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/balancer_stats_registry.cpp:145: MISSING_LOCK 140911 Accessing "this->this->_initOpCtxHolder" without holding lock "mongo::BalancerStatsRegistry._stateMutex". Elsewhere, "mongo::BalancerStatsRegistry._initOpCtxHolder" is written to with "BalancerStatsRegistry._stateMutex" held 2 out of 2 times.