s" % (address_tuple[1])
     tcp_socket.close()
 
 

gRPC-C++.podspec

@@ -272,6 +272,10 @@ Pod::Spec.new do |s|
                       'src/core/lib/gprpp/arena.h',
                       'src/core/lib/gprpp/atomic.h',
                       'src/core/lib/gprpp/fork.h',
+                      'src/core/lib/gprpp/global_config.h',
+                      'src/core/lib/gprpp/global_config_custom.h',
+                      'src/core/lib/gprpp/global_config_env.h',
+                      'src/core/lib/gprpp/global_config_generic.h',
                       'src/core/lib/gprpp/manual_constructor.h',
                       'src/core/lib/gprpp/map.h',
                       'src/core/lib/gprpp/memory.h',
@@ -558,6 +562,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/lb_policy/subchannel_list.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h',
                       'src/core/ext/filters/max_age/max_age_filter.h',
                       'src/core/ext/filters/message_size/message_size_filter.h',
                       'src/core/ext/filters/http/client_authority_filter.h',
@@ -594,6 +599,10 @@ Pod::Spec.new do |s|
                               'src/core/lib/gprpp/arena.h',
                               'src/core/lib/gprpp/atomic.h',
                               'src/core/lib/gprpp/fork.h',
+                              'src/core/lib/gprpp/global_config.h',
+                              'src/core/lib/gprpp/global_config_custom.h',
+                              'src/core/lib/gprpp/global_config_env.h',
+                              'src/core/lib/gprpp/global_config_generic.h',
                               'src/core/lib/gprpp/manual_constructor.h',
                               'src/core/lib/gprpp/map.h',
                               'src/core/lib/gprpp/memory.h',

gRPC-Core.podspec

@@ -208,6 +208,10 @@ Pod::Spec.new do |s|
                       'src/core/lib/gprpp/arena.h',
                       'src/core/lib/gprpp/atomic.h',
                       'src/core/lib/gprpp/fork.h',
+                      'src/core/lib/gprpp/global_config.h',
+                      'src/core/lib/gprpp/global_config_custom.h',
+                      'src/core/lib/gprpp/global_config_env.h',
+                      'src/core/lib/gprpp/global_config_generic.h',
                       'src/core/lib/gprpp/manual_constructor.h',
                       'src/core/lib/gprpp/map.h',
                       'src/core/lib/gprpp/memory.h',
@@ -250,6 +254,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/gpr/wrap_memcpy.cc',
                       'src/core/lib/gprpp/arena.cc',
                       'src/core/lib/gprpp/fork.cc',
+                      'src/core/lib/gprpp/global_config_env.cc',
                       'src/core/lib/gprpp/thd_posix.cc',
                       'src/core/lib/gprpp/thd_windows.cc',
                       'src/core/lib/profiling/basic_timers.cc',
@@ -533,6 +538,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/lb_policy/subchannel_list.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h',
                       'src/core/ext/filters/max_age/max_age_filter.h',
                       'src/core/ext/filters/message_size/message_size_filter.h',
                       'src/core/ext/filters/http/client_authority_filter.h',
@@ -854,10 +860,13 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
@@ -890,6 +899,10 @@ Pod::Spec.new do |s|
                               'src/core/lib/gprpp/arena.h',
                               'src/core/lib/gprpp/atomic.h',
                               'src/core/lib/gprpp/fork.h',
+                              'src/core/lib/gprpp/global_config.h',
+                              'src/core/lib/gprpp/global_config_custom.h',
+                              'src/core/lib/gprpp/global_config_env.h',
+                              'src/core/lib/gprpp/global_config_generic.h',
                               'src/core/lib/gprpp/manual_constructor.h',
                               'src/core/lib/gprpp/map.h',
                               'src/core/lib/gprpp/memory.h',
@@ -1176,6 +1189,7 @@ Pod::Spec.new do |s|
                               'src/core/ext/filters/client_channel/lb_policy/subchannel_list.h',
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h',
                               'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h',
+                              'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h',
                               'src/core/ext/filters/max_age/max_age_filter.h',
                               'src/core/ext/filters/message_size/message_size_filter.h',
                               'src/core/ext/filters/http/client_authority_filter.h',

grpc.gemspec

@@ -102,6 +102,10 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/gprpp/arena.h )
   s.files += %w( src/core/lib/gprpp/atomic.h )
   s.files += %w( src/core/lib/gprpp/fork.h )
+  s.files += %w( src/core/lib/gprpp/global_config.h )
+  s.files += %w( src/core/lib/gprpp/global_config_custom.h )
+  s.files += %w( src/core/lib/gprpp/global_config_env.h )
+  s.files += %w( src/core/lib/gprpp/global_config_generic.h )
   s.files += %w( src/core/lib/gprpp/manual_constructor.h )
   s.files += %w( src/core/lib/gprpp/map.h )
   s.files += %w( src/core/lib/gprpp/memory.h )
@@ -144,6 +148,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/gpr/wrap_memcpy.cc )
   s.files += %w( src/core/lib/gprpp/arena.cc )
   s.files += %w( src/core/lib/gprpp/fork.cc )
+  s.files += %w( src/core/lib/gprpp/global_config_env.cc )
   s.files += %w( src/core/lib/gprpp/thd_posix.cc )
   s.files += %w( src/core/lib/gprpp/thd_windows.cc )
   s.files += %w( src/core/lib/profiling/basic_timers.cc )
@@ -467,6 +472,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/lb_policy/subchannel_list.h )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h )
   s.files += %w( src/core/ext/filters/max_age/max_age_filter.h )
   s.files += %w( src/core/ext/filters/message_size/message_size_filter.h )
   s.files += %w( src/core/ext/filters/http/client_authority_filter.h )
@@ -791,10 +797,13 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc )

grpc.gyp

@@ -252,6 +252,7 @@
         'src/core/lib/gpr/wrap_memcpy.cc',
         'src/core/lib/gprpp/arena.cc',
         'src/core/lib/gprpp/fork.cc',
+        'src/core/lib/gprpp/global_config_env.cc',
         'src/core/lib/gprpp/thd_posix.cc',
         'src/core/lib/gprpp/thd_windows.cc',
         'src/core/lib/profiling/basic_timers.cc',
@@ -584,10 +585,13 @@
         'src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
@@ -1341,10 +1345,13 @@
         'src/core/ext/transport/inproc/inproc_transport.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
@@ -1398,6 +1405,15 @@
         'test/core/util/test_tcp_server.cc',
       ],
     },
+    {
+      'target_name': 'dns_test_util',
+      'type': 'static_library',
+      'dependencies': [
+      ],
+      'sources': [
+        'test/cpp/naming/dns_test_util.cc',
+      ],
+    },
     {
       'target_name': 'grpc++',
       'type': 'static_library',

include/grpc/impl/codegen/grpc_types.h

@@ -359,10 +359,12 @@ typedef struct {
  * load balancing policy. Note that this only works with the "ares"
  * DNS resolver, and isn't supported by the "native" DNS resolver. */
 #define GRPC_ARG_DNS_ENABLE_SRV_QUERIES "grpc.dns_enable_srv_queries"
-/** If set, determines the number of milliseconds that the c-ares based
- * DNS resolver will wait on queries before cancelling them. The default value
- * is 10000. Setting this to "0" will disable c-ares query timeouts
- * entirely. */
+/** If set, determines an upper bound on the number of milliseconds that the
+ * c-ares based DNS resolver will wait on queries before cancelling them.
+ * The default value is 120,000. Setting this to "0" will disable the
+ * overall timeout entirely. Note that this doesn't include internal c-ares
+ * timeouts/backoff/retry logic, and so the actual DNS resolution may time out
+ * sooner than the value specified here. */
 #define GRPC_ARG_DNS_ARES_QUERY_TIMEOUT_MS "grpc.dns_ares_query_timeout"
 /** If set, uses a local subchannel pool within the channel. Otherwise, uses the
  * global subchannel pool. */

include/grpc/impl/codegen/port_platform.h

@@ -77,7 +77,6 @@
 #define GPR_WINDOWS 1
 #define GPR_WINDOWS_SUBPROCESS 1
 #define GPR_WINDOWS_ENV
-#define GPR_HAS_ALIGNED_MALLOC 1
 #ifdef __MSYS__
 #define GPR_GETPID_IN_UNISTD_H 1
 #define GPR_MSYS_TMPFILE
@@ -174,7 +173,6 @@
 #define GPR_POSIX_SYNC 1
 #define GPR_POSIX_TIME 1
 #define GPR_HAS_PTHREAD_H 1
-#define GPR_HAS_ALIGNED_ALLOC 1
 #define GPR_GETPID_IN_UNISTD_H 1
 #ifdef _LP64
 #define GPR_ARCH_64 1
@@ -240,7 +238,6 @@
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
 #define GPR_POSIX_TIME 1
-#define GPR_HAS_POSIX_MEMALIGN 1
 #define GPR_HAS_PTHREAD_H 1
 #define GPR_GETPID_IN_UNISTD_H 1
 #ifndef GRPC_CFSTREAM

include/grpc/impl/codegen/status.h

@@ -128,7 +128,8 @@ typedef enum {
 
   /** The service is currently unavailable.  This is a most likely a
      transient condition and may be corrected by retrying with
-     a backoff.
+     a backoff. Note that it is not always safe to retry non-idempotent
+     operations.
 
      WARNING: Although data MIGHT not have been transmitted when this
      status occurs, there is NOT A GUARANTEE that the server has not seen

include/grpc/support/alloc.h

@@ -32,8 +32,6 @@ typedef struct gpr_allocation_functions {
   void* (*zalloc_fn)(size_t size); /** if NULL, uses malloc_fn then memset */
   void* (*realloc_fn)(void* ptr, size_t size);
   void (*free_fn)(void* ptr);
-  void* (*aligned_alloc_fn)(size_t size, size_t alignment);
-  void (*aligned_free_fn)(void* ptr);
 } gpr_allocation_functions;
 
 /** malloc.

include/grpcpp/impl/codegen/status_code_enum.h

@@ -119,7 +119,8 @@ enum StatusCode {
   INTERNAL = 13,
 
   /// The service is currently unavailable. This is a most likely a transient
-  /// condition and may be corrected by retrying with a backoff.
+  /// condition and may be corrected by retrying with a backoff. Note that it is
+  /// not always safe to retry non-idempotent operations.
   ///
   /// \warning Although data MIGHT not have been transmitted when this
   /// status occurs, there is NOT A GUARANTEE that the server has not seen

include/grpcpp/server_impl.h

@@ -105,7 +105,7 @@ class Server : public grpc::ServerInterface, private grpc::GrpcLibraryCodegen {
   }
 
   /// Establish a channel for in-process communication
-  std::shared_ptr<grpc::Channel> InProcessChannel(
+  std::shared_ptr<::grpc::Channel> InProcessChannel(
       const grpc::ChannelArguments& args);
 
   /// NOTE: class experimental_type is not part of the public API of this class.
@@ -117,7 +117,7 @@ class Server : public grpc::ServerInterface, private grpc::GrpcLibraryCodegen {
 
     /// Establish a channel for in-process communication with client
     /// interceptors
-    std::shared_ptr<grpc::Channel> InProcessChannelWithInterceptors(
+    std::shared_ptr<::grpc::Channel> InProcessChannelWithInterceptors(
         const grpc::ChannelArguments& args,
         std::vector<std::unique_ptr<
             grpc::experimental::ClientInterceptorFactoryInterface>>

package.xml

@@ -107,6 +107,10 @@
     <file baseinstalldir="/" name="src/core/lib/gprpp/arena.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/atomic.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/fork.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/global_config.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/global_config_custom.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/global_config_env.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/global_config_generic.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/manual_constructor.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/map.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/memory.h" role="src" />
@@ -149,6 +153,7 @@
     <file baseinstalldir="/" name="src/core/lib/gpr/wrap_memcpy.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/arena.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/fork.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/global_config_env.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/thd_posix.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/thd_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/profiling/basic_timers.cc" role="src" />
@@ -472,6 +477,7 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/lb_policy/subchannel_list.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/max_age/max_age_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/message_size/message_size_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/http/client_authority_filter.h" role="src" />
@@ -796,10 +802,13 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc" role="src" />

src/compiler/cpp_plugin.cc

@@ -18,137 +18,7 @@
 
 // Generates cpp gRPC service interface out of Protobuf IDL.
 //
-
-#include <memory>
-#include <sstream>
-
-#include "src/compiler/config.h"
-
-#include "src/compiler/cpp_generator.h"
-#include "src/compiler/generator_helpers.h"
-#include "src/compiler/protobuf_plugin.h"
-
-class CppGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
- public:
-  CppGrpcGenerator() {}
-  virtual ~CppGrpcGenerator() {}
-
-  virtual bool Generate(const grpc::protobuf::FileDescriptor* file,
-                        const grpc::string& parameter,
-                        grpc::protobuf::compiler::GeneratorContext* context,
-                        grpc::string* error) const {
-    if (file->options().cc_generic_services()) {
-      *error =
-          "cpp grpc proto compiler plugin does not work with generic "
-          "services. To generate cpp grpc APIs, please set \""
-          "cc_generic_service = false\".";
-      return false;
-    }
-
-    grpc_cpp_generator::Parameters generator_parameters;
-    generator_parameters.use_system_headers = true;
-    generator_parameters.generate_mock_code = false;
-    generator_parameters.include_import_headers = false;
-
-    ProtoBufFile pbfile(file);
-
-    if (!parameter.empty()) {
-      std::vector<grpc::string> parameters_list =
-          grpc_generator::tokenize(parameter, ",");
-      for (auto parameter_string = parameters_list.begin();
-           parameter_string != parameters_list.end(); parameter_string++) {
-        std::vector<grpc::string> param =
-            grpc_generator::tokenize(*parameter_string, "=");
-        if (param[0] == "services_namespace") {
-          generator_parameters.services_namespace = param[1];
-        } else if (param[0] == "use_system_headers") {
-          if (param[1] == "true") {
-            generator_parameters.use_system_headers = true;
-          } else if (param[1] == "false") {
-            generator_parameters.use_system_headers = false;
-          } else {
-            *error = grpc::string("Invalid parameter: ") + *parameter_string;
-            return false;
-          }
-        } else if (param[0] == "grpc_search_path") {
-          generator_parameters.grpc_search_path = param[1];
-        } else if (param[0] == "generate_mock_code") {
-          if (param[1] == "true") {
-            generator_parameters.generate_mock_code = true;
-          } else if (param[1] != "false") {
-            *error = grpc::string("Invalid parameter: ") + *parameter_string;
-            return false;
-          }
-        } else if (param[0] == "gmock_search_path") {
-          generator_parameters.gmock_search_path = param[1];
-        } else if (param[0] == "additional_header_includes") {
-          generator_parameters.additional_header_includes =
-              grpc_generator::tokenize(param[1], ":");
-        } else if (param[0] == "message_header_extension") {
-          generator_parameters.message_header_extension = param[1];
-        } else if (param[0] == "include_import_headers") {
-          if (param[1] == "true") {
-            generator_parameters.include_import_headers = true;
-          } else if (param[1] != "false") {
-            *error = grpc::string("Invalid parameter: ") + *parameter_string;
-            return false;
-          }
-        } else {
-          *error = grpc::string("Unknown parameter: ") + *parameter_string;
-          return false;
-        }
-      }
-    }
-
-    grpc::string file_name = grpc_generator::StripProto(file->name());
-
-    grpc::string header_code =
-        grpc_cpp_generator::GetHeaderPrologue(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetHeaderIncludes(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetHeaderServices(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetHeaderEpilogue(&pbfile, generator_parameters);
-    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> header_output(
-        context->Open(file_name + ".grpc.pb.h"));
-    grpc::protobuf::io::CodedOutputStream header_coded_out(header_output.get());
-    header_coded_out.WriteRaw(header_code.data(), header_code.size());
-
-    grpc::string source_code =
-        grpc_cpp_generator::GetSourcePrologue(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetSourceIncludes(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetSourceServices(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetSourceEpilogue(&pbfile, generator_parameters);
-    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> source_output(
-        context->Open(file_name + ".grpc.pb.cc"));
-    grpc::protobuf::io::CodedOutputStream source_coded_out(source_output.get());
-    source_coded_out.WriteRaw(source_code.data(), source_code.size());
-
-    if (!generator_parameters.generate_mock_code) {
-      return true;
-    }
-    grpc::string mock_code =
-        grpc_cpp_generator::GetMockPrologue(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetMockIncludes(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetMockServices(&pbfile, generator_parameters) +
-        grpc_cpp_generator::GetMockEpilogue(&pbfile, generator_parameters);
-    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> mock_output(
-        context->Open(file_name + "_mock.grpc.pb.h"));
-    grpc::protobuf::io::CodedOutputStream mock_coded_out(mock_output.get());
-    mock_coded_out.WriteRaw(mock_code.data(), mock_code.size());
-
-    return true;
-  }
-
- private:
-  // Insert the given code into the given file at the given insertion point.
-  void Insert(grpc::protobuf::compiler::GeneratorContext* context,
-              const grpc::string& filename, const grpc::string& insertion_point,
-              const grpc::string& code) const {
-    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> output(
-        context->OpenForInsert(filename, insertion_point));
-    grpc::protobuf::io::CodedOutputStream coded_out(output.get());
-    coded_out.WriteRaw(code.data(), code.size());
-  }
-};
+#include "src/compiler/cpp_plugin.h"
 
 int main(int argc, char* argv[]) {
   CppGrpcGenerator generator;

src/compiler/cpp_plugin.h

@@ -0,0 +1,154 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_COMPILER_CPP_PLUGIN_H
+#define GRPC_INTERNAL_COMPILER_CPP_PLUGIN_H
+
+#include <memory>
+#include <sstream>
+
+#include "src/compiler/config.h"
+
+#include "src/compiler/cpp_generator.h"
+#include "src/compiler/generator_helpers.h"
+#include "src/compiler/protobuf_plugin.h"
+
+// Cpp Generator for Protobug IDL
+class CppGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
+ public:
+  CppGrpcGenerator() {}
+  virtual ~CppGrpcGenerator() {}
+
+  virtual bool Generate(const grpc::protobuf::FileDescriptor* file,
+                        const grpc::string& parameter,
+                        grpc::protobuf::compiler::GeneratorContext* context,
+                        grpc::string* error) const {
+    if (file->options().cc_generic_services()) {
+      *error =
+          "cpp grpc proto compiler plugin does not work with generic "
+          "services. To generate cpp grpc APIs, please set \""
+          "cc_generic_service = false\".";
+      return false;
+    }
+
+    grpc_cpp_generator::Parameters generator_parameters;
+    generator_parameters.use_system_headers = true;
+    generator_parameters.generate_mock_code = false;
+    generator_parameters.include_import_headers = false;
+
+    ProtoBufFile pbfile(file);
+
+    if (!parameter.empty()) {
+      std::vector<grpc::string> parameters_list =
+          grpc_generator::tokenize(parameter, ",");
+      for (auto parameter_string = parameters_list.begin();
+           parameter_string != parameters_list.end(); parameter_string++) {
+        std::vector<grpc::string> param =
+            grpc_generator::tokenize(*parameter_string, "=");
+        if (param[0] == "services_namespace") {
+          generator_parameters.services_namespace = param[1];
+        } else if (param[0] == "use_system_headers") {
+          if (param[1] == "true") {
+            generator_parameters.use_system_headers = true;
+          } else if (param[1] == "false") {
+            generator_parameters.use_system_headers = false;
+          } else {
+            *error = grpc::string("Invalid parameter: ") + *parameter_string;
+            return false;
+          }
+        } else if (param[0] == "grpc_search_path") {
+          generator_parameters.grpc_search_path = param[1];
+        } else if (param[0] == "generate_mock_code") {
+          if (param[1] == "true") {
+            generator_parameters.generate_mock_code = true;
+          } else if (param[1] != "false") {
+            *error = grpc::string("Invalid parameter: ") + *parameter_string;
+            return false;
+          }
+        } else if (param[0] == "gmock_search_path") {
+          generator_parameters.gmock_search_path = param[1];
+        } else if (param[0] == "additional_header_includes") {
+          generator_parameters.additional_header_includes =
+              grpc_generator::tokenize(param[1], ":");
+        } else if (param[0] == "message_header_extension") {
+          generator_parameters.message_header_extension = param[1];
+        } else if (param[0] == "include_import_headers") {
+          if (param[1] == "true") {
+            generator_parameters.include_import_headers = true;
+          } else if (param[1] != "false") {
+            *error = grpc::string("Invalid parameter: ") + *parameter_string;
+            return false;
+          }
+        } else {
+          *error = grpc::string("Unknown parameter: ") + *parameter_string;
+          return false;
+        }
+      }
+    }
+
+    grpc::string file_name = grpc_generator::StripProto(file->name());
+
+    grpc::string header_code =
+        grpc_cpp_generator::GetHeaderPrologue(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetHeaderIncludes(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetHeaderServices(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetHeaderEpilogue(&pbfile, generator_parameters);
+    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> header_output(
+        context->Open(file_name + ".grpc.pb.h"));
+    grpc::protobuf::io::CodedOutputStream header_coded_out(header_output.get());
+    header_coded_out.WriteRaw(header_code.data(), header_code.size());
+
+    grpc::string source_code =
+        grpc_cpp_generator::GetSourcePrologue(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetSourceIncludes(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetSourceServices(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetSourceEpilogue(&pbfile, generator_parameters);
+    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> source_output(
+        context->Open(file_name + ".grpc.pb.cc"));
+    grpc::protobuf::io::CodedOutputStream source_coded_out(source_output.get());
+    source_coded_out.WriteRaw(source_code.data(), source_code.size());
+
+    if (!generator_parameters.generate_mock_code) {
+      return true;
+    }
+    grpc::string mock_code =
+        grpc_cpp_generator::GetMockPrologue(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetMockIncludes(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetMockServices(&pbfile, generator_parameters) +
+        grpc_cpp_generator::GetMockEpilogue(&pbfile, generator_parameters);
+    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> mock_output(
+        context->Open(file_name + "_mock.grpc.pb.h"));
+    grpc::protobuf::io::CodedOutputStream mock_coded_out(mock_output.get());
+    mock_coded_out.WriteRaw(mock_code.data(), mock_code.size());
+
+    return true;
+  }
+
+ private:
+  // Insert the given code into the given file at the given insertion point.
+  void Insert(grpc::protobuf::compiler::GeneratorContext* context,
+              const grpc::string& filename, const grpc::string& insertion_point,
+              const grpc::string& code) const {
+    std::unique_ptr<grpc::protobuf::io::ZeroCopyOutputStream> output(
+        context->OpenForInsert(filename, insertion_point));
+    grpc::protobuf::io::CodedOutputStream coded_out(output.get());
+    coded_out.WriteRaw(code.data(), code.size());
+  }
+};
+
+#endif  // GRPC_INTERNAL_COMPILER_CPP_PLUGIN_H

src/core/ext/filters/client_channel/backup_poller.cc

@@ -25,8 +25,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 #include "src/core/ext/filters/client_channel/client_channel.h"
-#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gprpp/global_config.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/timer.h"
@@ -56,21 +56,22 @@ static backup_poller* g_poller = nullptr;  // guarded by g_poller_mu
 // treated as const.
 static int g_poll_interval_ms = DEFAULT_POLL_INTERVAL_MS;
 
+GPR_GLOBAL_CONFIG_DEFINE_INT32(grpc_client_channel_backup_poll_interval_ms,
+                               DEFAULT_POLL_INTERVAL_MS,
+                               "Client channel backup poll interval (ms)");
+
 static void init_globals() {
   gpr_mu_init(&g_poller_mu);
-  char* env = gpr_getenv("GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS");
-  if (env != nullptr) {
-    int poll_interval_ms = gpr_parse_nonnegative_int(env);
-    if (poll_interval_ms == -1) {
-      gpr_log(GPR_ERROR,
-              "Invalid GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS: %s, "
-              "default value %d will be used.",
-              env, g_poll_interval_ms);
-    } else {
-      g_poll_interval_ms = poll_interval_ms;
-    }
+  int32_t poll_interval_ms =
+      GPR_GLOBAL_CONFIG_GET(grpc_client_channel_backup_poll_interval_ms);
+  if (poll_interval_ms < 0) {
+    gpr_log(GPR_ERROR,
+            "Invalid GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS: %d, "
+            "default value %d will be used.",
+            poll_interval_ms, g_poll_interval_ms);
+  } else {
+    g_poll_interval_ms = poll_interval_ms;
   }
-  gpr_free(env);
 }
 
 static void backup_poller_shutdown_unref(backup_poller* p) {

src/core/ext/filters/client_channel/backup_poller.h

@@ -23,6 +23,9 @@
 
 #include <grpc/grpc.h>
 #include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/gprpp/global_config.h"
+
+GPR_GLOBAL_CONFIG_DECLARE_INT32(grpc_client_channel_backup_poll_interval_ms);
 
