//
	// Protected by lock.
	fault []liveUserArenaChunk
}

// userArenaNextFree reserves space in the user arena for an item of the specified
// type. If cap is not -1, this is for an array of cap elements of type t.
func (s *mspan) userArenaNextFree(typ *_type, cap int) unsafe.Pointer {
	size := typ.Size_
	if cap > 0 {
		if size > ^uintptr(0)/uintptr(cap) {
			// Overflow.