Re: SSI patch version 14

On Tue, Feb 08, 2011 at 11:25:34AM +0200, Heikki Linnakangas wrote:
> On 08.02.2011 10:43, Kevin Grittner wrote:
> > I see that at least three BuildFarm critters don't have UINT64_MAX
> > defined.
> 
> I guess we'll have to just #define it ourselves. Or could we just pick 
> another magic value, do we actually rely on InvalidSerCommitSeqno being 
> higher than all other values anywhere?

As far as I know we don't specifically rely on that anywhere, and
indeed I did have it #defined to 1 at one point (with the other
constants adjusted to match) and I don't recall any problems. But given
that we most often use InvalidSerCommitSeqNo to mean "not committed
yet", it made more sense to set it to UINT64_MAX so that if a
comparison did sneak in it would do the right thing.

I did dust off a copy of the ANSI standard at the time, and it was
pretty explicit that UINT64_MAX is supposed to be defined in .
But that may just be a C99 requirement (I didn't have an older copy of
the standard), and it's obviously no guarantee that it actually is
defined.

Dan

-- 
Dan R. K. Ports              MIT CSAIL                http://drkp.net/