 /* Start polling \a interested_parties periodically in the timer thread  */
 void grpc_client_channel_start_backup_polling(

src/core/ext/filters/client_channel/channel_connectivity.cc

@@ -125,7 +125,7 @@ static void partly_done(state_watcher* w, bool due_to_completion,
   gpr_mu_lock(&w->mu);
 
   if (due_to_completion) {
-    if (grpc_trace_operation_failures.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_operation_failures)) {
       GRPC_LOG_IF_ERROR("watch_completion_error", GRPC_ERROR_REF(error));
     }
     GRPC_ERROR_UNREF(error);

src/core/ext/filters/client_channel/client_channel.cc

@@ -970,7 +970,7 @@ class ChannelData::ClientChannelControlHelper
       UniquePtr<LoadBalancingPolicy::SubchannelPicker> picker) override {
     grpc_error* disconnect_error =
         chand_->disconnect_error_.Load(MemoryOrder::ACQUIRE);
-    if (grpc_client_channel_routing_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
       const char* extra = disconnect_error == GRPC_ERROR_NONE
                               ? ""
                               : " (ignoring -- channel shutting down)";
@@ -1105,7 +1105,7 @@ ChannelData::ChannelData(grpc_channel_element_args* args, grpc_error** error)
   } else {
     grpc_pollset_set_add_pollset_set(resolving_lb_policy_->interested_parties(),
                                      interested_parties_);
-    if (grpc_client_channel_routing_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
       gpr_log(GPR_INFO, "chand=%p: created resolving_lb_policy=%p", this,
               resolving_lb_policy_.get());
     }
@@ -1136,7 +1136,7 @@ bool ChannelData::ProcessResolverResultLocked(
   ChannelData* chand = static_cast<ChannelData*>(arg);
   ProcessedResolverResult resolver_result(result);
   char* service_config_json = gpr_strdup(resolver_result.service_config_json());
-  if (grpc_client_channel_routing_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
     gpr_log(GPR_INFO, "chand=%p: resolver returned service config: \"%s\"",
             chand, service_config_json);
   }
@@ -1407,7 +1407,7 @@ void CallData::StartTransportStreamOpBatch(
   }
   // If we've previously been cancelled, immediately fail any new batches.
   if (GPR_UNLIKELY(calld->cancel_error_ != GRPC_ERROR_NONE)) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO, "chand=%p calld=%p: failing batch with error: %s",
               chand, calld, grpc_error_string(calld->cancel_error_));
     }
@@ -1426,7 +1426,7 @@ void CallData::StartTransportStreamOpBatch(
     GRPC_ERROR_UNREF(calld->cancel_error_);
     calld->cancel_error_ =
         GRPC_ERROR_REF(batch->payload->cancel_stream.cancel_error);
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO, "chand=%p calld=%p: recording cancel_error=%s", chand,
               calld, grpc_error_string(calld->cancel_error_));
     }
@@ -1454,7 +1454,7 @@ void CallData::StartTransportStreamOpBatch(
   // the channel combiner, which is more efficient (especially for
   // streaming calls).
   if (calld->subchannel_call_ != nullptr) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: starting batch on subchannel_call=%p", chand,
               calld, calld->subchannel_call_.get());
@@ -1466,7 +1466,7 @@ void CallData::StartTransportStreamOpBatch(
   // For batches containing a send_initial_metadata op, enter the channel
   // combiner to start a pick.
   if (GPR_LIKELY(batch->send_initial_metadata)) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO, "chand=%p calld=%p: entering client_channel combiner",
               chand, calld);
     }
@@ -1477,7 +1477,7 @@ void CallData::StartTransportStreamOpBatch(
         GRPC_ERROR_NONE);
   } else {
     // For all other batches, release the call combiner.
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: saved batch, yielding call combiner", chand,
               calld);
@@ -1535,7 +1535,7 @@ void CallData::MaybeCacheSendOpsForBatch(PendingBatch* pending) {
 }
 
 void CallData::FreeCachedSendInitialMetadata(ChannelData* chand) {
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: destroying calld->send_initial_metadata", chand,
             this);
@@ -1544,7 +1544,7 @@ void CallData::FreeCachedSendInitialMetadata(ChannelData* chand) {
 }
 
 void CallData::FreeCachedSendMessage(ChannelData* chand, size_t idx) {
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: destroying calld->send_messages[%" PRIuPTR "]",
             chand, this, idx);
@@ -1553,7 +1553,7 @@ void CallData::FreeCachedSendMessage(ChannelData* chand, size_t idx) {
 }
 
 void CallData::FreeCachedSendTrailingMetadata(ChannelData* chand) {
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: destroying calld->send_trailing_metadata",
             chand, this);
@@ -1630,7 +1630,7 @@ void CallData::PendingBatchesAdd(grpc_call_element* elem,
                                  grpc_transport_stream_op_batch* batch) {
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
   const size_t idx = GetBatchIndex(batch);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: adding pending batch at index %" PRIuPTR, chand,
             this, idx);
@@ -1659,7 +1659,7 @@ void CallData::PendingBatchesAdd(grpc_call_element* elem,
     }
     if (GPR_UNLIKELY(bytes_buffered_for_retry_ >
                      chand->per_rpc_retry_buffer_size())) {
-      if (grpc_client_channel_call_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
         gpr_log(GPR_INFO,
                 "chand=%p calld=%p: exceeded retry buffer size, committing",
                 chand, this);
@@ -1672,7 +1672,7 @@ void CallData::PendingBatchesAdd(grpc_call_element* elem,
       // If we are not going to retry and have not yet started, pretend
       // retries are disabled so that we don't bother with retry overhead.
       if (num_attempts_completed_ == 0) {
-        if (grpc_client_channel_call_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
           gpr_log(GPR_INFO,
                   "chand=%p calld=%p: disabling retries before first attempt",
                   chand, this);
@@ -1713,7 +1713,7 @@ void CallData::MaybeClearPendingBatch(grpc_call_element* elem,
       (!batch->recv_trailing_metadata ||
        batch->payload->recv_trailing_metadata.recv_trailing_metadata_ready ==
            nullptr)) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO, "chand=%p calld=%p: clearing pending batch", chand,
               this);
     }
@@ -1736,7 +1736,7 @@ void CallData::PendingBatchesFail(
     grpc_call_element* elem, grpc_error* error,
     YieldCallCombinerPredicate yield_call_combiner_predicate) {
   GPR_ASSERT(error != GRPC_ERROR_NONE);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     size_t num_batches = 0;
     for (size_t i = 0; i < GPR_ARRAY_SIZE(pending_batches_); ++i) {
       if (pending_batches_[i].batch != nullptr) ++num_batches;
@@ -1790,7 +1790,7 @@ void CallData::PendingBatchesResume(grpc_call_element* elem) {
     return;
   }
   // Retries not enabled; send down batches as-is.
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     size_t num_batches = 0;
     for (size_t i = 0; i < GPR_ARRAY_SIZE(pending_batches_); ++i) {
       if (pending_batches_[i].batch != nullptr) ++num_batches;
@@ -1831,7 +1831,7 @@ CallData::PendingBatch* CallData::PendingBatchFind(grpc_call_element* elem,
     PendingBatch* pending = &pending_batches_[i];
     grpc_transport_stream_op_batch* batch = pending->batch;
     if (batch != nullptr && predicate(batch)) {
-      if (grpc_client_channel_call_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
         gpr_log(GPR_INFO,
                 "chand=%p calld=%p: %s pending batch at index %" PRIuPTR, chand,
                 this, log_message, i);
@@ -1851,7 +1851,7 @@ void CallData::RetryCommit(grpc_call_element* elem,
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
   if (retry_committed_) return;
   retry_committed_ = true;
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO, "chand=%p calld=%p: committing retries", chand, this);
   }
   if (retry_state != nullptr) {
@@ -1886,7 +1886,7 @@ void CallData::DoRetry(grpc_call_element* elem,
     }
     next_attempt_time = retry_backoff_->NextAttemptTime();
   }
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: retrying failed call in %" PRId64 " ms", chand,
             this, next_attempt_time - ExecCtx::Get()->Now());
@@ -1916,7 +1916,7 @@ bool CallData::MaybeRetry(grpc_call_element* elem,
     retry_state = static_cast<SubchannelCallRetryState*>(
         batch_data->subchannel_call->GetParentData());
     if (retry_state->retry_dispatched) {
-      if (grpc_client_channel_call_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
         gpr_log(GPR_INFO, "chand=%p calld=%p: retry already dispatched", chand,
                 this);
       }
@@ -1928,14 +1928,14 @@ bool CallData::MaybeRetry(grpc_call_element* elem,
     if (retry_throttle_data_ != nullptr) {
       retry_throttle_data_->RecordSuccess();
     }
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO, "chand=%p calld=%p: call succeeded", chand, this);
     }
     return false;
   }
   // Status is not OK.  Check whether the status is retryable.
   if (!retry_policy->retryable_status_codes.Contains(status)) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: status %s not configured as retryable", chand,
               this, grpc_status_code_to_string(status));
@@ -1951,14 +1951,14 @@ bool CallData::MaybeRetry(grpc_call_element* elem,
   // checks, so that we don't fail to record failures due to other factors.
   if (retry_throttle_data_ != nullptr &&
       !retry_throttle_data_->RecordFailure()) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO, "chand=%p calld=%p: retries throttled", chand, this);
     }
     return false;
   }
   // Check whether the call is committed.
   if (retry_committed_) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO, "chand=%p calld=%p: retries already committed", chand,
               this);
     }
@@ -1967,7 +1967,7 @@ bool CallData::MaybeRetry(grpc_call_element* elem,
   // Check whether we have retries remaining.
   ++num_attempts_completed_;
   if (num_attempts_completed_ >= retry_policy->max_attempts) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO, "chand=%p calld=%p: exceeded %d retry attempts", chand,
               this, retry_policy->max_attempts);
     }
@@ -1975,7 +1975,7 @@ bool CallData::MaybeRetry(grpc_call_element* elem,
   }
   // If the call was cancelled from the surface, don't retry.
   if (cancel_error_ != GRPC_ERROR_NONE) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: call cancelled from surface, not retrying",
               chand, this);
@@ -1988,14 +1988,14 @@ bool CallData::MaybeRetry(grpc_call_element* elem,
     // If the value is "-1" or any other unparseable string, we do not retry.
     uint32_t ms;
     if (!grpc_parse_slice_to_uint32(GRPC_MDVALUE(*server_pushback_md), &ms)) {
-      if (grpc_client_channel_call_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
         gpr_log(GPR_INFO,
                 "chand=%p calld=%p: not retrying due to server push-back",
                 chand, this);
       }
       return false;
     } else {
-      if (grpc_client_channel_call_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
         gpr_log(GPR_INFO, "chand=%p calld=%p: server push-back: retry in %u ms",
                 chand, this, ms);
       }
@@ -2098,7 +2098,7 @@ void CallData::RecvInitialMetadataReady(void* arg, grpc_error* error) {
   grpc_call_element* elem = batch_data->elem;
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
   CallData* calld = static_cast<CallData*>(elem->call_data);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: got recv_initial_metadata_ready, error=%s",
             chand, calld, grpc_error_string(error));
@@ -2122,7 +2122,7 @@ void CallData::RecvInitialMetadataReady(void* arg, grpc_error* error) {
   if (GPR_UNLIKELY((retry_state->trailing_metadata_available ||
                     error != GRPC_ERROR_NONE) &&
                    !retry_state->completed_recv_trailing_metadata)) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: deferring recv_initial_metadata_ready "
               "(Trailers-Only)",
@@ -2188,7 +2188,7 @@ void CallData::RecvMessageReady(void* arg, grpc_error* error) {
   grpc_call_element* elem = batch_data->elem;
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
   CallData* calld = static_cast<CallData*>(elem->call_data);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO, "chand=%p calld=%p: got recv_message_ready, error=%s",
             chand, calld, grpc_error_string(error));
   }
@@ -2210,7 +2210,7 @@ void CallData::RecvMessageReady(void* arg, grpc_error* error) {
   if (GPR_UNLIKELY(
           (retry_state->recv_message == nullptr || error != GRPC_ERROR_NONE) &&
           !retry_state->completed_recv_trailing_metadata)) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: deferring recv_message_ready (nullptr "
               "message and recv_trailing_metadata pending)",
@@ -2348,7 +2348,7 @@ void CallData::AddClosuresToFailUnstartedPendingBatches(
   for (size_t i = 0; i < GPR_ARRAY_SIZE(pending_batches_); ++i) {
     PendingBatch* pending = &pending_batches_[i];
     if (PendingBatchIsUnstarted(pending, retry_state)) {
-      if (grpc_client_channel_call_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
         gpr_log(GPR_INFO,
                 "chand=%p calld=%p: failing unstarted pending batch at index "
                 "%" PRIuPTR,
@@ -2394,7 +2394,7 @@ void CallData::RecvTrailingMetadataReady(void* arg, grpc_error* error) {
   grpc_call_element* elem = batch_data->elem;
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
   CallData* calld = static_cast<CallData*>(elem->call_data);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: got recv_trailing_metadata_ready, error=%s",
             chand, calld, grpc_error_string(error));
@@ -2410,7 +2410,7 @@ void CallData::RecvTrailingMetadataReady(void* arg, grpc_error* error) {
       batch_data->batch.payload->recv_trailing_metadata.recv_trailing_metadata;
   calld->GetCallStatus(elem, md_batch, GRPC_ERROR_REF(error), &status,
                        &server_pushback_md);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO, "chand=%p calld=%p: call finished, status=%s", chand,
             calld, grpc_status_code_to_string(status));
   }
@@ -2489,7 +2489,7 @@ void CallData::AddClosuresForReplayOrPendingSendOps(
     }
   }
   if (have_pending_send_message_ops || have_pending_send_trailing_metadata_op) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: starting next batch for pending send op(s)",
               chand, this);
@@ -2508,7 +2508,7 @@ void CallData::OnComplete(void* arg, grpc_error* error) {
   grpc_call_element* elem = batch_data->elem;
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
   CallData* calld = static_cast<CallData*>(elem->call_data);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     char* batch_str = grpc_transport_stream_op_batch_string(&batch_data->batch);
     gpr_log(GPR_INFO, "chand=%p calld=%p: got on_complete, error=%s, batch=%s",
             chand, calld, grpc_error_string(error), batch_str);
@@ -2584,7 +2584,7 @@ void CallData::AddClosureForSubchannelBatch(
   batch->handler_private.extra_arg = subchannel_call_.get();
   GRPC_CLOSURE_INIT(&batch->handler_private.closure, StartBatchInCallCombiner,
                     batch, grpc_schedule_on_exec_ctx);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     char* batch_str = grpc_transport_stream_op_batch_string(batch);
     gpr_log(GPR_INFO, "chand=%p calld=%p: starting subchannel batch: %s", chand,
             this, batch_str);
@@ -2647,7 +2647,7 @@ void CallData::AddRetriableSendMessageOp(grpc_call_element* elem,
                                          SubchannelCallRetryState* retry_state,
                                          SubchannelCallBatchData* batch_data) {
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: starting calld->send_messages[%" PRIuPTR "]",
             chand, this, retry_state->started_send_message_count);
@@ -2730,7 +2730,7 @@ void CallData::AddRetriableRecvTrailingMetadataOp(
 
 void CallData::StartInternalRecvTrailingMetadata(grpc_call_element* elem) {
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: call failed but recv_trailing_metadata not "
             "started; starting it internally",
@@ -2762,7 +2762,7 @@ CallData::MaybeCreateSubchannelBatchForReplay(
   if (seen_send_initial_metadata_ &&
       !retry_state->started_send_initial_metadata &&
       !pending_send_initial_metadata_) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: replaying previously completed "
               "send_initial_metadata op",
@@ -2778,7 +2778,7 @@ CallData::MaybeCreateSubchannelBatchForReplay(
       retry_state->started_send_message_count ==
           retry_state->completed_send_message_count &&
       !pending_send_message_) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: replaying previously completed "
               "send_message op",
@@ -2798,7 +2798,7 @@ CallData::MaybeCreateSubchannelBatchForReplay(
       retry_state->started_send_message_count == send_messages_.size() &&
       !retry_state->started_send_trailing_metadata &&
       !pending_send_trailing_metadata_) {
-    if (grpc_client_channel_call_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: replaying previously completed "
               "send_trailing_metadata op",
@@ -2941,7 +2941,7 @@ void CallData::StartRetriableSubchannelBatches(void* arg, grpc_error* ignored) {
   grpc_call_element* elem = static_cast<grpc_call_element*>(arg);
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
   CallData* calld = static_cast<CallData*>(elem->call_data);
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO, "chand=%p calld=%p: constructing retriable batches",
             chand, calld);
   }
@@ -2966,7 +2966,7 @@ void CallData::StartRetriableSubchannelBatches(void* arg, grpc_error* ignored) {
   // Now add pending batches.
   calld->AddSubchannelBatchesForPendingBatches(elem, retry_state, &closures);
   // Start batches on subchannel call.
-  if (grpc_client_channel_call_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_call_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: starting %" PRIuPTR
             " retriable batches on subchannel_call=%p",
@@ -2992,7 +2992,7 @@ void CallData::CreateSubchannelCall(grpc_call_element* elem) {
   grpc_error* error = GRPC_ERROR_NONE;
   subchannel_call_ =
       pick_.pick.connected_subchannel->CreateCall(call_args, &error);
-  if (grpc_client_channel_routing_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
     gpr_log(GPR_INFO, "chand=%p calld=%p: create subchannel_call=%p: error=%s",
             chand, this, subchannel_call_.get(), grpc_error_string(error));
   }
@@ -3012,7 +3012,7 @@ void CallData::PickDone(void* arg, grpc_error* error) {
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
   CallData* calld = static_cast<CallData*>(elem->call_data);
   if (error != GRPC_ERROR_NONE) {
-    if (grpc_client_channel_routing_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: failed to pick subchannel: error=%s", chand,
               calld, grpc_error_string(error));
@@ -3041,7 +3041,7 @@ class CallData::QueuedPickCanceller {
     auto* self = static_cast<QueuedPickCanceller*>(arg);
     auto* chand = static_cast<ChannelData*>(self->elem_->channel_data);
     auto* calld = static_cast<CallData*>(self->elem_->call_data);
-    if (grpc_client_channel_routing_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p calld=%p: cancelling queued pick: "
               "error=%s self=%p calld->pick_canceller=%p",
@@ -3065,7 +3065,7 @@ class CallData::QueuedPickCanceller {
 
 void CallData::RemoveCallFromQueuedPicksLocked(grpc_call_element* elem) {
   auto* chand = static_cast<ChannelData*>(elem->channel_data);
-  if (grpc_client_channel_routing_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
     gpr_log(GPR_INFO, "chand=%p calld=%p: removing from queued picks list",
             chand, this);
   }
@@ -3077,7 +3077,7 @@ void CallData::RemoveCallFromQueuedPicksLocked(grpc_call_element* elem) {
 
 void CallData::AddCallToQueuedPicksLocked(grpc_call_element* elem) {
   auto* chand = static_cast<ChannelData*>(elem->channel_data);
-  if (grpc_client_channel_routing_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
     gpr_log(GPR_INFO, "chand=%p calld=%p: adding to queued picks list", chand,
             this);
   }
@@ -3090,7 +3090,7 @@ void CallData::AddCallToQueuedPicksLocked(grpc_call_element* elem) {
 
 void CallData::ApplyServiceConfigToCallLocked(grpc_call_element* elem) {
   ChannelData* chand = static_cast<ChannelData*>(elem->channel_data);
-  if (grpc_client_channel_routing_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
     gpr_log(GPR_INFO, "chand=%p calld=%p: applying service config to call",
             chand, this);
   }
@@ -3199,7 +3199,7 @@ void CallData::StartPickLocked(void* arg, grpc_error* error) {
   // Attempt pick.
   error = GRPC_ERROR_NONE;
   auto pick_result = chand->picker()->Pick(&calld->pick_.pick, &error);
-  if (grpc_client_channel_routing_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
     gpr_log(GPR_INFO,
             "chand=%p calld=%p: LB pick returned %s (connected_subchannel=%p, "
             "error=%s)",

src/core/ext/filters/client_channel/health/health_check_client.cc

@@ -63,7 +63,7 @@ HealthCheckClient::HealthCheckClient(
               .set_jitter(HEALTH_CHECK_RECONNECT_JITTER)
               .set_max_backoff(HEALTH_CHECK_RECONNECT_MAX_BACKOFF_SECONDS *
                                1000)) {
-  if (grpc_health_check_client_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
     gpr_log(GPR_INFO, "created HealthCheckClient %p", this);
   }
   GRPC_CLOSURE_INIT(&retry_timer_callback_, OnRetryTimer, this,
@@ -72,7 +72,7 @@ HealthCheckClient::HealthCheckClient(
 }
 
 HealthCheckClient::~HealthCheckClient() {
-  if (grpc_health_check_client_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
     gpr_log(GPR_INFO, "destroying HealthCheckClient %p", this);
   }
   GRPC_ERROR_UNREF(error_);
@@ -99,7 +99,7 @@ void HealthCheckClient::SetHealthStatus(grpc_connectivity_state state,
 
 void HealthCheckClient::SetHealthStatusLocked(grpc_connectivity_state state,
                                               grpc_error* error) {
-  if (grpc_health_check_client_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
     gpr_log(GPR_INFO, "HealthCheckClient %p: setting state=%d error=%s", this,
             state, grpc_error_string(error));
   }
@@ -115,7 +115,7 @@ void HealthCheckClient::SetHealthStatusLocked(grpc_connectivity_state state,
 }
 
 void HealthCheckClient::Orphan() {
-  if (grpc_health_check_client_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
     gpr_log(GPR_INFO, "HealthCheckClient %p: shutting down", this);
   }
   {
@@ -145,7 +145,7 @@ void HealthCheckClient::StartCallLocked() {
   GPR_ASSERT(call_state_ == nullptr);
   SetHealthStatusLocked(GRPC_CHANNEL_CONNECTING, GRPC_ERROR_NONE);
   call_state_ = MakeOrphanable<CallState>(Ref(), interested_parties_);
-  if (grpc_health_check_client_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
     gpr_log(GPR_INFO, "HealthCheckClient %p: created CallState %p", this,
             call_state_.get());
   }
@@ -159,7 +159,7 @@ void HealthCheckClient::StartRetryTimer() {
       GRPC_ERROR_CREATE_FROM_STATIC_STRING(
           "health check call failed; will retry after backoff"));
   grpc_millis next_try = retry_backoff_.NextAttemptTime();
-  if (grpc_health_check_client_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
     gpr_log(GPR_INFO, "HealthCheckClient %p: health check call lost...", this);
     grpc_millis timeout = next_try - ExecCtx::Get()->Now();
     if (timeout > 0) {
@@ -184,7 +184,7 @@ void HealthCheckClient::OnRetryTimer(void* arg, grpc_error* error) {
     self->retry_timer_callback_pending_ = false;
     if (!self->shutting_down_ && error == GRPC_ERROR_NONE &&
         self->call_state_ == nullptr) {
-      if (grpc_health_check_client_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
         gpr_log(GPR_INFO, "HealthCheckClient %p: restarting health check call",
                 self);
       }
@@ -285,7 +285,7 @@ HealthCheckClient::CallState::CallState(
       payload_(context_) {}
 
 HealthCheckClient::CallState::~CallState() {
-  if (grpc_health_check_client_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
     gpr_log(GPR_INFO, "HealthCheckClient %p: destroying CallState %p",
             health_check_client_.get(), this);
   }
@@ -589,7 +589,7 @@ void HealthCheckClient::CallState::RecvTrailingMetadataReady(
     status = grpc_get_status_code_from_metadata(
         self->recv_trailing_metadata_.idx.named.grpc_status->md);
   }
-  if (grpc_health_check_client_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_health_check_client_trace)) {
     gpr_log(GPR_INFO,
             "HealthCheckClient %p CallState %p: health watch failed with "
             "status %d",

src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc

@@ -640,7 +640,7 @@ void GrpcLb::Helper::UpdateState(grpc_connectivity_state state,
   // If this request is from the pending child policy, ignore it until
   // it reports READY, at which point we swap it into place.
   if (CalledByPendingChild()) {
-    if (grpc_lb_glb_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
       gpr_log(GPR_INFO,
               "[grpclb %p helper %p] pending child policy %p reports state=%s",
               parent_.get(), this, parent_->pending_child_policy_.get(),
@@ -682,7 +682,7 @@ void GrpcLb::Helper::UpdateState(grpc_connectivity_state state,
   if (parent_->serverlist_ == nullptr ||
       (!parent_->serverlist_->ContainsAllDropEntries() &&
        state != GRPC_CHANNEL_READY)) {
-    if (grpc_lb_glb_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
       gpr_log(GPR_INFO,
               "[grpclb %p helper %p] state=%s passing child picker %p as-is",
               parent_.get(), this, grpc_connectivity_state_name(state),
@@ -692,7 +692,7 @@ void GrpcLb::Helper::UpdateState(grpc_connectivity_state state,
     return;
   }
   // Cases 2 and 3a: wrap picker from the child in our own picker.
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     gpr_log(GPR_INFO, "[grpclb %p helper %p] state=%s wrapping child picker %p",
             parent_.get(), this, grpc_connectivity_state_name(state),
             picker.get());
@@ -715,7 +715,7 @@ void GrpcLb::Helper::RequestReresolution() {
           ? parent_->pending_child_policy_.get()
           : parent_->child_policy_.get();
   if (child_ != latest_child_policy) return;
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     gpr_log(GPR_INFO,
             "[grpclb %p] Re-resolution requested from %schild policy (%p).",
             parent_.get(), CalledByPendingChild() ? "pending " : "", child_);
@@ -802,7 +802,7 @@ void GrpcLb::BalancerCallState::Orphan() {
 
 void GrpcLb::BalancerCallState::StartQuery() {
   GPR_ASSERT(lb_call_ != nullptr);
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     gpr_log(GPR_INFO, "[grpclb %p] lb_calld=%p: Starting LB call %p",
             grpclb_policy_.get(), this, lb_call_);
   }
@@ -1009,7 +1009,7 @@ void GrpcLb::BalancerCallState::OnBalancerMessageReceivedLocked(
       lb_calld->client_stats_report_interval_ = GPR_MAX(
           GPR_MS_PER_SEC, grpc_grpclb_duration_to_millis(
                               &initial_response->client_stats_report_interval));
-      if (grpc_lb_glb_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
         gpr_log(GPR_INFO,
                 "[grpclb %p] lb_calld=%p: Received initial LB response "
                 "message; client load reporting interval = %" PRId64
@@ -1017,7 +1017,7 @@ void GrpcLb::BalancerCallState::OnBalancerMessageReceivedLocked(
                 grpclb_policy, lb_calld,
                 lb_calld->client_stats_report_interval_);
       }
-    } else if (grpc_lb_glb_trace.enabled()) {
+    } else if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
       gpr_log(GPR_INFO,
               "[grpclb %p] lb_calld=%p: Received initial LB response message; "
               "client load reporting NOT enabled",
@@ -1030,7 +1030,7 @@ void GrpcLb::BalancerCallState::OnBalancerMessageReceivedLocked(
     // Have seen initial response, look for serverlist.
     GPR_ASSERT(lb_calld->lb_call_ != nullptr);
     auto serverlist_wrapper = MakeRefCounted<Serverlist>(serverlist);
-    if (grpc_lb_glb_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
       UniquePtr<char> serverlist_text = serverlist_wrapper->AsText();
       gpr_log(GPR_INFO,
               "[grpclb %p] lb_calld=%p: Serverlist with %" PRIuPTR
@@ -1051,7 +1051,7 @@ void GrpcLb::BalancerCallState::OnBalancerMessageReceivedLocked(
     // Check if the serverlist differs from the previous one.
     if (grpclb_policy->serverlist_ != nullptr &&
         *grpclb_policy->serverlist_ == *serverlist_wrapper) {
-      if (grpc_lb_glb_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
         gpr_log(GPR_INFO,
                 "[grpclb %p] lb_calld=%p: Incoming server list identical to "
                 "current, ignoring.",
@@ -1129,7 +1129,7 @@ void GrpcLb::BalancerCallState::OnBalancerStatusReceivedLocked(
   BalancerCallState* lb_calld = static_cast<BalancerCallState*>(arg);
   GrpcLb* grpclb_policy = lb_calld->grpclb_policy();
   GPR_ASSERT(lb_calld->lb_call_ != nullptr);
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     char* status_details =
         grpc_slice_to_c_string(lb_calld->lb_call_status_details_);
     gpr_log(GPR_INFO,
@@ -1291,7 +1291,7 @@ GrpcLb::GrpcLb(Args args)
   grpc_uri* uri = grpc_uri_parse(server_uri, true);
   GPR_ASSERT(uri->path[0] != '\0');
   server_name_ = gpr_strdup(uri->path[0] == '/' ? uri->path + 1 : uri->path);
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     gpr_log(GPR_INFO,
             "[grpclb %p] Will use '%s' as the server name for LB request.",
             this, server_name_);
@@ -1535,7 +1535,7 @@ void GrpcLb::StartBalancerCallLocked() {
   // Init the LB call data.
   GPR_ASSERT(lb_calld_ == nullptr);
   lb_calld_ = MakeOrphanable<BalancerCallState>(Ref());
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     gpr_log(GPR_INFO,
             "[grpclb %p] Query for backends (lb_channel: %p, lb_calld: %p)",
             this, lb_channel_, lb_calld_.get());
@@ -1545,7 +1545,7 @@ void GrpcLb::StartBalancerCallLocked() {
 
 void GrpcLb::StartBalancerCallRetryTimerLocked() {
   grpc_millis next_try = lb_call_backoff_.NextAttemptTime();
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     gpr_log(GPR_INFO, "[grpclb %p] Connection to LB server lost...", this);
     grpc_millis timeout = next_try - ExecCtx::Get()->Now();
     if (timeout > 0) {
@@ -1572,7 +1572,7 @@ void GrpcLb::OnBalancerCallRetryTimerLocked(void* arg, grpc_error* error) {
   grpclb_policy->retry_timer_callback_pending_ = false;
   if (!grpclb_policy->shutting_down_ && error == GRPC_ERROR_NONE &&
       grpclb_policy->lb_calld_ == nullptr) {
-    if (grpc_lb_glb_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
       gpr_log(GPR_INFO, "[grpclb %p] Restarting call to LB server",
               grpclb_policy);
     }
@@ -1656,7 +1656,7 @@ OrphanablePtr<LoadBalancingPolicy> GrpcLb::CreateChildPolicyLocked(
     return nullptr;
   }
   helper->set_child(lb_policy.get());
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     gpr_log(GPR_INFO, "[grpclb %p] Created new child policy %s (%p)", this,
             name, lb_policy.get());
   }
@@ -1755,7 +1755,7 @@ void GrpcLb::CreateOrUpdateChildPolicyLocked() {
     // Cases 1, 2b, and 3b: create a new child policy.
     // If child_policy_ is null, we set it (case 1), else we set
     // pending_child_policy_ (cases 2b and 3b).
-    if (grpc_lb_glb_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
       gpr_log(GPR_INFO, "[grpclb %p] Creating new %schild policy %s", this,
               child_policy_ == nullptr ? "" : "pending ", child_policy_name);
     }
@@ -1779,7 +1779,7 @@ void GrpcLb::CreateOrUpdateChildPolicyLocked() {
   }
   GPR_ASSERT(policy_to_update != nullptr);
   // Update the policy.
-  if (grpc_lb_glb_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_glb_trace)) {
     gpr_log(GPR_INFO, "[grpclb %p] Updating %schild policy %p", this,
             policy_to_update == pending_child_policy_.get() ? "pending " : "",
             policy_to_update);

src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc

@@ -160,13 +160,13 @@ class PickFirst : public LoadBalancingPolicy {
 };
 
