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/client/fetcher.h:228: MISSING_LOCK 145169 Accessing "this->_completionPromise" without holding lock "mongo::Fetcher._mutex". Elsewhere, "mongo::Fetcher._completionPromise" is written to with "Fetcher._mutex" held 2 out of 2 times.