Kijk mama! Ik heb een infinite loop gemaakt!

guarded.rb

# ...

  def sema_key; "stock-observer-semaphores"; end

  # make sure the stock off all coupled products is always equal
  def update_coupled_stock(stock)
    # get the current list of semaphores 
    semaphores = Rails.cache.read(sema_key) || [] 
 
    # when this stocks is already being updated, leave now 
    return if semaphores.include? stock.id 
 
    # update the list of semaphores 
    Rails.cache.write(sema_key, semaphores << stock.id ) 
 
    attributes = { 
      :stock  => stock.stock, 
      :min    => stock.min, 
      :max    => stock.max, 
      :active => stock.active 
    } 
     
    unless stock.coupled_stocks.empty? 
      stock.coupled_stocks.each do |coupled| 
        Rails.logger.info "Updating coupled stock: #{coupled.product}" 
        coupled.update_attributes( attributes ) 
      end 
    end 
     
    unless stock.coupled_to.nil? 
      stock.coupled_to.update_attributes( attributes ) 
    end 
 
    # now that we're done, the semaphore can be removed 
    semaphores = Rails.cache.read(sema_key) 
    semaphores.delete stock.id 
 
    # rewrite the list of semaphores 
    Rails.cache.write(sema_key, semaphores) 
  end

# ...

infinite_loop.rb

class StockObserver < ActiveRecord::Observer 
  observe :stock 

  # ...

  # make sure the stock off all coupled products is always equal
  def update_coupled_stock(stock)
    attributes = { 
      :stock  => stock.stock, 
      :min    => stock.min, 
      :max    => stock.max, 
      :active => stock.active 
    } 
     
    unless stock.coupled_stocks.empty? 
      stock.coupled_stocks.each do |coupled| 
        Rails.logger.info "Updating coupled stock: #{coupled.product}" 
        coupled.update_attributes( attributes ) 
      end 
    end 
     
    unless stock.coupled_to.nil? 
      stock.coupled_to.update_attributes( attributes ) 
    end
  end
end