From: Wilson Bilkovich <wilsonb@...>
Date: 2005-11-09T04:45:25+09:00
Subject: Re: Checking for race conditions with Ruby threads

Thanks. This code exposed the problem successfully. Not sure if it's
the cleanest way, though.

require 'test/unit'
require 'open-uri'
class TestStream < Test::Unit::TestCase
  def test_work_unit_uniqueness
    ids = []
    pipes = []
    test_cmd = %q{ ruby -ropen-uri -e"print URI('the_url').read" }
    100.times do |i|
        pipes[i] = IO::popen(test_cmd)
    end
    pipes.each do |p|
      p.each_line {|ln| ids << ln}
    end
    assert_equal(ids, ids.uniq)
  end
end

On 11/8/05, mental@rydia.net <mental@rydia.net> wrote:
> Quoting Wilson Bilkovich <wilsonb@gmail.com>:
>
> > I've got an untrustworthy legacy app that seems to have a nasty
> > race condition when a certain number of users click on a link at
> > just the right time.
>
> > I'm trying to write a Ruby unit test to trigger this, but I'm a
> > bit stumped.
>
> You cannot test for race conditions, only prove them.
>
> -mental
>
>