Allocate a socket set for use with SDLNet_CheckSockets().
int maxsockets);SDLNet_SocketSet SDLNet_AllocSocketSet(
the maximum amount of sockets to include in this set.
Returns a socket set for up to
maxsockets sockets, or NULL if the function ran out of memory.
To query if new data is available on a socket, you use a "socket set" with SDLNet_CheckSockets(). A socket set is just a list of sockets behind the scenes; you allocate a set and then add/remove individual sockets to/from the set.
When done with a socket set, you can free it with SDLNet_FreeSocketSet.
This function is available since SDL_net 2.0.0.