Re: [HACKERS] A design for amcheck heapam verification

Hi!

> 8 февр. 2018 г., в 22:45, Peter Geoghegan <pg(at)bowt(dot)ie> написал(а):
>
> On Thu, Feb 8, 2018 at 6:05 AM, Andrey Borodin <x4mmm(at)yandex-team(dot)ru> wrote:
>> I do not see a reason behind hashing the seed.
>
> It made some sense when I was XOR'ing it to mix. A uniform
> distribution of bits seemed desirable then, since random() won't use
> the most significant bit -- it generates random numbers in the range
> of 0 to 2^31-1. It does seem unnecessary now.
>
>> Also, I'd like to reformulate this paragraph. I understand what you want to say, but the sentence is incorrect.
>> + * The Bloom filter behaves non-deterministically when caller passes a random
>> + * seed value. This ensures that the same false positives will not occur from
>> + * one run to the next, which is useful to some callers.
>> Bloom filter behaves deterministically, but differently. This does not ensures any thing, but probably will give something with hight probability.
>
> I agree that that's unclear. I should probably cut it down, and say
> something like "caller can pass a random seed to make it unlikely that
> the same false positives will occur from one run to the next".

I've just flipped patch to WoA. But if above issues will be fixed I think that patch is ready for committer.

Best regards, Andrey Borodin.