Thanks, It looks like I have no busy handler, only greedy waiter (no sleeping), and I just looked several times, the main thread tried to do commit for update operations and got SQLITE_BUSY two times (sqlite3_step calls), after that SQLITE_DONE with the consequences I described. I checked this several times, no exception, every time the counter of SQLITE_BUSY results is always 2 before SQLITE_DONE. And very fast (subjectively) I know that it's better to do a graceful waiting with my own sleep or little help from Sqlite, but I suppose the greedy waiter can't be the reason behind this issue.