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/all_database_cloner.cpp:383: MISSING_LOCK 140466 Accessing "this->databasesCloned" without holding lock "mongo::repl::BaseCloner._mutex". Elsewhere, "mongo::repl::AllDatabaseCloner::Stats.databasesCloned" is written to with "BaseCloner._mutex" held 1 out of 2 times (1 of these accesses strongly imply that it is necessary).