skiplist/access_barrier.go
func CompareBS(this, that unsafe.Pointer) int {
	thisItm := (*BarrierSession)(this)
	thatItm := (*BarrierSession)(that)

	return int(thisItm.seqno) - int(thatItm.seqno)
}
func CompareBS(this, that unsafe.Pointer) int {
	thisItm := (*BarrierSession)(this)
	thatItm := (*BarrierSession)(that)

	return int(thisItm.seqno) - int(thatItm.seqno)
}
// CompareBS is a barrier session comparator based on seqno