Bump up memory order of ref counting of ColumnFamilyData #5723
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Summary:
We see this TSAN warning:
WARNING: ThreadSanitizer: data race (pid=282806)
Write of size 8 at 0x7b6c00000e38 by thread T16 (mutexes: write M1023578822185846136):
#0 operator delete(void*) <null> (libtsan.so.0+0x0000000795f8)
#1 rocksdb::DBImpl::BackgroundFlush(bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::FlushReason*, rocksdb::Env::Priority) db/db_impl/db_impl_compaction_flush.cc:2202 (db_flush_test+0x00000060b462)
facebook#2 rocksdb::DBImpl::BackgroundCallFlush(rocksdb::Env::Priority) db/db_impl/db_impl_compaction_flush.cc:2226 (db_flush_test+0x00000060cbd8)
facebook#3 rocksdb::DBImpl::BGWorkFlush(void*) db/db_impl/db_impl_compaction_flush.cc:2073 (db_flush_test+0x00000060d5ac)
......
Previous atomic write of size 4 at 0x7b6c00000e38 by main thread:
#0 __tsan_atomic32_fetch_sub <null> (libtsan.so.0+0x00000006d721)
#1 std::__atomic_base<int>::fetch_sub(int, std::memory_order) /mnt/gvfs/third-party2/libgcc/c67031f0f739ac61575a061518d6ef5038f99f90/7.x/platform007/5620abc/include/c++/7.3.0/bits/atomic_base.h:524 (db_flush_test+0x0000005f9e38)
facebook#2 rocksdb::ColumnFamilyData::Unref() db/column_family.h:286 (db_flush_test+0x0000005f9e38)
facebook#3 rocksdb::DBImpl::FlushMemTable(rocksdb::ColumnFamilyData*, rocksdb::FlushOptions const&, rocksdb::FlushReason, bool) db/db_impl/db_impl_compaction_flush.cc:1624 (db_flush_test+0x0000005f9e38)
facebook#4 rocksdb::DBImpl::TEST_FlushMemTable(rocksdb::ColumnFamilyData*, rocksdb::FlushOptions const&) db/db_impl/db_impl_debug.cc:127 (db_flush_test+0x00000061ace9)
facebook#5 rocksdb::DBFlushTest_CFDropRaceWithWaitForFlushMemTables_Test::TestBody() db/db_flush_test.cc:320 (db_flush_test+0x0000004b44e5)
facebook#6 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) third-party/gtest-1.7.0/fused-src/gtest/gtest-all.cc:3824 (db_flush_test+0x000000be2988)
......
It's still very clear the cause of the warning is because that TSAN treats results from relaxed atomic::fetch_sub() as non-atomic with the operation itself. We can make it more explicit by bumping up the order to CS.
Test Plan: Run all existing test.
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miasantreble
approved these changes
Aug 20, 2019
|
This pull request has been merged in 4c74dba. |
merryChris
pushed a commit
to merryChris/rocksdb
that referenced
this pull request
Nov 18, 2019
Summary:
We see this TSAN warning:
WARNING: ThreadSanitizer: data race (pid=282806)
Write of size 8 at 0x7b6c00000e38 by thread T16 (mutexes: write M1023578822185846136):
#0 operator delete(void*) <null> (libtsan.so.0+0x0000000795f8)
facebook#1 rocksdb::DBImpl::BackgroundFlush(bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::FlushReason*, rocksdb::Env::Priority) db/db_impl/db_impl_compaction_flush.cc:2202 (db_flush_test+0x00000060b462)
facebook#2 rocksdb::DBImpl::BackgroundCallFlush(rocksdb::Env::Priority) db/db_impl/db_impl_compaction_flush.cc:2226 (db_flush_test+0x00000060cbd8)
facebook#3 rocksdb::DBImpl::BGWorkFlush(void*) db/db_impl/db_impl_compaction_flush.cc:2073 (db_flush_test+0x00000060d5ac)
......
