Data race condition

The value of the shared data will be determined by the interleaving of thread execution. Thread shared data is accessed without holding an appropriate lock, possibly causing a race condition
/src/mongo/db/repl/database_cloner.cpp:191: MISSING_LOCK 143049 Accessing "this->_stats" without holding lock "mongo::repl::BaseCloner._mutex". Elsewhere, "mongo::repl::DatabaseCloner._stats" is written to with "BaseCloner._mutex" held 1 out of 1 times.