Details

Notice, that the amount of free space returned by this property does not take into account any uncommitted data that might reside in the buffer (this can be checked via sock.newtxlen). Therefore, actual free space in the buffer is sock.txfree-sock.newtxlen. Your application will not be able to store more data than this amount.

To achieve asynchronous data processing, use the sock.notifysent method to get on_sock_data_sent event once the TX buffer gains required amount of free space.