Re: [ patch ] async stuff fix(?) (was Re: 0.3 and async pre-fetch)

[Lars Magne Ingebrigtsen <larsi@ifi.uio.no>]

Sudish Joseph <sudish@mindspring.com> writes:

> There's only one shared variable: the queue tracking group/article
> pairs.  This variable has nice properties that make it easy to share.
> 
> a) It's a strict producer-consumer buffer with the very useful
> property of being unbounded (we look at a finite subset of the buffer
> at any given time, but that subset moves monotonically along the
> unbounded buffer).  This means that the thornier of the two issues
> requiring a lock in P-C problems is eliminated: we never have to check
> for overflow.  This leaves underflow.
> 
> b) The producer (gnus-async-prefetch-article) always stays a fixed
> number of items ahead of the consumer (*).  More importantly, the
> producer stops producing at a point when gnus-use-article-prefetch
> items are still left in the buffer.  So, underflow is trivially
> testable in the consumer w/o needing a lock.

Well, but all this isn't really an issue -- we don't have a general
producer/consumer situation.  We instead have an, uhm, link of actions
-- fetch, wait, fetch, wait, etc.  Sort of.  So you seem to be adding
complexity to a situation I thought was rather simple...

-- 
  "Yes.  The journey through the human heart 
     would have to wait until some other time."