 PickFirst::PickFirst(Args args) : LoadBalancingPolicy(std::move(args)) {
-  if (grpc_lb_pick_first_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
     gpr_log(GPR_INFO, "Pick First %p created.", this);
   }
 }
 
 PickFirst::~PickFirst() {
-  if (grpc_lb_pick_first_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
     gpr_log(GPR_INFO, "Destroying Pick First %p", this);
   }
   GPR_ASSERT(subchannel_list_ == nullptr);
@@ -175,7 +175,7 @@ PickFirst::~PickFirst() {
 
 void PickFirst::ShutdownLocked() {
   AutoChildRefsUpdater guard(this);
-  if (grpc_lb_pick_first_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
     gpr_log(GPR_INFO, "Pick First %p Shutting down", this);
   }
   shutdown_ = true;
@@ -245,7 +245,7 @@ void PickFirst::UpdateChildRefsLocked() {
 
 void PickFirst::UpdateLocked(UpdateArgs args) {
   AutoChildRefsUpdater guard(this);
-  if (grpc_lb_pick_first_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
     gpr_log(GPR_INFO,
             "Pick First %p received update with %" PRIuPTR " addresses", this,
             args.addresses.size());
@@ -317,7 +317,7 @@ void PickFirst::UpdateLocked(UpdateArgs args) {
     // We do have a selected subchannel (which means it's READY), so keep
     // using it until one of the subchannels in the new list reports READY.
     if (latest_pending_subchannel_list_ != nullptr) {
-      if (grpc_lb_pick_first_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
         gpr_log(GPR_INFO,
                 "Pick First %p Shutting down latest pending subchannel list "
                 "%p, about to be replaced by newer latest %p",
@@ -349,7 +349,7 @@ void PickFirst::PickFirstSubchannelData::ProcessConnectivityChangeLocked(
   GPR_ASSERT(connectivity_state != GRPC_CHANNEL_SHUTDOWN);
   // Handle updates for the currently selected subchannel.
   if (p->selected_ == this) {
-    if (grpc_lb_pick_first_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
       gpr_log(GPR_INFO,
               "Pick First %p selected subchannel connectivity changed to %s", p,
               grpc_connectivity_state_name(connectivity_state));
@@ -358,7 +358,7 @@ void PickFirst::PickFirstSubchannelData::ProcessConnectivityChangeLocked(
     // pending update, switch to the pending update.
     if (connectivity_state != GRPC_CHANNEL_READY &&
         p->latest_pending_subchannel_list_ != nullptr) {
-      if (grpc_lb_pick_first_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
         gpr_log(GPR_INFO,
                 "Pick First %p promoting pending subchannel list %p to "
                 "replace %p",
@@ -492,7 +492,7 @@ void PickFirst::PickFirstSubchannelData::ProcessUnselectedReadyLocked() {
              subchannel_list() == p->latest_pending_subchannel_list_.get());
   // Case 2.  Promote p->latest_pending_subchannel_list_ to p->subchannel_list_.
   if (subchannel_list() == p->latest_pending_subchannel_list_.get()) {
-    if (grpc_lb_pick_first_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
       gpr_log(GPR_INFO,
               "Pick First %p promoting pending subchannel list %p to "
               "replace %p",
@@ -506,7 +506,7 @@ void PickFirst::PickFirstSubchannelData::ProcessUnselectedReadyLocked() {
   p->channel_control_helper()->UpdateState(
       GRPC_CHANNEL_READY,
       UniquePtr<SubchannelPicker>(New<Picker>(connected_subchannel()->Ref())));
-  if (grpc_lb_pick_first_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_pick_first_trace)) {
     gpr_log(GPR_INFO, "Pick First %p selected subchannel %p", p, subchannel());
   }
 }

src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc

@@ -212,7 +212,7 @@ RoundRobin::Picker::Picker(RoundRobin* parent,
   // TODO(roth): rand(3) is not thread-safe.  This should be replaced with
   // something better as part of https://github.com/grpc/grpc/issues/17891.
   last_picked_index_ = rand() % subchannels_.size();
-  if (grpc_lb_round_robin_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
     gpr_log(GPR_INFO,
             "[RR %p picker %p] created picker from subchannel_list=%p "
             "with %" PRIuPTR " READY subchannels; last_picked_index_=%" PRIuPTR,
@@ -224,7 +224,7 @@ RoundRobin::Picker::Picker(RoundRobin* parent,
 RoundRobin::PickResult RoundRobin::Picker::Pick(PickArgs* pick,
                                                 grpc_error** error) {
   last_picked_index_ = (last_picked_index_ + 1) % subchannels_.size();
-  if (grpc_lb_round_robin_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
     gpr_log(GPR_INFO,
             "[RR %p picker %p] returning index %" PRIuPTR
             ", connected_subchannel=%p",
@@ -240,13 +240,13 @@ RoundRobin::PickResult RoundRobin::Picker::Pick(PickArgs* pick,
 //
 
 RoundRobin::RoundRobin(Args args) : LoadBalancingPolicy(std::move(args)) {
-  if (grpc_lb_round_robin_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
     gpr_log(GPR_INFO, "[RR %p] Created", this);
   }
 }
 
 RoundRobin::~RoundRobin() {
-  if (grpc_lb_round_robin_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
     gpr_log(GPR_INFO, "[RR %p] Destroying Round Robin policy", this);
   }
   GPR_ASSERT(subchannel_list_ == nullptr);
@@ -255,7 +255,7 @@ RoundRobin::~RoundRobin() {
 
 void RoundRobin::ShutdownLocked() {
   AutoChildRefsUpdater guard(this);
-  if (grpc_lb_round_robin_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
     gpr_log(GPR_INFO, "[RR %p] Shutting down", this);
   }
   shutdown_ = true;
@@ -403,7 +403,7 @@ void RoundRobin::RoundRobinSubchannelList::
       // therefore we would not be receiving a notification for them.
       GPR_ASSERT(p->latest_pending_subchannel_list_.get() == this);
       GPR_ASSERT(!shutting_down());
-      if (grpc_lb_round_robin_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
         const size_t old_num_subchannels =
             p->subchannel_list_ != nullptr
                 ? p->subchannel_list_->num_subchannels()
@@ -424,7 +424,7 @@ void RoundRobin::RoundRobinSubchannelList::
 void RoundRobin::RoundRobinSubchannelData::UpdateConnectivityStateLocked(
     grpc_connectivity_state connectivity_state) {
   RoundRobin* p = static_cast<RoundRobin*>(subchannel_list()->policy());
-  if (grpc_lb_round_robin_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
     gpr_log(
         GPR_INFO,
         "[RR %p] connectivity changed for subchannel %p, subchannel_list %p "
@@ -449,7 +449,7 @@ void RoundRobin::RoundRobinSubchannelData::ProcessConnectivityChangeLocked(
   // when the subchannel list was created, we'd wind up in a constant
   // loop of re-resolution.
   if (connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
-    if (grpc_lb_round_robin_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
       gpr_log(GPR_INFO,
               "[RR %p] Subchannel %p has gone into TRANSIENT_FAILURE. "
               "Requesting re-resolution",
@@ -467,13 +467,13 @@ void RoundRobin::RoundRobinSubchannelData::ProcessConnectivityChangeLocked(
 
 void RoundRobin::UpdateLocked(UpdateArgs args) {
   AutoChildRefsUpdater guard(this);
-  if (grpc_lb_round_robin_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
     gpr_log(GPR_INFO, "[RR %p] received update with %" PRIuPTR " addresses",
             this, args.addresses.size());
   }
   // Replace latest_pending_subchannel_list_.
   if (latest_pending_subchannel_list_ != nullptr) {
-    if (grpc_lb_round_robin_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_round_robin_trace)) {
       gpr_log(GPR_INFO,
               "[RR %p] Shutting down previous pending subchannel list %p", this,
               latest_pending_subchannel_list_.get());

src/core/ext/filters/client_channel/lb_policy/subchannel_list.h

@@ -298,7 +298,7 @@ template <typename SubchannelListType, typename SubchannelDataType>
 void SubchannelData<SubchannelListType, SubchannelDataType>::
     UnrefSubchannelLocked(const char* reason) {
   if (subchannel_ != nullptr) {
-    if (subchannel_list_->tracer()->enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(*subchannel_list_->tracer())) {
       gpr_log(GPR_INFO,
               "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
               " (subchannel %p): unreffing subchannel",
@@ -323,7 +323,7 @@ void SubchannelData<SubchannelListType,
 template <typename SubchannelListType, typename SubchannelDataType>
 void SubchannelData<SubchannelListType,
                     SubchannelDataType>::StartConnectivityWatchLocked() {
-  if (subchannel_list_->tracer()->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*subchannel_list_->tracer())) {
     gpr_log(GPR_INFO,
             "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
             " (subchannel %p): starting watch: requesting connectivity change "
@@ -345,7 +345,7 @@ void SubchannelData<SubchannelListType,
 template <typename SubchannelListType, typename SubchannelDataType>
 void SubchannelData<SubchannelListType,
                     SubchannelDataType>::RenewConnectivityWatchLocked() {
-  if (subchannel_list_->tracer()->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*subchannel_list_->tracer())) {
     gpr_log(GPR_INFO,
             "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
             " (subchannel %p): renewing watch: requesting connectivity change "
@@ -365,7 +365,7 @@ void SubchannelData<SubchannelListType,
 template <typename SubchannelListType, typename SubchannelDataType>
 void SubchannelData<SubchannelListType,
                     SubchannelDataType>::StopConnectivityWatchLocked() {
-  if (subchannel_list_->tracer()->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*subchannel_list_->tracer())) {
     gpr_log(GPR_INFO,
             "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
             " (subchannel %p): stopping connectivity watch",
@@ -381,7 +381,7 @@ void SubchannelData<SubchannelListType,
 template <typename SubchannelListType, typename SubchannelDataType>
 void SubchannelData<SubchannelListType, SubchannelDataType>::
     CancelConnectivityWatchLocked(const char* reason) {
-  if (subchannel_list_->tracer()->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*subchannel_list_->tracer())) {
     gpr_log(GPR_INFO,
             "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
             " (subchannel %p): canceling connectivity watch (%s)",
@@ -413,7 +413,7 @@ bool SubchannelData<SubchannelListType,
     // is READY again (e.g., if the subchannel has transitioned back to
     // READY before the next watch gets requested).
     if (connected_subchannel_ == nullptr) {
-      if (subchannel_list_->tracer()->enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(*subchannel_list_->tracer())) {
         gpr_log(GPR_INFO,
                 "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
                 " (subchannel %p): state is READY but connected subchannel is "
@@ -436,7 +436,7 @@ template <typename SubchannelListType, typename SubchannelDataType>
 void SubchannelData<SubchannelListType, SubchannelDataType>::
     OnConnectivityChangedLocked(void* arg, grpc_error* error) {
   SubchannelData* sd = static_cast<SubchannelData*>(arg);
-  if (sd->subchannel_list_->tracer()->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*sd->subchannel_list_->tracer())) {
     gpr_log(
         GPR_INFO,
         "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
@@ -490,7 +490,7 @@ SubchannelList<SubchannelListType, SubchannelDataType>::SubchannelList(
       policy_(policy),
       tracer_(tracer),
       combiner_(GRPC_COMBINER_REF(combiner, "subchannel_list")) {
-  if (tracer_->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
     gpr_log(GPR_INFO,
             "[%s %p] Creating subchannel list %p for %" PRIuPTR " subchannels",
             tracer_->name(), policy, this, addresses.size());
@@ -524,7 +524,7 @@ SubchannelList<SubchannelListType, SubchannelDataType>::SubchannelList(
     grpc_channel_args_destroy(new_args);
     if (subchannel == nullptr) {
       // Subchannel could not be created.
-      if (tracer_->enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
         char* address_uri = grpc_sockaddr_to_uri(&addresses[i].address());
         gpr_log(GPR_INFO,
                 "[%s %p] could not create subchannel for address uri %s, "
@@ -534,7 +534,7 @@ SubchannelList<SubchannelListType, SubchannelDataType>::SubchannelList(
       }
       continue;
     }
-    if (tracer_->enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
       char* address_uri = grpc_sockaddr_to_uri(&addresses[i].address());
       gpr_log(GPR_INFO,
               "[%s %p] subchannel list %p index %" PRIuPTR
@@ -549,7 +549,7 @@ SubchannelList<SubchannelListType, SubchannelDataType>::SubchannelList(
 
 template <typename SubchannelListType, typename SubchannelDataType>
 SubchannelList<SubchannelListType, SubchannelDataType>::~SubchannelList() {
-  if (tracer_->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
     gpr_log(GPR_INFO, "[%s %p] Destroying subchannel_list %p", tracer_->name(),
             policy_, this);
   }
@@ -558,7 +558,7 @@ SubchannelList<SubchannelListType, SubchannelDataType>::~SubchannelList() {
 
 template <typename SubchannelListType, typename SubchannelDataType>
 void SubchannelList<SubchannelListType, SubchannelDataType>::ShutdownLocked() {
-  if (tracer_->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
     gpr_log(GPR_INFO, "[%s %p] Shutting down subchannel_list %p",
             tracer_->name(), policy_, this);
   }

src/core/ext/filters/client_channel/lb_policy/xds/xds.cc

@@ -608,7 +608,7 @@ void XdsLb::FallbackHelper::UpdateState(grpc_connectivity_state state,
   // If this request is from the pending fallback policy, ignore it until
   // it reports READY, at which point we swap it into place.
   if (CalledByPendingFallback()) {
-    if (grpc_lb_xds_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
       gpr_log(
           GPR_INFO,
           "[xdslb %p helper %p] pending fallback policy %p reports state=%s",
@@ -635,7 +635,7 @@ void XdsLb::FallbackHelper::RequestReresolution() {
           ? parent_->pending_fallback_policy_.get()
           : parent_->fallback_policy_.get();
   if (child_ != latest_fallback_policy) return;
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO,
             "[xdslb %p] Re-resolution requested from the fallback policy (%p).",
             parent_.get(), child_);
@@ -755,7 +755,7 @@ void XdsLb::BalancerChannelState::Orphan() {
 
 void XdsLb::BalancerChannelState::StartCallRetryTimerLocked() {
   grpc_millis next_try = lb_call_backoff_.NextAttemptTime();
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO,
             "[xdslb %p] Failed to connect to LB server (lb_chand: %p)...",
             xdslb_policy_.get(), this);
@@ -781,7 +781,7 @@ void XdsLb::BalancerChannelState::OnCallRetryTimerLocked(void* arg,
   lb_chand->retry_timer_callback_pending_ = false;
   if (!lb_chand->shutting_down_ && error == GRPC_ERROR_NONE &&
       lb_chand->lb_calld_ == nullptr) {
-    if (grpc_lb_xds_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
       gpr_log(GPR_INFO,
               "[xdslb %p] Restarting call to LB server (lb_chand: %p)",
               lb_chand->xdslb_policy_.get(), lb_chand);
@@ -796,7 +796,7 @@ void XdsLb::BalancerChannelState::StartCallLocked() {
   GPR_ASSERT(channel_ != nullptr);
   GPR_ASSERT(lb_calld_ == nullptr);
   lb_calld_ = MakeOrphanable<BalancerCallState>(Ref());
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO,
             "[xdslb %p] Query for backends (lb_chand: %p, lb_calld: %p)",
             xdslb_policy_.get(), this, lb_calld_.get());
@@ -932,7 +932,7 @@ void XdsLb::BalancerChannelState::BalancerCallState::Orphan() {
 
 void XdsLb::BalancerChannelState::BalancerCallState::StartQuery() {
   GPR_ASSERT(lb_call_ != nullptr);
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO, "[xdslb %p] Starting LB call (lb_calld: %p, lb_call: %p)",
             xdslb_policy(), this, lb_call_);
   }
@@ -1121,7 +1121,7 @@ void XdsLb::BalancerChannelState::BalancerCallState::
             GPR_MAX(GPR_MS_PER_SEC, interval);
       }
     }
-    if (grpc_lb_xds_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
       if (lb_calld->client_stats_report_interval_ != 0) {
         gpr_log(GPR_INFO,
                 "[xdslb %p] Received initial LB response message; "
@@ -1140,7 +1140,7 @@ void XdsLb::BalancerChannelState::BalancerCallState::
                   response_slice)) != nullptr) {
     // Have seen initial response, look for serverlist.
     GPR_ASSERT(lb_calld->lb_call_ != nullptr);
-    if (grpc_lb_xds_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
       gpr_log(GPR_INFO,
               "[xdslb %p] Serverlist with %" PRIuPTR " servers received",
               xdslb_policy, serverlist->num_servers);
@@ -1159,7 +1159,7 @@ void XdsLb::BalancerChannelState::BalancerCallState::
     // such channels don't have any current call but we have checked this call
     // is a current call.
     if (!lb_calld->lb_chand_->IsCurrentChannel()) {
-      if (grpc_lb_xds_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
         gpr_log(GPR_INFO,
                 "[xdslb %p] Promoting pending LB channel %p to replace "
                 "current LB channel %p",
@@ -1180,7 +1180,7 @@ void XdsLb::BalancerChannelState::BalancerCallState::
     if (!xdslb_policy->locality_serverlist_.empty() &&
         xds_grpclb_serverlist_equals(
             xdslb_policy->locality_serverlist_[0]->serverlist, serverlist)) {
-      if (grpc_lb_xds_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
         gpr_log(GPR_INFO,
                 "[xdslb %p] Incoming server list identical to current, "
                 "ignoring.",
@@ -1252,7 +1252,7 @@ void XdsLb::BalancerChannelState::BalancerCallState::
   XdsLb* xdslb_policy = lb_calld->xdslb_policy();
   BalancerChannelState* lb_chand = lb_calld->lb_chand_.get();
   GPR_ASSERT(lb_calld->lb_call_ != nullptr);
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     char* status_details =
         grpc_slice_to_c_string(lb_calld->lb_call_status_details_);
     gpr_log(GPR_INFO,
@@ -1271,7 +1271,7 @@ void XdsLb::BalancerChannelState::BalancerCallState::
     if (lb_chand != xdslb_policy->LatestLbChannel()) {
       // This channel must be the current one and there is a pending one. Swap
       // in the pending one and we are done.
-      if (grpc_lb_xds_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
         gpr_log(GPR_INFO,
                 "[xdslb %p] Promoting pending LB channel %p to replace "
                 "current LB channel %p",
@@ -1370,7 +1370,7 @@ XdsLb::XdsLb(Args args)
   grpc_uri* uri = grpc_uri_parse(server_uri, true);
   GPR_ASSERT(uri->path[0] != '\0');
   server_name_ = gpr_strdup(uri->path[0] == '/' ? uri->path + 1 : uri->path);
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO,
             "[xdslb %p] Will use '%s' as the server name for LB request.", this,
             server_name_);
@@ -1569,7 +1569,7 @@ void XdsLb::OnFallbackTimerLocked(void* arg, grpc_error* error) {
   // this callback actually runs, don't fall back.
   if (xdslb_policy->fallback_at_startup_checks_pending_ &&
       !xdslb_policy->shutting_down_ && error == GRPC_ERROR_NONE) {
-    if (grpc_lb_xds_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
       gpr_log(GPR_INFO,
               "[xdslb %p] Child policy not ready after fallback timeout; "
               "entering fallback mode",
@@ -1657,7 +1657,7 @@ void XdsLb::UpdateFallbackPolicyLocked() {
     // Cases 1, 2b, and 3b: create a new child policy.
     // If child_policy_ is null, we set it (case 1), else we set
     // pending_child_policy_ (cases 2b and 3b).
-    if (grpc_lb_xds_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
       gpr_log(GPR_INFO, "[xdslb %p] Creating new %sfallback policy %s", this,
               fallback_policy_ == nullptr ? "" : "pending ",
               fallback_policy_name);
@@ -1681,7 +1681,7 @@ void XdsLb::UpdateFallbackPolicyLocked() {
   }
   GPR_ASSERT(policy_to_update != nullptr);
   // Update the policy.
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(
         GPR_INFO, "[xdslb %p] Updating %sfallback policy %p", this,
         policy_to_update == pending_fallback_policy_.get() ? "pending " : "",
@@ -1707,7 +1707,7 @@ OrphanablePtr<LoadBalancingPolicy> XdsLb::CreateFallbackPolicyLocked(
     return nullptr;
   }
   helper->set_child(lb_policy.get());
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO, "[xdslb %p] Created new fallback policy %s (%p)", this,
             name, lb_policy.get());
   }
@@ -1829,7 +1829,7 @@ XdsLb::LocalityMap::LocalityEntry::CreateChildPolicyLocked(
     return nullptr;
   }
   helper->set_child(lb_policy.get());
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO, "[xdslb %p] Created new child policy %s (%p)", this, name,
             lb_policy.get());
   }
@@ -1920,7 +1920,7 @@ void XdsLb::LocalityMap::LocalityEntry::UpdateLocked(
     // Cases 1, 2b, and 3b: create a new child policy.
     // If child_policy_ is null, we set it (case 1), else we set
     // pending_child_policy_ (cases 2b and 3b).
-    if (grpc_lb_xds_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
       gpr_log(GPR_INFO, "[xdslb %p] Creating new %schild policy %s", this,
               child_policy_ == nullptr ? "" : "pending ", child_policy_name);
     }
@@ -1943,7 +1943,7 @@ void XdsLb::LocalityMap::LocalityEntry::UpdateLocked(
   }
   GPR_ASSERT(policy_to_update != nullptr);
   // Update the policy.
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO, "[xdslb %p] Updating %schild policy %p", this,
             policy_to_update == pending_child_policy_.get() ? "pending " : "",
             policy_to_update);
@@ -2029,7 +2029,7 @@ void XdsLb::LocalityMap::LocalityEntry::Helper::UpdateState(
   // If this request is from the pending child policy, ignore it until
   // it reports READY, at which point we swap it into place.
   if (CalledByPendingChild()) {
-    if (grpc_lb_xds_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
       gpr_log(GPR_INFO,
               "[xdslb %p helper %p] pending child policy %p reports state=%s",
               entry_->parent_.get(), this, entry_->pending_child_policy_.get(),
@@ -2129,7 +2129,7 @@ void XdsLb::LocalityMap::LocalityEntry::Helper::RequestReresolution() {
   if (entry_->pending_child_policy_ != nullptr && !CalledByPendingChild()) {
     return;
   }
-  if (grpc_lb_xds_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_lb_xds_trace)) {
     gpr_log(GPR_INFO,
             "[xdslb %p] Re-resolution requested from the internal RR policy "
             "(%p).",

src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc

@@ -18,7 +18,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#if GRPC_ARES == 1 && !defined(GRPC_UV)
+#if GRPC_ARES == 1
 
 #include <limits.h>
 #include <stdio.h>
@@ -430,6 +430,13 @@ static grpc_error* blocking_resolve_address_ares(
 static grpc_address_resolver_vtable ares_resolver = {
     grpc_resolve_address_ares, blocking_resolve_address_ares};
 
+#ifdef GRPC_UV
+/* TODO(murgatroid99): Remove this when we want the cares resolver to be the
+ * default when using libuv */
+static bool should_use_ares(const char* resolver_env) {
+  return resolver_env != nullptr && gpr_stricmp(resolver_env, "ares") == 0;
+}
+#else  /* GRPC_UV */
 static bool should_use_ares(const char* resolver_env) {
   // TODO(lidiz): Remove the "g_custom_iomgr_enabled" flag once c-ares support
   // custom IO managers (e.g. gevent).
@@ -437,6 +444,7 @@ static bool should_use_ares(const char* resolver_env) {
          (resolver_env == nullptr || strlen(resolver_env) == 0 ||
           gpr_stricmp(resolver_env, "ares") == 0);
 }
+#endif /* GRPC_UV */
 
 void grpc_resolver_dns_ares_init() {
   char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER");
@@ -468,10 +476,10 @@ void grpc_resolver_dns_ares_shutdown() {
   gpr_free(resolver_env);
 }
 
