func selectnbsend(hchan chan<- any, elem *any) bool
func selectnbrecv(elem *any, hchan <-chan any) (bool, bool)

func selectsetpc(pc *uintptr)
func selectgo(cas0 *byte, order0 *byte, pc0 *uintptr, nsends int, nrecvs int, block bool) (int, bool)
func block()

func makeslice(typ *byte, len int, cap int) unsafe.Pointer
func makeslice64(typ *byte, len int64, cap int64) unsafe.Pointer