From: Pito Salas <rps@...>
Date: 2010-05-13T01:45:36+09:00
Subject: TcpIp, Sockets, Gserver question

I'm writing a simple pair of client and server apps to demonstrate a
concept and it's doing something weird. I will show the source code
below but basically there seems to be a syncing problem or a cache
flushing problem. When text is sent from the client to the server it
doesn't seem to receive it in one shot, or vice versa when the server
responds the client doesn't see it when I expect, and as a result,
things get out of sync in weird ways. Again I think it's some kind of
cache flushing problem. I hope someone on this list has tried something
like this and might be able to help me explain what's going on.

Thanks a lot for taking a look. I hope it's something really simple like
some flag or setting somewhere. Thanks!!

Pito

Here's the problem code reduced to a simple test case:

CLIENT:

require 'socket'

tcp_socket = TCPSocket.new('0.0.0.0', 8888)
tcp_socket.puts "Hi there server"
servers_resp = tcp_socket.gets.chomp
puts servers_resp

loop do
  print "> "
  command_string = gets
  break if command_string =~ /x/
  tcp_socket.puts command_string
  servers_resp = tcp_socket.gets.chomp
  puts servers_resp
end

SERVER:

require 'gserver'

class MyServer < GServer
  def serve(io_object)
    # Increment the client ID so each client gets a unique ID
    io_object.sync = true

    io_object.puts("Welcome to the server")
    puts "client attached."
    loop do
      line = io_object.readline
      case line
      when /^t/
          io_object.puts "The time of day is #{Time.now}"
      when /^x/
        puts "Exiting!"
        break
      when /^f/
      else
        puts "received line #{line}"
        io_object.puts "What does #{line} mean, anyway?"
      end
    end
  end
end

puts "Starting to listen for a connection on port 8888"
server = MyServer.new(8888)
server.start
server.join


SHELL TRANSCRIPT ON SERVER SIDE:

ruby deleteme.rb
Starting to listen for a connection on port 8888
client attached.
received line Hi there server
received line lalal
received line dadad
received line wowowow
received line
received line
received line
received line
received line
received line
received line
received line
received line


AND ON THE CLIENT SIDE:
$ ruby myclient.rb
Welcome to the server
> lalal
What does Hi there server
> dadad
 mean, anyway?
> wowowow
What does lalal
> 
 mean, anyway?
> 
What does dadad
> 
 mean, anyway?
> 
What does wowowow
> 
 mean, anyway?
> 
What does
> 
 mean, anyway?
> 
What does
> 
 mean, anyway?
> 
-- 
Posted via http://www.ruby-forum.com/.