[Gnump3d-devel] Re: Idea for realtime tagcache updating

[Stuffed Crust]

On Sat, Mar 12, 2005 at 11:26:16AM +0000, Steve Kemp wrote:
> > Child discovers file is not in cache.  Parses out tags, appends them to 
> > CACHEFILE_NEW.  (using O_EXCL access to prevent other children from 
> > hitting the file and screwing us up concurrently).

To do an exclusive open, it looks like I'm going to have to use 
IO::Handle.  It was added to the core package set in perl 5.004, which I 
believe is reasonable to require, if it's not already so.

>   Checking for duplicates can be done when the HUP signal is received
>  so that multiple entries aren't added?  (Although I guess there is no
>  harm in it except for the size growth).

Yes, it's no big deal, as duplicates will just overwrite the previous 
entries, and the odds of two children hitting duplicate files 
simultaneously are pretty low, especially repeatedly.

>   I've tried to attack the problem using shared memory segments
>  a few times, but I can never get it to work as well as I think
>  it should :(

Given the potential size of the cache (>140 megs in my case) we'd be 
better off threading, IMO.

Anyway, I'm almost done with the patch.  Just a little more work (and 
the IO::Handle stuff) and it'll be ready for a spin.

 - Solomon
-- 
Solomon Peachy                                   ICQ: 1318344
Melbourne, FL                                    JID: address@hidden
Quidquid latine dictum sit, altum viditur

pgp7s_VgVAXrL.pgp
Description: PGP signature