A simple non-blocking TCP server. This is a single threaded TCP server that does not block on I/O.

I used the select() system call over non-blocking sockets for polling for detecting socket readiness for read and write.

Long reads and writes will be done in round robin fashion: instead of finishing one long read or write in one go it will be interspered with other reads and writes. Thus no clinet connections will be starved off server attention. And there will always be some progress in terms of data reads/writes.

In the test server and clients the client sends a file name to the server. The server reads the contents of the file from the disk and writes the data back to the client. Note that this type of read-then-write operations could be done faster using the sendfile (http://linux.die.net/man/2/sendfile) system call. But we don't use that here.