Mentioned in #333 (comment)

Currently stratum_connection_mapping is protected with a Mutex and is locked on each RPC call such as get_miner_info. This can block critical Stratum tasks (e.g., miner connect/disconnect or message dispatch) if RPC calls are frequent.

Using an RwLock could allow concurrent read access for RPC calls while still maintaining exclusive write access for state updates.

This issue tracks refactoring the locking strategy for stratum_connection_mapping to improve concurrency.