Question

I got a c++ non-blocking server socket, with all the clients stored in a std::map structure.

I can call the send() method for each clientObject to send something to the connected client and that works pretty good already.

But for sending a message to all (broadcast?) i wanna know:
there is something better than do a for/loop with all the clients and call to ClientObject->send(“foo”) each iteration?

Or should i just try having a peek on multicast sockets?

Thanks in advance.
Rag.

Answer 1

Multicast is only an option if you’re communicating over a LAN. It won’t work over the Internet.

What you may want to do here is to demultiplex the sockets using asynchronous I/O. This allows you to send data to multiple sockets at the same time, and use asynchronous event handlers to deal with each transmission.

I would recommend looking into Boost ASIO for a portable way to do this. You can also use OS specific system calls, (such as poll/select on UNIX or epoll on Linux) to do this, but it is a lot more complicated.