Re: [boost] Boost.Uuid and header-only support

Subject: Re: [boost] Boost.Uuid and header-only support
From: Peter Dimov (lists_at_[hidden])
Date: 2017-11-05 04:55:13

James E. King, III wrote:
> On Sat, Nov 4, 2017 at 10:59 PM, Peter Dimov via Boost 
> <boost_at_[hidden]> wrote:
>
> > James E. King, III wrote:
> >
> > Benchmark Times reusing a generator (1M loops):
> >>   old implementation:
> >>  0.021822s wall, 0.031250s user + 0.000000s system = 0.031250s CPU 
> >> (143.2%)
> >>   new implementation:
> >>  0.373160s wall, 0.375000s user + 0.000000s system = 0.375000s CPU 
> >> (100.5%)
> >>
> >> Benchmark Times using a new generator for each uuid (10K loops):
> >>   old implementation:
> >>  1.168479s wall, 1.171875s user + 0.000000s system = 1.171875s CPU 
> >> (100.3%)
> >>   new implementation:
> >>  0.010272s wall, 0.015625s user + 0.000000s system = 0.015625s CPU 
> >> (152.1%)
> >>
> >
> > These results look odd to me. What code exactly is being tested?
> >
> >
> I went over it a number of times to be sure, and stepped through with the 
> debugger to make sure it was actually going into the right code paths. 
> I'll have to recreate the test as a separate benchmark that I can submit 
> and build as part of the project.

I was confused by the first set using 1M loops, and the second one using 
only 10K. Didn't catch that at first, so the results didn't make any sense. 
Need to multiply the second test by 100 for the two to be comparable.

Have you tried RtlGenRandom by any chance?