-#else /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+#else /* GRPC_ARES == 1 */
 
 void grpc_resolver_dns_ares_init(void) {}
 
 void grpc_resolver_dns_ares_shutdown(void) {}
 
-#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+#endif /* GRPC_ARES == 1 */

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc

@@ -18,7 +18,7 @@
 #include <grpc/support/port_platform.h>
 
 #include "src/core/lib/iomgr/port.h"
-#if GRPC_ARES == 1 && !defined(GRPC_UV)
+#if GRPC_ARES == 1
 
 #include <ares.h>
 #include <string.h>
@@ -84,6 +84,10 @@ struct grpc_ares_ev_driver {
   grpc_timer query_timeout;
   /** cancels queries on a timeout */
   grpc_closure on_timeout_locked;
+  /** alarm to poll ares_process on in case fd events don't happen */
+  grpc_timer ares_backup_poll_alarm;
+  /** polls ares_process on a periodic timer */
+  grpc_closure on_ares_backup_poll_alarm_locked;
 };
 
 static void grpc_ares_notify_on_event_locked(grpc_ares_ev_driver* ev_driver);
@@ -130,6 +134,13 @@ static void fd_node_shutdown_locked(fd_node* fdn, const char* reason) {
 
 static void on_timeout_locked(void* arg, grpc_error* error);
 
+static void on_ares_backup_poll_alarm_locked(void* arg, grpc_error* error);
+
+static void noop_inject_channel_config(ares_channel channel) {}
+
+void (*grpc_ares_test_only_inject_config)(ares_channel channel) =
+    noop_inject_channel_config;
+
 grpc_error* grpc_ares_ev_driver_create_locked(grpc_ares_ev_driver** ev_driver,
                                               grpc_pollset_set* pollset_set,
                                               int query_timeout_ms,
@@ -140,6 +151,7 @@ grpc_error* grpc_ares_ev_driver_create_locked(grpc_ares_ev_driver** ev_driver,
   memset(&opts, 0, sizeof(opts));
   opts.flags |= ARES_FLAG_STAYOPEN;
   int status = ares_init_options(&(*ev_driver)->channel, &opts, ARES_OPT_FLAGS);
+  grpc_ares_test_only_inject_config((*ev_driver)->channel);
   GRPC_CARES_TRACE_LOG("request:%p grpc_ares_ev_driver_create_locked", request);
   if (status != ARES_SUCCESS) {
     char* err_msg;
@@ -163,6 +175,9 @@ grpc_error* grpc_ares_ev_driver_create_locked(grpc_ares_ev_driver** ev_driver,
       ->polled_fd_factory->ConfigureAresChannelLocked((*ev_driver)->channel);
   GRPC_CLOSURE_INIT(&(*ev_driver)->on_timeout_locked, on_timeout_locked,
                     *ev_driver, grpc_combiner_scheduler(combiner));
+  GRPC_CLOSURE_INIT(&(*ev_driver)->on_ares_backup_poll_alarm_locked,
+                    on_ares_backup_poll_alarm_locked, *ev_driver,
+                    grpc_combiner_scheduler(combiner));
   (*ev_driver)->query_timeout_ms = query_timeout_ms;
   return GRPC_ERROR_NONE;
 }
@@ -174,6 +189,7 @@ void grpc_ares_ev_driver_on_queries_complete_locked(
   // fds; if it's not working, there are no fds to shut down.
   ev_driver->shutting_down = true;
   grpc_timer_cancel(&ev_driver->query_timeout);
+  grpc_timer_cancel(&ev_driver->ares_backup_poll_alarm);
   grpc_ares_ev_driver_unref(ev_driver);
 }
 
@@ -204,6 +220,21 @@ static fd_node* pop_fd_node_locked(fd_node** head, ares_socket_t as) {
   return nullptr;
 }
 
+static grpc_millis calculate_next_ares_backup_poll_alarm_ms(
+    grpc_ares_ev_driver* driver) {
+  // An alternative here could be to use ares_timeout to try to be more
+  // accurate, but that would require using "struct timeval"'s, which just makes
+  // things a bit more complicated. So just poll every second, as suggested
+  // by the c-ares code comments.
+  grpc_millis ms_until_next_ares_backup_poll_alarm = 1000;
+  GRPC_CARES_TRACE_LOG(
+      "request:%p ev_driver=%p. next ares process poll time in "
+      "%" PRId64 " ms",
+      driver->request, driver, ms_until_next_ares_backup_poll_alarm);
+  return ms_until_next_ares_backup_poll_alarm +
+         grpc_core::ExecCtx::Get()->Now();
+}
+
 static void on_timeout_locked(void* arg, grpc_error* error) {
   grpc_ares_ev_driver* driver = static_cast<grpc_ares_ev_driver*>(arg);
   GRPC_CARES_TRACE_LOG(
@@ -216,8 +247,50 @@ static void on_timeout_locked(void* arg, grpc_error* error) {
   grpc_ares_ev_driver_unref(driver);
 }
 
+/* In case of non-responsive DNS servers, dropped packets, etc., c-ares has
+ * intelligent timeout and retry logic, which we can take advantage of by
+ * polling ares_process_fd on time intervals. Overall, the c-ares library is
+ * meant to be called into and given a chance to proceed name resolution:
+ *   a) when fd events happen
+ *   b) when some time has passed without fd events having happened
+ * For the latter, we use this backup poller. Also see
+ * https://github.com/grpc/grpc/pull/17688 description for more details. */
+static void on_ares_backup_poll_alarm_locked(void* arg, grpc_error* error) {
+  grpc_ares_ev_driver* driver = static_cast<grpc_ares_ev_driver*>(arg);
+  GRPC_CARES_TRACE_LOG(
+      "request:%p ev_driver=%p on_ares_backup_poll_alarm_locked. "
+      "driver->shutting_down=%d. "
+      "err=%s",
+      driver->request, driver, driver->shutting_down, grpc_error_string(error));
+  if (!driver->shutting_down && error == GRPC_ERROR_NONE) {
+    fd_node* fdn = driver->fds;
+    while (fdn != nullptr) {
+      if (!fdn->already_shutdown) {
+        GRPC_CARES_TRACE_LOG(
+            "request:%p ev_driver=%p on_ares_backup_poll_alarm_locked; "
+            "ares_process_fd. fd=%s",
+            driver->request, driver, fdn->grpc_polled_fd->GetName());
+        ares_socket_t as = fdn->grpc_polled_fd->GetWrappedAresSocketLocked();
+        ares_process_fd(driver->channel, as, as);
+      }
+      fdn = fdn->next;
+    }
+    if (!driver->shutting_down) {
+      grpc_millis next_ares_backup_poll_alarm =
+          calculate_next_ares_backup_poll_alarm_ms(driver);
+      grpc_ares_ev_driver_ref(driver);
+      grpc_timer_init(&driver->ares_backup_poll_alarm,
+                      next_ares_backup_poll_alarm,
+                      &driver->on_ares_backup_poll_alarm_locked);
+    }
+    grpc_ares_notify_on_event_locked(driver);
+  }
+  grpc_ares_ev_driver_unref(driver);
+}
+
 static void on_readable_locked(void* arg, grpc_error* error) {
   fd_node* fdn = static_cast<fd_node*>(arg);
+  GPR_ASSERT(fdn->readable_registered);
   grpc_ares_ev_driver* ev_driver = fdn->ev_driver;
   const ares_socket_t as = fdn->grpc_polled_fd->GetWrappedAresSocketLocked();
   fdn->readable_registered = false;
@@ -242,6 +315,7 @@ static void on_readable_locked(void* arg, grpc_error* error) {
 
 static void on_writable_locked(void* arg, grpc_error* error) {
   fd_node* fdn = static_cast<fd_node*>(arg);
+  GPR_ASSERT(fdn->writable_registered);
   grpc_ares_ev_driver* ev_driver = fdn->ev_driver;
   const ares_socket_t as = fdn->grpc_polled_fd->GetWrappedAresSocketLocked();
   fdn->writable_registered = false;
@@ -351,6 +425,7 @@ void grpc_ares_ev_driver_start_locked(grpc_ares_ev_driver* ev_driver) {
   if (!ev_driver->working) {
     ev_driver->working = true;
     grpc_ares_notify_on_event_locked(ev_driver);
+    // Initialize overall DNS resolution timeout alarm
     grpc_millis timeout =
         ev_driver->query_timeout_ms == 0
             ? GRPC_MILLIS_INF_FUTURE
@@ -362,7 +437,14 @@ void grpc_ares_ev_driver_start_locked(grpc_ares_ev_driver* ev_driver) {
     grpc_ares_ev_driver_ref(ev_driver);
     grpc_timer_init(&ev_driver->query_timeout, timeout,
                     &ev_driver->on_timeout_locked);
+    // Initialize the backup poll alarm
+    grpc_millis next_ares_backup_poll_alarm =
+        calculate_next_ares_backup_poll_alarm_ms(ev_driver);
+    grpc_ares_ev_driver_ref(ev_driver);
+    grpc_timer_init(&ev_driver->ares_backup_poll_alarm,
+                    next_ares_backup_poll_alarm,
+                    &ev_driver->on_ares_backup_poll_alarm_locked);
   }
 }
 
-#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+#endif /* GRPC_ARES == 1 */

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h

@@ -54,6 +54,9 @@ void grpc_ares_ev_driver_on_queries_complete_locked(
 /* Shutdown all the grpc_fds used by \a ev_driver */
 void grpc_ares_ev_driver_shutdown_locked(grpc_ares_ev_driver* ev_driver);
 
+/* Exposed in this header for C-core tests only */
+extern void (*grpc_ares_test_only_inject_config)(ares_channel channel);
+
 namespace grpc_core {
 
 /* A wrapped fd that integrates with the grpc iomgr of the current platform.

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_libuv.cc

@@ -0,0 +1,179 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/port.h"
+#if GRPC_ARES == 1 && defined(GRPC_UV)
+
+#include <ares.h>
+#include <uv.h>
+
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/iomgr/combiner.h"
+
+namespace grpc_core {
+
+void ares_uv_poll_cb(uv_poll_t* handle, int status, int events);
+
+void ares_uv_poll_close_cb(uv_handle_t* handle) { Delete(handle); }
+
+class GrpcPolledFdLibuv : public GrpcPolledFd {
+ public:
+  GrpcPolledFdLibuv(ares_socket_t as, grpc_combiner* combiner)
+      : as_(as), combiner_(combiner) {
+    gpr_asprintf(&name_, "c-ares socket: %" PRIdPTR, (intptr_t)as);
+    handle_ = New<uv_poll_t>();
+    uv_poll_init_socket(uv_default_loop(), handle_, as);
+    handle_->data = this;
+    GRPC_COMBINER_REF(combiner_, "libuv ares event driver");
+  }
+
+  ~GrpcPolledFdLibuv() {
+    gpr_free(name_);
+    GRPC_COMBINER_UNREF(combiner_, "libuv ares event driver");
+  }
+
+  void RegisterForOnReadableLocked(grpc_closure* read_closure) override {
+    GPR_ASSERT(read_closure_ == nullptr);
+    GPR_ASSERT((poll_events_ & UV_READABLE) == 0);
+    read_closure_ = read_closure;
+    poll_events_ |= UV_READABLE;
+    uv_poll_start(handle_, poll_events_, ares_uv_poll_cb);
+  }
+
+  void RegisterForOnWriteableLocked(grpc_closure* write_closure) override {
+    GPR_ASSERT(write_closure_ == nullptr);
+    GPR_ASSERT((poll_events_ & UV_WRITABLE) == 0);
+    write_closure_ = write_closure;
+    poll_events_ |= UV_WRITABLE;
+    uv_poll_start(handle_, poll_events_, ares_uv_poll_cb);
+  }
+
+  bool IsFdStillReadableLocked() override {
+    /* uv_poll_t is based on poll, which is level triggered. So, if cares
+     * leaves some data unread, the event will trigger again. */
+    return false;
+  }
+
+  void ShutdownInternalLocked(grpc_error* error) {
+    uv_poll_stop(handle_);
+    uv_close(reinterpret_cast<uv_handle_t*>(handle_), ares_uv_poll_close_cb);
+    if (read_closure_ != nullptr) {
+      GRPC_CLOSURE_SCHED(read_closure_, GRPC_ERROR_CANCELLED);
+    }
+    if (write_closure_ != nullptr) {
+      GRPC_CLOSURE_SCHED(write_closure_, GRPC_ERROR_CANCELLED);
+    }
+  }
+
+  void ShutdownLocked(grpc_error* error) override {
+    if (grpc_core::ExecCtx::Get() == nullptr) {
+      grpc_core::ExecCtx exec_ctx;
+      ShutdownInternalLocked(error);
+    } else {
+      ShutdownInternalLocked(error);
+    }
+  }
+
+  ares_socket_t GetWrappedAresSocketLocked() override { return as_; }
+
+  const char* GetName() override { return name_; }
+
+  char* name_;
+  ares_socket_t as_;
+  uv_poll_t* handle_;
+  grpc_closure* read_closure_ = nullptr;
+  grpc_closure* write_closure_ = nullptr;
+  int poll_events_ = 0;
+  grpc_combiner* combiner_;
+};
+
+struct AresUvPollCbArg {
+  AresUvPollCbArg(uv_poll_t* handle, int status, int events)
+      : handle(handle), status(status), events(events) {}
+
+  uv_poll_t* handle;
+  int status;
+  int events;
+};
+
+static void ares_uv_poll_cb_locked(void* arg, grpc_error* error) {
+  grpc_core::UniquePtr<AresUvPollCbArg> arg_struct(
+      reinterpret_cast<AresUvPollCbArg*>(arg));
+  uv_poll_t* handle = arg_struct->handle;
+  int status = arg_struct->status;
+  int events = arg_struct->events;
+  GrpcPolledFdLibuv* polled_fd =
+      reinterpret_cast<GrpcPolledFdLibuv*>(handle->data);
+  if (status < 0) {
+    error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("cares polling error");
+    error =
+        grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR,
+                           grpc_slice_from_static_string(uv_strerror(status)));
+  }
+  if (events & UV_READABLE) {
+    GPR_ASSERT(polled_fd->read_closure_ != nullptr);
+    GRPC_CLOSURE_SCHED(polled_fd->read_closure_, error);
+    polled_fd->read_closure_ = nullptr;
+    polled_fd->poll_events_ &= ~UV_READABLE;
+  }
+  if (events & UV_WRITABLE) {
+    GPR_ASSERT(polled_fd->write_closure_ != nullptr);
+    GRPC_CLOSURE_SCHED(polled_fd->write_closure_, error);
+    polled_fd->write_closure_ = nullptr;
+    polled_fd->poll_events_ &= ~UV_WRITABLE;
+  }
+  uv_poll_start(handle, polled_fd->poll_events_, ares_uv_poll_cb);
+}
+
+void ares_uv_poll_cb(uv_poll_t* handle, int status, int events) {
+  grpc_core::ExecCtx exec_ctx;
+  GrpcPolledFdLibuv* polled_fd =
+      reinterpret_cast<GrpcPolledFdLibuv*>(handle->data);
+  AresUvPollCbArg* arg = New<AresUvPollCbArg>(handle, status, events);
+  GRPC_CLOSURE_SCHED(
+      GRPC_CLOSURE_CREATE(ares_uv_poll_cb_locked, arg,
+                          grpc_combiner_scheduler(polled_fd->combiner_)),
+      GRPC_ERROR_NONE);
+}
+
+class GrpcPolledFdFactoryLibuv : public GrpcPolledFdFactory {
+ public:
+  GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
+                                      grpc_pollset_set* driver_pollset_set,
+                                      grpc_combiner* combiner) override {
+    return New<GrpcPolledFdLibuv>(as, combiner);
+  }
+
+  void ConfigureAresChannelLocked(ares_channel channel) override {}
+};
+
+UniquePtr<GrpcPolledFdFactory> NewGrpcPolledFdFactory(grpc_combiner* combiner) {
+  return UniquePtr<GrpcPolledFdFactory>(New<GrpcPolledFdFactoryLibuv>());
+}
+
+}  // namespace grpc_core
+
+#endif /* GRPC_ARES == 1 && defined(GRPC_UV) */

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc

@@ -109,6 +109,7 @@ class GrpcPolledFdWindows : public GrpcPolledFd {
     read_closure_ = read_closure;
     GPR_ASSERT(GRPC_SLICE_LENGTH(read_buf_) == 0);
     grpc_slice_unref_internal(read_buf_);
+    GPR_ASSERT(!read_buf_has_data_);
     read_buf_ = GRPC_SLICE_MALLOC(4192);
     WSABUF buffer;
     buffer.buf = (char*)GRPC_SLICE_START_PTR(read_buf_);
@@ -175,7 +176,7 @@ class GrpcPolledFdWindows : public GrpcPolledFd {
     GRPC_CARES_TRACE_LOG(
         "RecvFrom called on fd:|%s|. Current read buf length:|%d|", GetName(),
         GRPC_SLICE_LENGTH(read_buf_));
-    if (GRPC_SLICE_LENGTH(read_buf_) == 0) {
+    if (!read_buf_has_data_) {
       WSASetLastError(WSAEWOULDBLOCK);
       return -1;
     }
@@ -186,6 +187,9 @@ class GrpcPolledFdWindows : public GrpcPolledFd {
     }
     read_buf_ = grpc_slice_sub_no_ref(read_buf_, bytes_read,
                                       GRPC_SLICE_LENGTH(read_buf_));
+    if (GRPC_SLICE_LENGTH(read_buf_) == 0) {
+      read_buf_has_data_ = false;
+    }
     /* c-ares overloads this recv_from virtual socket function to receive
      * data on both UDP and TCP sockets, and from is nullptr for TCP. */
     if (from != nullptr) {
@@ -302,6 +306,11 @@ class GrpcPolledFdWindows : public GrpcPolledFd {
     polled_fd->OnIocpReadableInner(error);
   }
 
+  // TODO(apolcyn): improve this error handling to be less conversative.
+  // An e.g. ECONNRESET error here should result in errors when
+  // c-ares reads from this socket later, but it shouldn't necessarily cancel
+  // the entire resolution attempt. Doing so will allow the "inject broken
+  // nameserver list" test to pass on Windows.
   void OnIocpReadableInner(grpc_error* error) {
     if (error == GRPC_ERROR_NONE) {
       if (winsocket_->read_info.wsa_error != 0) {
@@ -323,6 +332,7 @@ class GrpcPolledFdWindows : public GrpcPolledFd {
     if (error == GRPC_ERROR_NONE) {
       read_buf_ = grpc_slice_sub_no_ref(read_buf_, 0,
                                         winsocket_->read_info.bytes_transfered);
+      read_buf_has_data_ = true;
     } else {
       grpc_slice_unref_internal(read_buf_);
       read_buf_ = grpc_empty_slice();
@@ -370,6 +380,7 @@ class GrpcPolledFdWindows : public GrpcPolledFd {
   char recv_from_source_addr_[200];
   ares_socklen_t recv_from_source_addr_len_;
   grpc_slice read_buf_;
+  bool read_buf_has_data_ = false;
   grpc_slice write_buf_;
   grpc_closure* read_closure_ = nullptr;
   grpc_closure* write_closure_ = nullptr;

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc

@@ -18,7 +18,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#if GRPC_ARES == 1 && !defined(GRPC_UV)
+#if GRPC_ARES == 1
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/lib/iomgr/sockaddr.h"
@@ -101,7 +101,7 @@ static void log_address_sorting_list(const ServerAddressList& addresses,
 }
 
 void grpc_cares_wrapper_address_sorting_sort(ServerAddressList* addresses) {
-  if (grpc_trace_cares_address_sorting.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_cares_address_sorting)) {
     log_address_sorting_list(*addresses, "input");
   }
   address_sorting_sortable* sortables = (address_sorting_sortable*)gpr_zalloc(
@@ -120,7 +120,7 @@ void grpc_cares_wrapper_address_sorting_sort(ServerAddressList* addresses) {
   }
   gpr_free(sortables);
   *addresses = std::move(sorted);
-  if (grpc_trace_cares_address_sorting.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_cares_address_sorting)) {
     log_address_sorting_list(*addresses, "output");
   }
 }
@@ -687,4 +687,4 @@ void (*grpc_resolve_address_ares)(
     grpc_pollset_set* interested_parties, grpc_closure* on_done,
     grpc_resolved_addresses** addrs) = grpc_resolve_address_ares_impl;
 
-#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
+#endif /* GRPC_ARES == 1 */

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h

@@ -26,16 +26,18 @@
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 
-#define GRPC_DNS_ARES_DEFAULT_QUERY_TIMEOUT_MS 10000
+#define GRPC_DNS_ARES_DEFAULT_QUERY_TIMEOUT_MS 120000
 
 extern grpc_core::TraceFlag grpc_trace_cares_address_sorting;
 
 extern grpc_core::TraceFlag grpc_trace_cares_resolver;
 
-#define GRPC_CARES_TRACE_LOG(format, ...)                         \
-  if (grpc_trace_cares_resolver.enabled()) {                      \
-    gpr_log(GPR_DEBUG, "(c-ares resolver) " format, __VA_ARGS__); \
-  }
+#define GRPC_CARES_TRACE_LOG(format, ...)                           \
+  do {                                                              \
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_cares_resolver)) {       \
+      gpr_log(GPR_DEBUG, "(c-ares resolver) " format, __VA_ARGS__); \
+    }                                                               \
+  } while (0)
 
 typedef struct grpc_ares_request grpc_ares_request;
 

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc

@@ -18,7 +18,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#if GRPC_ARES != 1 || defined(GRPC_UV)
+#if GRPC_ARES != 1
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 
@@ -62,4 +62,4 @@ void (*grpc_resolve_address_ares)(
     grpc_pollset_set* interested_parties, grpc_closure* on_done,
     grpc_resolved_addresses** addrs) = grpc_resolve_address_ares_impl;
 
-#endif /* GRPC_ARES != 1 || defined(GRPC_UV) */
+#endif /* GRPC_ARES != 1 */

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv.cc

@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/port.h"
+#if GRPC_ARES == 1 && defined(GRPC_UV)
+
+#include <grpc/support/string_util.h>
+
+#include "src/core/ext/filters/client_channel/parse_address.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h"
+#include "src/core/ext/filters/client_channel/server_address.h"
+#include "src/core/lib/gpr/host_port.h"
+#include "src/core/lib/gpr/string.h"
+
+bool grpc_ares_query_ipv6() {
+  /* The libuv grpc code currently does not have the code to probe for this,
+   * so we assume for now that IPv6 is always available in contexts where this
+   * code will be used. */
+  return true;
+}
+
+bool grpc_ares_maybe_resolve_localhost_manually_locked(
+    const char* name, const char* default_port,
+    grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs) {
+  char* host = nullptr;
+  char* port = nullptr;
+  bool out = inner_maybe_resolve_localhost_manually_locked(name, default_port,
+                                                           addrs, &host, &port);
+  gpr_free(host);
+  gpr_free(port);
+  return out;
+}
+
+#endif /* GRPC_ARES == 1 && defined(GRPC_UV) */

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.cc

@@ -0,0 +1,83 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/port.h"
+#if GRPC_ARES == 1 && (defined(GRPC_UV) || defined(GPR_WINDOWS))
+
+#include <grpc/support/string_util.h>
+
+#include "src/core/ext/filters/client_channel/parse_address.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h"
+#include "src/core/ext/filters/client_channel/server_address.h"
+#include "src/core/lib/gpr/host_port.h"
+#include "src/core/lib/gpr/string.h"
+
+bool inner_maybe_resolve_localhost_manually_locked(
+    const char* name, const char* default_port,
+    grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs, char** host,
+    char** port) {
+  gpr_split_host_port(name, host, port);
+  if (*host == nullptr) {
+    gpr_log(GPR_ERROR,
+            "Failed to parse %s into host:port during manual localhost "
+            "resolution check.",
+            name);
+    return false;
+  }
+  if (*port == nullptr) {
+    if (default_port == nullptr) {
+      gpr_log(GPR_ERROR,
+              "No port or default port for %s during manual localhost "
+              "resolution check.",
+              name);
+      return false;
+    }
+    *port = gpr_strdup(default_port);
+  }
+  if (gpr_stricmp(*host, "localhost") == 0) {
+    GPR_ASSERT(*addrs == nullptr);
+    *addrs = grpc_core::MakeUnique<grpc_core::ServerAddressList>();
+    uint16_t numeric_port = grpc_strhtons(*port);
+    // Append the ipv6 loopback address.
+    struct sockaddr_in6 ipv6_loopback_addr;
+    memset(&ipv6_loopback_addr, 0, sizeof(ipv6_loopback_addr));
+    ((char*)&ipv6_loopback_addr.sin6_addr)[15] = 1;
+    ipv6_loopback_addr.sin6_family = AF_INET6;
+    ipv6_loopback_addr.sin6_port = numeric_port;
+    (*addrs)->emplace_back(&ipv6_loopback_addr, sizeof(ipv6_loopback_addr),
+                           nullptr /* args */);
+    // Append the ipv4 loopback address.
+    struct sockaddr_in ipv4_loopback_addr;
+    memset(&ipv4_loopback_addr, 0, sizeof(ipv4_loopback_addr));
+    ((char*)&ipv4_loopback_addr.sin_addr)[0] = 0x7f;
+    ((char*)&ipv4_loopback_addr.sin_addr)[3] = 0x01;
+    ipv4_loopback_addr.sin_family = AF_INET;
+    ipv4_loopback_addr.sin_port = numeric_port;
+    (*addrs)->emplace_back(&ipv4_loopback_addr, sizeof(ipv4_loopback_addr),
+                           nullptr /* args */);
+    // Let the address sorter figure out which one should be tried first.
+    grpc_cares_wrapper_address_sorting_sort(addrs->get());
+    return true;
+  }
+  return false;
+}
+
+#endif /* GRPC_ARES == 1 && (defined(GRPC_UV) || defined(GPR_WINDOWS)) */

