What are the pros/cons of select(), non-blocking I/O and SIGIO?
Using non-blocking I/O means that you have to poll sockets to see if
there is data to be read from them. Polling should usually be avoided
since it uses more CPU time than other techniques.
Using SIGIO allows your application to do what it does and have the
operating system tell it (with a signal) that there is data waiting
for it on a socket. The only drawback to this soltion is that it can
be confusing, and if you are dealing with multiple sockets you will
have to do a select() anyway to find out which one(s) is ready to be
Using select() is great if your application has to accept data from
more than one socket at a time since it will block until any one of a
number of sockets is ready with data. One other advantage to select()
is that you can set a time-out value after which control will be
returned to you whether any of the sockets have data for you or not.