Previous atomic write of size 4 at 0x7b6c00000e38 by main thread:
#0 __tsan_atomic32_fetch_sub <null> (libtsan.so.0+0x00000006d721)
facebook#1 std::__atomic_base<int>::fetch_sub(int, std::memory_order) /mnt/gvfs/third-party2/libgcc/c67031f0f739ac61575a061518d6ef5038f99f90/7.x/platform007/5620abc/include/c++/7.3.0/bits/atomic_base.h:524 (db_flush_test+0x0000005f9e38)
facebook#2 rocksdb::ColumnFamilyData::Unref() db/column_family.h:286 (db_flush_test+0x0000005f9e38)
facebook#3 rocksdb::DBImpl::FlushMemTable(rocksdb::ColumnFamilyData*, rocksdb::FlushOptions const&, rocksdb::FlushReason, bool) db/db_impl/db_impl_compaction_flush.cc:1624 (db_flush_test+0x0000005f9e38)
facebook#4 rocksdb::DBImpl::TEST_FlushMemTable(rocksdb::ColumnFamilyData*, rocksdb::FlushOptions const&) db/db_impl/db_impl_debug.cc:127 (db_flush_test+0x00000061ace9)
facebook#5 rocksdb::DBFlushTest_CFDropRaceWithWaitForFlushMemTables_Test::TestBody() db/db_flush_test.cc:320 (db_flush_test+0x0000004b44e5)
facebook#6 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) third-party/gtest-1.7.0/fused-src/gtest/gtest-all.cc:3824 (db_flush_test+0x000000be2988)
......
It's still very clear the cause of the warning is because that TSAN treats results from relaxed atomic::fetch_sub() as non-atomic with the operation itself. We can make it more explicit by bumping up the order to CS.
Pull Request resolved: facebook#5723
Test Plan: Run all existing test.
Differential Revision: D16908250
fbshipit-source-id: bf17d39ed19058372bdf97f6440a743f88153021
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Summary:
We see this TSAN warning:
WARNING: ThreadSanitizer: data race (pid=282806)
Write of size 8 at 0x7b6c00000e38 by thread T16 (mutexes: write M1023578822185846136):
#0 operator delete(void*) (libtsan.so.0+0x0000000795f8)
#1 rocksdb::DBImpl::BackgroundFlush(bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::FlushReason*, rocksdb::Env::Priority) db/db_impl/db_impl_compaction_flush.cc:2202 (db_flush_test+0x00000060b462)
#2 rocksdb::DBImpl::BackgroundCallFlush(rocksdb::Env::Priority) db/db_impl/db_impl_compaction_flush.cc:2226 (db_flush_test+0x00000060cbd8)
#3 rocksdb::DBImpl::BGWorkFlush(void*) db/db_impl/db_impl_compaction_flush.cc:2073 (db_flush_test+0x00000060d5ac)
......
Previous atomic write of size 4 at 0x7b6c00000e38 by main thread:
#0 __tsan_atomic32_fetch_sub (libtsan.so.0+0x00000006d721)
#1 std::__atomic_base::fetch_sub(int, std::memory_order) /mnt/gvfs/third-party2/libgcc/c67031f0f739ac61575a061518d6ef5038f99f90/7.x/platform007/5620abc/include/c++/7.3.0/bits/atomic_base.h:524 (db_flush_test+0x0000005f9e38)
#2 rocksdb::ColumnFamilyData::Unref() db/column_family.h:286 (db_flush_test+0x0000005f9e38)
#3 rocksdb::DBImpl::FlushMemTable(rocksdb::ColumnFamilyData*, rocksdb::FlushOptions const&, rocksdb::FlushReason, bool) db/db_impl/db_impl_compaction_flush.cc:1624 (db_flush_test+0x0000005f9e38)
#4 rocksdb::DBImpl::TEST_FlushMemTable(rocksdb::ColumnFamilyData*, rocksdb::FlushOptions const&) db/db_impl/db_impl_debug.cc:127 (db_flush_test+0x00000061ace9)
#5 rocksdb::DBFlushTest_CFDropRaceWithWaitForFlushMemTables_Test::TestBody() db/db_flush_test.cc:320 (db_flush_test+0x0000004b44e5)
#6 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::)(), char const) third-party/gtest-1.7.0/fused-src/gtest/gtest-all.cc:3824 (db_flush_test+0x000000be2988)
......
It's still very clear the cause of the warning is because that TSAN treats results from relaxed atomic::fetch_sub() as non-atomic with the operation itself. We can make it more explicit by bumping up the order to CS.
Test Plan: Run all existing test.