From: Robert Klemme <bob.news@...>
Date: 2005-02-11T18:45:02+09:00
Subject: Re: network program


"Jeff Davis" <jdavis-list@empires.org> schrieb im Newsbeitrag
news:420C371D.4060604@empires.org...
> I am writing an application and my design is for a non blocking tcp
> server. I have written non blocking network apps in C before.
>
> I am having trouble digging through the standard library. I have done
> this before in C with no problems. Are there some basic wrappers for the
> normal C functions and constants? I couldn't even find the F_SETFL
> constant to change the socket descriptor to non blocking. The constants
> seem to be all over the place (some in Socket, but I also need
> File::NONBLOCK, which is named differently than O_NONBLOCK...). When
> reading the documentation it's asking for a packed sockaddr to be passed
> to connect.
>
> Is this really the simplest, ruby-like way to build a non-blocking
> network app? It seems like this is harder and messier than C. It's also
> hard to find the constants and functions even if they do exist.

AFAIK Ruby uses nonblocking IO interenally.  The easiest is typically to
use threads to cope with multiple concurrent IO.  Example

require 'socket'
port = (ARGV[0] || 80).to_i
server = TCPServer.new('localhost', port)
while (session = server.accept)
  Thread.new(session) do |sock|
    begin
      # use sock
    ensure
      sock.close
    end
  end
end

Alternatively you can set up a fixed number of threads that handle
requests.

require 'socket'
require 'thread'

queue = Queue.new

threads = (1..10).map do
  Thread.new(queue) do |q|
    while ( sock = q.deq )
      begin
        # use sock
      rescue Exception => e
        $stderr.puts e
      ensure
        sock.close
      end
    end
  end
end

port = (ARGV[0] || 80).to_i
server = TCPServer.new('localhost', port)
while (session = server.accept)
  queue.enq session
end


Kind regards

    robert