On 08/28/2013 09:13 AM, Peter Levart wrote:
It seems that the iteration can traverse through the same tables multiple times (back and forth) by following ForwardingNode.nextTable links. Aren't nextTable links supposed to be only in "forward" direction, leading to from smaller to larger tables?
They aren't required to be -- to preserve nonblockingness of traversal, they can revert to old versions of table. This is legal but disconcerting and surprising. I now think that giving up on pure non-blockingness (only in the case of concurrent resizes) and helping to transfer (which can block), thus forcing monotonicity, is a better policy. An update is forthcoming. (Thanks to Paul for finding a use case leading to this better policy!) -Doug
