What will happen when another thread delete all records after first fillwindow operation in sqlite?

If execute a query in a thread, it will acquire connection from the connection pool and execute fillwindow at the first time move the cursor, when fillwindow finished the connection will be released, at this time another thread acquire the connection and delete all the records, then the first thread move the cursor position out of the window range and trigger another fillwindow operation, what would happen in this situation?

The database is sqlite and the connection pool only have one connection.