Merge pull request #21846 from yashykt/workserializer

Replace LogicalThread with WorkSerializer

BUILD

@@ -752,7 +752,6 @@ grpc_cc_library(
         "src/core/lib/iomgr/is_epollexclusive_available.cc",
         "src/core/lib/iomgr/load_file.cc",
         "src/core/lib/iomgr/lockfree_event.cc",
-        "src/core/lib/iomgr/logical_thread.cc",
         "src/core/lib/iomgr/polling_entity.cc",
         "src/core/lib/iomgr/pollset.cc",
         "src/core/lib/iomgr/pollset_custom.cc",
@@ -804,6 +803,7 @@ grpc_cc_library(
         "src/core/lib/iomgr/wakeup_fd_nospecial.cc",
         "src/core/lib/iomgr/wakeup_fd_pipe.cc",
         "src/core/lib/iomgr/wakeup_fd_posix.cc",
+        "src/core/lib/iomgr/work_serializer.cc",
         "src/core/lib/json/json.cc",
         "src/core/lib/json/json_reader.cc",
         "src/core/lib/json/json_reader_new.cc",
@@ -906,7 +906,6 @@ grpc_cc_library(
         "src/core/lib/iomgr/is_epollexclusive_available.h",
         "src/core/lib/iomgr/load_file.h",
         "src/core/lib/iomgr/lockfree_event.h",
-        "src/core/lib/iomgr/logical_thread.h",
         "src/core/lib/iomgr/nameser.h",
         "src/core/lib/iomgr/polling_entity.h",
         "src/core/lib/iomgr/pollset.h",
@@ -949,6 +948,7 @@ grpc_cc_library(
         "src/core/lib/iomgr/unix_sockets_posix.h",
         "src/core/lib/iomgr/wakeup_fd_pipe.h",
         "src/core/lib/iomgr/wakeup_fd_posix.h",
+        "src/core/lib/iomgr/work_serializer.h",
         "src/core/lib/json/json.h",
         "src/core/lib/slice/b64.h",
         "src/core/lib/slice/percent_encoding.h",

BUILD.gn

@@ -620,8 +620,6 @@ config("grpc_config") {
         "src/core/lib/iomgr/load_file.h",
         "src/core/lib/iomgr/lockfree_event.cc",
         "src/core/lib/iomgr/lockfree_event.h",
-        "src/core/lib/iomgr/logical_thread.cc",
-        "src/core/lib/iomgr/logical_thread.h",
         "src/core/lib/iomgr/nameser.h",
         "src/core/lib/iomgr/poller/eventmanager_libuv.cc",
         "src/core/lib/iomgr/poller/eventmanager_libuv.h",
@@ -715,6 +713,8 @@ config("grpc_config") {
         "src/core/lib/iomgr/wakeup_fd_pipe.h",
         "src/core/lib/iomgr/wakeup_fd_posix.cc",
         "src/core/lib/iomgr/wakeup_fd_posix.h",
+        "src/core/lib/iomgr/work_serializer.cc",
+        "src/core/lib/iomgr/work_serializer.h",
         "src/core/lib/json/json.cc",
         "src/core/lib/json/json.h",
         "src/core/lib/json/json_reader.cc",
@@ -1313,7 +1313,6 @@ config("grpc_config") {
         "src/core/lib/iomgr/is_epollexclusive_available.h",
         "src/core/lib/iomgr/load_file.h",
         "src/core/lib/iomgr/lockfree_event.h",
-        "src/core/lib/iomgr/logical_thread.h",
         "src/core/lib/iomgr/nameser.h",
         "src/core/lib/iomgr/poller/eventmanager_libuv.h",
         "src/core/lib/iomgr/polling_entity.h",
@@ -1354,6 +1353,7 @@ config("grpc_config") {
         "src/core/lib/iomgr/unix_sockets_posix.h",
         "src/core/lib/iomgr/wakeup_fd_pipe.h",
         "src/core/lib/iomgr/wakeup_fd_posix.h",
+        "src/core/lib/iomgr/work_serializer.h",
         "src/core/lib/json/json.h",
         "src/core/lib/profiling/timers.h",
         "src/core/lib/slice/b64.h",

CMakeLists.txt

@@ -827,7 +827,6 @@ if(gRPC_BUILD_TESTS)
     add_dependencies(buildtests_cxx json_run_localhost)
   endif()
   add_dependencies(buildtests_cxx json_test_new)
-  add_dependencies(buildtests_cxx logical_thread_test)
   add_dependencies(buildtests_cxx message_allocator_end2end_test)
   add_dependencies(buildtests_cxx metrics_client)
   add_dependencies(buildtests_cxx mock_test)
@@ -894,6 +893,7 @@ if(gRPC_BUILD_TESTS)
   add_dependencies(buildtests_cxx transport_connectivity_state_test)
   add_dependencies(buildtests_cxx transport_pid_controller_test)
   add_dependencies(buildtests_cxx transport_security_common_api_test)
+  add_dependencies(buildtests_cxx work_serializer_test)
   if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
     add_dependencies(buildtests_cxx writes_per_rpc_test)
   endif()
@@ -1070,7 +1070,6 @@ add_library(alts_test_util
   src/core/lib/iomgr/is_epollexclusive_available.cc
   src/core/lib/iomgr/load_file.cc
   src/core/lib/iomgr/lockfree_event.cc
-  src/core/lib/iomgr/logical_thread.cc
   src/core/lib/iomgr/poller/eventmanager_libuv.cc
   src/core/lib/iomgr/polling_entity.cc
   src/core/lib/iomgr/pollset.cc
@@ -1124,6 +1123,7 @@ add_library(alts_test_util
   src/core/lib/iomgr/wakeup_fd_nospecial.cc
   src/core/lib/iomgr/wakeup_fd_pipe.cc
   src/core/lib/iomgr/wakeup_fd_posix.cc
+  src/core/lib/iomgr/work_serializer.cc
   src/core/lib/json/json.cc
   src/core/lib/json/json_reader.cc
   src/core/lib/json/json_reader_new.cc
@@ -1560,7 +1560,6 @@ add_library(grpc
   src/core/lib/iomgr/is_epollexclusive_available.cc
   src/core/lib/iomgr/load_file.cc
   src/core/lib/iomgr/lockfree_event.cc
-  src/core/lib/iomgr/logical_thread.cc
   src/core/lib/iomgr/poller/eventmanager_libuv.cc
   src/core/lib/iomgr/polling_entity.cc
   src/core/lib/iomgr/pollset.cc
@@ -1614,6 +1613,7 @@ add_library(grpc
   src/core/lib/iomgr/wakeup_fd_nospecial.cc
   src/core/lib/iomgr/wakeup_fd_pipe.cc
   src/core/lib/iomgr/wakeup_fd_posix.cc
+  src/core/lib/iomgr/work_serializer.cc
   src/core/lib/json/json.cc
   src/core/lib/json/json_reader.cc
   src/core/lib/json/json_reader_new.cc
@@ -2046,7 +2046,6 @@ add_library(grpc_cronet
   src/core/lib/iomgr/is_epollexclusive_available.cc
   src/core/lib/iomgr/load_file.cc
   src/core/lib/iomgr/lockfree_event.cc
-  src/core/lib/iomgr/logical_thread.cc
   src/core/lib/iomgr/poller/eventmanager_libuv.cc
   src/core/lib/iomgr/polling_entity.cc
   src/core/lib/iomgr/pollset.cc
@@ -2100,6 +2099,7 @@ add_library(grpc_cronet
   src/core/lib/iomgr/wakeup_fd_nospecial.cc
   src/core/lib/iomgr/wakeup_fd_pipe.cc
   src/core/lib/iomgr/wakeup_fd_posix.cc
+  src/core/lib/iomgr/work_serializer.cc
   src/core/lib/json/json.cc
   src/core/lib/json/json_reader.cc
   src/core/lib/json/json_reader_new.cc
@@ -2477,7 +2477,6 @@ add_library(grpc_test_util
   src/core/lib/iomgr/is_epollexclusive_available.cc
   src/core/lib/iomgr/load_file.cc
   src/core/lib/iomgr/lockfree_event.cc
-  src/core/lib/iomgr/logical_thread.cc
   src/core/lib/iomgr/poller/eventmanager_libuv.cc
   src/core/lib/iomgr/polling_entity.cc
   src/core/lib/iomgr/pollset.cc
@@ -2531,6 +2530,7 @@ add_library(grpc_test_util
   src/core/lib/iomgr/wakeup_fd_nospecial.cc
   src/core/lib/iomgr/wakeup_fd_pipe.cc
   src/core/lib/iomgr/wakeup_fd_posix.cc
+  src/core/lib/iomgr/work_serializer.cc
   src/core/lib/json/json.cc
   src/core/lib/json/json_reader.cc
   src/core/lib/json/json_reader_new.cc
@@ -2822,7 +2822,6 @@ add_library(grpc_test_util_unsecure
   src/core/lib/iomgr/is_epollexclusive_available.cc
   src/core/lib/iomgr/load_file.cc
   src/core/lib/iomgr/lockfree_event.cc
-  src/core/lib/iomgr/logical_thread.cc
   src/core/lib/iomgr/poller/eventmanager_libuv.cc
   src/core/lib/iomgr/polling_entity.cc
   src/core/lib/iomgr/pollset.cc
@@ -2876,6 +2875,7 @@ add_library(grpc_test_util_unsecure
   src/core/lib/iomgr/wakeup_fd_nospecial.cc
   src/core/lib/iomgr/wakeup_fd_pipe.cc
   src/core/lib/iomgr/wakeup_fd_posix.cc
+  src/core/lib/iomgr/work_serializer.cc
   src/core/lib/json/json.cc
   src/core/lib/json/json_reader.cc
   src/core/lib/json/json_reader_new.cc
@@ -3143,7 +3143,6 @@ add_library(grpc_unsecure
   src/core/lib/iomgr/is_epollexclusive_available.cc
   src/core/lib/iomgr/load_file.cc
   src/core/lib/iomgr/lockfree_event.cc
-  src/core/lib/iomgr/logical_thread.cc
   src/core/lib/iomgr/poller/eventmanager_libuv.cc
   src/core/lib/iomgr/polling_entity.cc
   src/core/lib/iomgr/pollset.cc
@@ -3197,6 +3196,7 @@ add_library(grpc_unsecure
   src/core/lib/iomgr/wakeup_fd_nospecial.cc
   src/core/lib/iomgr/wakeup_fd_pipe.cc
   src/core/lib/iomgr/wakeup_fd_posix.cc
+  src/core/lib/iomgr/work_serializer.cc
   src/core/lib/json/json.cc
   src/core/lib/json/json_reader.cc
   src/core/lib/json/json_reader_new.cc
@@ -14051,42 +14051,6 @@ target_link_libraries(json_test_new
 )
 
