#==============================================================================
# ** Drago - Replicated Fiber
# Version : 1.01
# Author : LiTTleDRAgo
#==============================================================================

($imported ||= {})[:drg_replicated_fiber] = 1.01
#==============================================================================
# ** Fiber
#------------------------------------------------------------------------------
#  
#==============================================================================
unless defined?(Fiber)
  class Fiber
    #-------------------------------------------------------------------------
    # * New method: initialize
    #-------------------------------------------------------------------------
    def initialize
      block_given? || raise(ArgumentError,'new Fiber requires a block')
      @yield  = Queue.new
      @resume = Queue.new
      @thread = Thread.new { @yield.push [yield(*@resume.pop)] }
      @thread.abort_on_exception = true
      @thread[:fiber] = self
    end
    #-------------------------------------------------------------------------
    # * New method: self.current
    #-------------------------------------------------------------------------
    def self.current
      Thread.current[:fiber] || raise(FiberError,'not inside a fiber',caller(1))
    end
    #-------------------------------------------------------------------------
    # * New method: self.yield
    #-------------------------------------------------------------------------
    def self.yield(*args)
      (fiber = Thread.current[:fiber]) || (raise "can't yield from root fiber")
      fiber.yield(*args)
    end
    #-------------------------------------------------------------------------
    # * New method: inspect
    #-------------------------------------------------------------------------
    def inspect
      "#<#{self.class}:0x#{self.object_id.to_s(16)}>"
    end
    #-------------------------------------------------------------------------
    # * New method: resume
    #-------------------------------------------------------------------------
    def resume(*args)
      alive? || raise(FiberError,'dead fiber called',caller(1))
      @resume.push(args)
      result = @yield.pop
      result.size > 1 ? result : result.first
    end
    #-------------------------------------------------------------------------
    # * New method: alive?
    #-------------------------------------------------------------------------
    def alive?
      @thread.alive? 
    end
    #-------------------------------------------------------------------------
    # * New method: yield
    #-------------------------------------------------------------------------
    def yield(*args)
      @yield.push(args)
      result = @resume.pop
      result.size > 1 ? result : result.first
    end
  end
end

#==============================================================================
# ** Queue
#------------------------------------------------------------------------------
#  
#==============================================================================
unless defined?(Queue)
  class Queue
    #-------------------------------------------------------------------------
    # * New method: initialize
    #-------------------------------------------------------------------------
    def initialize
      (@que     ||= []).taint 
      (@waiting ||= []).taint # enable tainted comunication
      self.taint
    end
    #-------------------------------------------------------------------------
    # * New method: clear
    #-------------------------------------------------------------------------
    def clear
      @que.clear
    end
    #-------------------------------------------------------------------------
    # * New method: empty?
    #-------------------------------------------------------------------------
    def empty?
      @que.empty?
    end
    #-------------------------------------------------------------------------
    # * New method: length
    #-------------------------------------------------------------------------
    def length
      @que.length
    end
    #-------------------------------------------------------------------------
    # * New method: num_waiting
    #-------------------------------------------------------------------------
    def num_waiting
      @waiting.size
    end
    #-------------------------------------------------------------------------
    # * New method: pop
    #-------------------------------------------------------------------------
    def pop(non_block=false)
      while (Thread.critical = true; @que.empty?)
        non_block && raise(ThreadError,"queue empty",caller(1))
        @waiting.push(Thread.current)
        Thread.stop
      end
      @que.shift
    ensure
      Thread.critical = false
    end
    #-------------------------------------------------------------------------
    # * New method: push
    #-------------------------------------------------------------------------
    def push(obj)
      Thread.critical = true
      @que.push obj
      begin
        t = @waiting.shift
        t && t.wakeup
      rescue ThreadError
        retry
      ensure
        Thread.critical = false
      end
      begin
        t && t.run 
      rescue ThreadError
      end
    end
    #-------------------------------------------------------------------------
    # * Alias Listing
    #-------------------------------------------------------------------------
    method_defined?(:size)  || (alias_method :size,  :length)
    method_defined?(:shift) || (alias_method :shift, :pop)
    method_defined?(:deq)   || (alias_method :deq,   :pop)
    method_defined?(:"<<")  || (alias_method :"<<",  :push)
    method_defined?(:enq)   || (alias_method :enq,   :push)
  end
end

#==============================================================================
# ** FiberError
#------------------------------------------------------------------------------
#  
#==============================================================================
defined?(FiberError) || (class FiberError < StandardError ; end)