position cache has a lock and position itself has a lock.
during normal position update, the sequence is position -> cache
but when flush, it's opposite, which may cause deadlock
this pr releases cache lock before encode position to prevent such case, closes #309
position cache has a lock and position itself has a lock. during normal position update, the sequence is position -> cache but when flush, it's opposite, which may cause deadlock
this pr releases cache lock before encode position to prevent such case, closes #309