 
-endif()
-if(gRPC_BUILD_TESTS)
-
-add_executable(logical_thread_test
-  test/core/iomgr/logical_thread_test.cc
-  third_party/googletest/googletest/src/gtest-all.cc
-  third_party/googletest/googlemock/src/gmock-all.cc
-)
-
-target_include_directories(logical_thread_test
-  PRIVATE
-    ${CMAKE_CURRENT_SOURCE_DIR}
-    ${CMAKE_CURRENT_SOURCE_DIR}/include
-    ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
-    ${_gRPC_SSL_INCLUDE_DIR}
-    ${_gRPC_UPB_GENERATED_DIR}
-    ${_gRPC_UPB_GRPC_GENERATED_DIR}
-    ${_gRPC_UPB_INCLUDE_DIR}
-    ${_gRPC_ZLIB_INCLUDE_DIR}
-    third_party/googletest/googletest/include
-    third_party/googletest/googletest
-    third_party/googletest/googlemock/include
-    third_party/googletest/googlemock
-    ${_gRPC_PROTO_GENS_DIR}
-)
-
-target_link_libraries(logical_thread_test
-  ${_gRPC_PROTOBUF_LIBRARIES}
-  ${_gRPC_ALLTARGETS_LIBRARIES}
-  grpc_test_util
-  grpc
-  gpr
-  ${_gRPC_GFLAGS_LIBRARIES}
-)
-
-
 endif()
 if(gRPC_BUILD_TESTS)
 
@@ -16062,6 +16026,42 @@ target_link_libraries(transport_security_common_api_test
 )
 
 
+endif()
+if(gRPC_BUILD_TESTS)
+
+add_executable(work_serializer_test
+  test/core/iomgr/work_serializer_test.cc
+  third_party/googletest/googletest/src/gtest-all.cc
+  third_party/googletest/googlemock/src/gmock-all.cc
+)
+
+target_include_directories(work_serializer_test
+  PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/include
+    ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
+    ${_gRPC_SSL_INCLUDE_DIR}
+    ${_gRPC_UPB_GENERATED_DIR}
+    ${_gRPC_UPB_GRPC_GENERATED_DIR}
+    ${_gRPC_UPB_INCLUDE_DIR}
+    ${_gRPC_ZLIB_INCLUDE_DIR}
+    third_party/googletest/googletest/include
+    third_party/googletest/googletest
+    third_party/googletest/googlemock/include
+    third_party/googletest/googlemock
+    ${_gRPC_PROTO_GENS_DIR}
+)
+
+target_link_libraries(work_serializer_test
+  ${_gRPC_PROTOBUF_LIBRARIES}
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  grpc_test_util
+  grpc
+  gpr
+  ${_gRPC_GFLAGS_LIBRARIES}
+)
+
+
 endif()
 if(gRPC_BUILD_TESTS)
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)

