ruby condition variable and broadcast

condvar_broadcast.rb

m   = Mutex.new
c   = ConditionVariable.new

tg  = ThreadGroup.new

t = 5.times.map do |n|
  tg.add(Thread.new do
    print "starting #{n}\n"
  
    m.synchronize do
      c.wait(m)
    end
    
    print "#{n} done!\n"
  end)
end

tg.list.count
# => 5

c.broadcast

tg.list.count
# => 0