Address data race seen with the module dcp tests

16:50:07 WARNING: ThreadSanitizer: data race (pid=36686)
16:50:07   Write of size 8 at 0x7d0c00003ad8 by main thread (mutexes: write M130807):
16:50:07     #0 operator delete(void*) <null> (ep-engine_dcp_test+0x00000047357b)
16:50:07     #1 std::_Rb_tree<void const*, std::pair<void const* const, DcpConsumer*>, std::_Select1st<std::pair<void const* const, DcpConsumer*> >, std::less<void const*>, std::allocator<std::pair<void const* const, DcpConsumer*> > >::_M_erase_aux(std::_Rb_tree_const_iterator<std::pair<void const* const, DcpConsumer*> >) /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/ext/new_allocator.h:110 (ep-engine_dcp_test+0x00000052ad65)
16:50:07     #2 FlowControl::~FlowControl() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/dcp/flow-control.cc:44 (ep-engine_dcp_test+0x000000528ea1)
16:50:07     #3 DcpConsumer::~DcpConsumer() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/dcp/consumer.cc:133 (ep-engine_dcp_test+0x00000051b223)
16:50:07     #4 DcpConsumer::~DcpConsumer() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/dcp/consumer.cc:130 (ep-engine_dcp_test+0x00000051b815)
16:50:07     #5 Processer::~Processer() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/atomic.h:272 (ep-engine_dcp_test+0x00000051a51c)
16:50:07     #6 ~SingleThreadedRCPtr /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/atomic.h:272 (ep-engine_dcp_test+0x0000005ba662)
16:50:07     #7 ExecutorPool::stopTaskGroup(unsigned long, task_type_t, bool) /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/executorpool.cc:594 (ep-engine_dcp_test+0x0000005badee)
16:50:07     #8 EventuallyPersistentStore::~EventuallyPersistentStore() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/ep.cc:565 (ep-engine_dcp_test+0x00000054f302)
16:50:07     #9 EventuallyPersistentEngine::~EventuallyPersistentEngine() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/ep_engine.cc:6349 (ep-engine_dcp_test+0x00000059bf7a)
16:50:07     #10 EvpDestroy(engine_interface*, bool) /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/ep_engine.cc:148 (ep-engine_dcp_test+0x00000057e2b7)
16:50:07     #11 DCPTest::TearDown() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/tests/module_tests/dcp_test.cc:126 (ep-engine_dcp_test+0x0000004e5737)
16:50:07     #12 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/googletest/googletest/src/gtest.cc:2402 (ep-engine_dcp_test+0x0000006d7792)
16:50:07     #13 testing::Test::Run() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/googletest/googletest/src/gtest.cc:2482 (ep-engine_dcp_test+0x0000006a4e31)
16:50:07     #14 testing::TestInfo::Run() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/googletest/googletest/src/gtest.cc:2656 (ep-engine_dcp_test+0x0000006a6e0b)
16:50:07     #15 testing::TestCase::Run() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/googletest/googletest/src/gtest.cc:2774 (ep-engine_dcp_test+0x0000006a78ba)
16:50:07     #16 testing::internal::UnitTestImpl::RunAllTests() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/googletest/googletest/src/gtest.cc:4649 (ep-engine_dcp_test+0x0000006b84f3)
16:50:07     #17 bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/googletest/googletest/src/gtest.cc:2402 (ep-engine_dcp_test+0x0000006d8902)
16:50:07     #18 testing::UnitTest::Run() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/googletest/googletest/src/gtest.cc:4257 (ep-engine_dcp_test+0x0000006b7ad0)
16:50:07     #19 main /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/googletest/googletest/include/gtest/gtest.h:2237 (ep-engine_dcp_test+0x0000004e2cc0)
16:50:07
16:50:07   Previous read of size 8 at 0x7d0c00003ad8 by thread T5 (mutexes: write M130950):
16:50:07     #0 DcpFlowControlManagerAggressive::handleDisconnect(DcpConsumer*) /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/dcp/flow-control-manager.cc:211 (ep-engine_dcp_test+0x00000052aea8)
16:50:07     #1 FlowControl::~FlowControl() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/dcp/flow-control.cc:44 (ep-engine_dcp_test+0x000000528ea1)
16:50:07     #2 DcpConsumer::~DcpConsumer() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/dcp/consumer.cc:133 (ep-engine_dcp_test+0x00000051b223)
16:50:07     #3 DcpConsumer::~DcpConsumer() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/dcp/consumer.cc:130 (ep-engine_dcp_test+0x00000051b815)
16:50:07     #4 Processer::~Processer() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/atomic.h:272 (ep-engine_dcp_test+0x00000051a51c)
16:50:07     #5 ExecutorThread::run() /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/atomic.h:325 (ep-engine_dcp_test+0x0000005bfa5b)
16:50:07     #6 launch_executor_thread(void*) /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/ep-engine/src/executorthread.cc:33 (ep-engine_dcp_test+0x0000005bf885)
16:50:07     #7 platform_thread_wrap(void*) /home/couchbase/jenkins/workspace/ep-engine-threadsanitizer-master/platform/src/cb_pthreads.cc:54 (libplatform.so.0.1.0+0x00000000568b)

Change-Id: I84860030d78d0bc2e5010255e8ba30bec6109719
Reviewed-on: http://review.couchbase.org/62527
Tested-by: buildbot <[email protected]>
Reviewed-by: Manu Dhundi <[email protected]>

Author: abhinavdangeti

tests/module_tests/dcp_test.cc

@@ -378,7 +378,9 @@ TEST_F(ConnectionTest, test_mb17042_duplicate_name_consumer_connections) {
     dcp_consumer_t duplicateconsumer = connMap.newConsumer(cookie2, "test_consumer");
     EXPECT_NE(0, (int)duplicateconsumer) << "duplicateconsumer is null";
 
+    consumer->cancelTask();
     consumer.reset();
+    duplicateconsumer->cancelTask();
     duplicateconsumer.reset();
     delete cookie1;
     delete cookie2;
@@ -412,6 +414,7 @@ TEST_F(ConnectionTest, test_mb17042_duplicate_cookie_consumer_connections) {
     dcp_consumer_t duplicateconsumer = connMap.newConsumer(cookie, "test_consumer2");
     EXPECT_EQ(0, (int)duplicateconsumer) << "duplicateconsumer is not null";
 
+    consumer->cancelTask();
     consumer.reset();
     delete cookie;
 }