UBsan: Issue identified with DCPConnMap

/home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/dcp/backfill-manager.cc:138:62: runtime error: member call on address 0x7f0778bee000 which does not point to an object of type 'DcpConnMap'

14:01:06 0x7f0778bee000: note: object is of type 'ConnMap'

14:01:06  00 00 00 00  50 e8 a0 01 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00

14:01:06               ^~~~~~~~~~~~~~~~~~~~~~~

14:01:06               vptr for 'ConnMap'

14:01:06     #0 0x11511bc in BackfillManager::~BackfillManager() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/dcp/backfill-manager.cc:138

14:01:06     #1 0x849118 in MockDcpBackfillManager::~MockDcpBackfillManager() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/tests/mock/mock_dcp_backfill_mgr.h:26

14:01:06     #2 0x849118 in MockDcpBackfillManager::~MockDcpBackfillManager() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/tests/mock/mock_dcp_backfill_mgr.h:26

14:01:06     #3 0x848cd4 in std::_Sp_counted_ptr<MockDcpBackfillManager*, (__gnu_cxx::_Lock_policy)2>::_M_dispose() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:376

14:01:06     #4 0x755e29 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:154

14:01:06     #5 0x11bc9fc in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:684

14:01:06     #6 0x11bc9fc in std::__shared_ptr<BackfillManager, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:1123

14:01:06     #7 0x11bc9fc in std::__shared_ptr<BackfillManager, (__gnu_cxx::_Lock_policy)2>::reset() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:1235

14:01:06     #8 0x11bc9fc in DcpProducer::~DcpProducer() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/dcp/producer.cc:231

14:01:06     #9 0x848f06 in MockDcpProducer::~MockDcpProducer() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/tests/mock/mock_dcp_producer.h:32

14:01:06     #10 0x84b128 in void __gnu_cxx::new_allocator<MockDcpProducer>::destroy<MockDcpProducer>(MockDcpProducer*) /usr/local/include/c++/7.3.0/ext/new_allocator.h:140

14:01:06     #11 0x84b128 in void std::allocator_traits<std::allocator<MockDcpProducer> >::destroy<MockDcpProducer>(std::allocator<MockDcpProducer>&, MockDcpProducer*) /usr/local/include/c++/7.3.0/bits/alloc_traits.h:487

14:01:06     #12 0x84b128 in std::_Sp_counted_ptr_inplace<MockDcpProducer, std::allocator<MockDcpProducer>, (__gnu_cxx::_Lock_policy)2>::_M_dispose() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:535

14:01:06     #13 0x1146226 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:154

14:01:06     #14 0x1146226 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:684

14:01:06     #15 0x1146226 in std::__shared_ptr<ConnHandler, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr() /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:1123

14:01:06     #16 0x1146226 in std::shared_ptr<ConnHandler>::~shared_ptr() /usr/local/include/c++/7.3.0/bits/shared_ptr.h:93

14:01:06     #17 0x1146226 in void std::_Destroy<std::shared_ptr<ConnHandler> >(std::shared_ptr<ConnHandler>*) /usr/local/include/c++/7.3.0/bits/stl_construct.h:98

14:01:06     #18 0x1146226 in void std::_Destroy_aux<false>::__destroy<std::shared_ptr<ConnHandler>*>(std::shared_ptr<ConnHandler>*, std::shared_ptr<ConnHandler>*) /usr/local/include/c++/7.3.0/bits/stl_construct.h:108

14:01:06     #19 0x1146226 in void std::_Destroy<std::shared_ptr<ConnHandler>*>(std::shared_ptr<ConnHandler>*, std::shared_ptr<ConnHandler>*) /usr/local/include/c++/7.3.0/bits/stl_construct.h:137

14:01:06     #20 0x1146226 in void std::_Destroy<std::shared_ptr<ConnHandler>*, std::shared_ptr<ConnHandler> >(std::shared_ptr<ConnHandler>*, std::shared_ptr<ConnHandler>*, std::allocator<std::shared_ptr<ConnHandler> >&) /usr/local/include/c++/7.3.0/bits/stl_construct.h:206

14:01:06     #21 0x1146226 in std::deque<std::shared_ptr<ConnHandler>, std::allocator<std::shared_ptr<ConnHandler> > >::_M_destroy_data_aux(std::_Deque_iterator<std::shared_ptr<ConnHandler>, std::shared_ptr<ConnHandler>&, std::shared_ptr<ConnHandler>*>, std::_Deque_iterator<std::shared_ptr<ConnHandler>, std::shared_ptr<ConnHandler>&, std::shared_ptr<ConnHandler>*>) /usr/local/include/c++/7.3.0/bits/deque.tcc:861