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h

@@ -0,0 +1,34 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_LIBUV_WINDOWS_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_LIBUV_WINDOWS_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/support/string_util.h>
+
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+
+bool inner_maybe_resolve_localhost_manually_locked(
+    const char* name, const char* default_port,
+    grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs, char** host,
+    char** port);
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_LIBUV_WINDOWS_H \
+        */

src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc

@@ -25,6 +25,7 @@
 
 #include "src/core/ext/filters/client_channel/parse_address.h"
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_libuv_windows.h"
 #include "src/core/ext/filters/client_channel/server_address.h"
 #include "src/core/lib/gpr/host_port.h"
 #include "src/core/lib/gpr/string.h"
@@ -32,56 +33,6 @@
 
 bool grpc_ares_query_ipv6() { return grpc_ipv6_loopback_available(); }
 
-static bool inner_maybe_resolve_localhost_manually_locked(
-    const char* name, const char* default_port,
-    grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs, char** host,
-    char** port) {
-  gpr_split_host_port(name, host, port);
-  if (*host == nullptr) {
-    gpr_log(GPR_ERROR,
-            "Failed to parse %s into host:port during Windows localhost "
-            "resolution check.",
-            name);
-    return false;
-  }
-  if (*port == nullptr) {
-    if (default_port == nullptr) {
-      gpr_log(GPR_ERROR,
-              "No port or default port for %s during Windows localhost "
-              "resolution check.",
-              name);
-      return false;
-    }
-    *port = gpr_strdup(default_port);
-  }
-  if (gpr_stricmp(*host, "localhost") == 0) {
-    GPR_ASSERT(*addrs == nullptr);
-    *addrs = grpc_core::MakeUnique<grpc_core::ServerAddressList>();
-    uint16_t numeric_port = grpc_strhtons(*port);
-    // Append the ipv6 loopback address.
-    struct sockaddr_in6 ipv6_loopback_addr;
-    memset(&ipv6_loopback_addr, 0, sizeof(ipv6_loopback_addr));
-    ((char*)&ipv6_loopback_addr.sin6_addr)[15] = 1;
-    ipv6_loopback_addr.sin6_family = AF_INET6;
-    ipv6_loopback_addr.sin6_port = numeric_port;
-    (*addrs)->emplace_back(&ipv6_loopback_addr, sizeof(ipv6_loopback_addr),
-                           nullptr /* args */);
-    // Append the ipv4 loopback address.
-    struct sockaddr_in ipv4_loopback_addr;
-    memset(&ipv4_loopback_addr, 0, sizeof(ipv4_loopback_addr));
-    ((char*)&ipv4_loopback_addr.sin_addr)[0] = 0x7f;
-    ((char*)&ipv4_loopback_addr.sin_addr)[3] = 0x01;
-    ipv4_loopback_addr.sin_family = AF_INET;
-    ipv4_loopback_addr.sin_port = numeric_port;
-    (*addrs)->emplace_back(&ipv4_loopback_addr, sizeof(ipv4_loopback_addr),
-                           nullptr /* args */);
-    // Let the address sorter figure out which one should be tried first.
-    grpc_cares_wrapper_address_sorting_sort(addrs->get());
-    return true;
-  }
-  return false;
-}
-
 bool grpc_ares_maybe_resolve_localhost_manually_locked(
     const char* name, const char* default_port,
     grpc_core::UniquePtr<grpc_core::ServerAddressList>* addrs) {

src/core/ext/filters/client_channel/resolving_lb_policy.cc

@@ -77,7 +77,7 @@ class ResolvingLoadBalancingPolicy::ResolverResultHandler
       : parent_(std::move(parent)) {}
 
   ~ResolverResultHandler() {
-    if (parent_->tracer_->enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(*(parent_->tracer_))) {
       gpr_log(GPR_INFO, "resolving_lb=%p: resolver shutdown complete",
               parent_.get());
     }
@@ -125,7 +125,7 @@ class ResolvingLoadBalancingPolicy::ResolvingControlHelper
     // If this request is from the pending child policy, ignore it until
     // it reports READY, at which point we swap it into place.
     if (CalledByPendingChild()) {
-      if (parent_->tracer_->enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(*(parent_->tracer_))) {
         gpr_log(GPR_INFO,
                 "resolving_lb=%p helper=%p: pending child policy %p reports "
                 "state=%s",
@@ -151,7 +151,7 @@ class ResolvingLoadBalancingPolicy::ResolvingControlHelper
     if (parent_->pending_lb_policy_ != nullptr && !CalledByPendingChild()) {
       return;
     }
-    if (parent_->tracer_->enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(*(parent_->tracer_))) {
       gpr_log(GPR_INFO, "resolving_lb=%p: started name re-resolving",
               parent_.get());
     }
@@ -241,7 +241,7 @@ void ResolvingLoadBalancingPolicy::ShutdownLocked() {
     resolver_.reset();
     MutexLock lock(&lb_policy_mu_);
     if (lb_policy_ != nullptr) {
-      if (tracer_->enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
         gpr_log(GPR_INFO, "resolving_lb=%p: shutting down lb_policy=%p", this,
                 lb_policy_.get());
       }
@@ -250,7 +250,7 @@ void ResolvingLoadBalancingPolicy::ShutdownLocked() {
       lb_policy_.reset();
     }
     if (pending_lb_policy_ != nullptr) {
-      if (tracer_->enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
         gpr_log(GPR_INFO, "resolving_lb=%p: shutting down pending lb_policy=%p",
                 this, pending_lb_policy_.get());
       }
@@ -298,7 +298,7 @@ void ResolvingLoadBalancingPolicy::FillChildRefsForChannelz(
 }
 
 void ResolvingLoadBalancingPolicy::StartResolvingLocked() {
-  if (tracer_->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
     gpr_log(GPR_INFO, "resolving_lb=%p: starting name resolution", this);
   }
   GPR_ASSERT(!started_resolving_);
@@ -314,7 +314,7 @@ void ResolvingLoadBalancingPolicy::OnResolverError(grpc_error* error) {
     GRPC_ERROR_UNREF(error);
     return;
   }
-  if (tracer_->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
     gpr_log(GPR_INFO, "resolving_lb=%p: resolver transient failure: %s", this,
             grpc_error_string(error));
   }
@@ -398,7 +398,7 @@ void ResolvingLoadBalancingPolicy::CreateOrUpdateLbPolicyLocked(
     // Cases 1, 2b, and 3b: create a new child policy.
     // If lb_policy_ is null, we set it (case 1), else we set
     // pending_lb_policy_ (cases 2b and 3b).
-    if (tracer_->enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
       gpr_log(GPR_INFO, "resolving_lb=%p: Creating new %schild policy %s", this,
               lb_policy_ == nullptr ? "" : "pending ", lb_policy_name);
     }
@@ -419,7 +419,7 @@ void ResolvingLoadBalancingPolicy::CreateOrUpdateLbPolicyLocked(
   }
   GPR_ASSERT(policy_to_update != nullptr);
   // Update the policy.
-  if (tracer_->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
     gpr_log(GPR_INFO, "resolving_lb=%p: Updating %schild policy %p", this,
             policy_to_update == pending_lb_policy_.get() ? "pending " : "",
             policy_to_update);
@@ -458,7 +458,7 @@ ResolvingLoadBalancingPolicy::CreateLbPolicyLocked(
     return nullptr;
   }
   helper->set_child(lb_policy.get());
-  if (tracer_->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
     gpr_log(GPR_INFO, "resolving_lb=%p: created new LB policy \"%s\" (%p)",
             this, lb_policy_name, lb_policy.get());
   }
@@ -514,7 +514,7 @@ void ResolvingLoadBalancingPolicy::OnResolverResultChangedLocked(
     Resolver::Result result) {
   // Handle race conditions.
   if (resolver_ == nullptr) return;
-  if (tracer_->enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(*tracer_)) {
     gpr_log(GPR_INFO, "resolving_lb=%p: got resolver result", this);
   }
   // We only want to trace the address resolution in the follow cases:

src/core/ext/filters/client_channel/subchannel.cc

@@ -66,13 +66,12 @@
 #define GRPC_SUBCHANNEL_RECONNECT_JITTER 0.2
 
 // Conversion between subchannel call and call stack.
-#define SUBCHANNEL_CALL_TO_CALL_STACK(call)                              \
-  (grpc_call_stack*)((char*)(call) + GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE( \
-                                         sizeof(SubchannelCall)))
-#define CALL_STACK_TO_SUBCHANNEL_CALL(callstack)        \
-  (SubchannelCall*)(((char*)(call_stack)) -             \
-                    GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE( \
-                        sizeof(SubchannelCall)))
+#define SUBCHANNEL_CALL_TO_CALL_STACK(call) \
+  (grpc_call_stack*)((char*)(call) +        \
+                     GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(SubchannelCall)))
+#define CALL_STACK_TO_SUBCHANNEL_CALL(callstack) \
+  (SubchannelCall*)(((char*)(call_stack)) -      \
+                    GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(SubchannelCall)))
 
 namespace grpc_core {
 
@@ -152,10 +151,10 @@ RefCountedPtr<SubchannelCall> ConnectedSubchannel::CreateCall(
 size_t ConnectedSubchannel::GetInitialCallSizeEstimate(
     size_t parent_data_size) const {
   size_t allocation_size =
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(SubchannelCall));
+      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(SubchannelCall));
   if (parent_data_size > 0) {
     allocation_size +=
-        GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(channel_stack_->call_stack_size) +
+        GPR_ROUND_UP_TO_ALIGNMENT_SIZE(channel_stack_->call_stack_size) +
         parent_data_size;
   } else {
     allocation_size += channel_stack_->call_stack_size;
@@ -179,9 +178,8 @@ void SubchannelCall::StartTransportStreamOpBatch(
 
 void* SubchannelCall::GetParentData() {
   grpc_channel_stack* chanstk = connected_subchannel_->channel_stack();
-  return (char*)this +
-         GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(SubchannelCall)) +
-         GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(chanstk->call_stack_size);
+  return (char*)this + GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(SubchannelCall)) +
+         GPR_ROUND_UP_TO_ALIGNMENT_SIZE(chanstk->call_stack_size);
 }
 
 grpc_call_stack* SubchannelCall::GetCallStack() {

src/core/ext/filters/http/message_compress/message_compress_filter.cc

@@ -249,7 +249,7 @@ static void finish_send_message(grpc_call_element* elem) {
   bool did_compress = grpc_msg_compress(calld->message_compression_algorithm,
                                         &calld->slices, &tmp);
   if (did_compress) {
-    if (grpc_compression_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_compression_trace)) {
       const char* algo_name;
       const size_t before_size = calld->slices.length;
       const size_t after_size = tmp.length;
@@ -265,7 +265,7 @@ static void finish_send_message(grpc_call_element* elem) {
     grpc_slice_buffer_swap(&calld->slices, &tmp);
     send_flags |= GRPC_WRITE_INTERNAL_COMPRESS;
   } else {
-    if (grpc_compression_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_compression_trace)) {
       const char* algo_name;
       GPR_ASSERT(grpc_message_compression_algorithm_name(
           calld->message_compression_algorithm, &algo_name));

src/core/ext/transport/chttp2/transport/chttp2_plugin.cc

@@ -20,16 +20,15 @@
 
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/debug/trace.h"
-#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gprpp/global_config.h"
 #include "src/core/lib/transport/metadata.h"
 
+GPR_GLOBAL_CONFIG_DEFINE_BOOL(grpc_experimental_disable_flow_control, false,
+                              "Disable flow control");
+
 void grpc_chttp2_plugin_init(void) {
-  g_flow_control_enabled = true;
-  char* env_variable = gpr_getenv("GRPC_EXPERIMENTAL_DISABLE_FLOW_CONTROL");
-  if (env_variable != nullptr) {
-    g_flow_control_enabled = false;
-    gpr_free(env_variable);
-  }
+  g_flow_control_enabled =
+      !GPR_GLOBAL_CONFIG_GET(grpc_experimental_disable_flow_control);
 }
 
 void grpc_chttp2_plugin_shutdown(void) {}

src/core/ext/transport/chttp2/transport/chttp2_transport.cc

@@ -679,8 +679,6 @@ grpc_chttp2_stream::grpc_chttp2_stream(grpc_chttp2_transport* t,
   grpc_slice_buffer_init(&frame_storage);
   grpc_slice_buffer_init(&unprocessed_incoming_frames_buffer);
   grpc_slice_buffer_init(&flow_controlled_buffer);
-  grpc_slice_buffer_init(&compressed_data_buffer);
-  grpc_slice_buffer_init(&decompressed_data_buffer);
 
   GRPC_CLOSURE_INIT(&complete_fetch_locked, ::complete_fetch_locked, this,
                     grpc_combiner_scheduler(t->combiner));
@@ -704,8 +702,13 @@ grpc_chttp2_stream::~grpc_chttp2_stream() {
 
   grpc_slice_buffer_destroy_internal(&unprocessed_incoming_frames_buffer);
   grpc_slice_buffer_destroy_internal(&frame_storage);
-  grpc_slice_buffer_destroy_internal(&compressed_data_buffer);
-  grpc_slice_buffer_destroy_internal(&decompressed_data_buffer);
+  if (stream_compression_method != GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS) {
+    grpc_slice_buffer_destroy_internal(&compressed_data_buffer);
+  }
+  if (stream_decompression_method !=
+      GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS) {
+    grpc_slice_buffer_destroy_internal(&decompressed_data_buffer);
+  }
 
   grpc_chttp2_list_remove_stalled_by_transport(t, this);
   grpc_chttp2_list_remove_stalled_by_stream(t, this);
@@ -759,12 +762,15 @@ static void destroy_stream(grpc_transport* gt, grpc_stream* gs,
   GPR_TIMER_SCOPE("destroy_stream", 0);
   grpc_chttp2_transport* t = reinterpret_cast<grpc_chttp2_transport*>(gt);
   grpc_chttp2_stream* s = reinterpret_cast<grpc_chttp2_stream*>(gs);
-
-  if (s->stream_compression_ctx != nullptr) {
+  if (s->stream_compression_method !=
+          GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS &&
+      s->stream_compression_ctx != nullptr) {
     grpc_stream_compression_context_destroy(s->stream_compression_ctx);
     s->stream_compression_ctx = nullptr;
   }
-  if (s->stream_decompression_ctx != nullptr) {
+  if (s->stream_decompression_method !=
+          GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS &&
+      s->stream_decompression_ctx != nullptr) {
     grpc_stream_compression_context_destroy(s->stream_decompression_ctx);
     s->stream_decompression_ctx = nullptr;
   }
@@ -1243,7 +1249,7 @@ void grpc_chttp2_complete_closure_step(grpc_chttp2_transport* t,
     return;
   }
   closure->next_data.scratch -= CLOSURE_BARRIER_FIRST_REF_BIT;
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     const char* errstr = grpc_error_string(error);
     gpr_log(
         GPR_INFO,
@@ -1395,7 +1401,7 @@ static void perform_stream_op_locked(void* stream_op,
 
   s->context = op->payload->context;
   s->traced = op->is_traced;
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     char* str = grpc_transport_stream_op_batch_string(op);
     gpr_log(GPR_INFO, "perform_stream_op_locked: %s; on_complete = %p", str,
             op->on_complete);
@@ -1442,7 +1448,12 @@ static void perform_stream_op_locked(void* stream_op,
             true, &s->stream_compression_method) == 0) {
       s->stream_compression_method = GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS;
     }
-
+    if (s->stream_compression_method !=
+        GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS) {
+      s->uncompressed_data_size = 0;
+      s->stream_compression_ctx = nullptr;
+      grpc_slice_buffer_init(&s->compressed_data_buffer);
+    }
     s->send_initial_metadata_finished = add_closure_barrier(on_complete);
     s->send_initial_metadata =
         op_payload->send_initial_metadata.send_initial_metadata;
@@ -1694,7 +1705,7 @@ static void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
     }
   }
 
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     char* str = grpc_transport_stream_op_batch_string(op);
     gpr_log(GPR_INFO, "perform_stream_op[s=%p]: %s", s, str);
     gpr_free(str);
@@ -1861,7 +1872,7 @@ static void perform_transport_op_locked(void* stream_op,
 
 static void perform_transport_op(grpc_transport* gt, grpc_transport_op* op) {
   grpc_chttp2_transport* t = reinterpret_cast<grpc_chttp2_transport*>(gt);
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     char* msg = grpc_transport_op_string(op);
     gpr_log(GPR_INFO, "perform_transport_op[t=%p]: %s", t, msg);
     gpr_free(msg);
@@ -1998,27 +2009,39 @@ void grpc_chttp2_maybe_complete_recv_trailing_metadata(grpc_chttp2_transport* t,
         !s->seen_error && s->recv_trailing_metadata_finished != nullptr) {
       /* Maybe some SYNC_FLUSH data is left in frame_storage. Consume them and
        * maybe decompress the next 5 bytes in the stream. */
-      bool end_of_context;
-      if (!s->stream_decompression_ctx) {
-        s->stream_decompression_ctx = grpc_stream_compression_context_create(
-            s->stream_decompression_method);
-      }
-      if (!grpc_stream_decompress(
-              s->stream_decompression_ctx, &s->frame_storage,
-              &s->unprocessed_incoming_frames_buffer, nullptr,
-              GRPC_HEADER_SIZE_IN_BYTES, &end_of_context)) {
-        grpc_slice_buffer_reset_and_unref_internal(&s->frame_storage);
-        grpc_slice_buffer_reset_and_unref_internal(
-            &s->unprocessed_incoming_frames_buffer);
-        s->seen_error = true;
-      } else {
+      if (s->stream_decompression_method ==
+          GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS) {
+        grpc_slice_buffer_move_first(&s->frame_storage,
+                                     GRPC_HEADER_SIZE_IN_BYTES,
+                                     &s->unprocessed_incoming_frames_buffer);
         if (s->unprocessed_incoming_frames_buffer.length > 0) {
           s->unprocessed_incoming_frames_decompressed = true;
           pending_data = true;
         }
-        if (end_of_context) {
-          grpc_stream_compression_context_destroy(s->stream_decompression_ctx);
-          s->stream_decompression_ctx = nullptr;
+      } else {
+        bool end_of_context;
+        if (!s->stream_decompression_ctx) {
+          s->stream_decompression_ctx = grpc_stream_compression_context_create(
+              s->stream_decompression_method);
+        }
+        if (!grpc_stream_decompress(
+                s->stream_decompression_ctx, &s->frame_storage,
+                &s->unprocessed_incoming_frames_buffer, nullptr,
+                GRPC_HEADER_SIZE_IN_BYTES, &end_of_context)) {
+          grpc_slice_buffer_reset_and_unref_internal(&s->frame_storage);
+          grpc_slice_buffer_reset_and_unref_internal(
+              &s->unprocessed_incoming_frames_buffer);
+          s->seen_error = true;
+        } else {
+          if (s->unprocessed_incoming_frames_buffer.length > 0) {
+            s->unprocessed_incoming_frames_decompressed = true;
+            pending_data = true;
+          }
+          if (end_of_context) {
+            grpc_stream_compression_context_destroy(
+                s->stream_decompression_ctx);
+            s->stream_decompression_ctx = nullptr;
+          }
         }
       }
     }
@@ -2596,7 +2619,7 @@ static void schedule_bdp_ping_locked(grpc_chttp2_transport* t) {
 
 static void start_bdp_ping_locked(void* tp, grpc_error* error) {
   grpc_chttp2_transport* t = static_cast<grpc_chttp2_transport*>(tp);
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     gpr_log(GPR_INFO, "%s: Start BDP ping err=%s", t->peer_string,
             grpc_error_string(error));
   }
@@ -2612,7 +2635,7 @@ static void start_bdp_ping_locked(void* tp, grpc_error* error) {
 
 static void finish_bdp_ping_locked(void* tp, grpc_error* error) {
   grpc_chttp2_transport* t = static_cast<grpc_chttp2_transport*>(tp);
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     gpr_log(GPR_INFO, "%s: Complete BDP ping err=%s", t->peer_string,
             grpc_error_string(error));
   }
@@ -2744,7 +2767,7 @@ static void start_keepalive_ping_locked(void* arg, grpc_error* error) {
   if (t->channelz_socket != nullptr) {
     t->channelz_socket->RecordKeepaliveSent();
   }
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     gpr_log(GPR_INFO, "%s: Start keepalive ping", t->peer_string);
   }
   GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive watchdog");
@@ -2757,7 +2780,7 @@ static void finish_keepalive_ping_locked(void* arg, grpc_error* error) {
   grpc_chttp2_transport* t = static_cast<grpc_chttp2_transport*>(arg);
   if (t->keepalive_state == GRPC_CHTTP2_KEEPALIVE_STATE_PINGING) {
     if (error == GRPC_ERROR_NONE) {
-      if (grpc_http_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
         gpr_log(GPR_INFO, "%s: Finish keepalive ping", t->peer_string);
       }
       t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_WAITING;
@@ -2941,6 +2964,8 @@ bool Chttp2IncomingByteStream::Next(size_t max_size_hint,
 }
 
 void Chttp2IncomingByteStream::MaybeCreateStreamDecompressionCtx() {
+  GPR_DEBUG_ASSERT(stream_->stream_decompression_method !=
+                   GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS);
   if (!stream_->stream_decompression_ctx) {
     stream_->stream_decompression_ctx = grpc_stream_compression_context_create(
         stream_->stream_decompression_method);
@@ -2951,7 +2976,9 @@ grpc_error* Chttp2IncomingByteStream::Pull(grpc_slice* slice) {
   GPR_TIMER_SCOPE("incoming_byte_stream_pull", 0);
   grpc_error* error;
   if (stream_->unprocessed_incoming_frames_buffer.length > 0) {
-    if (!stream_->unprocessed_incoming_frames_decompressed) {
+    if (!stream_->unprocessed_incoming_frames_decompressed &&
+        stream_->stream_decompression_method !=
+            GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS) {
       bool end_of_context;
       MaybeCreateStreamDecompressionCtx();
       if (!grpc_stream_decompress(stream_->stream_decompression_ctx,
@@ -3063,7 +3090,7 @@ static void benign_reclaimer_locked(void* arg, grpc_error* error) {
       grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
     /* Channel with no active streams: send a goaway to try and make it
      * disconnect cleanly */
-    if (grpc_resource_quota_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_resource_quota_trace)) {
       gpr_log(GPR_INFO, "HTTP2: %s - send goaway to free memory",
               t->peer_string);
     }
@@ -3071,7 +3098,8 @@ static void benign_reclaimer_locked(void* arg, grpc_error* error) {
                 grpc_error_set_int(
                     GRPC_ERROR_CREATE_FROM_STATIC_STRING("Buffers full"),
                     GRPC_ERROR_INT_HTTP2_ERROR, GRPC_HTTP2_ENHANCE_YOUR_CALM));
-  } else if (error == GRPC_ERROR_NONE && grpc_resource_quota_trace.enabled()) {
+  } else if (error == GRPC_ERROR_NONE &&
+             GRPC_TRACE_FLAG_ENABLED(grpc_resource_quota_trace)) {
     gpr_log(GPR_INFO,
             "HTTP2: %s - skip benign reclamation, there are still %" PRIdPTR
             " streams",
@@ -3092,7 +3120,7 @@ static void destructive_reclaimer_locked(void* arg, grpc_error* error) {
   if (error == GRPC_ERROR_NONE && n > 0) {
     grpc_chttp2_stream* s = static_cast<grpc_chttp2_stream*>(
         grpc_chttp2_stream_map_rand(&t->stream_map));
-    if (grpc_resource_quota_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_resource_quota_trace)) {
       gpr_log(GPR_INFO, "HTTP2: %s - abandon stream id %d", t->peer_string,
               s->id);
     }

src/core/ext/transport/chttp2/transport/flow_control.h

@@ -127,7 +127,7 @@ class FlowControlTrace {
             StreamFlowControl* sfc);
   void Finish();
 
-  const bool enabled_ = grpc_flowctl_trace.enabled();
+  const bool enabled_ = GRPC_TRACE_FLAG_ENABLED(grpc_flowctl_trace);
 
   TransportFlowControl* tfc_;
   StreamFlowControl* sfc_;

src/core/ext/transport/chttp2/transport/frame_settings.cc

@@ -217,19 +217,20 @@ grpc_error* grpc_chttp2_settings_parser_parse(void* p, grpc_chttp2_transport* t,
               parser->incoming_settings[id] != parser->value) {
             t->initial_window_update += static_cast<int64_t>(parser->value) -
                                         parser->incoming_settings[id];
-            if (grpc_http_trace.enabled() || grpc_flowctl_trace.enabled()) {
+            if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace) ||
+                GRPC_TRACE_FLAG_ENABLED(grpc_flowctl_trace)) {
               gpr_log(GPR_INFO, "%p[%s] adding %d for initial_window change", t,
                       t->is_client ? "cli" : "svr",
                       static_cast<int>(t->initial_window_update));
             }
           }
           parser->incoming_settings[id] = parser->value;
-          if (grpc_http_trace.enabled()) {
+          if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
             gpr_log(GPR_INFO, "CHTTP2:%s:%s: got setting %s = %d",
                     t->is_client ? "CLI" : "SVR", t->peer_string, sp->name,
                     parser->value);
           }
-        } else if (grpc_http_trace.enabled()) {
+        } else if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
           gpr_log(GPR_ERROR, "CHTTP2: Ignoring unknown setting %d (value %d)",
                   parser->id, parser->value);
         }

src/core/ext/transport/chttp2/transport/hpack_encoder.cc

@@ -461,7 +461,7 @@ static void hpack_enc(grpc_chttp2_hpack_compressor* c, grpc_mdelem elem,
         "Reserved header (colon-prefixed) happening after regular ones.");
   }
 