Makefile

@@ -1257,7 +1257,6 @@ interop_server: $(BINDIR)/$(CONFIG)/interop_server
 interop_test: $(BINDIR)/$(CONFIG)/interop_test
 json_run_localhost: $(BINDIR)/$(CONFIG)/json_run_localhost
 json_test_new: $(BINDIR)/$(CONFIG)/json_test_new
-logical_thread_test: $(BINDIR)/$(CONFIG)/logical_thread_test
 message_allocator_end2end_test: $(BINDIR)/$(CONFIG)/message_allocator_end2end_test
 metrics_client: $(BINDIR)/$(CONFIG)/metrics_client
 mock_test: $(BINDIR)/$(CONFIG)/mock_test
@@ -1308,6 +1307,7 @@ timer_test: $(BINDIR)/$(CONFIG)/timer_test
 transport_connectivity_state_test: $(BINDIR)/$(CONFIG)/transport_connectivity_state_test
 transport_pid_controller_test: $(BINDIR)/$(CONFIG)/transport_pid_controller_test
 transport_security_common_api_test: $(BINDIR)/$(CONFIG)/transport_security_common_api_test
+work_serializer_test: $(BINDIR)/$(CONFIG)/work_serializer_test
 writes_per_rpc_test: $(BINDIR)/$(CONFIG)/writes_per_rpc_test
 xds_bootstrap_test: $(BINDIR)/$(CONFIG)/xds_bootstrap_test
 xds_end2end_test: $(BINDIR)/$(CONFIG)/xds_end2end_test
@@ -1728,7 +1728,6 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/interop_test \
   $(BINDIR)/$(CONFIG)/json_run_localhost \
   $(BINDIR)/$(CONFIG)/json_test_new \
-  $(BINDIR)/$(CONFIG)/logical_thread_test \
   $(BINDIR)/$(CONFIG)/message_allocator_end2end_test \
   $(BINDIR)/$(CONFIG)/metrics_client \
   $(BINDIR)/$(CONFIG)/mock_test \
@@ -1779,6 +1778,7 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/transport_connectivity_state_test \
   $(BINDIR)/$(CONFIG)/transport_pid_controller_test \
   $(BINDIR)/$(CONFIG)/transport_security_common_api_test \
+  $(BINDIR)/$(CONFIG)/work_serializer_test \
   $(BINDIR)/$(CONFIG)/writes_per_rpc_test \
   $(BINDIR)/$(CONFIG)/xds_bootstrap_test \
   $(BINDIR)/$(CONFIG)/xds_end2end_test \
@@ -1904,7 +1904,6 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/interop_test \
   $(BINDIR)/$(CONFIG)/json_run_localhost \
   $(BINDIR)/$(CONFIG)/json_test_new \
-  $(BINDIR)/$(CONFIG)/logical_thread_test \
   $(BINDIR)/$(CONFIG)/message_allocator_end2end_test \
   $(BINDIR)/$(CONFIG)/metrics_client \
   $(BINDIR)/$(CONFIG)/mock_test \
@@ -1955,6 +1954,7 @@ buildtests_cxx: privatelibs_cxx \
   $(BINDIR)/$(CONFIG)/transport_connectivity_state_test \
   $(BINDIR)/$(CONFIG)/transport_pid_controller_test \
   $(BINDIR)/$(CONFIG)/transport_security_common_api_test \
+  $(BINDIR)/$(CONFIG)/work_serializer_test \
   $(BINDIR)/$(CONFIG)/writes_per_rpc_test \
   $(BINDIR)/$(CONFIG)/xds_bootstrap_test \
   $(BINDIR)/$(CONFIG)/xds_end2end_test \
@@ -2419,8 +2419,6 @@ test_cxx: buildtests_cxx
 	$(Q) $(BINDIR)/$(CONFIG)/interop_test || ( echo test interop_test failed ; exit 1 )
 	$(E) "[RUN]     Testing json_test_new"
 	$(Q) $(BINDIR)/$(CONFIG)/json_test_new || ( echo test json_test_new failed ; exit 1 )
-	$(E) "[RUN]     Testing logical_thread_test"
-	$(Q) $(BINDIR)/$(CONFIG)/logical_thread_test || ( echo test logical_thread_test failed ; exit 1 )
 	$(E) "[RUN]     Testing message_allocator_end2end_test"
 	$(Q) $(BINDIR)/$(CONFIG)/message_allocator_end2end_test || ( echo test message_allocator_end2end_test failed ; exit 1 )
 	$(E) "[RUN]     Testing mock_test"
@@ -2505,6 +2503,8 @@ test_cxx: buildtests_cxx
 	$(Q) $(BINDIR)/$(CONFIG)/transport_pid_controller_test || ( echo test transport_pid_controller_test failed ; exit 1 )
 	$(E) "[RUN]     Testing transport_security_common_api_test"
 	$(Q) $(BINDIR)/$(CONFIG)/transport_security_common_api_test || ( echo test transport_security_common_api_test failed ; exit 1 )
+	$(E) "[RUN]     Testing work_serializer_test"
+	$(Q) $(BINDIR)/$(CONFIG)/work_serializer_test || ( echo test work_serializer_test failed ; exit 1 )
 	$(E) "[RUN]     Testing writes_per_rpc_test"
 	$(Q) $(BINDIR)/$(CONFIG)/writes_per_rpc_test || ( echo test writes_per_rpc_test failed ; exit 1 )
 	$(E) "[RUN]     Testing xds_bootstrap_test"
@@ -3584,7 +3584,6 @@ LIBALTS_TEST_UTIL_SRC = \
     src/core/lib/iomgr/is_epollexclusive_available.cc \
     src/core/lib/iomgr/load_file.cc \
     src/core/lib/iomgr/lockfree_event.cc \
-    src/core/lib/iomgr/logical_thread.cc \
     src/core/lib/iomgr/poller/eventmanager_libuv.cc \
     src/core/lib/iomgr/polling_entity.cc \
     src/core/lib/iomgr/pollset.cc \
@@ -3638,6 +3637,7 @@ LIBALTS_TEST_UTIL_SRC = \
     src/core/lib/iomgr/wakeup_fd_nospecial.cc \
     src/core/lib/iomgr/wakeup_fd_pipe.cc \
     src/core/lib/iomgr/wakeup_fd_posix.cc \
+    src/core/lib/iomgr/work_serializer.cc \
     src/core/lib/json/json.cc \
     src/core/lib/json/json_reader.cc \
     src/core/lib/json/json_reader_new.cc \
@@ -4042,7 +4042,6 @@ LIBGRPC_SRC = \
     src/core/lib/iomgr/is_epollexclusive_available.cc \
     src/core/lib/iomgr/load_file.cc \
     src/core/lib/iomgr/lockfree_event.cc \
-    src/core/lib/iomgr/logical_thread.cc \
     src/core/lib/iomgr/poller/eventmanager_libuv.cc \
     src/core/lib/iomgr/polling_entity.cc \
     src/core/lib/iomgr/pollset.cc \
@@ -4096,6 +4095,7 @@ LIBGRPC_SRC = \
     src/core/lib/iomgr/wakeup_fd_nospecial.cc \
     src/core/lib/iomgr/wakeup_fd_pipe.cc \
     src/core/lib/iomgr/wakeup_fd_posix.cc \
+    src/core/lib/iomgr/work_serializer.cc \
     src/core/lib/json/json.cc \
     src/core/lib/json/json_reader.cc \
     src/core/lib/json/json_reader_new.cc \
@@ -4520,7 +4520,6 @@ LIBGRPC_CRONET_SRC = \
     src/core/lib/iomgr/is_epollexclusive_available.cc \
     src/core/lib/iomgr/load_file.cc \
     src/core/lib/iomgr/lockfree_event.cc \
-    src/core/lib/iomgr/logical_thread.cc \
     src/core/lib/iomgr/poller/eventmanager_libuv.cc \
     src/core/lib/iomgr/polling_entity.cc \
     src/core/lib/iomgr/pollset.cc \
@@ -4574,6 +4573,7 @@ LIBGRPC_CRONET_SRC = \
     src/core/lib/iomgr/wakeup_fd_nospecial.cc \
     src/core/lib/iomgr/wakeup_fd_pipe.cc \
     src/core/lib/iomgr/wakeup_fd_posix.cc \
+    src/core/lib/iomgr/work_serializer.cc \
     src/core/lib/json/json.cc \
     src/core/lib/json/json_reader.cc \
     src/core/lib/json/json_reader_new.cc \
@@ -4942,7 +4942,6 @@ LIBGRPC_TEST_UTIL_SRC = \
     src/core/lib/iomgr/is_epollexclusive_available.cc \
     src/core/lib/iomgr/load_file.cc \
     src/core/lib/iomgr/lockfree_event.cc \
-    src/core/lib/iomgr/logical_thread.cc \
     src/core/lib/iomgr/poller/eventmanager_libuv.cc \
     src/core/lib/iomgr/polling_entity.cc \
     src/core/lib/iomgr/pollset.cc \
@@ -4996,6 +4995,7 @@ LIBGRPC_TEST_UTIL_SRC = \
     src/core/lib/iomgr/wakeup_fd_nospecial.cc \
     src/core/lib/iomgr/wakeup_fd_pipe.cc \
     src/core/lib/iomgr/wakeup_fd_posix.cc \
+    src/core/lib/iomgr/work_serializer.cc \
     src/core/lib/json/json.cc \
     src/core/lib/json/json_reader.cc \
     src/core/lib/json/json_reader_new.cc \
@@ -5273,7 +5273,6 @@ LIBGRPC_TEST_UTIL_UNSECURE_SRC = \
     src/core/lib/iomgr/is_epollexclusive_available.cc \
     src/core/lib/iomgr/load_file.cc \
     src/core/lib/iomgr/lockfree_event.cc \
-    src/core/lib/iomgr/logical_thread.cc \
     src/core/lib/iomgr/poller/eventmanager_libuv.cc \
     src/core/lib/iomgr/polling_entity.cc \
     src/core/lib/iomgr/pollset.cc \
@@ -5327,6 +5326,7 @@ LIBGRPC_TEST_UTIL_UNSECURE_SRC = \
     src/core/lib/iomgr/wakeup_fd_nospecial.cc \
     src/core/lib/iomgr/wakeup_fd_pipe.cc \
     src/core/lib/iomgr/wakeup_fd_posix.cc \
+    src/core/lib/iomgr/work_serializer.cc \
     src/core/lib/json/json.cc \
     src/core/lib/json/json_reader.cc \
     src/core/lib/json/json_reader_new.cc \
@@ -5567,7 +5567,6 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/lib/iomgr/is_epollexclusive_available.cc \
     src/core/lib/iomgr/load_file.cc \
     src/core/lib/iomgr/lockfree_event.cc \
-    src/core/lib/iomgr/logical_thread.cc \
     src/core/lib/iomgr/poller/eventmanager_libuv.cc \
     src/core/lib/iomgr/polling_entity.cc \
     src/core/lib/iomgr/pollset.cc \
@@ -5621,6 +5620,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/lib/iomgr/wakeup_fd_nospecial.cc \
     src/core/lib/iomgr/wakeup_fd_pipe.cc \
     src/core/lib/iomgr/wakeup_fd_posix.cc \
+    src/core/lib/iomgr/work_serializer.cc \
     src/core/lib/json/json.cc \
     src/core/lib/json/json_reader.cc \
     src/core/lib/json/json_reader_new.cc \
@@ -18410,49 +18410,6 @@ endif
 endif
 
