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

[Toby Corkindale]

Perrin Harkins wrote:
> On Thu, 2006-06-22 at 14:01 -0500, Wade.Stuart at fallon.com wrote:
>> Or have the first hit after the expire set the expire time counter to the
>> next interval so the next hit does not even think to rebuild.  Then you can
>> also rebuild the cache to a temp name and overwrite the current cache when
>> it is complete.  This way to sleeping is required on long building pages
>> with many hits (they all just serve the old page until the new one
>> overwrites in an atomic write).
> 
> FYI, that's how Mason does it.

What is the behaviour for the first and second requests, before there is 
*any* cached content available?

tjc