Most efficient server method?

non-blocking is almost required nowadays. Especially for games.

I would read everything on multiplayer here on gamedev, and I would also read beej's guide to nework programming at http://www.ecst.csuchico.edu/~beej/guide/net/

Here is source code to a IOCP-based UDP network core. IOCP is the most efficient networking method on Win32 for a very large number of connections. But that's a solution that would work on NT/2K/XP class machines only.

http://pages.infinit.net/cbenoi1/iocp_udp.zip

If you are looking for a broader set of solutions, including cross-platforms, take a look here:

http://www.kegel.com/c10k.html
http://tangentsoft.net/wskfaq/articles/io-strategies.html

Hope this helps.

-cb

You can use select() without blocking in the select(). And you can use non-blocking sockets with select(). In fact, that's often better, because select() tells you you can read at least one byte without blocking; it doesn't tell you how much you can actually read.

If you're using UDP, you only need a single socket on the server, and you can use recvfrom() and sendto() to separate the different clients. This is most efficient. You can still select() on this socket. Also, if you're using UDP and select(), you don't need to make the socket non-blocking, because select() tells you that at least one call to recvfrom() will succeed without blocking.

If you run server physics at some fixed rate (good idea!) then your loop looks something like:

Time lastStep = Now();while( true ) {  RunAPhysicsStep();  Time then = lastStep + PhysicsStepSize;  while( true ) {    now = Now();    timeout = then-now;    if( timeout < 0 ) timeout = 0;    select( ...., timeout );    ServiceSocket( .... );    if( timeout <= 0 ) {      break;    }  }  lastStep = then;}

You might want to add some safe-guards, in case your physics step takes longer than real time. However, the loop, as written, will degrade to running as fast as it can at that point, with at least one call to service networks per physics step.

If you make your socket non-blocking, you can read as many datagrams as there are inside ServiceSocket(), until no more are in the queue; that's most efficient. If it's blocking, you can only (safely) read one, and have to go back through the loop again to get the next; slightly less efficient.