[Tarantool-patches] [PATCH v2 1/2] fiber: introduce a callback for fibers switch-over

[Igor Munkin <imun@tarantool.org>]

Tarantool integrates several complex environments together and there are
issues occurring at their junction leading to the platform failures.
E.g. fiber switch-over is implemented outside the Lua world, so when one
lua_State substitutes another one, main LuaJIT engines, such as JIT and
GC, are left unnotified leading to the further platform misbehaviour.

To solve this severe integration drawback <cord_on_yield> function is
introduced. This routine encloses the checks and actions to be done when
the running fiber yields the execution.

Unfortunately the way callback is implemented introduces a circular
dependency. Considering linker symbol resolving methods for static build
an auxiliary translation unit is added to the particular tests mocking
(i.e. exporting) <cord_on_yield> undefined symbol.

Part of #1700
Relates to #4491

Signed-off-by: Igor Munkin <imun@tarantool.org>
---

Here are also the benchmark results for the Release build:
* Vanilla (8477b6c) -> Patched (86bfd45) (min, median, mean, max):
| fibers: 10; iters: 100	0%	0%	0%	-3%
| fibers: 10; iters: 1000	2%	2%	1%	-1%
| fibers: 10; iters: 10000	6%	4%	4%	5%
| fibers: 10; iters: 100000	4%	3%	3%	-2%
| fibers: 100; iters: 100	0%	0%	0%	0%
| fibers: 100; iters: 1000	0%	0%	0%	-8%
| fibers: 100; iters: 10000	1%	0%	0%	1%
| fibers: 100; iters: 100000	0%	0%	1%	2%
| fibers: 1000; iters: 100	0%	0%	0%	0%
| fibers: 1000; iters: 1000	0%	0%	0%	0%
| fibers: 1000; iters: 10000	0%	0%	0%	1%
| fibers: 1000; iters: 100000	0%	0%	0%	0%
| fibers: 10000; iters: 100	-1%	-3%	-1%	0%
| fibers: 10000; iters: 1000	0%	0%	0%	0%
| fibers: 10000; iters: 10000	0%	0%	0%	0%
| fibers: 10000; iters: 100000	0%	-1%	-2%	-6%

 src/lib/core/fiber.c        | 10 +++++++
 src/lua/utils.c             |  8 +++++
 test/unit/CMakeLists.txt    | 59 +++++++++++++++++++------------------
 test/unit/core_test_utils.c | 37 +++++++++++++++++++++++
 4 files changed, 86 insertions(+), 28 deletions(-)
 create mode 100644 test/unit/core_test_utils.c

diff --git a/src/lib/core/fiber.c b/src/lib/core/fiber.c
index 483ae3ce1..1b7d255ff 100644
--- a/src/lib/core/fiber.c
+++ b/src/lib/core/fiber.c
@@ -46,6 +46,8 @@
 #if ENABLE_FIBER_TOP
 #include <x86intrin.h> /* __rdtscp() */
 
+extern void cord_on_yield(void);
+
 static inline void
 clock_stat_add_delta(struct clock_stat *stat, uint64_t clock_delta)
 {
@@ -416,6 +418,10 @@ fiber_call(struct fiber *callee)
 	/** By convention, these triggers must not throw. */
 	if (! rlist_empty(&caller->on_yield))
 		trigger_run(&caller->on_yield, NULL);
+
+	if (cord_is_main())
+		cord_on_yield();
+
 	clock_set_on_csw(caller);
 	callee->caller = caller;
 	callee->flags |= FIBER_IS_READY;
@@ -645,6 +651,10 @@ fiber_yield(void)
 	/** By convention, these triggers must not throw. */
 	if (! rlist_empty(&caller->on_yield))
 		trigger_run(&caller->on_yield, NULL);
+
+	if (cord_is_main())
+		cord_on_yield();
+
 	clock_set_on_csw(caller);
 
 	assert(callee->flags & FIBER_IS_READY || callee == &cord->sched);
diff --git a/src/lua/utils.c b/src/lua/utils.c
index af114b0a2..8e98f7607 100644
--- a/src/lua/utils.c
+++ b/src/lua/utils.c
@@ -1308,3 +1308,11 @@ tarantool_lua_utils_init(struct lua_State *L)
 	luaT_newthread_ref = luaL_ref(L, LUA_REGISTRYINDEX);
 	return 0;
 }
+
+/**
+ * This routine encloses the checks and actions to be done when
+ * the running fiber yields the execution.
+ */
+void cord_on_yield(void)
+{
+}
diff --git a/test/unit/CMakeLists.txt b/test/unit/CMakeLists.txt
index 419477748..aace8cf50 100644
--- a/test/unit/CMakeLists.txt
+++ b/test/unit/CMakeLists.txt
@@ -50,7 +50,7 @@ add_executable(bitset_index.test bitset_index.c)
 target_link_libraries(bitset_index.test bitset)
 add_executable(base64.test base64.c)
 target_link_libraries(base64.test misc unit)
-add_executable(uuid.test uuid.c)
+add_executable(uuid.test uuid.c core_test_utils.c)
 target_link_libraries(uuid.test uuid unit)
 
