Class: FiberPool

Inherits:
Object
  • Object
show all
Defined in:
lib/vendor/fiber_pool.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(count = 100) ⇒ FiberPool

Prepare a list of fibers that are able to run different blocks of code every time. Once a fiber is done with its block, it attempts to fetch another one from the queue



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# File 'lib/vendor/fiber_pool.rb', line 43

def initialize(count = 100)
  @fibers,@busy_fibers,@queue,@generic_callbacks = [],{},[],[]
  count.times do |i|
    fiber = Fiber.new do |block|
      loop do
        block.call

        # callbacks are called in a reverse order, much like c++ destructor
        Fiber.current[:callbacks].pop.call while Fiber.current[:callbacks].length > 0
        generic_callbacks.each do |cb|
          cb.call
        end

        if @queue.any?
          block = @queue.shift
        else
          @busy_fibers.delete(Fiber.current.object_id)
          @fibers.unshift Fiber.current
          block = Fiber.yield
        end

      end
    end
    fiber[:callbacks] = []
    fiber[:em_keys] = []
    @fibers << fiber
  end
end

Instance Attribute Details

#busy_fibers ⇒ Object (readonly)

Returns the value of attribute busy_fibers.



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# File 'lib/vendor/fiber_pool.rb', line 33

def busy_fibers
  @busy_fibers
end

#fibers ⇒ Object (readonly)

gives access to the currently free fibers



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# File 'lib/vendor/fiber_pool.rb', line 32

def fibers
  @fibers
end

#generic_callbacks ⇒ Object

Code can register a proc with this FiberPool to be called every time a Fiber is finished. Good for releasing resources like ActiveRecord database connections.



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# File 'lib/vendor/fiber_pool.rb', line 38

def generic_callbacks
  @generic_callbacks
end

Instance Method Details

#spawn(&block) ⇒ Object

If there is an available fiber use it, otherwise, leave it to linger in a queue



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# File 'lib/vendor/fiber_pool.rb', line 74

def spawn(&block)
  if fiber = @fibers.shift
    fiber[:callbacks] = []
    @busy_fibers[fiber.object_id] = fiber
    fiber.resume(block)
  else
    @queue << block
  end
  self # we are keen on hiding our queue
end