func runtime_pollWait(ctx uintptr, mode int) int
func runtime_pollWaitCanceled(ctx uintptr, mode int)
func runtime_pollReset(ctx uintptr, mode int) int
func runtime_pollSetDeadline(ctx uintptr, d int64, mode int)
func runtime_pollUnblock(ctx uintptr)
func runtime_isPollServerDescriptor(fd uintptr) bool

type pollDesc struct {
	runtimeCtx uintptr
}

var serverInit sync.Once

func (pd *pollDesc) init(fd *FD) error {