Re: Dllist public/private part - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Dllist public/private part
Date
Msg-id 200307011903.h61J3p413869@candle.pha.pa.us
Whole thread Raw
In response to Re: Dllist public/private part  ("Mendola Gaetano" <mendola@bigfoot.com>)
List pgsql-hackers
Mendola Gaetano wrote:
> "Tom Lane" <tgl@sss.pgh.pa.us> wrote:
> > "Mendola Gaetano" <mendola@bigfoot.com> writes:
> > > I'm improving the Dllist in these direction:
> >
> > AFAIR, catcache.c is the *only* remaining backend customer for Dllist,
> > and so any improvement for Dllist that breaks catcache is hardly an
> > improvement, no?
> >
> > > 1) Avoid "if" statements in insertion/remove phase, for instance now the
> > > AddHeader appear like this:
> >
> > <shrug> ... unless you can convert DLAddHead into a inline macro,
> > I doubt there'll be any visible performance difference.
> > > 2) Not using a malloc but using a "special" malloc that not perform
> > >    a malloc for each request but do a BIG malloc at first request...
> >
> > It would make more sense to migrate Dllist to use palloc.  That's not
> > compatible with its use in frontend libpq; I've been speculating about
> > splitting off libpq to have a separate implementation instead of trying
> > to share code.  I believe libpq only uses Dllist for the
> > pending-notify-events list, for which the code is poorly optimized
> > anyway (we don't need a doubly-linked list for that).

I certainly would like to see Dllist removed too.

> This mean that is waste of time work on dllist.
> I seen that exist a TODO list about "features",
> exist a list about: "code to optimize" ?

What TODO item where you looking at? 

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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