class IO::Event::Selector::Select

@parameter events [Integer] The events to wait for.
@parameter io [IO] The IO object to wait on.
@parameter fiber [Fiber] The fiber that is waiting.

Wait for the given IO to become readable or writable.

def io_wait(fiber, io, events)
	waiter = @waiting[io] = Waiter.new(fiber, events, @waiting[io])
	
	@loop.transfer
ensure
	waiter&.invalidate
end