From: codeslinger <codeslinger@...>
Date: 2006-02-24T02:38:32+09:00
Subject: Two Ruby threading questions

Hi all,

I have a number of issues that I'm dealing with regarding Ruby threads
and I was wondering if someone might point me in the right direction
with some or all of them:

1. Is there a commensurate to Java's setDaemon() functionality for
Ruby? I've looked around on the Web, but I can't find reference to
anything and there's nothing in the docs about it. For those not
familiar with Java, setDaemon() is equivalent to setting a thread to a
"detached" state in pthread lingo.

2. Here's some demonstration code that will help understand this next
issue:

puma:~> cat a.rb
require 'socket'

class X
  def initialize
    srv = TCPServer.new nil, 8008
    Thread.abort_on_exception = true
    Thread.start srv, &ServerMain
    while true
        # doing main thread stuff in here
        sleep 10
    end
  end

  def handle_sock_data data
    # do something with data here
  end

  ServerMain = lambda do |srv|
    begin
      while true
        s = srv.accept
        Thread.start s, &ConnectionMain
      end
    rescue => e
      puts "#{e.message}:\n\t#{e.backtrace.join("\n\t")}"
    ensure
      srv.close
    end
  end

  ConnectionMain = lambda do |sock|
    begin
      data = sock.gets
      handle_sock_data data
    rescue => e
      puts "#{e.message}:\n\t#{e.backtrace.join("\n\t")}"
      raise e
    ensure
      sock.close rescue nil
    end
  end

end  # class X

x = X.new
puma:~>

Here's what I get when I run this, connect to it and send it a string:

puma:~> ruby a.rb
undefined method `handle_sock_data' for X:Class:
        a.rb:34
        a.rb:22
        a.rb:7:in `initialize'
        a.rb:45
a.rb:34: undefined method `handle_sock_data' for X:Class
(NoMethodError)
        from a.rb:22
        from a.rb:7:in `initialize'
        from a.rb:45
puma:~>

Since ServerMain and ConnectionMain are lambdas, I would have expected
them to be able to locate the handle_sock_data() method. Why can't
they, and is there some way for me to get them to be able to see said
method?

Thanks in advance for any help you can provide.

--
Toby DiPasquale