 add_executable(bps_tree.test bps_tree.cc)
@@ -69,53 +69,53 @@ add_executable(bloom.test bloom.cc)
 target_link_libraries(bloom.test salad)
 add_executable(vclock.test vclock.cc)
 target_link_libraries(vclock.test vclock unit)
-add_executable(xrow.test xrow.cc)
+add_executable(xrow.test xrow.cc core_test_utils.c)
 target_link_libraries(xrow.test xrow unit)
 add_executable(decimal.test decimal.c)
 target_link_libraries(decimal.test core unit)
-add_executable(mp_error.test mp_error.cc)
+add_executable(mp_error.test mp_error.cc core_test_utils.c)
 target_link_libraries(mp_error.test box_error core unit)
 
-add_executable(fiber.test fiber.cc)
+add_executable(fiber.test fiber.cc core_test_utils.c)
 set_source_files_properties(fiber.cc PROPERTIES COMPILE_FLAGS -O0)
 target_link_libraries(fiber.test core unit)
 
-add_executable(fiber_stack.test fiber_stack.c)
+add_executable(fiber_stack.test fiber_stack.c core_test_utils.c)
 set_source_files_properties(fiber_stack.c PROPERTIES COMPILE_FLAGS -O0)
 target_link_libraries(fiber_stack.test core unit)
 
 if (NOT ENABLE_GCOV)
     # This test is known to be broken with GCOV
-    add_executable(guard.test guard.cc)
+    add_executable(guard.test guard.cc core_test_utils.c)
     target_link_libraries(guard.test core unit)
 endif ()
 
-add_executable(fiber_stress.test fiber_stress.cc)
+add_executable(fiber_stress.test fiber_stress.cc core_test_utils.c)
 target_link_libraries(fiber_stress.test core)
 
-add_executable(fiber_cond.test fiber_cond.c unit.c)
+add_executable(fiber_cond.test fiber_cond.c unit.c core_test_utils.c)
 target_link_libraries(fiber_cond.test core)
 
-add_executable(fiber_channel.test fiber_channel.cc unit.c)
+add_executable(fiber_channel.test fiber_channel.cc unit.c core_test_utils.c)
 target_link_libraries(fiber_channel.test core)
 
-add_executable(fiber_channel_stress.test fiber_channel_stress.cc)
+add_executable(fiber_channel_stress.test fiber_channel_stress.cc core_test_utils.c)
 target_link_libraries(fiber_channel_stress.test core)
 
-add_executable(cbus_stress.test cbus_stress.c)
+add_executable(cbus_stress.test cbus_stress.c core_test_utils.c)
 target_link_libraries(cbus_stress.test core stat)
 
-add_executable(cbus.test cbus.c)
+add_executable(cbus.test cbus.c core_test_utils.c)
 target_link_libraries(cbus.test core unit stat)
 
 include(CheckSymbolExists)
 check_symbol_exists(__GLIBC__ features.h GLIBC_USED)
 if (GLIBC_USED)
-    add_executable(cbus_hang.test cbus_hang.c)
+    add_executable(cbus_hang.test cbus_hang.c core_test_utils.c)
     target_link_libraries(cbus_hang.test core unit stat)
 endif ()
 
-add_executable(coio.test coio.cc)
+add_executable(coio.test coio.cc core_test_utils.c)
 target_link_libraries(coio.test core eio bit uri unit)
 
 if (ENABLE_BUNDLED_MSGPUCK)
@@ -132,7 +132,7 @@ if (ENABLE_BUNDLED_MSGPUCK)
     target_link_libraries(msgpack.test ${MSGPUCK_LIBRARIES})
 endif ()
 
-add_executable(scramble.test scramble.c)
+add_executable(scramble.test scramble.c core_test_utils.c)
 target_link_libraries(scramble.test scramble)
 
 add_executable(guava.test guava.c)
@@ -155,7 +155,7 @@ target_link_libraries(csv.test csv)
 add_executable(json.test json.c)
 target_link_libraries(json.test json unit ${ICU_LIBRARIES})
 
-add_executable(rmean.test rmean.cc)
+add_executable(rmean.test rmean.cc core_test_utils.c)
 target_link_libraries(rmean.test stat unit)
 add_executable(histogram.test histogram.c)
 target_link_libraries(histogram.test stat unit)
@@ -170,7 +170,7 @@ target_link_libraries(luaL_iterator.test unit server coll core misc
     ${CURL_LIBRARIES} ${LIBYAML_LIBRARIES} ${READLINE_LIBRARIES}
     ${ICU_LIBRARIES} ${LUAJIT_LIBRARIES} ${LIB_DL})
 