 
-LOGICAL_THREAD_TEST_SRC = \
-    test/core/iomgr/logical_thread_test.cc \
-
-LOGICAL_THREAD_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(LOGICAL_THREAD_TEST_SRC))))
-ifeq ($(NO_SECURE),true)
-
-# You can't build secure targets if you don't have OpenSSL.
-
-$(BINDIR)/$(CONFIG)/logical_thread_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)/$(CONFIG)/logical_thread_test: protobuf_dep_error
-
-else
-
-$(BINDIR)/$(CONFIG)/logical_thread_test: $(PROTOBUF_DEP) $(LOGICAL_THREAD_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a
-	$(E) "[LD]      Linking $@"
-	$(Q) mkdir -p `dirname $@`
-	$(Q) $(LDXX) $(LDFLAGS) $(LOGICAL_THREAD_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/logical_thread_test
-
-endif
-
-endif
-
-$(OBJDIR)/$(CONFIG)/test/core/iomgr/logical_thread_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a
-
-deps_logical_thread_test: $(LOGICAL_THREAD_TEST_OBJS:.o=.dep)
-
-ifneq ($(NO_SECURE),true)
-ifneq ($(NO_DEPS),true)
--include $(LOGICAL_THREAD_TEST_OBJS:.o=.dep)
-endif
-endif
-
-
 MESSAGE_ALLOCATOR_END2END_TEST_SRC = \
     test/cpp/end2end/message_allocator_end2end_test.cc \
 
@@ -20677,6 +20634,49 @@ endif
 endif
 
 
+WORK_SERIALIZER_TEST_SRC = \
+    test/core/iomgr/work_serializer_test.cc \
+
+WORK_SERIALIZER_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(WORK_SERIALIZER_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/work_serializer_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)/$(CONFIG)/work_serializer_test: protobuf_dep_error
+
+else
+
+$(BINDIR)/$(CONFIG)/work_serializer_test: $(PROTOBUF_DEP) $(WORK_SERIALIZER_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LDXX) $(LDFLAGS) $(WORK_SERIALIZER_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBSXX) $(LDLIBS_PROTOBUF) $(LDLIBS) $(LDLIBS_SECURE) $(GTEST_LIB) -o $(BINDIR)/$(CONFIG)/work_serializer_test
+
+endif
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/iomgr/work_serializer_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_work_serializer_test: $(WORK_SERIALIZER_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(WORK_SERIALIZER_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 WRITES_PER_RPC_TEST_SRC = \
     test/cpp/performance/writes_per_rpc_test.cc \
 

build.yaml

@@ -716,7 +716,6 @@ filegroups:
   - src/core/lib/iomgr/is_epollexclusive_available.cc
   - src/core/lib/iomgr/load_file.cc
   - src/core/lib/iomgr/lockfree_event.cc
-  - src/core/lib/iomgr/logical_thread.cc
   - src/core/lib/iomgr/poller/eventmanager_libuv.cc
   - src/core/lib/iomgr/polling_entity.cc
   - src/core/lib/iomgr/pollset.cc
@@ -770,6 +769,7 @@ filegroups:
   - src/core/lib/iomgr/wakeup_fd_nospecial.cc
   - src/core/lib/iomgr/wakeup_fd_pipe.cc
   - src/core/lib/iomgr/wakeup_fd_posix.cc
+  - src/core/lib/iomgr/work_serializer.cc
   - src/core/lib/json/json.cc
   - src/core/lib/json/json_reader.cc
   - src/core/lib/json/json_reader_new.cc
@@ -898,7 +898,6 @@ filegroups:
   - src/core/lib/iomgr/is_epollexclusive_available.h
   - src/core/lib/iomgr/load_file.h
   - src/core/lib/iomgr/lockfree_event.h
-  - src/core/lib/iomgr/logical_thread.h
   - src/core/lib/iomgr/nameser.h
   - src/core/lib/iomgr/poller/eventmanager_libuv.h
   - src/core/lib/iomgr/polling_entity.h
@@ -939,6 +938,7 @@ filegroups:
   - src/core/lib/iomgr/unix_sockets_posix.h
   - src/core/lib/iomgr/wakeup_fd_pipe.h
   - src/core/lib/iomgr/wakeup_fd_posix.h
+  - src/core/lib/iomgr/work_serializer.h
   - src/core/lib/json/json.h
   - src/core/lib/slice/b64.h
   - src/core/lib/slice/percent_encoding.h
@@ -5407,16 +5407,6 @@ targets:
   - grpc
   - gpr
   uses_polling: false
-- name: logical_thread_test
-  cpu_cost: 10
-  build: test
-  language: c++
-  src:
-  - test/core/iomgr/logical_thread_test.cc
-  deps:
-  - grpc_test_util
-  - grpc
-  - gpr
 - name: message_allocator_end2end_test
   gtest: true
   cpu_cost: 0.5
@@ -6088,6 +6078,16 @@ targets:
   - alts_test_util
   - gpr
   - grpc
+- name: work_serializer_test
+  cpu_cost: 10
+  build: test
+  language: c++
+  src:
+  - test/core/iomgr/work_serializer_test.cc
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr
 - name: writes_per_rpc_test
   gtest: true
   cpu_cost: 0.5

config.m4

@@ -291,7 +291,6 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/iomgr/is_epollexclusive_available.cc \
     src/core/lib/iomgr/load_file.cc \
     src/core/lib/iomgr/lockfree_event.cc \
-    src/core/lib/iomgr/logical_thread.cc \
     src/core/lib/iomgr/poller/eventmanager_libuv.cc \
     src/core/lib/iomgr/polling_entity.cc \
     src/core/lib/iomgr/pollset.cc \
@@ -345,6 +344,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/iomgr/wakeup_fd_nospecial.cc \
     src/core/lib/iomgr/wakeup_fd_pipe.cc \
     src/core/lib/iomgr/wakeup_fd_posix.cc \
+    src/core/lib/iomgr/work_serializer.cc \
     src/core/lib/json/json.cc \
     src/core/lib/json/json_reader.cc \
     src/core/lib/json/json_reader_new.cc \

