Question

I want multiple threads to all fire at the same time.

10.times do
  Thread.new do
    sleep rand(5)               # Initialize all the stuff
    wait_for_all_other_threads  # Wait for other threads to initialize their stuff
    fire!                       # Go.
  end
end

How would I implement wait_for_all_other_threads so they all fire! at the same time?

Answer 1

Use a barrier sync: http://rubygems.org/gems/barrier/

A call to barrier will cause each thread to block until all of the threads have called it.