Notes and Jottings

“Doc Searls”:http://doc.weblogs.com/ is just across the canal in the Old Schoolhouse. How handy is that I’m off to say hi now (and probably to stay for a few drinks too).

Pointed to by “Dave”:http://www.maths.tcd.ie/~dwmalone/.

“H4×0r Economist”:http://www.rdwarf.com/~kioh/ — the weirdest site you’ll see today! I’m not sure if I actually enjoy it, but it’s fascinatingly _different_… 4ll h41l 4l4n Gr33nspun!

The IPR Enforcement Directive “was passed yesterday”:http://plone.ffii.org/events/2004/ipred/, in large part due to the championing of the Irish delegation during the term of our presidency.

Well I said it before (when they were trying to get it passed), but I’ll say it again **really loudly** that I cannot possibly vote for Fianna Fáil or the Progressive Democrats after what was done here. As the parties responsible for pushing this through, over the wishes of the EU parliament, they deserve the disgust of all people associated with the computer industry in Europe.

For many reasons, which have been discussed by people over the years, this is _not_ just a free software issue. For any SME which does not have the funds or resources to acquire/create patents, the whole software sphere could eventually be closed off. Any reasonable thinker in the industry fears a future where any reasonably useful product in the market *has* to infringe on many patents just to work, with almost no way to work around them. I haven’t seen the term of patents in Europe yet, but if software patents last for 20 years, like in the US, then it is also a completely inappropriate length of time for the environment.

Not to mention submarine patents (such as the discrete cosine stuff being bandied around by Forgent at the moment). The creator of the software patents waived royalties, and JPEG became a standard. But the company was sold, and the new company decided to renege on that promise–this feels like the future of the industry, and it doesn’t feel good.

Canvassing begins at work.

The “Trinity Ball”:http://www.trinity-ball.tcd.ie/ takes place on Friday 7 May, in the environs of Trinity College Dublin. Once again many women don high heels and risk life and limb on those fabled cobblestones. Am I going? Depends on how many people I know who are going. I think I know enough people going… if I include the definites and the maybes. Definitely more maybes at the moment! The Divine Comedy are good, I’m sure they won’t say no in the end!

Aaagh–what am I going to do? I sold my camera! No fabulous photos of the night. Though, thinking about it, maybe it’s for the best. How my camera never got stolen or destroyed on previous nights out is a complete mystery…

According to “Kathryn Cramer”:http://www.kathryncramer.com/wblog/archives/000530.html, Shahriar S. Afshar (a physicist from Harvard) has implemented a variant of the two-pin-hole test which appears to invalidates the two most popular ways of interpreting quantum mechanics in a real-world way (those being the Copenhagen Interpretation and the Many-Worlds Interpretation). Kathryn points out that her father’s theory, “Transactional Interpretation”:http://mist.npl.washington.edu/npl/int_rep/tiqm/TI_toc.html, may be the only current theory which survives the experiment. I wait with interest for further comments from the Physics community.

Must stop posting about algorithm-y stuff… but one more.

I found some interesting reading at the weekend about implementing structures in shared memory, so as to minimise locking requirements. I’m not looking for lock-free solutions, that is just slightly like overkill. But locking a shared data structure over a long-lived operation is a no-no, and it *does* happen.

The most promising approach is to modify the list (or other data structure) in a certain way, so that new iterators of the list will see the new structure, whereas it is possible for old iterators to see the old structure; links from the old structure to the new structure remain valid for the lifetime of the old iterators. The only even remotely challenging part of this is implementing an efficient way to work out what that lifetime is (so that deleted nodes can be safely freed). Sometimes Java people have it easy No data lifetime problems when you’re using a garbage collector…

Many thanks to “Paul”:http://matrix.netsoc.tcd.ie/~paul/ for pointing out skip lists as an alternative to b-tree implementations like AVL trees. Much less complexity in programming, and similar performance in the normal case to highly tuned AVL algorithms. Skip lists were developed relatively recently (a paper was presented to the ACM in 1990) by “William Pugh”:http://www.cs.umd.edu/~pugh/. I’ll have to actually implement a version of this in a real product (again, by replacing a linked list structure) and see what happens
The next frontier after that is text indexing. “Modern Information Retrieval”:http://www.amazon.com/exec/obidos/tg/detail/-/020139829X/qid=1082639150/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/103-9422780-4738264?v=glance&s=books&n=507846 seems like just the ticket for a good introduction to the area. I’ve also been reading some articles about inversions and text signatures in “Citeseer”:http://citeseer.ist.psu.edu/ (which is an amazingly useful resource for this kind of research).

Maybe some day I’ll be given some time in my day job to work at this For the moment, it’s mostly limited to some investigative reading during lunchtime and at weekends.

Selling my camera - Sony DSC-F717. Spare battery, 1×128M memorystick, 1×64M memorystick. The camera itself costs €900 right now in the (Irish) shops (used to be €1600 when I bought it). The other extras are worth at least €250.

How much should I ask for them? Anybody interested? And what’s the best place to put it up for sale - boards.ie? buyandsell.ie?

“Douglas Bowman”:http://www.stopdesign.com/log/2004/04/15/page23.html told me to:

# Grab the nearest book.
# Open the book to page 23.
# Find the fifth sentence.
# Post the text of the sentence in your journal along with these instructions.

The nearest book: “Peril’s Gate”:http://www.amazon.com/exec/obidos/tg/detail/-/0061054674/qid=1082070738/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/103-3338538-2697442?v=glance&s=books&n=507846 by Janny Wurts:

bq. Why else should you contrive your passage of the Wheel while I was diverted by the pretense of proving my worth?

The next nearest book, “Linux Kernel Development”:http://www.amazon.com/exec/obidos/tg/detail/-/0672325128/qid=1082070783/sr=1-1/ref=sr_1_1/103-3338538-2697442?v=glance&s=books by Robert Love, would have said the following (but it, of course, doesn’t count for the purposes of this game):

bq. The only overhead incurred by fork() is the duplication of the parent’s page tables and the creation of a unique process descriptor for the child.

Hello everybody! I will try and be more available to posts and discussion (if any) and suchlike here. Ahem. What will I talk about on this fine (and wine-filled) evening?

Firstly, when Debian GNU/Linux checks an ext3 partition, why does it say “check after next mount” on *every* boot?

Secondly, udev, hald, hotplug, g-v-m form a very dynamic foursome in the quest for a usable desktop. You can get some of those from Debian unstable, some from Debian experimental; the combination as a whole gives a feeling of a nicely designed system that will *work* in the future.

Thirdly, I’m sure everybody knows that totem is the up-and-coming GNOME app for viewing multimedia (DivX, DVDs, VCDs, etc.). It’s a very well designed program which beats almost everything else available for the GNOME platform into non-existence. What some people may not be aware of is muine. It’s a competitor with rhythmbox as a sound organiser/player (MP3, Ogg, FLAC, WAV, etc.), but it just feels *right* as a UI. Try it out. It’ll require fairly recent Mono packages, as well as gtk-sharp. But it’s worth installing and running.

Fourthly, the US president seems to have made a right muck-up of his speech/conference on prime time TV yesterday. Yay
Fifthly, what the hell does the Irish government think they’re doing, trying to get a really restrictive software patenting regime installed in the EU??? This is the #1 thing which might make me consider never voting for Fianna Fail again. Yeah, that’s a selfish reason for choosing why to vote for a party or not. But really, it does emphasize their stupidity to a degree which wasn’t quite as clear before. Bah.