config.w32

@@ -260,7 +260,6 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\iomgr\\is_epollexclusive_available.cc " +
     "src\\core\\lib\\iomgr\\load_file.cc " +
     "src\\core\\lib\\iomgr\\lockfree_event.cc " +
-    "src\\core\\lib\\iomgr\\logical_thread.cc " +
     "src\\core\\lib\\iomgr\\poller\\eventmanager_libuv.cc " +
     "src\\core\\lib\\iomgr\\polling_entity.cc " +
     "src\\core\\lib\\iomgr\\pollset.cc " +
@@ -314,6 +313,7 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\iomgr\\wakeup_fd_nospecial.cc " +
     "src\\core\\lib\\iomgr\\wakeup_fd_pipe.cc " +
     "src\\core\\lib\\iomgr\\wakeup_fd_posix.cc " +
+    "src\\core\\lib\\iomgr\\work_serializer.cc " +
     "src\\core\\lib\\json\\json.cc " +
     "src\\core\\lib\\json\\json_reader.cc " +
     "src\\core\\lib\\json\\json_reader_new.cc " +

gRPC-C++.podspec

@@ -443,7 +443,6 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/is_epollexclusive_available.h',
                       'src/core/lib/iomgr/load_file.h',
                       'src/core/lib/iomgr/lockfree_event.h',
-                      'src/core/lib/iomgr/logical_thread.h',
                       'src/core/lib/iomgr/nameser.h',
                       'src/core/lib/iomgr/poller/eventmanager_libuv.h',
                       'src/core/lib/iomgr/polling_entity.h',
@@ -484,6 +483,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/unix_sockets_posix.h',
                       'src/core/lib/iomgr/wakeup_fd_pipe.h',
                       'src/core/lib/iomgr/wakeup_fd_posix.h',
+                      'src/core/lib/iomgr/work_serializer.h',
                       'src/core/lib/json/json.h',
                       'src/core/lib/profiling/timers.h',
                       'src/core/lib/security/context/security_context.h',
@@ -875,7 +875,6 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/is_epollexclusive_available.h',
                               'src/core/lib/iomgr/load_file.h',
                               'src/core/lib/iomgr/lockfree_event.h',
-                              'src/core/lib/iomgr/logical_thread.h',
                               'src/core/lib/iomgr/nameser.h',
                               'src/core/lib/iomgr/poller/eventmanager_libuv.h',
                               'src/core/lib/iomgr/polling_entity.h',
@@ -916,6 +915,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/unix_sockets_posix.h',
                               'src/core/lib/iomgr/wakeup_fd_pipe.h',
                               'src/core/lib/iomgr/wakeup_fd_posix.h',
+                              'src/core/lib/iomgr/work_serializer.h',
                               'src/core/lib/json/json.h',
                               'src/core/lib/profiling/timers.h',
                               'src/core/lib/security/context/security_context.h',

gRPC-Core.podspec

@@ -655,8 +655,6 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/load_file.h',
                       'src/core/lib/iomgr/lockfree_event.cc',
                       'src/core/lib/iomgr/lockfree_event.h',
-                      'src/core/lib/iomgr/logical_thread.cc',
-                      'src/core/lib/iomgr/logical_thread.h',
                       'src/core/lib/iomgr/nameser.h',
                       'src/core/lib/iomgr/poller/eventmanager_libuv.cc',
                       'src/core/lib/iomgr/poller/eventmanager_libuv.h',
@@ -750,6 +748,8 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/wakeup_fd_pipe.h',
                       'src/core/lib/iomgr/wakeup_fd_posix.cc',
                       'src/core/lib/iomgr/wakeup_fd_posix.h',
+                      'src/core/lib/iomgr/work_serializer.cc',
+                      'src/core/lib/iomgr/work_serializer.h',
                       'src/core/lib/json/json.cc',
                       'src/core/lib/json/json.h',
                       'src/core/lib/json/json_reader.cc',
@@ -1204,7 +1204,6 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/is_epollexclusive_available.h',
                               'src/core/lib/iomgr/load_file.h',
                               'src/core/lib/iomgr/lockfree_event.h',
-                              'src/core/lib/iomgr/logical_thread.h',
                               'src/core/lib/iomgr/nameser.h',
                               'src/core/lib/iomgr/poller/eventmanager_libuv.h',
                               'src/core/lib/iomgr/polling_entity.h',
@@ -1245,6 +1244,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/unix_sockets_posix.h',
                               'src/core/lib/iomgr/wakeup_fd_pipe.h',
                               'src/core/lib/iomgr/wakeup_fd_posix.h',
+                              'src/core/lib/iomgr/work_serializer.h',
                               'src/core/lib/json/json.h',
                               'src/core/lib/profiling/timers.h',
                               'src/core/lib/security/context/security_context.h',

grpc.gemspec

@@ -577,8 +577,6 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/iomgr/load_file.h )
   s.files += %w( src/core/lib/iomgr/lockfree_event.cc )
   s.files += %w( src/core/lib/iomgr/lockfree_event.h )
-  s.files += %w( src/core/lib/iomgr/logical_thread.cc )
-  s.files += %w( src/core/lib/iomgr/logical_thread.h )
   s.files += %w( src/core/lib/iomgr/nameser.h )
   s.files += %w( src/core/lib/iomgr/poller/eventmanager_libuv.cc )
   s.files += %w( src/core/lib/iomgr/poller/eventmanager_libuv.h )
@@ -672,6 +670,8 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/iomgr/wakeup_fd_pipe.h )
   s.files += %w( src/core/lib/iomgr/wakeup_fd_posix.cc )
   s.files += %w( src/core/lib/iomgr/wakeup_fd_posix.h )
+  s.files += %w( src/core/lib/iomgr/work_serializer.cc )
+  s.files += %w( src/core/lib/iomgr/work_serializer.h )
   s.files += %w( src/core/lib/json/json.cc )
   s.files += %w( src/core/lib/json/json.h )
   s.files += %w( src/core/lib/json/json_reader.cc )

