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/s/migration_chunk_cloner_source.cpp:486: MISSING_LOCK 148520 Accessing "this->_state" without holding lock "mongo::MigrationChunkClonerSource._mutex". Elsewhere, "mongo::MigrationChunkClonerSource._state" is written to with "MigrationChunkClonerSource._mutex" held 2 out of 2 times (2 of these accesses strongly imply that it is necessary).