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Postings from October 2012
On Mon, Oct 29, 2012 at 06:55:21PM +0100, demerphq wrote: > I propose that in 5.18 we should finally take the plunge and switch to > a fully randomized hash seed and eliminate the rehash mechanism. I > have patches which do this ready, and for the cpan/ modules involved > I have pushed patches upstream to get the hash order dependencies > removed. > > Besides the advantages of avoiding the costs of the rehash mechanism > this change will smoke out any hash order dependency bugs in the > modules on CPAN, and in our own code. (I found at least two unrelated > bugs in code in core due to hash randomization.) It will also prepare > the ground for people to choose alternative hash algorithms for Perl > to use, or to make it possible to use specialized hash algorithms in > certain contexts such as 64 bit builds. > > The downside however will be that it almost certainly will make lots > of lazily written code to fail. But IMO the cost is worth it. > +1. I have been looking at achieving this *somehow* for a while now, at least to run on smokers. I even wrote some code with the help of [Tux], but never brought it to the list, as it seemed to kludgy. It never occured to me to take the approach you present - simple quick and elegant. As a data point - perl 5.8.1 is the only perl which actually behaves the way you propose (5.8.0 didn't randomize, and 5.8.2 got the rehash bit added). Since all my CPAN code supports 5.8.1, I had the ability of running my tests with a random seed. My experience wrt how many silly errors this catches mirrors yours. So yes please! CheersThread Previous | Thread Next