From: ale@...
Date: 2001-08-16T01:30:16+09:00
Subject: [ruby-talk:19800] Exception handling bug?

Didn't post this to the bug database, as I'm not completely sure this is a
bug. But let's see what you think about it.

     - Aleksi


=begin

Bug?

Hangs if called as   ruby ping_hang.rb hang
Works if called as   ruby ping_hang.rb

Hangs or works on Linux platforms with ruby 1.6.[234] 
and latest (2001-08-12).

=end

require 'timeout'
require 'socket'

class Ping

  def initialize(host)
    @host = host
  end

  def ping_hangs
    begin
      s = TCPsocket.new(@host, "echo")
      s.close
    rescue # Errno::ECONNREFUSED  ### Attention !!
    end
  end

  def ping_works
    begin
      s = TCPsocket.new(@host, "echo")
      s.close
    rescue Errno::ECONNREFUSED    # rescuing econnrefused works
    end
  end
  
end

def start_pinging_hangs
  ponger = Ping.new("localhost")
  loop do
    ponger.ping_hangs
  end
end

def start_pinging_works
  ponger = Ping.new("localhost")
  loop do
    ponger.ping_works
  end
end

begin
  if ARGV.size > 0 && ARGV.shift == "hang"
    timeout(0.1) do
      start_pinging_hangs
    end
  else
    timeout(0.1) do
      start_pinging_works
    end
  end
rescue
end