class Concurrent::Synchronization::RbxLockableObject

def initialize(*defaults)
  super(*defaults)
  @__Waiters__ = []
  @__owner__   = nil
end

def ns_broadcast
  @__Waiters__.shift << true until @__Waiters__.empty?
  self
end

def ns_signal
  @__Waiters__.shift << true unless @__Waiters__.empty?
  self
end

def ns_wait(timeout = nil)
  wchan = Rubinius::Channel.new
  begin
    @__Waiters__.push wchan
    Rubinius.unlock(self)
    signaled = wchan.receive_timeout timeout
  ensure
    Rubinius.lock(self)
    if !signaled && !@__Waiters__.delete(wchan)
      # we timed out, but got signaled afterwards,
      # so pass that signal on to the next waiter
      @__Waiters__.shift << true unless @__Waiters__.empty?
    end
  end
  self
end

def synchronize(&block)
  if @__owner__ == Thread.current
    yield
  else
    result = nil
    Rubinius.synchronize(self) do
      begin
        @__owner__ = Thread.current
        result     = yield
      ensure
        @__owner__ = nil
      end
    end
    result
  end
end