How to read from a TCPServer socket in ruby using read, readpartial and read_nonblock

I have a 2 part question on reading from sockets and how is it managed on Ruby servers like Unicorn or Mongrel

1. I've learnt that to read from a socket is different from reading a file and that there are no distinct EOF message sent and the data is an endless stream. So how do you know when to stop reading? My TCPServer for example in this case when I hit my server by accessing http://localhost:9799 from a browser, it hangs after there is no more data to read and it won't throw the EOFError either.

require 'socket'

READ_CHUNK = 1024
socket = Socket.new(Socket::AF_INET, Socket::SOCK_STREAM)
addr = Socket.pack_sockaddr_in(9799, '127.0.0.1')
socket.bind(addr)
socket.listen(Socket::SOMAXCONN)
socket.setsockopt(:SOCKET, :REUSEADDR, true)

puts "Server is listening on port = 9799"
loop do 
    connection, addr_info = socket.accept
    data_buffer = ""

    loop do
        begin
            connection.read_nonblock(READ_CHUNK, data_buffer)
            puts "Buffer = #{data_buffer}"
        rescue Errno::EAGAIN => e
            IO.select([connection])         
            retry
        rescue EOFError
            break
        end
    end
    connection.write("HTTP/1.1 200 \r\n")
    connection.write("Content-Type: text/html\r\n")
    connection.write("Status 200 \r\n")
    connection.write("Connection: close \r\n")
    connection.write("Hello World \r\n")
    connection.close
end

I'd like to know whats the best practice/standard approach used by Ruby servers. I see the Unicorn uses read_nonblock from kgio library and mongrel uses readpartial (I'm not sure about these but going through the code this is what I feel is the approach adopted.) Even with checks for \r\n how does the server know the input is complete. Could explain how this should be done (and I think gets is not the approach - its with read, readpartial, read_nonblock).

2). I would really appreciate a few lines on how this is achieved in servers like unicorn or passenger

Thank you.

Copyright License：
Author:「Sid」,Reproduced under the CC 4.0 BY-SA copyright license with link to original source & disclaimer.
Link to：https://stackoverflow.com/questions/13533382/how-to-read-from-a-tcpserver-socket-in-ruby-using-read-readpartial-and-read-non