14:01:06     #22 0x1138d93 in std::deque<std::shared_ptr<ConnHandler>, std::allocator<std::shared_ptr<ConnHandler> > >::_M_destroy_data(std::_Deque_iterator<std::shared_ptr<ConnHandler>, std::shared_ptr<ConnHandler>&, std::shared_ptr<ConnHandler>*>, std::_Deque_iterator<std::shared_ptr<ConnHandler>, std::shared_ptr<ConnHandler>&, std::shared_ptr<ConnHandler>*>, std::allocator<std::shared_ptr<ConnHandler> > const&) /usr/local/include/c++/7.3.0/bits/stl_deque.h:2072

14:01:06     #23 0x1138d93 in std::deque<std::shared_ptr<ConnHandler>, std::allocator<std::shared_ptr<ConnHandler> > >::~deque() /usr/local/include/c++/7.3.0/bits/stl_deque.h:1045

14:01:06     #24 0x1138d93 in std::queue<std::shared_ptr<ConnHandler>, std::deque<std::shared_ptr<ConnHandler>, std::allocator<std::shared_ptr<ConnHandler> > > >::~queue() /usr/local/include/c++/7.3.0/bits/stl_queue.h:96

14:01:06     #25 0x1138d93 in AtomicQueue<std::shared_ptr<ConnHandler> >::~AtomicQueue() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/atomicqueue.h:39

14:01:06     #26 0x1138d93 in ConnMap::~ConnMap() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/connmap.cc:183

14:01:06     #27 0x119f919 in DcpConnMap::~DcpConnMap() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/dcp/dcpconnmap.cc:60

14:01:06     #28 0x119f998 in DcpConnMap::~DcpConnMap() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/dcp/dcpconnmap.cc:62

14:01:06     #29 0x12875d6 in std::default_delete<DcpConnMap>::operator()(DcpConnMap*) const /usr/local/include/c++/7.3.0/bits/unique_ptr.h:78

14:01:06     #30 0x12875d6 in std::unique_ptr<DcpConnMap, std::default_delete<DcpConnMap> >::~unique_ptr() /usr/local/include/c++/7.3.0/bits/unique_ptr.h:268

14:01:06     #31 0x12875d6 in EventuallyPersistentEngine::~EventuallyPersistentEngine() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/ep_engine.cc:6034

14:01:06     #32 0x1287ba0 in EventuallyPersistentEngine::~EventuallyPersistentEngine() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/ep_engine.cc:6042

14:01:06     #33 0x124da24 in EvpDestroy /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/src/ep_engine.cc:151

14:01:06     #34 0xae78f1 in EventuallyPersistentEngineTest::TearDown() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/tests/module_tests/evp_engine_test.cc:78

14:01:06     #35 0xa19890 in DCPTest::TearDown() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/tests/module_tests/dcp_test.cc:86

14:01:06     #36 0xa19890 in StreamTest::TearDown() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/tests/module_tests/dcp_test.cc:255

14:01:06     #37 0x15f4c63 in void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:2402

14:01:06     #38 0x1601f75 in void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:2438

14:01:06     #39 0x15e489e in testing::Test::Run() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:2482

14:01:06     #40 0x15e536f in testing::TestInfo::Run() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:2656

14:01:06     #41 0x15e5863 in testing::TestCase::Run() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:2774

14:01:06     #42 0x15e8a2e in testing::internal::UnitTestImpl::RunAllTests() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:4649

14:01:06     #43 0x15f5132 in bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:2402

14:01:06     #44 0x1602ae6 in bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:2438

14:01:06     #45 0x15e4bfd in testing::UnitTest::Run() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/src/gtest.cc:4257

14:01:06     #46 0xa62f02 in RUN_ALL_TESTS() /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/googletest/googletest/include/gtest/gtest.h:2237

14:01:06     #47 0xa62f02 in main /home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/kv_engine/engines/ep/tests/module_tests/ep_unit_tests_main.cc:72

14:01:06     #48 0x7f07796b282f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)

14:01:06     #49 0x750b08 in _start (/home/couchbase/jenkins/workspace/kv_engine-undefinedsanitizer-master/build/kv_engine/ep-engine_ep_unit_tests+0x750b08)