-add_executable(say.test say.c)
+add_executable(say.test say.c core_test_utils.c)
 target_link_libraries(say.test core unit)
 
 set(ITERATOR_TEST_SOURCES
@@ -182,7 +182,7 @@ set(ITERATOR_TEST_SOURCES
     ${PROJECT_SOURCE_DIR}/src/box/vy_cache.c)
 set(ITERATOR_TEST_LIBS core tuple xrow unit)
 
-add_executable(vy_mem.test vy_mem.c ${ITERATOR_TEST_SOURCES})
+add_executable(vy_mem.test vy_mem.c ${ITERATOR_TEST_SOURCES} core_test_utils.c)
 target_link_libraries(vy_mem.test ${ITERATOR_TEST_LIBS} ${LIB_DL})
 
 add_executable(vy_point_lookup.test
@@ -204,11 +204,13 @@ add_executable(vy_point_lookup.test
     ${PROJECT_SOURCE_DIR}/src/box/index_def.c
     ${PROJECT_SOURCE_DIR}/src/box/schema_def.c
     ${PROJECT_SOURCE_DIR}/src/box/identifier.c
+    core_test_utils.c
 )
 target_link_libraries(vy_point_lookup.test core tuple xrow xlog unit ${LIB_DL})
 
 add_executable(column_mask.test
-    column_mask.c)
+    column_mask.c
+    core_test_utils.c)
 target_link_libraries(column_mask.test tuple unit)
 
 add_executable(vy_write_iterator.test
@@ -217,16 +219,17 @@ add_executable(vy_write_iterator.test
     ${PROJECT_SOURCE_DIR}/src/box/vy_upsert.c
     ${PROJECT_SOURCE_DIR}/src/box/vy_write_iterator.c
     ${ITERATOR_TEST_SOURCES}
+    core_test_utils.c
 )
 target_link_libraries(vy_write_iterator.test xlog ${ITERATOR_TEST_LIBS} ${LIB_DL})
 
-add_executable(vy_cache.test vy_cache.c ${ITERATOR_TEST_SOURCES})
+add_executable(vy_cache.test vy_cache.c ${ITERATOR_TEST_SOURCES} core_test_utils.c)
 target_link_libraries(vy_cache.test ${ITERATOR_TEST_LIBS} ${LIB_DL})
 
-add_executable(coll.test coll.cpp)
+add_executable(coll.test coll.cpp core_test_utils.c)
 target_link_libraries(coll.test coll unit misc ${LIB_DL})
 
-add_executable(tuple_bigref.test tuple_bigref.c)
+add_executable(tuple_bigref.test tuple_bigref.c core_test_utils.c)
 target_link_libraries(tuple_bigref.test tuple unit)
 
 add_executable(checkpoint_schedule.test
@@ -235,23 +238,23 @@ add_executable(checkpoint_schedule.test
 )
 target_link_libraries(checkpoint_schedule.test m unit)
 
-add_executable(sio.test sio.c)
+add_executable(sio.test sio.c core_test_utils.c)
 target_link_libraries(sio.test unit core)
 
-add_executable(crypto.test crypto.c)
+add_executable(crypto.test crypto.c core_test_utils.c)
 target_link_libraries(crypto.test crypto unit)
 
 add_executable(swim.test swim.c swim_test_transport.c swim_test_ev.c
-               swim_test_utils.c ${PROJECT_SOURCE_DIR}/src/version.c)
+               swim_test_utils.c ${PROJECT_SOURCE_DIR}/src/version.c core_test_utils.c)
 target_link_libraries(swim.test unit swim)
 
 add_executable(swim_proto.test swim_proto.c swim_test_transport.c swim_test_ev.c
-               swim_test_utils.c ${PROJECT_SOURCE_DIR}/src/version.c)
+               swim_test_utils.c ${PROJECT_SOURCE_DIR}/src/version.c core_test_utils.c)
 target_link_libraries(swim_proto.test unit swim)
 
 add_executable(swim_errinj.test swim_errinj.c swim_test_transport.c
                swim_test_ev.c swim_test_utils.c
-               ${PROJECT_SOURCE_DIR}/src/version.c)
+               ${PROJECT_SOURCE_DIR}/src/version.c core_test_utils.c)
 target_link_libraries(swim_errinj.test unit swim)
 
 add_executable(merger.test merger.test.c)
@@ -264,5 +267,5 @@ target_link_libraries(snap_quorum_delay.test box core unit)
 # Client for popen.test
 add_executable(popen-child popen-child.c)
 
-add_executable(popen.test popen.c)
+add_executable(popen.test popen.c core_test_utils.c)
 target_link_libraries(popen.test misc unit core)
diff --git a/test/unit/core_test_utils.c b/test/unit/core_test_utils.c
new file mode 100644
index 000000000..23452bbfd
--- /dev/null
+++ b/test/unit/core_test_utils.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2010-2020, Tarantool AUTHORS, please see AUTHORS file.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above
+ *    copyright notice, this list of conditions and the
+ *    following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/**
+ * Mock function to resolve circular dependencies in unit tests
+ */
+void cord_on_yield(void)
+{
+}
-- 
2.25.0