Re: How can I build OSSP UUID support on Windows to avoid duplicate UUIDs?

: (

still don't know how to build ossp-uuid on windows with MSVC.
Saito san's patch doesn't fix all errors during compiling...

I will try to combine this patch and the win32build on sf.net

Same questions again:
How was the dll file in the community binary built?
How to avoid duplicate UUIDs then?

thanks a lot.

2013-11-05 2:49 GMT+08:00 Christopher Browne <cbbrowne(at)gmail(dot)com>:

> On Thu, Oct 31, 2013 at 3:42 PM, Robert Haas <robertmhaas(at)gmail(dot)com>
> wrote:
> > On Thu, Oct 31, 2013 at 2:44 PM, Garick Hamlin <ghamlin(at)isc(dot)upenn(dot)edu>
> wrote:
> >> I think using /dev/urandom directly would be surprising. At least it
> would
> >> have probably have taken me a while to figure out what was depleting the
> >> entropy pool here.
> >
> > Perhaps so; a bigger problem IMHO is that it's not portable. I think
> > the only way to solve this problem is to import (or have an option to
> > link with) a strong, sophisticated PRNG with much larger internal
> > state than pg_lrand48, which uses precisely 48 bits of internal state.
> > For this kind of thing, I'm fairly sure that we need something with
> > at least 128 bits of internal state (as wide as the random value we
> > want to generate) and I suspect it might be advantageous to have
> > something a whole lot wider, maybe a few kB.
>
> I mentioned the notion of building an entropy pool, into which one might
> add various sorts of random inputs, under separate cover...
>
> The last time I had need of a rather non-repeating RNG, I went with
> a Fibonacci-based one, namely Mersenne Twister...
>
> <http://en.wikipedia.org/wiki/Mersenne_twister>
>
> The sample has 624 integers (presumably that means 624x32 bits) as
> its internal state. Apparently not terribly suitable for cryptographic
> purposes,
> but definitely highly non-repetitive, which is what we're notably
> worried about for UUIDs.
> --
> When confronted by a difficult problem, solve it by reducing it to the
> question, "How would the Lone Ranger handle this?"
>

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