multi-fiber.rb

# example for multi-fiber workers 

require "fiber"
require "eventmachine"

results = []
work = [:a, :b, :c]

EventMachine.run {
  Fiber.new do

    f = Fiber.current

    need = work.size
    work.each do |unit|
      Fiber.new do
        
        # simulate delay in query, etc
        EM.add_timer(0.5) do
          results << unit
          need -= 1

          p [:current, results]

          if need.zero?
            p [:finished, results]
            f.transfer
          end
        end
        
      end.resume
    end

    Fiber.yield
    p [:done, results]

    EventMachine.stop
  end.resume
}

# [:current, [:a]]
# [:current, [:a, :b]]
# [:current, [:a, :b, :c]]
# [:finished, [:a, :b, :c]]
# [:done, [:a, :b, :c]]