Using readv(), writev() and poll() from C++

The functions readv(), writev(), and poll() work the same way in C++ as they do in C.

C++ handles them exactly the same as C -- Here's a tutorial to get you started.

However, since you're writing it in C++, I'd strongly advise you to take a look at the powerful alternatives, like the Boost.Asio framework. Believe me, you'll save a lot of time and nerves in implementing a server using Asio.