From: codeslinger <codeslinger@...>
Date: 2006-02-24T03:13:33+09:00
Subject: Re: Two Ruby threading questions

Nevermind about question 2 above. I figured it out. Defining the
lambdas in the previous manner put them in the class scope, not object
instance scope. Here's how to make that work:

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

class X
  def thread_init
    @connection_main = 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
    @server_main = lambda do |srv|
      begin
        while true
          s = srv.accept
          Thread.start s, &@connection_main
        end
      rescue => e
        puts "#{e.message}:\n\t#{e.backtrace.join("\n\t")}"
      ensure
        srv.close
      end
    end
  end

  def initialize
    srv = TCPServer.new nil, 8008
    Thread.abort_on_exception = true
    thread_init
    Thread.start srv, &@server_main
    while true
        # doing main thread stuff in here
        sleep 5
        puts Thread.list.join(',')
    end
  end

  def handle_sock_data data
    # do something with data here
    puts "called handle_sock_data: '#{data.strip}'"
  end

end  # class X

x = X.new
puma:~>

This outputs:

puma:~> ruby a.rb
called handle_sock_data: 'hello'
#<Thread:0xb7d0fe3c>,#<Thread:0xb7d0fd10>,#<Thread:0xb7d1e748>
called handle_sock_data: 'goodbye'
#<Thread:0xb7d0fe3c>,#<Thread:0xb7d1e748>
#<Thread:0xb7d0fe3c>,#<Thread:0xb7d1e748>
#<Thread:0xb7d0fe3c>,#<Thread:0xb7d1e748>
a.rb:37:in `sleep': Interrupt
        from a.rb:37:in `initialize'
        from a.rb:49
puma:~>

I Ctrl-C'd it there at the end.

It would seem that I don't need to worry about the Thread
detached/setDaemon functionality, either, since the client
@connection_main threads seem to get cleaned up without having to
explicitly join them. Arigatou gozaimasu, Matsumoto-san :)