Starting point for parallel Ruby conversations

smores.rb

# frozen_string_literal: true

# problem code from Graceful.dev: https://graceful.dev/courses/tapastry/modules/2019/topic/full-utilization/
$tick = 0

def work(seconds)
  $tick += seconds
end

def log(message)
  puts "%3d: %s" % [$tick, message]
end

class Smore
  attr_accessor :started_at, :finished_at
  attr_reader   :camper

  def initialize(camper)
    @camper      = camper
    @started_at  = started_at
    @finished_at = finished_at
  end

  def wait
    finished_at - started_at
  end

  def to_s
    @camper
  end
end

class MarshmallowWrangler
  def start(smore)
    fail "I'm busy!" unless @ready_at.to_i <= $tick
    @ready_at = $tick + 20
    smore.started_at = $tick
  end

  def finish(smore)
    log("A marshmallow is ready for #{smore.camper}") 
  end
end

class Toaster
  def start(smore)
    fail "I'm busy!" unless @ready_at.to_i <= $tick
    @ready_at = $tick + 60
  end

  def finish(smore)
    log("A marshmallow is toasty warm for #{smore}")
  end
end

class Assembler
  def start(smore)
    fail "I'm busy!" unless @ready_at.to_i <= $tick
    @ready_at = $tick + 30
  end

  def finish(smore)
    smore.finished_at = $tick
    log("Your s'more is ready, #{smore}!")
  end
end

wrangler     = MarshmallowWrangler.new
toaster      = Toaster.new
assembler    = Assembler.new

smore_orders = ["Kashti", "Ebba", "Ylva"]
smores       = smore_orders.map { |camper| Smore.new(camper) }

puts "*"*50 + "non-ractor version start"
wrangler.start(smores[0])
work(20)
wrangler.finish(smores[0])
puts "*"*50 + "non-ractor version end"
# wrangler.start(smores[1])
# toaster.start(smores[0])
# work(20)
# wrangler.finish(smores[1])
# wrangler.start(smores[2])
# work(20)
# wrangler.finish(smores[2])
# work(20) # 80
# toaster.finish(smores[0])
# toaster.start(smores[1])
# assembler.start(smores[0])
# work(30) # 110
# assembler.finish(smores[0])
# work(30) # 140
# toaster.finish(smores[1])
# toaster.start(smores[2])
# assembler.start(smores[1])
# work(30) # 170 
# assembler.finish(smores[1])
# work(30) # 200
# toaster.finish(smores[2])
# assembler.start(smores[2])
# work(30) # 230
# assembler.finish(smores[2])

# example of Ractors from https://blog.appsignal.com/2022/08/24/an-introduction-to-ractors-in-ruby.html
# How do Ractors help? how can we call wrangler from a Ractor?

#supermarket = Ractor.new do
#  loop do
#    order = Ractor.receive
#    puts "The supermarket is preparing #{order}"
#    Ractor.yield "This is #{order}"
#  end
#end
#
#customers = 5.times.map{ |i|
# .pass supermarket ractor and index to the customer ractor
#  Ractor.new(supermarket, i) do |supermarket, i|
#    supermarket.send("a pack of sugar for customer #{i}")
#    fulfilled_order = supermarket.take
#    puts "#{fulfilled_order} received by customer #{i}"
#  end
#}