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     char* k = grpc_slice_to_c_string(GRPC_MDKEY(elem));
     char* v = nullptr;
     if (grpc_is_binary_header(GRPC_MDKEY(elem))) {
@@ -660,7 +660,7 @@ void grpc_chttp2_hpack_compressor_set_max_table_size(
     }
   }
   c->advertise_table_size_change = 1;
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     gpr_log(GPR_INFO, "set max table size from encoder to %d", max_table_size);
   }
 }

src/core/ext/transport/chttp2/transport/hpack_parser.cc

@@ -624,7 +624,7 @@ static const uint8_t inverse_base64[256] = {
 /* emission helpers */
 static grpc_error* on_hdr(grpc_chttp2_hpack_parser* p, grpc_mdelem md,
                           int add_to_table) {
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     char* k = grpc_slice_to_c_string(GRPC_MDKEY(md));
     char* v = nullptr;
     if (grpc_is_binary_header(GRPC_MDKEY(md))) {
@@ -994,7 +994,7 @@ static grpc_error* parse_lithdr_nvridx_v(grpc_chttp2_hpack_parser* p,
 /* finish parsing a max table size change */
 static grpc_error* finish_max_tbl_size(grpc_chttp2_hpack_parser* p,
                                        const uint8_t* cur, const uint8_t* end) {
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     gpr_log(GPR_INFO, "MAX TABLE SIZE: %d", p->index);
   }
   grpc_error* err =
@@ -1616,6 +1616,12 @@ static void parse_stream_compression_md(grpc_chttp2_transport* t,
     s->stream_decompression_method =
         GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS;
   }
+
+  if (s->stream_decompression_method !=
+      GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS) {
+    s->stream_decompression_ctx = nullptr;
+    grpc_slice_buffer_init(&s->decompressed_data_buffer);
+  }
 }
 
 grpc_error* grpc_chttp2_header_parser_parse(void* hpack_parser,

src/core/ext/transport/chttp2/transport/hpack_table.cc

@@ -247,7 +247,7 @@ void grpc_chttp2_hptbl_set_max_bytes(grpc_chttp2_hptbl* tbl,
   if (tbl->max_bytes == max_bytes) {
     return;
   }
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     gpr_log(GPR_INFO, "Update hpack parser max size to %d", max_bytes);
   }
   while (tbl->mem_used > max_bytes) {
@@ -270,7 +270,7 @@ grpc_error* grpc_chttp2_hptbl_set_current_table_size(grpc_chttp2_hptbl* tbl,
     gpr_free(msg);
     return err;
   }
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     gpr_log(GPR_INFO, "Update hpack parser table size to %d", bytes);
   }
   while (tbl->mem_used > bytes) {

src/core/ext/transport/chttp2/transport/internal.h

@@ -238,7 +238,7 @@ class Chttp2IncomingByteStream : public ByteStream {
   // switch to std::shared_ptr<>.
   void Ref() { refs_.Ref(); }
   void Unref() {
-    if (refs_.Unref()) {
+    if (GPR_UNLIKELY(refs_.Unref())) {
       grpc_core::Delete(this);
     }
   }
@@ -583,10 +583,6 @@ struct grpc_chttp2_stream {
 
   grpc_slice_buffer frame_storage; /* protected by t combiner */
 
-  /* Accessed only by transport thread when stream->pending_byte_stream == false
-   * Accessed only by application thread when stream->pending_byte_stream ==
-   * true */
-  grpc_slice_buffer unprocessed_incoming_frames_buffer;
   grpc_closure* on_next = nullptr;  /* protected by t combiner */
   bool pending_byte_stream = false; /* protected by t combiner */
   // cached length of buffer to be used by the transport thread in cases where
@@ -594,6 +590,10 @@ struct grpc_chttp2_stream {
   // application threads are allowed to modify
   // unprocessed_incoming_frames_buffer
   size_t unprocessed_incoming_frames_buffer_cached_length = 0;
+  /* Accessed only by transport thread when stream->pending_byte_stream == false
+   * Accessed only by application thread when stream->pending_byte_stream ==
+   * true */
+  grpc_slice_buffer unprocessed_incoming_frames_buffer;
   grpc_closure reset_byte_stream;
   grpc_error* byte_stream_error = GRPC_ERROR_NONE; /* protected by t combiner */
   bool received_last_frame = false;                /* protected by t combiner */
@@ -634,18 +634,7 @@ struct grpc_chttp2_stream {
   /* Stream decompression method to be used. */
   grpc_stream_compression_method stream_decompression_method =
       GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS;
-  /** Stream compression decompress context */
-  grpc_stream_compression_context* stream_decompression_ctx = nullptr;
-  /** Stream compression compress context */
-  grpc_stream_compression_context* stream_compression_ctx = nullptr;
 
-  /** Buffer storing data that is compressed but not sent */
-  grpc_slice_buffer compressed_data_buffer;
-  /** Amount of uncompressed bytes sent out when compressed_data_buffer is
-   * emptied */
-  size_t uncompressed_data_size = 0;
-  /** Temporary buffer storing decompressed data */
-  grpc_slice_buffer decompressed_data_buffer;
   /** Whether bytes stored in unprocessed_incoming_byte_stream is decompressed
    */
   bool unprocessed_incoming_frames_decompressed = false;
@@ -655,6 +644,22 @@ struct grpc_chttp2_stream {
   size_t decompressed_header_bytes = 0;
   /** Byte counter for number of bytes written */
   size_t byte_counter = 0;
+
+  /** Amount of uncompressed bytes sent out when compressed_data_buffer is
+   * emptied */
+  size_t uncompressed_data_size;
+  /** Stream compression compress context */
+  grpc_stream_compression_context* stream_compression_ctx;
+  /** Buffer storing data that is compressed but not sent */
+  grpc_slice_buffer compressed_data_buffer;
+
+  /** Stream compression decompress context */
+  grpc_stream_compression_context* stream_decompression_ctx;
+  /** Temporary buffer storing decompressed data.
+   * Initialized, used, and destroyed only when stream uses (non-identity)
+   * compression.
+   */
+  grpc_slice_buffer decompressed_data_buffer;
 };
 
 /** Transport writing call flow:
@@ -766,11 +771,12 @@ void grpc_chttp2_complete_closure_step(grpc_chttp2_transport* t,
 // extern grpc_core::TraceFlag grpc_http_trace;
 // extern grpc_core::TraceFlag grpc_flowctl_trace;
 
-#define GRPC_CHTTP2_IF_TRACING(stmt) \
-  if (!(grpc_http_trace.enabled()))  \
-    ;                                \
-  else                               \
-    stmt
+#define GRPC_CHTTP2_IF_TRACING(stmt)                \
+  do {                                              \
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) { \
+      (stmt);                                       \
+    }                                               \
+  } while (0)
 
 void grpc_chttp2_fake_status(grpc_chttp2_transport* t,
                              grpc_chttp2_stream* stream, grpc_error* error);

src/core/ext/transport/chttp2/transport/parsing.cc

@@ -304,7 +304,7 @@ static grpc_error* init_frame_parser(grpc_chttp2_transport* t) {
     case GRPC_CHTTP2_FRAME_GOAWAY:
       return init_goaway_parser(t);
     default:
-      if (grpc_http_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
         gpr_log(GPR_ERROR, "Unknown frame type %02x", t->incoming_frame_type);
       }
       return init_skip_frame_parser(t, 0);
@@ -400,7 +400,7 @@ static void on_initial_header(void* tp, grpc_mdelem md) {
   grpc_chttp2_stream* s = t->incoming_stream;
   GPR_ASSERT(s != nullptr);
 
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     char* key = grpc_slice_to_c_string(GRPC_MDKEY(md));
     char* value =
         grpc_dump_slice(GRPC_MDVALUE(md), GPR_DUMP_HEX | GPR_DUMP_ASCII);
@@ -496,7 +496,7 @@ static void on_trailing_header(void* tp, grpc_mdelem md) {
   grpc_chttp2_stream* s = t->incoming_stream;
   GPR_ASSERT(s != nullptr);
 
-  if (grpc_http_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
     char* key = grpc_slice_to_c_string(GRPC_MDKEY(md));
     char* value =
         grpc_dump_slice(GRPC_MDVALUE(md), GPR_DUMP_HEX | GPR_DUMP_ASCII);
@@ -761,7 +761,7 @@ static grpc_error* parse_frame_slice(grpc_chttp2_transport* t,
   if (GPR_LIKELY(err == GRPC_ERROR_NONE)) {
     return err;
   } else if (grpc_error_get_int(err, GRPC_ERROR_INT_STREAM_ID, &unused)) {
-    if (grpc_http_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
       const char* msg = grpc_error_string(err);
       gpr_log(GPR_ERROR, "%s", msg);
     }

src/core/ext/transport/chttp2/transport/stream_lists.cc

@@ -67,7 +67,7 @@ static bool stream_list_pop(grpc_chttp2_transport* t,
     s->included[id] = 0;
   }
   *stream = s;
-  if (s && grpc_trace_http2_stream_state.enabled()) {
+  if (s && GRPC_TRACE_FLAG_ENABLED(grpc_trace_http2_stream_state)) {
     gpr_log(GPR_INFO, "%p[%d][%s]: pop from %s", t, s->id,
             t->is_client ? "cli" : "svr", stream_list_id_string(id));
   }
@@ -89,7 +89,7 @@ static void stream_list_remove(grpc_chttp2_transport* t, grpc_chttp2_stream* s,
   } else {
     t->lists[id].tail = s->links[id].prev;
   }
-  if (grpc_trace_http2_stream_state.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_http2_stream_state)) {
     gpr_log(GPR_INFO, "%p[%d][%s]: remove from %s", t, s->id,
             t->is_client ? "cli" : "svr", stream_list_id_string(id));
   }
@@ -121,7 +121,7 @@ static void stream_list_add_tail(grpc_chttp2_transport* t,
   }
   t->lists[id].tail = s;
   s->included[id] = 1;
-  if (grpc_trace_http2_stream_state.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_http2_stream_state)) {
     gpr_log(GPR_INFO, "%p[%d][%s]: add to %s", t, s->id,
             t->is_client ? "cli" : "svr", stream_list_id_string(id));
   }

src/core/ext/transport/chttp2/transport/writing.cc

@@ -25,6 +25,7 @@
 
 #include <grpc/support/log.h>
 
+#include "src/core/lib/compression/stream_compression.h"
 #include "src/core/lib/debug/stats.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
@@ -52,7 +53,8 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
   }
   if (!grpc_closure_list_empty(pq->lists[GRPC_CHTTP2_PCL_INFLIGHT])) {
     /* ping already in-flight: wait */
-    if (grpc_http_trace.enabled() || grpc_bdp_estimator_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace) ||
+        GRPC_TRACE_FLAG_ENABLED(grpc_bdp_estimator_trace)) {
       gpr_log(GPR_INFO, "%s: Ping delayed [%p]: already pinging",
               t->is_client ? "CLIENT" : "SERVER", t->peer_string);
     }
@@ -61,7 +63,8 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
   if (t->ping_state.pings_before_data_required == 0 &&
       t->ping_policy.max_pings_without_data != 0) {
     /* need to receive something of substance before sending a ping again */
-    if (grpc_http_trace.enabled() || grpc_bdp_estimator_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace) ||
+        GRPC_TRACE_FLAG_ENABLED(grpc_bdp_estimator_trace)) {
       gpr_log(GPR_INFO, "%s: Ping delayed [%p]: too many recent pings: %d/%d",
               t->is_client ? "CLIENT" : "SERVER", t->peer_string,
               t->ping_state.pings_before_data_required,
@@ -81,7 +84,8 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
 
   if (next_allowed_ping > now) {
     /* not enough elapsed time between successive pings */
-    if (grpc_http_trace.enabled() || grpc_bdp_estimator_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace) ||
+        GRPC_TRACE_FLAG_ENABLED(grpc_bdp_estimator_trace)) {
       gpr_log(GPR_INFO,
               "%s: Ping delayed [%p]: not enough time elapsed since last ping. "
               " Last ping %f: Next ping %f: Now %f",
@@ -107,7 +111,8 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
                         grpc_chttp2_ping_create(false, pq->inflight_id));
   GRPC_STATS_INC_HTTP2_PINGS_SENT();
   t->ping_state.last_ping_sent_time = now;
-  if (grpc_http_trace.enabled() || grpc_bdp_estimator_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace) ||
+      GRPC_TRACE_FLAG_ENABLED(grpc_bdp_estimator_trace)) {
     gpr_log(GPR_INFO, "%s: Ping sent [%s]: %d/%d",
             t->is_client ? "CLIENT" : "SERVER", t->peer_string,
             t->ping_state.pings_before_data_required,
@@ -140,7 +145,7 @@ static bool update_list(grpc_chttp2_transport* t, grpc_chttp2_stream* s,
 
 static void report_stall(grpc_chttp2_transport* t, grpc_chttp2_stream* s,
                          const char* staller) {
-  if (grpc_flowctl_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_flowctl_trace)) {
     gpr_log(
         GPR_DEBUG,
         "%s:%p stream %d moved to stalled list by %s. This is FULLY expected "
@@ -150,7 +155,11 @@ static void report_stall(grpc_chttp2_transport* t, grpc_chttp2_stream* s,
         ":flowed=%" PRId64 ":peer_initwin=%d:t_win=%" PRId64
         ":s_win=%d:s_delta=%" PRId64 "]",
         t->peer_string, t, s->id, staller, s->flow_controlled_buffer.length,
-        s->compressed_data_buffer.length, s->flow_controlled_bytes_flowed,
+        s->stream_compression_method ==
+                GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS
+            ? 0
+            : s->compressed_data_buffer.length,
+        s->flow_controlled_bytes_flowed,
         t->settings[GRPC_ACKED_SETTINGS]
                    [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE],
         t->flow_control->remote_window(),
@@ -325,7 +334,23 @@ class DataSendContext {
 
   bool AnyOutgoing() const { return max_outgoing() > 0; }
 
+  void FlushUncompressedBytes() {
+    uint32_t send_bytes = static_cast<uint32_t> GPR_MIN(
+        max_outgoing(), s_->flow_controlled_buffer.length);
+    is_last_frame_ = send_bytes == s_->flow_controlled_buffer.length &&
+                     s_->fetching_send_message == nullptr &&
+                     s_->send_trailing_metadata != nullptr &&
+                     grpc_metadata_batch_is_empty(s_->send_trailing_metadata);
+    grpc_chttp2_encode_data(s_->id, &s_->flow_controlled_buffer, send_bytes,
+                            is_last_frame_, &s_->stats.outgoing, &t_->outbuf);
+    s_->flow_control->SentData(send_bytes);
+    s_->sending_bytes += send_bytes;
+  }
+
   void FlushCompressedBytes() {
+    GPR_DEBUG_ASSERT(s_->stream_compression_method !=
+                     GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS);
+
     uint32_t send_bytes = static_cast<uint32_t> GPR_MIN(
         max_outgoing(), s_->compressed_data_buffer.length);
     bool is_last_data_frame =
@@ -360,6 +385,9 @@ class DataSendContext {
   }
 
   void CompressMoreBytes() {
+    GPR_DEBUG_ASSERT(s_->stream_compression_method !=
+                     GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS);
+
     if (s_->stream_compression_ctx == nullptr) {
       s_->stream_compression_ctx =
           grpc_stream_compression_context_create(s_->stream_compression_method);
@@ -417,7 +445,7 @@ class StreamWriteContext {
     // https://github.com/grpc/proposal/blob/master/A6-client-retries.md#when-retries-are-valid
     if (!t_->is_client && s_->fetching_send_message == nullptr &&
         s_->flow_controlled_buffer.length == 0 &&
-        s_->compressed_data_buffer.length == 0 &&
+        compressed_data_buffer_len() == 0 &&
         s_->send_trailing_metadata != nullptr &&
         is_default_initial_metadata(s_->send_initial_metadata)) {
       ConvertInitialMetadataToTrailingMetadata();
@@ -446,6 +474,13 @@ class StreamWriteContext {
         "send_initial_metadata_finished");
   }
 
+  bool compressed_data_buffer_len() {
+    return s_->stream_compression_method ==
+                   GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS
+               ? 0
+               : s_->compressed_data_buffer.length;
+  }
+
   void FlushWindowUpdates() {
     /* send any window updates */
     const uint32_t stream_announce = s_->flow_control->MaybeSendUpdate();
@@ -462,7 +497,7 @@ class StreamWriteContext {
     if (!s_->sent_initial_metadata) return;
 
     if (s_->flow_controlled_buffer.length == 0 &&
-        s_->compressed_data_buffer.length == 0) {
+        compressed_data_buffer_len() == 0) {
       return;  // early out: nothing to do
     }
 
@@ -479,13 +514,21 @@ class StreamWriteContext {
       return;  // early out: nothing to do
     }
 
-    while ((s_->flow_controlled_buffer.length > 0 ||
-            s_->compressed_data_buffer.length > 0) &&
-           data_send_context.max_outgoing() > 0) {
-      if (s_->compressed_data_buffer.length > 0) {
-        data_send_context.FlushCompressedBytes();
-      } else {
-        data_send_context.CompressMoreBytes();
+    if (s_->stream_compression_method ==
+        GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS) {
+      while (s_->flow_controlled_buffer.length > 0 &&
+             data_send_context.max_outgoing() > 0) {
+        data_send_context.FlushUncompressedBytes();
+      }
+    } else {
+      while ((s_->flow_controlled_buffer.length > 0 ||
+              s_->compressed_data_buffer.length > 0) &&
+             data_send_context.max_outgoing() > 0) {
+        if (s_->compressed_data_buffer.length > 0) {
+          data_send_context.FlushCompressedBytes();
+        } else {
+          data_send_context.CompressMoreBytes();
+        }
       }
     }
     write_context_->ResetPingClock();
@@ -495,7 +538,7 @@ class StreamWriteContext {
     data_send_context.CallCallbacks();
     stream_became_writable_ = true;
     if (s_->flow_controlled_buffer.length > 0 ||
-        s_->compressed_data_buffer.length > 0) {
+        compressed_data_buffer_len() > 0) {
       GRPC_CHTTP2_STREAM_REF(s_, "chttp2_writing:fork");
       grpc_chttp2_list_add_writable_stream(t_, s_);
     }
@@ -508,7 +551,7 @@ class StreamWriteContext {
     if (s_->send_trailing_metadata == nullptr) return;
     if (s_->fetching_send_message != nullptr) return;
     if (s_->flow_controlled_buffer.length != 0) return;
-    if (s_->compressed_data_buffer.length != 0) return;
+    if (compressed_data_buffer_len() != 0) return;
 
     GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_INFO, "sending trailing_metadata"));
     if (grpc_metadata_batch_is_empty(s_->send_trailing_metadata)) {

src/core/ext/transport/inproc/inproc_transport.cc

@@ -35,9 +35,11 @@
 #include "src/core/lib/transport/error_utils.h"
 #include "src/core/lib/transport/transport_impl.h"
 
-#define INPROC_LOG(...)                                    \
-  do {                                                     \
-    if (grpc_inproc_trace.enabled()) gpr_log(__VA_ARGS__); \
+#define INPROC_LOG(...)                               \
+  do {                                                \
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_inproc_trace)) { \
+      gpr_log(__VA_ARGS__);                           \
+    }                                                 \
   } while (0)
 
 namespace {
@@ -296,7 +298,7 @@ grpc_error* fill_in_metadata(inproc_stream* s,
                              const grpc_metadata_batch* metadata,
                              uint32_t flags, grpc_metadata_batch* out_md,
                              uint32_t* outflags, bool* markfilled) {
-  if (grpc_inproc_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_inproc_trace)) {
     log_metadata(metadata, s->t->is_client, outflags != nullptr);
   }
 
@@ -907,7 +909,7 @@ void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
   gpr_mu* mu = &s->t->mu->mu;  // save aside in case s gets closed
   gpr_mu_lock(mu);
 
-  if (grpc_inproc_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_inproc_trace)) {
     if (op->send_initial_metadata) {
       log_metadata(op->payload->send_initial_metadata.send_initial_metadata,
                    s->t->is_client, true);

src/core/lib/channel/channel_stack.cc

@@ -47,9 +47,9 @@ grpc_core::TraceFlag grpc_trace_channel(false, "channel");
 size_t grpc_channel_stack_size(const grpc_channel_filter** filters,
                                size_t filter_count) {
   /* always need the header, and size for the channel elements */
-  size_t size = GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(grpc_channel_stack)) +
-                GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(
-                    filter_count * sizeof(grpc_channel_element));
+  size_t size = GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_channel_stack)) +
+                GPR_ROUND_UP_TO_ALIGNMENT_SIZE(filter_count *
+                                               sizeof(grpc_channel_element));
   size_t i;
 
   GPR_ASSERT((GPR_MAX_ALIGNMENT & (GPR_MAX_ALIGNMENT - 1)) == 0 &&
@@ -57,18 +57,18 @@ size_t grpc_channel_stack_size(const grpc_channel_filter** filters,
 
   /* add the size for each filter */
   for (i = 0; i < filter_count; i++) {
-    size += GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(filters[i]->sizeof_channel_data);
+    size += GPR_ROUND_UP_TO_ALIGNMENT_SIZE(filters[i]->sizeof_channel_data);
   }
 
   return size;
 }
 
-#define CHANNEL_ELEMS_FROM_STACK(stk)                                         \
-  ((grpc_channel_element*)((char*)(stk) + GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE( \
+#define CHANNEL_ELEMS_FROM_STACK(stk)                                     \
+  ((grpc_channel_element*)((char*)(stk) + GPR_ROUND_UP_TO_ALIGNMENT_SIZE( \
                                               sizeof(grpc_channel_stack))))
 
-#define CALL_ELEMS_FROM_STACK(stk)                                         \
-  ((grpc_call_element*)((char*)(stk) + GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE( \
+#define CALL_ELEMS_FROM_STACK(stk)                                     \
+  ((grpc_call_element*)((char*)(stk) + GPR_ROUND_UP_TO_ALIGNMENT_SIZE( \
                                            sizeof(grpc_call_stack))))
 
 grpc_channel_element* grpc_channel_stack_element(
@@ -92,9 +92,8 @@ grpc_error* grpc_channel_stack_init(
     const grpc_channel_args* channel_args, grpc_transport* optional_transport,
     const char* name, grpc_channel_stack* stack) {
   size_t call_size =
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(grpc_call_stack)) +
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(filter_count *
-                                         sizeof(grpc_call_element));
+      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_call_stack)) +
+      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(filter_count * sizeof(grpc_call_element));
   grpc_channel_element* elems;
   grpc_channel_element_args args;
   char* user_data;
@@ -105,8 +104,8 @@ grpc_error* grpc_channel_stack_init(
                        name);
   elems = CHANNEL_ELEMS_FROM_STACK(stack);
   user_data = (reinterpret_cast<char*>(elems)) +
-              GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(filter_count *
-                                                 sizeof(grpc_channel_element));
+              GPR_ROUND_UP_TO_ALIGNMENT_SIZE(filter_count *
+                                             sizeof(grpc_channel_element));
 
   /* init per-filter data */
   grpc_error* first_error = GRPC_ERROR_NONE;
@@ -127,9 +126,8 @@ grpc_error* grpc_channel_stack_init(
       }
     }
     user_data +=
-        GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(filters[i]->sizeof_channel_data);
-    call_size +=
-        GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(filters[i]->sizeof_call_data);
+        GPR_ROUND_UP_TO_ALIGNMENT_SIZE(filters[i]->sizeof_channel_data);
+    call_size += GPR_ROUND_UP_TO_ALIGNMENT_SIZE(filters[i]->sizeof_call_data);
   }
 
   GPR_ASSERT(user_data > (char*)stack);
@@ -164,9 +162,8 @@ grpc_error* grpc_call_stack_init(grpc_channel_stack* channel_stack,
   GRPC_STREAM_REF_INIT(&elem_args->call_stack->refcount, initial_refs, destroy,
                        destroy_arg, "CALL_STACK");
   call_elems = CALL_ELEMS_FROM_STACK(elem_args->call_stack);
-  user_data =
-      (reinterpret_cast<char*>(call_elems)) +
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(count * sizeof(grpc_call_element));
+  user_data = (reinterpret_cast<char*>(call_elems)) +
+              GPR_ROUND_UP_TO_ALIGNMENT_SIZE(count * sizeof(grpc_call_element));
 
   /* init per-filter data */
   grpc_error* first_error = GRPC_ERROR_NONE;
@@ -174,8 +171,8 @@ grpc_error* grpc_call_stack_init(grpc_channel_stack* channel_stack,
     call_elems[i].filter = channel_elems[i].filter;
     call_elems[i].channel_data = channel_elems[i].channel_data;
     call_elems[i].call_data = user_data;
-    user_data += GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(
-        call_elems[i].filter->sizeof_call_data);
+    user_data +=
+        GPR_ROUND_UP_TO_ALIGNMENT_SIZE(call_elems[i].filter->sizeof_call_data);
   }
   for (size_t i = 0; i < count; i++) {
     grpc_error* error =
@@ -245,11 +242,11 @@ grpc_channel_stack* grpc_channel_stack_from_top_element(
     grpc_channel_element* elem) {
   return reinterpret_cast<grpc_channel_stack*>(
       reinterpret_cast<char*>(elem) -
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(grpc_channel_stack)));
+      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_channel_stack)));
 }
 
 grpc_call_stack* grpc_call_stack_from_top_element(grpc_call_element* elem) {
   return reinterpret_cast<grpc_call_stack*>(
       reinterpret_cast<char*>(elem) -
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(grpc_call_stack)));
+      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_call_stack)));
 }

src/core/lib/channel/channel_stack.h

@@ -274,7 +274,11 @@ void grpc_call_log_op(const char* file, int line, gpr_log_severity severity,
 
 extern grpc_core::TraceFlag grpc_trace_channel;
 
-#define GRPC_CALL_LOG_OP(sev, elem, op) \
-  if (grpc_trace_channel.enabled()) grpc_call_log_op(sev, elem, op)
+#define GRPC_CALL_LOG_OP(sev, elem, op)                \
+  do {                                                 \
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_channel)) { \
+      grpc_call_log_op(sev, elem, op);                 \
+    }                                                  \
+  } while (0)
 
 #endif /* GRPC_CORE_LIB_CHANNEL_CHANNEL_STACK_H */

src/core/lib/channel/handshaker.cc

@@ -94,7 +94,7 @@ void HandshakeManager::ShutdownAllPending(grpc_error* why) {
 }
 
 void HandshakeManager::Add(RefCountedPtr<Handshaker> handshaker) {
-  if (grpc_handshaker_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_handshaker_trace)) {
     gpr_log(
         GPR_INFO,
         "handshake_manager %p: adding handshaker %s [%p] at index %" PRIuPTR,
@@ -125,7 +125,7 @@ void HandshakeManager::Shutdown(grpc_error* why) {
 // on_handshake_done callback.
 // Returns true if we've scheduled the on_handshake_done callback.
 bool HandshakeManager::CallNextHandshakerLocked(grpc_error* error) {
-  if (grpc_handshaker_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_handshaker_trace)) {
     char* args_str = HandshakerArgsString(&args_);
     gpr_log(GPR_INFO,
             "handshake_manager %p: error=%s shutdown=%d index=%" PRIuPTR
@@ -159,7 +159,7 @@ bool HandshakeManager::CallNextHandshakerLocked(grpc_error* error) {
         args_.read_buffer = nullptr;
       }
     }
-    if (grpc_handshaker_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_handshaker_trace)) {
       gpr_log(GPR_INFO,
               "handshake_manager %p: handshaking complete -- scheduling "
               "on_handshake_done with error=%s",
@@ -172,7 +172,7 @@ bool HandshakeManager::CallNextHandshakerLocked(grpc_error* error) {
     is_shutdown_ = true;
   } else {
     auto handshaker = handshakers_[index_];
-    if (grpc_handshaker_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_handshaker_trace)) {
       gpr_log(
           GPR_INFO,
           "handshake_manager %p: calling handshaker %s [%p] at index %" PRIuPTR,

src/core/lib/debug/trace.h

@@ -65,6 +65,8 @@ class TraceFlag {
 // wrapped language (wr don't want to force recompilation to get tracing).
 // Internally, however, for performance reasons, we compile them out by
 // default, since internal build systems make recompiling trivial.
+//
+// Prefer GRPC_TRACE_FLAG_ENABLED() macro instead of using enabled() directly.
 #define GRPC_USE_TRACERS  // tracers on by default in OSS
 #if defined(GRPC_USE_TRACERS) || !defined(NDEBUG)
   bool enabled() {
@@ -99,6 +101,8 @@ class TraceFlag {
 #endif
 };
 