grpc.gyp

@@ -263,7 +263,6 @@
         'src/core/lib/iomgr/is_epollexclusive_available.cc',
         'src/core/lib/iomgr/load_file.cc',
         'src/core/lib/iomgr/lockfree_event.cc',
-        'src/core/lib/iomgr/logical_thread.cc',
         'src/core/lib/iomgr/poller/eventmanager_libuv.cc',
         'src/core/lib/iomgr/polling_entity.cc',
         'src/core/lib/iomgr/pollset.cc',
@@ -317,6 +316,7 @@
         'src/core/lib/iomgr/wakeup_fd_nospecial.cc',
         'src/core/lib/iomgr/wakeup_fd_pipe.cc',
         'src/core/lib/iomgr/wakeup_fd_posix.cc',
+        'src/core/lib/iomgr/work_serializer.cc',
         'src/core/lib/json/json.cc',
         'src/core/lib/json/json_reader.cc',
         'src/core/lib/json/json_reader_new.cc',
@@ -563,7 +563,6 @@
         'src/core/lib/iomgr/is_epollexclusive_available.cc',
         'src/core/lib/iomgr/load_file.cc',
         'src/core/lib/iomgr/lockfree_event.cc',
-        'src/core/lib/iomgr/logical_thread.cc',
         'src/core/lib/iomgr/poller/eventmanager_libuv.cc',
         'src/core/lib/iomgr/polling_entity.cc',
         'src/core/lib/iomgr/pollset.cc',
@@ -617,6 +616,7 @@
         'src/core/lib/iomgr/wakeup_fd_nospecial.cc',
         'src/core/lib/iomgr/wakeup_fd_pipe.cc',
         'src/core/lib/iomgr/wakeup_fd_posix.cc',
+        'src/core/lib/iomgr/work_serializer.cc',
         'src/core/lib/json/json.cc',
         'src/core/lib/json/json_reader.cc',
         'src/core/lib/json/json_reader_new.cc',
@@ -988,7 +988,6 @@
         'src/core/lib/iomgr/is_epollexclusive_available.cc',
         'src/core/lib/iomgr/load_file.cc',
         'src/core/lib/iomgr/lockfree_event.cc',
-        'src/core/lib/iomgr/logical_thread.cc',
         'src/core/lib/iomgr/poller/eventmanager_libuv.cc',
         'src/core/lib/iomgr/polling_entity.cc',
         'src/core/lib/iomgr/pollset.cc',
@@ -1042,6 +1041,7 @@
         'src/core/lib/iomgr/wakeup_fd_nospecial.cc',
         'src/core/lib/iomgr/wakeup_fd_pipe.cc',
         'src/core/lib/iomgr/wakeup_fd_posix.cc',
+        'src/core/lib/iomgr/work_serializer.cc',
         'src/core/lib/json/json.cc',
         'src/core/lib/json/json_reader.cc',
         'src/core/lib/json/json_reader_new.cc',
@@ -1253,7 +1253,6 @@
         'src/core/lib/iomgr/is_epollexclusive_available.cc',
         'src/core/lib/iomgr/load_file.cc',
         'src/core/lib/iomgr/lockfree_event.cc',
-        'src/core/lib/iomgr/logical_thread.cc',
         'src/core/lib/iomgr/poller/eventmanager_libuv.cc',
         'src/core/lib/iomgr/polling_entity.cc',
         'src/core/lib/iomgr/pollset.cc',
@@ -1307,6 +1306,7 @@
         'src/core/lib/iomgr/wakeup_fd_nospecial.cc',
         'src/core/lib/iomgr/wakeup_fd_pipe.cc',
         'src/core/lib/iomgr/wakeup_fd_posix.cc',
+        'src/core/lib/iomgr/work_serializer.cc',
         'src/core/lib/json/json.cc',
         'src/core/lib/json/json_reader.cc',
         'src/core/lib/json/json_reader_new.cc',
@@ -1494,7 +1494,6 @@
         'src/core/lib/iomgr/is_epollexclusive_available.cc',
         'src/core/lib/iomgr/load_file.cc',
         'src/core/lib/iomgr/lockfree_event.cc',
-        'src/core/lib/iomgr/logical_thread.cc',
         'src/core/lib/iomgr/poller/eventmanager_libuv.cc',
         'src/core/lib/iomgr/polling_entity.cc',
         'src/core/lib/iomgr/pollset.cc',
@@ -1548,6 +1547,7 @@
         'src/core/lib/iomgr/wakeup_fd_nospecial.cc',
         'src/core/lib/iomgr/wakeup_fd_pipe.cc',
         'src/core/lib/iomgr/wakeup_fd_posix.cc',
+        'src/core/lib/iomgr/work_serializer.cc',
         'src/core/lib/json/json.cc',
         'src/core/lib/json/json_reader.cc',
         'src/core/lib/json/json_reader_new.cc',

package.xml

@@ -560,8 +560,6 @@
     <file baseinstalldir="/" name="src/core/lib/iomgr/load_file.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/lockfree_event.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/lockfree_event.h" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/iomgr/logical_thread.cc" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/iomgr/logical_thread.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/nameser.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/poller/eventmanager_libuv.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/poller/eventmanager_libuv.h" role="src" />
@@ -655,6 +653,8 @@
     <file baseinstalldir="/" name="src/core/lib/iomgr/wakeup_fd_pipe.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/wakeup_fd_posix.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/wakeup_fd_posix.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/work_serializer.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/work_serializer.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/json/json.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/json/json.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/json/json_reader.cc" role="src" />

src/core/lib/iomgr/logical_thread.cc

@@ -1,103 +0,0 @@
-/*
- *
- * 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/logical_thread.h"
-
-namespace grpc_core {
-
-DebugOnlyTraceFlag grpc_logical_thread_trace(false, "logical_thread");
-
-struct CallbackWrapper {
-  CallbackWrapper(std::function<void()> cb, const grpc_core::DebugLocation& loc)
-      : callback(std::move(cb)), location(loc) {}
-
-  MultiProducerSingleConsumerQueue::Node mpscq_node;
-  const std::function<void()> callback;
-  const DebugLocation location;
-};
-
-void LogicalThread::Run(std::function<void()> callback,
-                        const grpc_core::DebugLocation& location) {
-  if (GRPC_TRACE_FLAG_ENABLED(grpc_logical_thread_trace)) {
-    gpr_log(GPR_INFO, "LogicalThread::Run() %p Scheduling callback [%s:%d]",
-            this, location.file(), location.line());
-  }
-  const size_t prev_size = size_.FetchAdd(1);
-  if (prev_size == 0) {
-    // There is no other closure executing right now on this logical thread.
-    // Execute this closure immediately.
-    if (GRPC_TRACE_FLAG_ENABLED(grpc_logical_thread_trace)) {
-      gpr_log(GPR_INFO, "  Executing immediately");
-    }
-    callback();
-    // Loan this thread to the logical thread and drain the queue.
-    DrainQueue();
-  } else {
-    CallbackWrapper* cb_wrapper =
-        new CallbackWrapper(std::move(callback), location);
-    // There already are closures executing on this logical thread. Simply add
-    // this closure to the queue.
-    if (GRPC_TRACE_FLAG_ENABLED(grpc_logical_thread_trace)) {
-      gpr_log(GPR_INFO, "  Scheduling on queue : item %p", cb_wrapper);
-    }
-    queue_.Push(&cb_wrapper->mpscq_node);
-  }
-}
-
-// The thread that calls this loans itself to the logical thread so as to
-// execute all the scheduled callback. This is called from within
-// LogicalThread::Run() after executing a callback immediately, and hence size_
-// is atleast 1.
-void LogicalThread::DrainQueue() {
-  while (true) {
-    if (GRPC_TRACE_FLAG_ENABLED(grpc_logical_thread_trace)) {
-      gpr_log(GPR_INFO, "LogicalThread::DrainQueue() %p", this);
-    }
-    size_t prev_size = size_.FetchSub(1);
-    // prev_size should be atleast 1 since
-    GPR_DEBUG_ASSERT(prev_size >= 1);
-    if (prev_size == 1) {
-      if (GRPC_TRACE_FLAG_ENABLED(grpc_logical_thread_trace)) {
-        gpr_log(GPR_INFO, "  Queue Drained");
-      }
-      break;
-    }
-    // There is atleast one callback on the queue. Pop the callback from the
-    // queue and execute it.
-    CallbackWrapper* cb_wrapper = nullptr;
-    bool empty_unused;
-    while ((cb_wrapper = reinterpret_cast<CallbackWrapper*>(
-                queue_.PopAndCheckEnd(&empty_unused))) == nullptr) {
-      // This can happen either due to a race condition within the mpscq
-      // implementation or because of a race with Run()
-      if (GRPC_TRACE_FLAG_ENABLED(grpc_logical_thread_trace)) {
-        gpr_log(GPR_INFO, "  Queue returned nullptr, trying again");
-      }
-    }
-    if (GRPC_TRACE_FLAG_ENABLED(grpc_logical_thread_trace)) {
-      gpr_log(GPR_INFO, "  Running item %p : callback scheduled at [%s:%d]",
-              cb_wrapper, cb_wrapper->location.file(),
-              cb_wrapper->location.line());
-    }
-    cb_wrapper->callback();
-    delete cb_wrapper;
-  }
-}
-}  // namespace grpc_core

