class Async::Reactor

def block(blocker, timeout)
	fiber = Fiber.current
	
	if timeout
		timer = @timers.after(timeout) do
			if fiber.alive?
				fiber.resume(false)
			end
		end
	end
	
	begin
		@blocked += 1
		Fiber.yield
	ensure
		@blocked -= 1
	end
ensure
	timer&.cancel
end