+#define GRPC_TRACE_FLAG_ENABLED(f) GPR_UNLIKELY((f).enabled())
+
 #ifndef NDEBUG
 typedef TraceFlag DebugOnlyTraceFlag;
 #else

src/core/lib/gpr/alloc.cc

@@ -23,7 +23,6 @@
 #include <grpc/support/log.h>
 #include <stdlib.h>
 #include <string.h>
-#include "src/core/lib/gpr/alloc.h"
 #include "src/core/lib/profiling/timers.h"
 
 static void* zalloc_with_calloc(size_t sz) { return calloc(sz, 1); }
@@ -34,56 +33,8 @@ static void* zalloc_with_gpr_malloc(size_t sz) {
   return p;
 }
 
-#ifndef NDEBUG
-static constexpr bool is_power_of_two(size_t value) {
-  // 2^N =     100000...000
-  // 2^N - 1 = 011111...111
-  // (2^N) && ((2^N)-1)) = 0
-  return (value & (value - 1)) == 0;
-}
-#endif
-
-static void* platform_malloc_aligned(size_t size, size_t alignment) {
-#if defined(GPR_HAS_ALIGNED_ALLOC)
-  GPR_DEBUG_ASSERT(is_power_of_two(alignment));
-  size = GPR_ROUND_UP_TO_ALIGNMENT_SIZE(size, alignment);
-  void* ret = aligned_alloc(alignment, size);
-  GPR_ASSERT(ret != nullptr);
-  return ret;
-#elif defined(GPR_HAS_ALIGNED_MALLOC)
-  GPR_DEBUG_ASSERT(is_power_of_two(alignment));
-  void* ret = _aligned_malloc(size, alignment);
-  GPR_ASSERT(ret != nullptr);
-  return ret;
-#elif defined(GPR_HAS_POSIX_MEMALIGN)
-  GPR_DEBUG_ASSERT(is_power_of_two(alignment));
-  GPR_DEBUG_ASSERT(alignment % sizeof(void*) == 0);
-  void* ret = nullptr;
-  GPR_ASSERT(posix_memalign(&ret, alignment, size) == 0);
-  return ret;
-#else
-  GPR_DEBUG_ASSERT(is_power_of_two(alignment));
-  size_t extra = alignment - 1 + sizeof(void*);
-  void* p = gpr_malloc(size + extra);
-  void** ret = (void**)(((uintptr_t)p + extra) & ~(alignment - 1));
-  ret[-1] = p;
-  return (void*)ret;
-#endif
-}
-
-static void platform_free_aligned(void* ptr) {
-#if defined(GPR_HAS_ALIGNED_ALLOC) || defined(GPR_HAS_POSIX_MEMALIGN)
-  free(ptr);
-#elif defined(GPR_HAS_ALIGNED_MALLOC)
-  _aligned_free(ptr);
-#else
-  gpr_free((static_cast<void**>(ptr))[-1]);
-#endif
-}
-
-static gpr_allocation_functions g_alloc_functions = {
-    malloc, zalloc_with_calloc,      realloc,
-    free,   platform_malloc_aligned, platform_free_aligned};
+static gpr_allocation_functions g_alloc_functions = {malloc, zalloc_with_calloc,
+                                                     realloc, free};
 
 gpr_allocation_functions gpr_get_allocation_functions() {
   return g_alloc_functions;
@@ -96,12 +47,6 @@ void gpr_set_allocation_functions(gpr_allocation_functions functions) {
   if (functions.zalloc_fn == nullptr) {
     functions.zalloc_fn = zalloc_with_gpr_malloc;
   }
-  GPR_ASSERT((functions.aligned_alloc_fn == nullptr) ==
-             (functions.aligned_free_fn == nullptr));
-  if (functions.aligned_alloc_fn == nullptr) {
-    functions.aligned_alloc_fn = platform_malloc_aligned;
-    functions.aligned_free_fn = platform_free_aligned;
-  }
   g_alloc_functions = functions;
 }
 
@@ -143,12 +88,12 @@ void* gpr_realloc(void* p, size_t size) {
 }
 
 void* gpr_malloc_aligned(size_t size, size_t alignment) {
-  GPR_TIMER_SCOPE("gpr_malloc_aligned", 0);
-  if (size == 0) return nullptr;
-  return g_alloc_functions.aligned_alloc_fn(size, alignment);
+  GPR_ASSERT(((alignment - 1) & alignment) == 0);  // Must be power of 2.
+  size_t extra = alignment - 1 + sizeof(void*);
+  void* p = gpr_malloc(size + extra);
+  void** ret = (void**)(((uintptr_t)p + extra) & ~(alignment - 1));
+  ret[-1] = p;
+  return (void*)ret;
 }
 
-void gpr_free_aligned(void* ptr) {
-  GPR_TIMER_SCOPE("gpr_free_aligned", 0);
-  g_alloc_functions.aligned_free_fn(ptr);
-}
+void gpr_free_aligned(void* ptr) { gpr_free((static_cast<void**>(ptr))[-1]); }

src/core/lib/gpr/alloc.h

@@ -22,13 +22,7 @@
 #include <grpc/support/port_platform.h>
 
 /// Given a size, round up to the next multiple of sizeof(void*).
-#define GPR_ROUND_UP_TO_ALIGNMENT_SIZE(x, align) \
-  (((x) + (align)-1u) & ~((align)-1u))
-
-#define GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(x) \
-  GPR_ROUND_UP_TO_ALIGNMENT_SIZE((x), GPR_MAX_ALIGNMENT)
-
-#define GPR_ROUND_UP_TO_CACHELINE_SIZE(x) \
-  GPR_ROUND_UP_TO_ALIGNMENT_SIZE((x), GPR_CACHELINE_SIZE)
+#define GPR_ROUND_UP_TO_ALIGNMENT_SIZE(x) \
+  (((x) + GPR_MAX_ALIGNMENT - 1u) & ~(GPR_MAX_ALIGNMENT - 1u))
 
 #endif /* GRPC_CORE_LIB_GPR_ALLOC_H */

src/core/lib/gpr/env.h

@@ -40,4 +40,7 @@ void gpr_setenv(const char* name, const char* value);
    level of logging. So DO NOT USE THIS. */
 const char* gpr_getenv_silent(const char* name, char** dst);
 
+/* Deletes the variable name from the environment. */
+void gpr_unsetenv(const char* name);
+
 #endif /* GRPC_CORE_LIB_GPR_ENV_H */

src/core/lib/gpr/env_linux.cc

@@ -79,4 +79,9 @@ void gpr_setenv(const char* name, const char* value) {
   GPR_ASSERT(res == 0);
 }
 
+void gpr_unsetenv(const char* name) {
+  int res = unsetenv(name);
+  GPR_ASSERT(res == 0);
+}
+
 #endif /* GPR_LINUX_ENV */

src/core/lib/gpr/env_posix.cc

@@ -44,4 +44,9 @@ void gpr_setenv(const char* name, const char* value) {
   GPR_ASSERT(res == 0);
 }
 
+void gpr_unsetenv(const char* name) {
+  int res = unsetenv(name);
+  GPR_ASSERT(res == 0);
+}
+
 #endif /* GPR_POSIX_ENV */

src/core/lib/gpr/env_windows.cc

@@ -69,4 +69,11 @@ void gpr_setenv(const char* name, const char* value) {
   GPR_ASSERT(res);
 }
 
+void gpr_unsetenv(const char* name) {
+  LPTSTR tname = gpr_char_to_tchar(name);
+  BOOL res = SetEnvironmentVariable(tname, NULL);
+  gpr_free(tname);
+  GPR_ASSERT(res);
+}
+
 #endif /* GPR_WINDOWS_ENV */

src/core/lib/gpr/string.cc

@@ -332,16 +332,22 @@ void* gpr_memrchr(const void* s, int c, size_t n) {
   return nullptr;
 }
 
-bool gpr_is_true(const char* s) {
-  size_t i;
+bool gpr_parse_bool_value(const char* s, bool* dst) {
+  const char* kTrue[] = {"1", "t", "true", "y", "yes"};
+  const char* kFalse[] = {"0", "f", "false", "n", "no"};
+  static_assert(sizeof(kTrue) == sizeof(kFalse), "true_false_equal");
+
   if (s == nullptr) {
     return false;
   }
-  static const char* truthy[] = {"yes", "true", "1"};
-  for (i = 0; i < GPR_ARRAY_SIZE(truthy); i++) {
-    if (0 == gpr_stricmp(s, truthy[i])) {
+  for (size_t i = 0; i < GPR_ARRAY_SIZE(kTrue); ++i) {
+    if (gpr_stricmp(s, kTrue[i]) == 0) {
+      *dst = true;
+      return true;
+    } else if (gpr_stricmp(s, kFalse[i]) == 0) {
+      *dst = false;
       return true;
     }
   }
-  return false;
+  return false;  // didn't match a legal input
 }

src/core/lib/gpr/string.h

@@ -113,7 +113,9 @@ int gpr_stricmp(const char* a, const char* b);
 
 void* gpr_memrchr(const void* s, int c, size_t n);
 
-/** Return true if lower(s) equals "true", "yes" or "1", otherwise false. */
-bool gpr_is_true(const char* s);
+/* Try to parse given string into a boolean value.
+   When parsed successfully, dst will have the value and returns true.
+   Otherwise, it returns false. */
+bool gpr_parse_bool_value(const char* value, bool* dst);
 
 #endif /* GRPC_CORE_LIB_GPR_STRING_H */

src/core/lib/gprpp/arena.cc

@@ -35,8 +35,8 @@ namespace {
 
 void* ArenaStorage(size_t initial_size) {
   static constexpr size_t base_size =
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(grpc_core::Arena));
-  initial_size = GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(initial_size);
+      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_core::Arena));
+  initial_size = GPR_ROUND_UP_TO_ALIGNMENT_SIZE(initial_size);
   size_t alloc_size = base_size + initial_size;
   static constexpr size_t alignment =
       (GPR_CACHELINE_SIZE > GPR_MAX_ALIGNMENT &&
@@ -67,7 +67,7 @@ Arena* Arena::Create(size_t initial_size) {
 Pair<Arena*, void*> Arena::CreateWithAlloc(size_t initial_size,
                                            size_t alloc_size) {
   static constexpr size_t base_size =
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(Arena));
+      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(Arena));
   auto* new_arena =
       new (ArenaStorage(initial_size)) Arena(initial_size, alloc_size);
   void* first_alloc = reinterpret_cast<char*>(new_arena) + base_size;
@@ -88,7 +88,7 @@ void* Arena::AllocZone(size_t size) {
   // sizing hysteresis (that is, most calls should have a large enough initial
   // zone and will not need to grow the arena).
   static constexpr size_t zone_base_size =
-      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(Zone));
+      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(Zone));
   size_t alloc_size = zone_base_size + size;
   Zone* z = new (gpr_malloc_aligned(alloc_size, GPR_MAX_ALIGNMENT)) Zone();
   {

src/core/lib/gprpp/arena.h

@@ -58,10 +58,10 @@ class Arena {
   // Allocate \a size bytes from the arena.
   void* Alloc(size_t size) {
     static constexpr size_t base_size =
-        GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(Arena));
-    size = GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(size);
+        GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(Arena));
+    size = GPR_ROUND_UP_TO_ALIGNMENT_SIZE(size);
     size_t begin = total_used_.FetchAdd(size, MemoryOrder::RELAXED);
-    if (GPR_LIKELY(begin + size <= initial_zone_size_)) {
+    if (begin + size <= initial_zone_size_) {
       return reinterpret_cast<char*>(this) + base_size + begin;
     } else {
       return AllocZone(size);

src/core/lib/gprpp/global_config.h

@@ -0,0 +1,87 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_H
+#define GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_H
+
+#include <grpc/support/port_platform.h>
+
+#include <stdint.h>
+
+// --------------------------------------------------------------------
+// How to use global configuration variables:
+//
+// Defining config variables of a specified type:
+//   GPR_GLOBAL_CONFIG_DEFINE_*TYPE*(name, default_value, help);
+//
+// Supported TYPEs: BOOL, INT32, STRING
+//
+// It's recommended to use lowercase letters for 'name' like
+// regular variables. The builtin configuration system uses
+// environment variable and the name is converted to uppercase
+// when looking up the value. For example,
+// GPR_GLOBAL_CONFIG_DEFINE(grpc_latency) looks up the value with the
+// name, "GRPC_LATENCY".
+//
+// The variable initially has the specified 'default_value'
+// which must be an expression convertible to 'Type'.
+// 'default_value' may be evaluated 0 or more times,
+// and at an unspecified time; keep it
+// simple and usually free of side-effects.
+//
+// GPR_GLOBAL_CONFIG_DEFINE_*TYPE* should not be called in a C++ header.
+// It should be called at the top-level (outside any namespaces)
+// in a .cc file.
+//
+// Getting the variables:
+//   GPR_GLOBAL_CONFIG_GET(name)
+//
+// If error happens during getting variables, error messages will
+// be logged and default value will be returned.
+//
+// Setting the variables with new value:
+//   GPR_GLOBAL_CONFIG_SET(name, new_value)
+//
+// Declaring config variables for other modules to access:
+//   GPR_GLOBAL_CONFIG_DECLARE_*TYPE*(name)
+
+// --------------------------------------------------------------------
+// How to customize the global configuration system:
+//
+// How to read and write configuration value can be customized.
+// Builtin system uses environment variables but it can be extended to
+// support command-line flag, file, etc.
+//
+// To customize it, following macros should be redefined.
+//
+//   GPR_GLOBAL_CONFIG_DEFINE_BOOL
+//   GPR_GLOBAL_CONFIG_DEFINE_INT32
+//   GPR_GLOBAL_CONFIG_DEFINE_STRING
+//
+// These macros should define functions for getting and setting variable.
+// For example, GPR_GLOBAL_CONFIG_DEFINE_BOOL(test, ...) would define two
+// functions.
+//
+//   bool gpr_global_config_get_test();
+//   void gpr_global_config_set_test(bool value);
+
+#include "src/core/lib/gprpp/global_config_env.h"
+
+#include "src/core/lib/gprpp/global_config_custom.h"
+
+#endif /* GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_H */

src/core/lib/gprpp/global_config_custom.h

@@ -0,0 +1,29 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_CUSTOM_H
+#define GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_CUSTOM_H
+
+// This is a placeholder for custom global configuration implementaion.
+// To use the custom one, please define following macros here.
+//
+//   GPR_GLOBAL_CONFIG_DEFINE_BOOL
+//   GPR_GLOBAL_CONFIG_DEFINE_INT32
+//   GPR_GLOBAL_CONFIG_DEFINE_STRING
+
+#endif /* GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_CUSTOM_H */

src/core/lib/gprpp/global_config_env.cc

@@ -0,0 +1,135 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/gprpp/global_config_env.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
+
+#include <ctype.h>
+#include <string.h>
+
+namespace grpc_core {
+
+namespace {
+
+void DefaultGlobalConfigEnvErrorFunction(const char* error_message) {
+  gpr_log(GPR_ERROR, "%s", error_message);
+}
+
+GlobalConfigEnvErrorFunctionType g_global_config_env_error_func =
+    DefaultGlobalConfigEnvErrorFunction;
+
+void LogParsingError(const char* name, const char* value) {
+  char* error_message;
+  gpr_asprintf(&error_message,
+               "Illegal value '%s' specified for environment variable '%s'",
+               value, name);
+  (*g_global_config_env_error_func)(error_message);
+  gpr_free(error_message);
+}
+
+}  // namespace
+
+void SetGlobalConfigEnvErrorFunction(GlobalConfigEnvErrorFunctionType func) {
+  g_global_config_env_error_func = func;
+}
+
+UniquePtr<char> GlobalConfigEnv::GetValue() {
+  return UniquePtr<char>(gpr_getenv(GetName()));
+}
+
+void GlobalConfigEnv::SetValue(const char* value) {
+  gpr_setenv(GetName(), value);
+}
+
+void GlobalConfigEnv::Unset() { gpr_unsetenv(GetName()); }
+
+char* GlobalConfigEnv::GetName() {
+  // This makes sure that name_ is in a canonical form having uppercase
+  // letters. This is okay to be called serveral times.
+  for (char* c = name_; *c != 0; ++c) {
+    *c = toupper(*c);
+  }
+  return name_;
+}
+static_assert(std::is_trivially_destructible<GlobalConfigEnvBool>::value,
+              "GlobalConfigEnvBool needs to be trivially destructible.");
+
+bool GlobalConfigEnvBool::Get() {
+  UniquePtr<char> str = GetValue();
+  if (str == nullptr) {
+    return default_value_;
+  }
+  // parsing given value string.
+  bool result = false;
+  if (!gpr_parse_bool_value(str.get(), &result)) {
+    LogParsingError(GetName(), str.get());
+    result = default_value_;
+  }
+  return result;
+}
+
+void GlobalConfigEnvBool::Set(bool value) {
+  SetValue(value ? "true" : "false");
+}
+
+static_assert(std::is_trivially_destructible<GlobalConfigEnvInt32>::value,
+              "GlobalConfigEnvInt32 needs to be trivially destructible.");
+
+int32_t GlobalConfigEnvInt32::Get() {
+  UniquePtr<char> str = GetValue();
+  if (str == nullptr) {
+    return default_value_;
+  }
+  // parsing given value string.
+  char* end = str.get();
+  long result = strtol(str.get(), &end, 10);
+  if (*end != 0) {
+    LogParsingError(GetName(), str.get());
+    result = default_value_;
+  }
+  return static_cast<int32_t>(result);
+}
+
+void GlobalConfigEnvInt32::Set(int32_t value) {
+  char buffer[GPR_LTOA_MIN_BUFSIZE];
+  gpr_ltoa(value, buffer);
+  SetValue(buffer);
+}
+
+static_assert(std::is_trivially_destructible<GlobalConfigEnvString>::value,
+              "GlobalConfigEnvString needs to be trivially destructible.");
+
+UniquePtr<char> GlobalConfigEnvString::Get() {
+  UniquePtr<char> str = GetValue();
+  if (str == nullptr) {
+    return UniquePtr<char>(gpr_strdup(default_value_));
+  }
+  return str;
+}
+
+void GlobalConfigEnvString::Set(const char* value) { SetValue(value); }
+
+}  // namespace grpc_core

src/core/lib/gprpp/global_config_env.h

@@ -0,0 +1,131 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_ENV_H
+#define GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_ENV_H
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/gprpp/global_config_generic.h"
+#include "src/core/lib/gprpp/memory.h"
+
+namespace grpc_core {
+
+typedef void (*GlobalConfigEnvErrorFunctionType)(const char* error_message);
+
+/*
+ * Set global_config_env_error_function which is called when config system
+ * encounters errors such as parsing error. What the default function does
+ * is logging error message.
+ */
+void SetGlobalConfigEnvErrorFunction(GlobalConfigEnvErrorFunctionType func);
+
+// Base class for all classes to access environment variables.
+class GlobalConfigEnv {
+ protected:
+  // `name` should be writable and alive after constructor is called.
+  constexpr explicit GlobalConfigEnv(char* name) : name_(name) {}
+
+ public:
+  // Returns the value of `name` variable.
+  UniquePtr<char> GetValue();
+
+  // Sets the value of `name` variable.
+  void SetValue(const char* value);
+
+  // Unsets `name` variable.
+  void Unset();
+
+ protected:
+  char* GetName();
+
+ private:
+  char* name_;
+};
+
+class GlobalConfigEnvBool : public GlobalConfigEnv {
+ public:
+  constexpr GlobalConfigEnvBool(char* name, bool default_value)
+      : GlobalConfigEnv(name), default_value_(default_value) {}
+
+  bool Get();
+  void Set(bool value);
+
+ private:
+  bool default_value_;
+};
+
+class GlobalConfigEnvInt32 : public GlobalConfigEnv {
+ public:
+  constexpr GlobalConfigEnvInt32(char* name, int32_t default_value)
+      : GlobalConfigEnv(name), default_value_(default_value) {}
+
+  int32_t Get();
+  void Set(int32_t value);
+
+ private:
+  int32_t default_value_;
+};
+
+class GlobalConfigEnvString : public GlobalConfigEnv {
+ public:
+  constexpr GlobalConfigEnvString(char* name, const char* default_value)
+      : GlobalConfigEnv(name), default_value_(default_value) {}
+
+  UniquePtr<char> Get();
+  void Set(const char* value);
+
+ private:
+  const char* default_value_;
+};
+
+}  // namespace grpc_core
+
+// Macros for defining global config instances using environment variables.
+// This defines a GlobalConfig*Type* instance with arguments for
+// mutable variable name and default value.
+// Mutable name (g_env_str_##name) is here for having an array
+// for the canonical name without dynamic allocation.
+// `help` argument is ignored for this implementation.
+
+#define GPR_GLOBAL_CONFIG_DEFINE_BOOL(name, default_value, help)         \
+  static char g_env_str_##name[] = #name;                                \
+  static ::grpc_core::GlobalConfigEnvBool g_env_##name(g_env_str_##name, \
+                                                       default_value);   \
+  bool gpr_global_config_get_##name() { return g_env_##name.Get(); }     \
+  void gpr_global_config_set_##name(bool value) { g_env_##name.Set(value); }
+
+#define GPR_GLOBAL_CONFIG_DEFINE_INT32(name, default_value, help)         \
+  static char g_env_str_##name[] = #name;                                 \
+  static ::grpc_core::GlobalConfigEnvInt32 g_env_##name(g_env_str_##name, \
+                                                        default_value);   \
+  int32_t gpr_global_config_get_##name() { return g_env_##name.Get(); }   \
+  void gpr_global_config_set_##name(int32_t value) { g_env_##name.Set(value); }
+
+#define GPR_GLOBAL_CONFIG_DEFINE_STRING(name, default_value, help)         \
+  static char g_env_str_##name[] = #name;                                  \
+  static ::grpc_core::GlobalConfigEnvString g_env_##name(g_env_str_##name, \
+                                                         default_value);   \
+  ::grpc_core::UniquePtr<char> gpr_global_config_get_##name() {            \
+    return g_env_##name.Get();                                             \
+  }                                                                        \
+  void gpr_global_config_set_##name(const char* value) {                   \
+    g_env_##name.Set(value);                                               \
+  }
+
+#endif /* GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_ENV_H */

src/core/lib/gprpp/global_config_generic.h

@@ -0,0 +1,44 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_GENERIC_H
+#define GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_GENERIC_H
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/gprpp/memory.h"
+
+#include <stdint.h>
+
+#define GPR_GLOBAL_CONFIG_GET(name) gpr_global_config_get_##name()
+
+#define GPR_GLOBAL_CONFIG_SET(name, value) gpr_global_config_set_##name(value)
+
+#define GPR_GLOBAL_CONFIG_DECLARE_BOOL(name)  \
+  extern bool gpr_global_config_get_##name(); \
+  extern void gpr_global_config_set_##name(bool value)
+
+#define GPR_GLOBAL_CONFIG_DECLARE_INT32(name)    \
+  extern int32_t gpr_global_config_get_##name(); \
+  extern void gpr_global_config_set_##name(int32_t value)
+
+#define GPR_GLOBAL_CONFIG_DECLARE_STRING(name)                      \
+  extern grpc_core::UniquePtr<char> gpr_global_config_get_##name(); \
+  extern void gpr_global_config_set_##name(const char* value)
+
+#endif /* GRPC_CORE_LIB_GPRPP_GLOBAL_CONFIG_GENERIC_H */

src/core/lib/gprpp/orphanable.h

@@ -110,12 +110,12 @@ class InternallyRefCounted : public Orphanable {
   }
 
   void Unref() {
-    if (refs_.Unref()) {
+    if (GPR_UNLIKELY(refs_.Unref())) {
       Delete(static_cast<Child*>(this));
     }
   }
   void Unref(const DebugLocation& location, const char* reason) {
-    if (refs_.Unref(location, reason)) {
+    if (GPR_UNLIKELY(refs_.Unref(location, reason))) {
       Delete(static_cast<Child*>(this));
     }
   }

src/core/lib/gprpp/ref_counted.h

@@ -211,12 +211,12 @@ class RefCounted : public Impl {
   // private, since it will only be used by RefCountedPtr<>, which is a
   // friend of this class.
   void Unref() {
-    if (refs_.Unref()) {
+    if (GPR_UNLIKELY(refs_.Unref())) {
       Delete(static_cast<Child*>(this));
     }
   }
   void Unref(const DebugLocation& location, const char* reason) {
-    if (refs_.Unref(location, reason)) {
+    if (GPR_UNLIKELY(refs_.Unref(location, reason))) {
       Delete(static_cast<Child*>(this));
     }
   }

src/core/lib/http/parser.cc

@@ -300,7 +300,7 @@ static grpc_error* addbyte(grpc_http_parser* parser, uint8_t byte,
     case GRPC_HTTP_FIRST_LINE:
     case GRPC_HTTP_HEADERS:
       if (parser->cur_line_length >= GRPC_HTTP_PARSER_MAX_HEADER_LENGTH) {
-        if (grpc_http1_trace.enabled())
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_http1_trace))
           gpr_log(GPR_ERROR, "HTTP header max line length (%d) exceeded",
                   GRPC_HTTP_PARSER_MAX_HEADER_LENGTH);
         return GRPC_ERROR_CREATE_FROM_STATIC_STRING(

src/core/lib/iomgr/call_combiner.cc

@@ -113,7 +113,7 @@ void CallCombiner::ScheduleClosure(grpc_closure* closure, grpc_error* error) {
 void CallCombiner::Start(grpc_closure* closure, grpc_error* error,
                          DEBUG_ARGS const char* reason) {
   GPR_TIMER_SCOPE("CallCombiner::Start", 0);
-  if (grpc_call_combiner_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
     gpr_log(GPR_INFO,
             "==> CallCombiner::Start() [%p] closure=%p [" DEBUG_FMT_STR
             "%s] error=%s",
@@ -121,7 +121,7 @@ void CallCombiner::Start(grpc_closure* closure, grpc_error* error,
   }
   size_t prev_size =
       static_cast<size_t>(gpr_atm_full_fetch_add(&size_, (gpr_atm)1));
-  if (grpc_call_combiner_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
     gpr_log(GPR_INFO, "  size: %" PRIdPTR " -> %" PRIdPTR, prev_size,
             prev_size + 1);
   }
@@ -129,13 +129,13 @@ void CallCombiner::Start(grpc_closure* closure, grpc_error* error,
   if (prev_size == 0) {
     GRPC_STATS_INC_CALL_COMBINER_LOCKS_INITIATED();
     GPR_TIMER_MARK("call_combiner_initiate", 0);
-    if (grpc_call_combiner_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
       gpr_log(GPR_INFO, "  EXECUTING IMMEDIATELY");
     }
     // Queue was empty, so execute this closure immediately.
     ScheduleClosure(closure, error);
   } else {
-    if (grpc_call_combiner_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
       gpr_log(GPR_INFO, "  QUEUING");
     }
     // Queue was not empty, so add closure to queue.
@@ -146,20 +146,20 @@ void CallCombiner::Start(grpc_closure* closure, grpc_error* error,
 
