Gosu/fibers minimal fail

fibers.rb

# True fibers. WORKS!

require 'fiber'

class Fibers
  def initialize
    @fiber = Fiber.new do
      10.times do
        puts "hello"
        Fiber.yield
      end
    end
  end

  def update
    if @fiber.alive?
      @fiber.resume
      puts "bye"
    end
  end
end

w = Fibers.new
10.times do
  w.update
  sleep 0.01
end

gosu_fibers.rb

# Gosu using true fibers. FAILS!

require 'gosu'
require 'fiber'

class Window < Gosu::Window
  def initialize
    super(200, 200, false)
    @fiber = Fiber.new do
      10.times do
        puts "hello"
        Fiber.yield
      end
    end
  end
  def update
    if @fiber.alive?
      @fiber.resume
      puts "bye"
    end
  end
end

Window.new.show

gosu_thread_fibers.rb

# Gosu using threads acting like fibers. FAILS!

require 'gosu'
require 'thread'

Thread.abort_on_exception

class Window < Gosu::Window
  def initialize
    super(200, 200, false)
    @mutex = Mutex.new
    @cv = ConditionVariable.new
    @thread = Thread.new do     
      10.times do
        Thread.stop
        @mutex.synchronize do
          p Gosu::milliseconds         
          @cv.signal
        end      
      end
    end
    Thread.pass
  end

  def update
    if @thread.alive?
      @mutex.synchronize do
        @thread.run
        @cv.wait(@mutex)
        p "hello"
      end 
    else
      close
    end    
  end
end

Window.new.show

thread_fibers.rb

# Using threads acting like fibers (outside Gosu) - WORKS!

require 'thread'

Thread.abort_on_exception

class FakeFibers
  def initialize
    @cv = ConditionVariable.new
    @mutex = Mutex.new
    @thread = Thread.new do 
      p "Started"    
      10.times do
        Thread.stop
        @mutex.synchronize do
          p Gosu::milliseconds         
          @cv.signal
        end      
      end
    end
    Thread.pass
  end

  def update
    if @thread.status   
      @thread.wakeup  
      @mutex.synchronize do                     
        @cv.wait(@mutex)
        p "hello"
      end
    end    
  end
end

w = FakeFibers.new
20.times do
  w.update
  sleep 0.01
end