future_sample.rb

require 'celluloid'

def pusher(condition)
  sleep 5
  condition.signal 'Wibble'
end

def puller(condition)
  value = condition.wait
  puts "Pulled: #{value}"
end

condition = Celluloid::Condition.new

t1 = Thread.new {
  begin
    puller(condition)
  rescue Exception => e
    puts "Exception raised: #{e.message}\n    #{e.backtrace.join("\n    ")}"
  end
}
t2 = Thread.new {
  begin
    pusher(condition)
  rescue Exception => e
    puts "Exception raised: #{e.message}\n    #{e.backtrace.join("\n    ")}"
  end
}

t1.join
t2.join

__END__

$ ruby test.rb
Pulled: Wibble
D, [2013-10-02T11:12:19.773810 #12311] DEBUG -- : Shutdown completed cleanly