 void CallCombiner::Stop(DEBUG_ARGS const char* reason) {
   GPR_TIMER_SCOPE("CallCombiner::Stop", 0);
-  if (grpc_call_combiner_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
     gpr_log(GPR_INFO, "==> CallCombiner::Stop() [%p] [" DEBUG_FMT_STR "%s]",
             this DEBUG_FMT_ARGS, reason);
   }
   size_t prev_size =
       static_cast<size_t>(gpr_atm_full_fetch_add(&size_, (gpr_atm)-1));
-  if (grpc_call_combiner_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
     gpr_log(GPR_INFO, "  size: %" PRIdPTR " -> %" PRIdPTR, prev_size,
             prev_size - 1);
   }
   GPR_ASSERT(prev_size >= 1);
   if (prev_size > 1) {
     while (true) {
-      if (grpc_call_combiner_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
         gpr_log(GPR_INFO, "  checking queue");
       }
       bool empty;
@@ -168,19 +168,19 @@ void CallCombiner::Stop(DEBUG_ARGS const char* reason) {
       if (closure == nullptr) {
         // This can happen either due to a race condition within the mpscq
         // code or because of a race with Start().
-        if (grpc_call_combiner_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
           gpr_log(GPR_INFO, "  queue returned no result; checking again");
         }
         continue;
       }
-      if (grpc_call_combiner_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
         gpr_log(GPR_INFO, "  EXECUTING FROM QUEUE: closure=%p error=%s",
                 closure, grpc_error_string(closure->error_data.error));
       }
       ScheduleClosure(closure, closure->error_data.error);
       break;
     }
-  } else if (grpc_call_combiner_trace.enabled()) {
+  } else if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
     gpr_log(GPR_INFO, "  queue empty");
   }
 }
@@ -194,7 +194,7 @@ void CallCombiner::SetNotifyOnCancel(grpc_closure* closure) {
     // If error is set, invoke the cancellation closure immediately.
     // Otherwise, store the new closure.
     if (original_error != GRPC_ERROR_NONE) {
-      if (grpc_call_combiner_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
         gpr_log(GPR_INFO,
                 "call_combiner=%p: scheduling notify_on_cancel callback=%p "
                 "for pre-existing cancellation",
@@ -204,7 +204,7 @@ void CallCombiner::SetNotifyOnCancel(grpc_closure* closure) {
       break;
     } else {
       if (gpr_atm_full_cas(&cancel_state_, original_state, (gpr_atm)closure)) {
-        if (grpc_call_combiner_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
           gpr_log(GPR_INFO, "call_combiner=%p: setting notify_on_cancel=%p",
                   this, closure);
         }
@@ -213,7 +213,7 @@ void CallCombiner::SetNotifyOnCancel(grpc_closure* closure) {
         // up any resources they may be holding for the callback.
         if (original_state != 0) {
           closure = (grpc_closure*)original_state;
-          if (grpc_call_combiner_trace.enabled()) {
+          if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
             gpr_log(GPR_INFO,
                     "call_combiner=%p: scheduling old cancel callback=%p", this,
                     closure);
@@ -240,7 +240,7 @@ void CallCombiner::Cancel(grpc_error* error) {
                          EncodeCancelStateError(error))) {
       if (original_state != 0) {
         grpc_closure* notify_on_cancel = (grpc_closure*)original_state;
-        if (grpc_call_combiner_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
           gpr_log(GPR_INFO,
                   "call_combiner=%p: scheduling notify_on_cancel callback=%p",
                   this, notify_on_cancel);

src/core/lib/iomgr/call_combiner.h

@@ -169,7 +169,7 @@ class CallCombinerClosureList {
       GRPC_CALL_COMBINER_START(call_combiner, closure.closure, closure.error,
                                closure.reason);
     }
-    if (grpc_call_combiner_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
       gpr_log(GPR_INFO,
               "CallCombinerClosureList executing closure while already "
               "holding call_combiner %p: closure=%p error=%s reason=%s",

src/core/lib/iomgr/combiner.h

@@ -31,7 +31,7 @@
 // Provides serialized access to some resource.
 // Each action queued on a combiner is executed serially in a borrowed thread.
 // The actual thread executing actions may change over time (but there will only
-// every be one at a time).
+// ever be one at a time).
 
 // Initialize the lock, with an optional workqueue to shift load to when
 // necessary

src/core/lib/iomgr/ev_epoll1_linux.cc

@@ -351,7 +351,7 @@ static grpc_fd* fd_create(int fd, const char* name, bool track_err) {
   grpc_iomgr_register_object(&new_fd->iomgr_object, fd_name);
   fork_fd_list_add_grpc_fd(new_fd);
 #ifndef NDEBUG
-  if (grpc_trace_fd_refcount.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_fd_refcount)) {
     gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, new_fd, fd_name);
   }
 #endif
@@ -383,6 +383,13 @@ static void fd_shutdown_internal(grpc_fd* fd, grpc_error* why,
   if (fd->read_closure->SetShutdown(GRPC_ERROR_REF(why))) {
     if (!releasing_fd) {
       shutdown(fd->fd, SHUT_RDWR);
+    } else {
+      /* we need a dummy event for earlier linux versions. */
+      epoll_event dummy_event;
+      if (epoll_ctl(g_epoll_set.epfd, EPOLL_CTL_DEL, fd->fd, &dummy_event) !=
+          0) {
+        gpr_log(GPR_ERROR, "epoll_ctl failed: %s", strerror(errno));
+      }
     }
     fd->write_closure->SetShutdown(GRPC_ERROR_REF(why));
     fd->error_closure->SetShutdown(GRPC_ERROR_REF(why));
@@ -724,7 +731,7 @@ static grpc_error* do_epoll_wait(grpc_pollset* ps, grpc_millis deadline) {
 
   GRPC_STATS_INC_POLL_EVENTS_RETURNED(r);
 
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "ps: %p poll got %d events", ps, r);
   }
 
@@ -744,7 +751,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
   worker->schedule_on_end_work = (grpc_closure_list)GRPC_CLOSURE_LIST_INIT;
   pollset->begin_refs++;
 
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "PS:%p BEGIN_STARTS:%p", pollset, worker);
   }
 
@@ -763,7 +770,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
   retry_lock_neighborhood:
     gpr_mu_lock(&neighborhood->mu);
     gpr_mu_lock(&pollset->mu);
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, "PS:%p BEGIN_REORG:%p kick_state=%s is_reassigning=%d",
               pollset, worker, kick_state_string(worker->state),
               is_reassigning);
@@ -815,7 +822,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
     worker->initialized_cv = true;
     gpr_cv_init(&worker->cv);
     while (worker->state == UNKICKED && !pollset->shutting_down) {
-      if (grpc_polling_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
         gpr_log(GPR_INFO, "PS:%p BEGIN_WAIT:%p kick_state=%s shutdown=%d",
                 pollset, worker, kick_state_string(worker->state),
                 pollset->shutting_down);
@@ -832,7 +839,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
     grpc_core::ExecCtx::Get()->InvalidateNow();
   }
 
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO,
             "PS:%p BEGIN_DONE:%p kick_state=%s shutdown=%d "
             "kicked_without_poller: %d",
@@ -875,7 +882,7 @@ static bool check_neighborhood_for_available_poller(
           case UNKICKED:
             if (gpr_atm_no_barrier_cas(&g_active_poller, 0,
                                        (gpr_atm)inspect_worker)) {
-              if (grpc_polling_trace.enabled()) {
+              if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
                 gpr_log(GPR_INFO, " .. choose next poller to be %p",
                         inspect_worker);
               }
@@ -886,7 +893,7 @@ static bool check_neighborhood_for_available_poller(
                 gpr_cv_signal(&inspect_worker->cv);
               }
             } else {
-              if (grpc_polling_trace.enabled()) {
+              if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
                 gpr_log(GPR_INFO, " .. beaten to choose next poller");
               }
             }
@@ -904,7 +911,7 @@ static bool check_neighborhood_for_available_poller(
       } while (!found_worker && inspect_worker != inspect->root_worker);
     }
     if (!found_worker) {
-      if (grpc_polling_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
         gpr_log(GPR_INFO, " .. mark pollset %p inactive", inspect);
       }
       inspect->seen_inactive = true;
@@ -924,7 +931,7 @@ static bool check_neighborhood_for_available_poller(
 static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
                        grpc_pollset_worker** worker_hdl) {
   GPR_TIMER_SCOPE("end_worker", 0);
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "PS:%p END_WORKER:%p", pollset, worker);
   }
   if (worker_hdl != nullptr) *worker_hdl = nullptr;
@@ -934,7 +941,7 @@ static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
                          grpc_core::ExecCtx::Get()->closure_list());
   if (gpr_atm_no_barrier_load(&g_active_poller) == (gpr_atm)worker) {
     if (worker->next != worker && worker->next->state == UNKICKED) {
-      if (grpc_polling_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
         gpr_log(GPR_INFO, " .. choose next poller to be peer %p", worker);
       }
       GPR_ASSERT(worker->next->initialized_cv);
@@ -986,7 +993,7 @@ static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
   if (worker->initialized_cv) {
     gpr_cv_destroy(&worker->cv);
   }
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, " .. remove worker");
   }
   if (EMPTIED == worker_remove(pollset, worker)) {
@@ -1055,7 +1062,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
   GPR_TIMER_SCOPE("pollset_kick", 0);
   GRPC_STATS_INC_POLLSET_KICK();
   grpc_error* ret_err = GRPC_ERROR_NONE;
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_strvec log;
     gpr_strvec_init(&log);
     char* tmp;
@@ -1088,7 +1095,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
       if (root_worker == nullptr) {
         GRPC_STATS_INC_POLLSET_KICKED_WITHOUT_POLLER();
         pollset->kicked_without_poller = true;
-        if (grpc_polling_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
           gpr_log(GPR_INFO, " .. kicked_without_poller");
         }
         goto done;
@@ -1096,14 +1103,14 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
       grpc_pollset_worker* next_worker = root_worker->next;
       if (root_worker->state == KICKED) {
         GRPC_STATS_INC_POLLSET_KICKED_AGAIN();
-        if (grpc_polling_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
           gpr_log(GPR_INFO, " .. already kicked %p", root_worker);
         }
         SET_KICK_STATE(root_worker, KICKED);
         goto done;
       } else if (next_worker->state == KICKED) {
         GRPC_STATS_INC_POLLSET_KICKED_AGAIN();
-        if (grpc_polling_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
           gpr_log(GPR_INFO, " .. already kicked %p", next_worker);
         }
         SET_KICK_STATE(next_worker, KICKED);
@@ -1114,7 +1121,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
                  root_worker == (grpc_pollset_worker*)gpr_atm_no_barrier_load(
                                     &g_active_poller)) {
         GRPC_STATS_INC_POLLSET_KICK_WAKEUP_FD();
-        if (grpc_polling_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
           gpr_log(GPR_INFO, " .. kicked %p", root_worker);
         }
         SET_KICK_STATE(root_worker, KICKED);
@@ -1122,7 +1129,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
         goto done;
       } else if (next_worker->state == UNKICKED) {
         GRPC_STATS_INC_POLLSET_KICK_WAKEUP_CV();
-        if (grpc_polling_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
           gpr_log(GPR_INFO, " .. kicked %p", next_worker);
         }
         GPR_ASSERT(next_worker->initialized_cv);
@@ -1131,7 +1138,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
         goto done;
       } else if (next_worker->state == DESIGNATED_POLLER) {
         if (root_worker->state != DESIGNATED_POLLER) {
-          if (grpc_polling_trace.enabled()) {
+          if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
             gpr_log(
                 GPR_INFO,
                 " .. kicked root non-poller %p (initialized_cv=%d) (poller=%p)",
@@ -1145,7 +1152,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
           goto done;
         } else {
           GRPC_STATS_INC_POLLSET_KICK_WAKEUP_FD();
-          if (grpc_polling_trace.enabled()) {
+          if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
             gpr_log(GPR_INFO, " .. non-root poller %p (root=%p)", next_worker,
                     root_worker);
           }
@@ -1161,7 +1168,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
       }
     } else {
       GRPC_STATS_INC_POLLSET_KICK_OWN_THREAD();
-      if (grpc_polling_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
         gpr_log(GPR_INFO, " .. kicked while waking up");
       }
       goto done;
@@ -1171,14 +1178,14 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
   }
 
   if (specific_worker->state == KICKED) {
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, " .. specific worker already kicked");
     }
     goto done;
   } else if (gpr_tls_get(&g_current_thread_worker) ==
              (intptr_t)specific_worker) {
     GRPC_STATS_INC_POLLSET_KICK_OWN_THREAD();
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, " .. mark %p kicked", specific_worker);
     }
     SET_KICK_STATE(specific_worker, KICKED);
@@ -1186,7 +1193,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
   } else if (specific_worker ==
              (grpc_pollset_worker*)gpr_atm_no_barrier_load(&g_active_poller)) {
     GRPC_STATS_INC_POLLSET_KICK_WAKEUP_FD();
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, " .. kick active poller");
     }
     SET_KICK_STATE(specific_worker, KICKED);
@@ -1194,7 +1201,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
     goto done;
   } else if (specific_worker->initialized_cv) {
     GRPC_STATS_INC_POLLSET_KICK_WAKEUP_CV();
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, " .. kick waiting worker");
     }
     SET_KICK_STATE(specific_worker, KICKED);
@@ -1202,7 +1209,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
     goto done;
   } else {
     GRPC_STATS_INC_POLLSET_KICKED_AGAIN();
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, " .. kick non-waiting worker");
     }
     SET_KICK_STATE(specific_worker, KICKED);

src/core/lib/iomgr/ev_epollex_linux.cc

@@ -164,7 +164,7 @@ struct grpc_fd {
     gpr_asprintf(&fd_name, "%s fd=%d", name, fd);
     grpc_iomgr_register_object(&iomgr_object, fd_name);
 #ifndef NDEBUG
-    if (grpc_trace_fd_refcount.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_fd_refcount)) {
       gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, this, fd_name);
     }
 #endif
@@ -335,7 +335,7 @@ static gpr_mu fd_freelist_mu;
 #define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__)
 static void ref_by(grpc_fd* fd, int n, const char* reason, const char* file,
                    int line) {
-  if (grpc_trace_fd_refcount.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_fd_refcount)) {
     gpr_log(GPR_DEBUG,
             "FD %d %p   ref %d %" PRIdPTR " -> %" PRIdPTR " [%s; %s:%d]",
             fd->fd, fd, n, gpr_atm_no_barrier_load(&fd->refst),
@@ -364,7 +364,7 @@ static void fd_destroy(void* arg, grpc_error* error) {
 #ifndef NDEBUG
 static void unref_by(grpc_fd* fd, int n, const char* reason, const char* file,
                      int line) {
-  if (grpc_trace_fd_refcount.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_fd_refcount)) {
     gpr_log(GPR_DEBUG,
             "FD %d %p unref %d %" PRIdPTR " -> %" PRIdPTR " [%s; %s:%d]",
             fd->fd, fd, n, gpr_atm_no_barrier_load(&fd->refst),
@@ -586,7 +586,7 @@ static grpc_error* pollable_create(pollable_type type, pollable** p) {
 static pollable* pollable_ref(pollable* p) {
 #else
 static pollable* pollable_ref(pollable* p, int line, const char* reason) {
-  if (grpc_trace_pollable_refcount.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_pollable_refcount)) {
     int r = static_cast<int> gpr_atm_no_barrier_load(&p->refs.count);
     gpr_log(__FILE__, line, GPR_LOG_SEVERITY_DEBUG,
             "POLLABLE:%p   ref %d->%d %s", p, r, r + 1, reason);
@@ -601,7 +601,7 @@ static void pollable_unref(pollable* p) {
 #else
 static void pollable_unref(pollable* p, int line, const char* reason) {
   if (p == nullptr) return;
-  if (grpc_trace_pollable_refcount.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_pollable_refcount)) {
     int r = static_cast<int> gpr_atm_no_barrier_load(&p->refs.count);
     gpr_log(__FILE__, line, GPR_LOG_SEVERITY_DEBUG,
             "POLLABLE:%p unref %d->%d %s", p, r, r - 1, reason);
@@ -621,7 +621,7 @@ static grpc_error* pollable_add_fd(pollable* p, grpc_fd* fd) {
   grpc_error* error = GRPC_ERROR_NONE;
   static const char* err_desc = "pollable_add_fd";
   const int epfd = p->epfd;
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "add fd %p (%d) to pollable %p", fd, fd->fd, p);
   }
 
@@ -669,7 +669,7 @@ static void pollset_global_shutdown(void) {
 
 /* pollset->mu must be held while calling this function */
 static void pollset_maybe_finish_shutdown(grpc_pollset* pollset) {
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO,
             "PS:%p (pollable:%p) maybe_finish_shutdown sc=%p (target:!NULL) "
             "rw=%p (target:NULL) cpsc=%d (target:0)",
@@ -694,14 +694,14 @@ static grpc_error* kick_one_worker(grpc_pollset_worker* specific_worker) {
   grpc_core::MutexLock lock(&p->mu);
   GPR_ASSERT(specific_worker != nullptr);
   if (specific_worker->kicked) {
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, "PS:%p kicked_specific_but_already_kicked", p);
     }
     GRPC_STATS_INC_POLLSET_KICKED_AGAIN();
     return GRPC_ERROR_NONE;
   }
   if (gpr_tls_get(&g_current_thread_worker) == (intptr_t)specific_worker) {
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, "PS:%p kicked_specific_but_awake", p);
     }
     GRPC_STATS_INC_POLLSET_KICK_OWN_THREAD();
@@ -710,7 +710,7 @@ static grpc_error* kick_one_worker(grpc_pollset_worker* specific_worker) {
   }
   if (specific_worker == p->root_worker) {
     GRPC_STATS_INC_POLLSET_KICK_WAKEUP_FD();
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, "PS:%p kicked_specific_via_wakeup_fd", p);
     }
     specific_worker->kicked = true;
@@ -719,7 +719,7 @@ static grpc_error* kick_one_worker(grpc_pollset_worker* specific_worker) {
   }
   if (specific_worker->initialized_cv) {
     GRPC_STATS_INC_POLLSET_KICK_WAKEUP_CV();
-    if (grpc_polling_trace.enabled()) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
       gpr_log(GPR_INFO, "PS:%p kicked_specific_via_cv", p);
     }
     specific_worker->kicked = true;
@@ -735,7 +735,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
                                 grpc_pollset_worker* specific_worker) {
   GPR_TIMER_SCOPE("pollset_kick", 0);
   GRPC_STATS_INC_POLLSET_KICK();
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO,
             "PS:%p kick %p tls_pollset=%p tls_worker=%p pollset.root_worker=%p",
             pollset, specific_worker,
@@ -745,7 +745,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
   if (specific_worker == nullptr) {
     if (gpr_tls_get(&g_current_thread_pollset) != (intptr_t)pollset) {
       if (pollset->root_worker == nullptr) {
-        if (grpc_polling_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
           gpr_log(GPR_INFO, "PS:%p kicked_any_without_poller", pollset);
         }
         GRPC_STATS_INC_POLLSET_KICKED_WITHOUT_POLLER();
@@ -771,7 +771,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
             pollset->root_worker->links[PWLINK_POLLSET].next);
       }
     } else {
-      if (grpc_polling_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
         gpr_log(GPR_INFO, "PS:%p kicked_any_but_awake", pollset);
       }
       GRPC_STATS_INC_POLLSET_KICK_OWN_THREAD();
@@ -891,7 +891,7 @@ static grpc_error* pollable_process_events(grpc_pollset* pollset,
     struct epoll_event* ev = &pollable_obj->events[n];
     void* data_ptr = ev->data.ptr;
     if (1 & (intptr_t)data_ptr) {
-      if (grpc_polling_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
         gpr_log(GPR_INFO, "PS:%p got pollset_wakeup %p", pollset, data_ptr);
       }
       append_error(&error,
@@ -909,7 +909,7 @@ static grpc_error* pollable_process_events(grpc_pollset* pollset,
       bool write_ev = (ev->events & EPOLLOUT) != 0;
       bool err_fallback = error && !track_err;
 
-      if (grpc_polling_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
         gpr_log(GPR_INFO,
                 "PS:%p got fd %p: cancel=%d read=%d "
                 "write=%d",
@@ -941,7 +941,7 @@ static grpc_error* pollable_epoll(pollable* p, grpc_millis deadline) {
   GPR_TIMER_SCOPE("pollable_epoll", 0);
   int timeout = poll_deadline_to_millis_timeout(deadline);
 
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     char* desc = pollable_desc(p);
     gpr_log(GPR_INFO, "POLLABLE:%p[%s] poll for %dms", p, desc, timeout);
     gpr_free(desc);
@@ -961,7 +961,7 @@ static grpc_error* pollable_epoll(pollable* p, grpc_millis deadline) {
 
   if (r < 0) return GRPC_OS_ERROR(errno, "epoll_wait");
 
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "POLLABLE:%p got %d events", p, r);
   }
 
@@ -1031,7 +1031,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
     worker->initialized_cv = true;
     gpr_cv_init(&worker->cv);
     gpr_mu_unlock(&pollset->mu);
-    if (grpc_polling_trace.enabled() &&
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace) &&
         worker->pollable_obj->root_worker != worker) {
       gpr_log(GPR_INFO, "PS:%p wait %p w=%p for %dms", pollset,
               worker->pollable_obj, worker,
@@ -1040,18 +1040,18 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
     while (do_poll && worker->pollable_obj->root_worker != worker) {
       if (gpr_cv_wait(&worker->cv, &worker->pollable_obj->mu,
                       grpc_millis_to_timespec(deadline, GPR_CLOCK_REALTIME))) {
-        if (grpc_polling_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
           gpr_log(GPR_INFO, "PS:%p timeout_wait %p w=%p", pollset,
                   worker->pollable_obj, worker);
         }
         do_poll = false;
       } else if (worker->kicked) {
-        if (grpc_polling_trace.enabled()) {
+        if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
           gpr_log(GPR_INFO, "PS:%p wakeup %p w=%p", pollset,
                   worker->pollable_obj, worker);
         }
         do_poll = false;
-      } else if (grpc_polling_trace.enabled() &&
+      } else if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace) &&
                  worker->pollable_obj->root_worker != worker) {
         gpr_log(GPR_INFO, "PS:%p spurious_wakeup %p w=%p", pollset,
                 worker->pollable_obj, worker);
@@ -1124,7 +1124,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
 #ifndef NDEBUG
   WORKER_PTR->originator = gettid();
 #endif
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO,
             "PS:%p work hdl=%p worker=%p now=%" PRId64 " deadline=%" PRId64
             " kwp=%d pollable=%p",
@@ -1165,7 +1165,7 @@ static grpc_error* pollset_transition_pollable_from_empty_to_fd_locked(
     grpc_pollset* pollset, grpc_fd* fd) {
   static const char* err_desc = "pollset_transition_pollable_from_empty_to_fd";
   grpc_error* error = GRPC_ERROR_NONE;
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO,
             "PS:%p add fd %p (%d); transition pollable from empty to fd",
             pollset, fd, fd->fd);
@@ -1181,7 +1181,7 @@ static grpc_error* pollset_transition_pollable_from_fd_to_multi_locked(
     grpc_pollset* pollset, grpc_fd* and_add_fd) {
   static const char* err_desc = "pollset_transition_pollable_from_fd_to_multi";
   grpc_error* error = GRPC_ERROR_NONE;
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(
         GPR_INFO,
         "PS:%p add fd %p (%d); transition pollable from fd %p to multipoller",
@@ -1253,7 +1253,7 @@ static grpc_error* pollset_as_multipollable_locked(grpc_pollset* pollset,
       error = pollable_create(PO_MULTI, &pollset->active_pollable);
       /* Any workers currently polling on this pollset must now be woked up so
        * that they can pick up the new active_pollable */
-      if (grpc_polling_trace.enabled()) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
         gpr_log(GPR_INFO,
                 "PS:%p active pollable transition from empty to multi",
                 pollset);
@@ -1357,7 +1357,7 @@ static void pollset_set_unref(grpc_pollset_set* pss) {
 
 static void pollset_set_add_fd(grpc_pollset_set* pss, grpc_fd* fd) {
   GPR_TIMER_SCOPE("pollset_set_add_fd", 0);
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "PSS:%p: add fd %p (%d)", pss, fd, fd->fd);
   }
   grpc_error* error = GRPC_ERROR_NONE;
@@ -1381,7 +1381,7 @@ static void pollset_set_add_fd(grpc_pollset_set* pss, grpc_fd* fd) {
 
 static void pollset_set_del_fd(grpc_pollset_set* pss, grpc_fd* fd) {
   GPR_TIMER_SCOPE("pollset_set_del_fd", 0);
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "PSS:%p: del fd %p", pss, fd);
   }
   pss = pss_lock_adam(pss);
@@ -1402,7 +1402,7 @@ static void pollset_set_del_fd(grpc_pollset_set* pss, grpc_fd* fd) {
 
 static void pollset_set_del_pollset(grpc_pollset_set* pss, grpc_pollset* ps) {
   GPR_TIMER_SCOPE("pollset_set_del_pollset", 0);
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "PSS:%p: del pollset %p", pss, ps);
   }
   pss = pss_lock_adam(pss);
@@ -1454,7 +1454,7 @@ static grpc_error* add_fds_to_pollsets(grpc_fd** fds, size_t fd_count,
 
 static void pollset_set_add_pollset(grpc_pollset_set* pss, grpc_pollset* ps) {
   GPR_TIMER_SCOPE("pollset_set_add_pollset", 0);
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "PSS:%p: add pollset %p", pss, ps);
   }
   grpc_error* error = GRPC_ERROR_NONE;
@@ -1491,7 +1491,7 @@ static void pollset_set_add_pollset(grpc_pollset_set* pss, grpc_pollset* ps) {
 static void pollset_set_add_pollset_set(grpc_pollset_set* a,
                                         grpc_pollset_set* b) {
   GPR_TIMER_SCOPE("pollset_set_add_pollset_set", 0);
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "PSS: merge (%p, %p)", a, b);
   }
   grpc_error* error = GRPC_ERROR_NONE;
@@ -1525,7 +1525,7 @@ static void pollset_set_add_pollset_set(grpc_pollset_set* a,
   if (b_size > a_size) {
     GPR_SWAP(grpc_pollset_set*, a, b);
   }
-  if (grpc_polling_trace.enabled()) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_trace)) {
     gpr_log(GPR_INFO, "PSS: parent %p to %p", b, a);
   }
   gpr_ref(&a->refs);