[Catalyst] C::P::PageCache patch for reducing duplicate processing

[Wade.Stuart at fallon.com]

> Perrin Harkins wrote:
> > Toby Corkindale wrote:
> >> One of the aims of my patch is to avoid the expense of having numerous

> >> processes produce the same code simultaneously. So on the initial
bunch
> >> of requests, I'll still try and have the code delay all-but-one of
them
> >> from building the page.
> >
> > Presumably this only happens when a new cached page suddenly becomes
> > available and is instantly in high demand.  It's not very frequent.  In

> > my opinion, that isn't worth the danger of messing with something as
> > potentially troublesome as locks that block page generation, but I
> > suppose no one is forced to use the locking.
>
> Good point.
> I'll try and implement the features so they can be enabled separately.

I will second the "I don't think it is worth it" case.  99% of the time
caching is set at startup and the only time the case you are coding for is
hit is on the first page load if the second request comes in for the same
page before the page build is done from the first hit.  Seems like such an
outside case that I would be against all that extra locking an special case
code even if it is an option.