Can a tcp socket's send buffer be cleared/emptied manually?

[weiqi]

I have an application which sends data periodically. I want to clear its send buffer when an epoch ends so that the old data won't block next epoch's transmission.

Is there any method/func I can call? Haven't got any answer after so much google.

Or all I can do is just close the old socket at the epoch's end and open a new one in next epoch's beginning?

Thanks for all advises and help!!