src/core/lib/iomgr/logical_thread.h

@@ -1,52 +0,0 @@
-/*
- *
- * 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 <functional>
-
-#include "src/core/lib/debug/trace.h"
-#include "src/core/lib/gprpp/atomic.h"
-#include "src/core/lib/gprpp/debug_location.h"
-#include "src/core/lib/gprpp/mpscq.h"
-#include "src/core/lib/gprpp/ref_counted.h"
-
-#ifndef GRPC_CORE_LIB_IOMGR_LOGICAL_THREAD_H
-#define GRPC_CORE_LIB_IOMGR_LOGICAL_THREAD_H
-
-namespace grpc_core {
-extern DebugOnlyTraceFlag grpc_logical_thread_trace;
-
-// LogicalThread is a mechanism to schedule callbacks in a synchronized manner.
-// All callbacks scheduled on a LogicalThread instance will be executed serially
-// in a borrowed thread. The API provides a FIFO guarantee to the execution of
-// callbacks scheduled on the thread.
-class LogicalThread : public RefCounted<LogicalThread> {
- public:
-  void Run(std::function<void()> callback,
-           const grpc_core::DebugLocation& location);
-
- private:
-  void DrainQueue();
-
-  Atomic<size_t> size_{0};
-  MultiProducerSingleConsumerQueue queue_;
-};
-} /* namespace grpc_core */
-
-#endif /* GRPC_CORE_LIB_IOMGR_LOGICAL_THREAD_H */

src/core/lib/iomgr/work_serializer.cc

@@ -0,0 +1,155 @@
+/*
+ *
+ * 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/work_serializer.h"
+
+namespace grpc_core {
+
+DebugOnlyTraceFlag grpc_work_serializer_trace(false, "work_serializer");
+
+struct CallbackWrapper {
+  CallbackWrapper(std::function<void()> cb, const grpc_core::DebugLocation& loc)
+      : callback(std::move(cb)), location(loc) {}
+
+  MultiProducerSingleConsumerQueue::Node mpscq_node;
+  const std::function<void()> callback;
+  const DebugLocation location;
+};
+
+class WorkSerializer::WorkSerializerImpl : public Orphanable {
+ public:
+  void Run(std::function<void()> callback,
+           const grpc_core::DebugLocation& location);
+
+  void Orphan() override;
+
+ private:
+  void DrainQueue();
+
+  // An initial size of 1 keeps track of whether the work serializer has been
+  // orphaned.
+  Atomic<size_t> size_{1};
+  MultiProducerSingleConsumerQueue queue_;
+};
+
+void WorkSerializer::WorkSerializerImpl::Run(
+    std::function<void()> callback, const grpc_core::DebugLocation& location) {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+    gpr_log(GPR_INFO, "WorkSerializer::Run() %p Scheduling callback [%s:%d]",
+            this, location.file(), location.line());
+  }
+  const size_t prev_size = size_.FetchAdd(1);
+  // The work serializer should not have been orphaned.
+  GPR_DEBUG_ASSERT(prev_size > 0);
+  if (prev_size == 1) {
+    // There is no other closure executing right now on this work serializer.
+    // Execute this closure immediately.
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+      gpr_log(GPR_INFO, "  Executing immediately");
+    }
+    callback();
+    // Loan this thread to the work serializer thread and drain the queue.
+    DrainQueue();
+  } else {
+    CallbackWrapper* cb_wrapper =
+        new CallbackWrapper(std::move(callback), location);
+    // There already are closures executing on this work serializer. Simply add
+    // this closure to the queue.
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+      gpr_log(GPR_INFO, "  Scheduling on queue : item %p", cb_wrapper);
+    }
+    queue_.Push(&cb_wrapper->mpscq_node);
+  }
+}
+
+void WorkSerializer::WorkSerializerImpl::Orphan() {
+  if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+    gpr_log(GPR_INFO, "WorkSerializer::Orphan() %p", this);
+  }
+  size_t prev_size = size_.FetchSub(1);
+  if (prev_size == 1) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+      gpr_log(GPR_INFO, "  Destroying");
+    }
+    delete this;
+  }
+}
+
+// The thread that calls this loans itself to the work serializer so as to
+// execute all the scheduled callback. This is called from within
+// WorkSerializer::Run() after executing a callback immediately, and hence size_
+// is at least 1.
+void WorkSerializer::WorkSerializerImpl::DrainQueue() {
+  while (true) {
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+      gpr_log(GPR_INFO, "WorkSerializer::DrainQueue() %p", this);
+    }
+    size_t prev_size = size_.FetchSub(1);
+    GPR_DEBUG_ASSERT(prev_size >= 1);
+    // It is possible that while draining the queue, one of the callbacks ended
+    // up orphaning the work serializer. In that case, delete the object.
+    if (prev_size == 1) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+        gpr_log(GPR_INFO, "  Queue Drained. Destroying");
+      }
+      delete this;
+      return;
+    }
+    if (prev_size == 2) {
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+        gpr_log(GPR_INFO, "  Queue Drained");
+      }
+      return;
+    }
+    // There is at least one callback on the queue. Pop the callback from the
+    // queue and execute it.
+    CallbackWrapper* cb_wrapper = nullptr;
+    bool empty_unused;
+    while ((cb_wrapper = reinterpret_cast<CallbackWrapper*>(
+                queue_.PopAndCheckEnd(&empty_unused))) == nullptr) {
+      // This can happen either due to a race condition within the mpscq
+      // implementation or because of a race with Run()
+      if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+        gpr_log(GPR_INFO, "  Queue returned nullptr, trying again");
+      }
+    }
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_work_serializer_trace)) {
+      gpr_log(GPR_INFO, "  Running item %p : callback scheduled at [%s:%d]",
+              cb_wrapper, cb_wrapper->location.file(),
+              cb_wrapper->location.line());
+    }
+    cb_wrapper->callback();
+    delete cb_wrapper;
+  }
+}
+
+// WorkSerializer
+
+WorkSerializer::WorkSerializer()
+    : impl_(MakeOrphanable<WorkSerializerImpl>()) {}
+
+WorkSerializer::~WorkSerializer() {}
+
+void WorkSerializer::Run(std::function<void()> callback,
+                         const grpc_core::DebugLocation& location) {
+  impl_->Run(std::move(callback), location);
+}
+
+}  // namespace grpc_core

src/core/lib/iomgr/work_serializer.h

@@ -0,0 +1,65 @@
+/*
+ *
+ * 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 <functional>
+
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gprpp/atomic.h"
+#include "src/core/lib/gprpp/debug_location.h"
+#include "src/core/lib/gprpp/mpscq.h"
+#include "src/core/lib/gprpp/orphanable.h"
+#include "src/core/lib/gprpp/ref_counted.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
+
+#ifndef GRPC_CORE_LIB_IOMGR_WORK_SERIALIZER_H
+#define GRPC_CORE_LIB_IOMGR_WORK_SERIALIZER_H
+
+namespace grpc_core {
+
+// WorkSerializer is a mechanism to schedule callbacks in a synchronized manner.
+// All callbacks scheduled on a WorkSerializer instance will be executed
+// serially in a borrowed thread. The API provides a FIFO guarantee to the
+// execution of callbacks scheduled on the thread.
+// When a thread calls Run() with a callback, the thread is considered borrowed.
+// The callback might run inline, or it might run asynchronously in a different
+// thread that is already inside of Run(). If the callback runs directly inline,
+// other callbacks from other threads might also be executed before Run()
+// returns. Since an arbitrary set of callbacks might be executed when Run() is
+// called, generally no locks should be held while calling Run().
+class WorkSerializer {
+ public:
+  WorkSerializer();
+
+  ~WorkSerializer();
+
+  // TODO(yashkt): Replace grpc_core::DebugLocation with absl::SourceLocation
+  // once we can start using it directly.
+  void Run(std::function<void()> callback,
+           const grpc_core::DebugLocation& location);
+
+ private:
+  class WorkSerializerImpl;
+
+  OrphanablePtr<WorkSerializerImpl> impl_;
+};
+
+} /* namespace grpc_core */
+
+#endif /* GRPC_CORE_LIB_IOMGR_WORK_SERIALIZER_H */

