threadsafe?

threadsafe_array.rb

#!/usr/bin/env ruby

class Foo
  def initialize level
    @level = level
  end

  def decrease it
    @level[it] -= 1
  end

  def [] it
    @level[it]
  end
end

foo = Foo.new a: 1000, b: 200, c: 300

print 'Before: '
p foo

threads = []

100.times do
  threads << Thread.new do
    10.times do
      foo.decrease :a
    end

    puts "#{foo[:a]}\n"
  end
end

threads.each &:join

print 'After: '
p foo