#! /usr/bin/env ruby

#$ ruby better_select.rb
#=> read2
#=> end

require 'thread'

def better_select(reads, writes={}, excepts={}, timeout=nil)
  rs, ws, es = IO.select(reads.keys, writes.keys, excepts.keys, timeout)
  rs.each do |io|
    reads[io].call(io)
  end
  ws.each do |io|
    writes[io].call(io)
  end
  es.each do |io|
    excepts[io].call(io)
  end
end

q = Queue.new
r, w = IO.pipe
r2, w2 = IO.pipe
Thread.new {
  better_select({
    r => ->(io) {
      puts "read1"
      q.push "end"
    },
    r2 => ->(io) {
      puts "read2"
      q.push "end"
    }
  })
}.abort_on_exception = true

w2.write("GO")
w2.close

puts q.pop