src/python/grpcio/grpc_core_dependencies.py

@@ -269,7 +269,6 @@ CORE_SOURCE_FILES = [
     'src/core/lib/iomgr/is_epollexclusive_available.cc',
     'src/core/lib/iomgr/load_file.cc',
     'src/core/lib/iomgr/lockfree_event.cc',
-    'src/core/lib/iomgr/logical_thread.cc',
     'src/core/lib/iomgr/poller/eventmanager_libuv.cc',
     'src/core/lib/iomgr/polling_entity.cc',
     'src/core/lib/iomgr/pollset.cc',
@@ -323,6 +322,7 @@ CORE_SOURCE_FILES = [
     'src/core/lib/iomgr/wakeup_fd_nospecial.cc',
     'src/core/lib/iomgr/wakeup_fd_pipe.cc',
     'src/core/lib/iomgr/wakeup_fd_posix.cc',
+    'src/core/lib/iomgr/work_serializer.cc',
     'src/core/lib/json/json.cc',
     'src/core/lib/json/json_reader.cc',
     'src/core/lib/json/json_reader_new.cc',

test/core/iomgr/BUILD

@@ -135,8 +135,8 @@ grpc_cc_test(
 )
 
 grpc_cc_test(
-    name = "logical_thread_test",
-    srcs = ["logical_thread_test.cc"],
+    name = "work_serializer_test",
+    srcs = ["work_serializer_test.cc"],
     exec_properties = LARGE_MACHINE,
     external_deps = [
         "gtest",

test/core/iomgr/logical_thread_test.cc → test/core/iomgr/work_serializer_test.cc

@@ -26,28 +26,25 @@
 
 #include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/gprpp/thd.h"
-#include "src/core/lib/iomgr/logical_thread.h"
+#include "src/core/lib/iomgr/work_serializer.h"
 #include "test/core/util/test_config.h"
 
 namespace {
-TEST(LogicalThreadTest, NoOp) {
-  auto lock = grpc_core::MakeRefCounted<grpc_core::LogicalThread>();
-}
+TEST(WorkSerializerTest, NoOp) { grpc_core::WorkSerializer lock; }
 
-TEST(LogicalThreadTest, ExecuteOne) {
-  auto lock = grpc_core::MakeRefCounted<grpc_core::LogicalThread>();
+TEST(WorkSerializerTest, ExecuteOne) {
+  grpc_core::WorkSerializer lock;
   gpr_event done;
   gpr_event_init(&done);
-  lock->Run([&done]() { gpr_event_set(&done, (void*)1); }, DEBUG_LOCATION);
+  lock.Run([&done]() { gpr_event_set(&done, (void*)1); }, DEBUG_LOCATION);
   EXPECT_TRUE(gpr_event_wait(&done, grpc_timeout_seconds_to_deadline(5)) !=
               nullptr);
 }
 
 class TestThread {
  public:
-  explicit TestThread(grpc_core::RefCountedPtr<grpc_core::LogicalThread> lock)
-      : lock_(std::move(lock)),
-        thread_("grpc_execute_many", ExecuteManyLoop, this) {
+  explicit TestThread(grpc_core::WorkSerializer* lock)
+      : lock_(lock), thread_("grpc_execute_many", ExecuteManyLoop, this) {
     gpr_event_init(&done_);
     thread_.Start();
   }
@@ -86,18 +83,18 @@ class TestThread {
                      DEBUG_LOCATION);
   }
 
-  grpc_core::RefCountedPtr<grpc_core::LogicalThread> lock_;
+  grpc_core::WorkSerializer* lock_ = nullptr;
   grpc_core::Thread thread_;
   size_t counter_ = 0;
   gpr_event done_;
 };
 
-TEST(LogicalThreadTest, ExecuteMany) {
-  auto lock = grpc_core::MakeRefCounted<grpc_core::LogicalThread>();
+TEST(WorkSerializerTest, ExecuteMany) {
+  grpc_core::WorkSerializer lock;
   {
     std::vector<std::unique_ptr<TestThread>> threads;
     for (size_t i = 0; i < 100; ++i) {
-      threads.push_back(std::unique_ptr<TestThread>(new TestThread(lock)));
+      threads.push_back(std::unique_ptr<TestThread>(new TestThread(&lock)));
     }
   }
 }

tools/doxygen/Doxyfile.c++.internal

@@ -1160,7 +1160,6 @@ src/core/lib/iomgr/iomgr_posix.h \
 src/core/lib/iomgr/is_epollexclusive_available.h \
 src/core/lib/iomgr/load_file.h \
 src/core/lib/iomgr/lockfree_event.h \
-src/core/lib/iomgr/logical_thread.h \
 src/core/lib/iomgr/nameser.h \
 src/core/lib/iomgr/poller/eventmanager_libuv.h \
 src/core/lib/iomgr/polling_entity.h \
@@ -1201,6 +1200,7 @@ src/core/lib/iomgr/udp_server.h \
 src/core/lib/iomgr/unix_sockets_posix.h \
 src/core/lib/iomgr/wakeup_fd_pipe.h \
 src/core/lib/iomgr/wakeup_fd_posix.h \
+src/core/lib/iomgr/work_serializer.h \
 src/core/lib/json/json.h \
 src/core/lib/profiling/timers.h \
 src/core/lib/slice/b64.h \

tools/doxygen/Doxyfile.core.internal

@@ -1368,8 +1368,6 @@ src/core/lib/iomgr/load_file.cc \
 src/core/lib/iomgr/load_file.h \
 src/core/lib/iomgr/lockfree_event.cc \
 src/core/lib/iomgr/lockfree_event.h \
-src/core/lib/iomgr/logical_thread.cc \
-src/core/lib/iomgr/logical_thread.h \
 src/core/lib/iomgr/nameser.h \
 src/core/lib/iomgr/poller/eventmanager_libuv.cc \
 src/core/lib/iomgr/poller/eventmanager_libuv.h \
@@ -1463,6 +1461,8 @@ src/core/lib/iomgr/wakeup_fd_pipe.cc \
 src/core/lib/iomgr/wakeup_fd_pipe.h \
 src/core/lib/iomgr/wakeup_fd_posix.cc \
 src/core/lib/iomgr/wakeup_fd_posix.h \
+src/core/lib/iomgr/work_serializer.cc \
+src/core/lib/iomgr/work_serializer.h \
 src/core/lib/json/json.cc \
 src/core/lib/json/json.h \
 src/core/lib/json/json_reader.cc \

tools/run_tests/generated/tests.json

@@ -5043,30 +5043,6 @@
     ], 
     "uses_polling": false
   }, 
-  {
-    "args": [], 
-    "benchmark": false, 
-    "ci_platforms": [
-      "linux", 
-      "mac", 
-      "posix", 
-      "windows"
-    ], 
-    "cpu_cost": 10, 
-    "exclude_configs": [], 
-    "exclude_iomgrs": [], 
-    "flaky": false, 
-    "gtest": false, 
-    "language": "c++", 
-    "name": "logical_thread_test", 
-    "platforms": [
-      "linux", 
-      "mac", 
-      "posix", 
-      "windows"
-    ], 
-    "uses_polling": true
-  }, 
   {
     "args": [], 
     "benchmark": false, 
@@ -6058,6 +6034,30 @@
     ], 
     "uses_polling": true
   }, 
+  {
+    "args": [], 
+    "benchmark": false, 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "cpu_cost": 10, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "gtest": false, 
+    "language": "c++", 
+    "name": "work_serializer_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "uses_polling": true
+  }, 
   {
     "args": [], 
     "benchmark": false,