Pierre Phaneuf's Diary

wlach wrote an excellent article recently on how to use (and not use!) assertions properly, and it reminded me of some of my reflections on assertions and exceptions (warning: this is mostly written with C++ in mind, which does not have checked exceptions, no matter what you may think).

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So, don't go forward and assert, but rather, go forward and throw!

Seems like I'm now a senior something-or-other at Cypra Media, which did cause me a bit of grief. It's a "targeted marketing" company, meaning at the moment that they'll be sending out emails with ads in them to people who, weirdly enough, asked for it.

I would have liked maybe a bit more "completely new and different" maybe, and while they seem open-minded, they're not quite an actual free/open source software company, merely using a lot of it. But C++ and Perl are two of my favourites at the moment (mostly for their ratio of how much I can bend them to my will to how much they suck), and I think I might be in for learning some AJAXy JavaScript hackery in the process, which I've been meaning to do for a while, so that's that. They're Scrum fans there, which is better than being, say, RUP! Still, I'm more of a chaos model type of person, myself. We'll see, I want to try Scrum first, as it doesn't look completely nuts.

So I'll be starting there as soon as tomorrow!

I'm in a weird headspace these days. This is the first time I'm unemployed in, what, ten years? Totalling about four jobless months since I dropped out of school (which was no big loss!), and it was willingly both times, once again to move to Montreal. I'm being a bit of a homebody, which is not that different from my year in France (yes, I'd go to work, but that'd be almost all I'd go out for), but this time I'm not depressed, I'm just, you know, at home. Rather relaxing, I must admit, but better not over-extend this!

I went out photo-walking with jul3z last Saturday, which was quite nice. I had nearly zero inspiration for photos for a long time now, and coming back to Montreal, I've had it coming back to me, but seems like I was never carrying my camera at the right times (despite carrying it around a good deal, doh!). We went along the Lachine Canal toward the Old Port, and while it was a good time chatting along with her, mid-day sun and my self-imposed restricting myself to my 28mm/f1.8 didn't make for anything great, I feel, but it was nice pushing myself a bit, and I did spot a few places that could make very interesting photos with better light (by the way, jul3z, here's that chain that's gone missing!).

We then watched Stranger Than Fiction, which I had seen bits and pieces of on the flight from Casablanca to Montreal. To start off, it has a nice casting, with Will Ferrell (but it's not a Will Ferrell movie at all), Maggie Gyllenhaal, Dustin Hoffman and Emma Thompson, and they did great job of giving some texture to the characters without being too blatant about it. For example, tiny details like Hoffman's character pouring himself some coffee at the start of a conversation, then as it ends, pouring back the content of his mug back into the coffee pot just had be imagine the lifecycle of his coffee, and what it must taste like at the end of the day. The subject is also one that I like, that of finding purpose and meaning in life, but it wasn't some overly cheesy grand meaning either, it was just the same kind of "ordinary" meaningfulness that I experience often, of appreciating what you have and being happy.

gregorama is right, girls in Montreal are a severe whiplash hazard! (hey, the subject says "random item", you were warned!)

The geeky type can find some dynamic language humour (Perl hackers know that there is indeed such a thing!) involving the Visigoths (that, the Perl hackers might not have known, but they probably suspected) here.

I boggle at how much attention to details Apple has sometimes, and how they manage to instil this attitude to their developer community. While I had previously noticed that, for some reason, moving around word by word in the location bar of my browser using the Control and arrow keys worked in a nicer way in Camino than it did in Firefox, where they use a slightly different set of delimiter characters, and they put the cursor in a different place depending on the direction you're going, avoiding the cases where you get just one character off of where you want to go (say, over a dot or a slash). But I just noticed that while double-clicking on a word selects that word, if you hit the Delete key, it deletes the word and the preceding space. Selecting character by character doesn't "discover" that you stopped at word boundaries, though. Oh well, for all I know, it's going to be in Leopard.

I'm probably one of very few people to be excited by what's coming in C++0x, especially as my top peeve about C++ templates seems to be fixed. One of my big use for template-based meta-programming was to detect errors at compile-time, but providing readable compile-time error messages is currently impossible (my error "messages" are often things like "variable YOU_FORGOT_TO_DO_THIS_THING does not exist", surrounded by a huge chunk of useless, unrelated context). Of course, actual lambda (even though Boost has a really neat hack to do it now) and type inference are very nice to have too. The latter will certainly help cut down on the amount of "foo<bar, baz>::const_iterator it = bob.begin()" typing I'll be doing, as it will now just be "auto it = bob.begin()"! My wrists thank the C++ language committee.

It seems one of my ideas has been picked up by some people in Waterloo, in the form of AideRSS. Now, I want an "Edit" button in the Firefox toolbar that would use AtomPub, okay?

I've been lagging behind in a lot of things (sorry if you've sent me mail and are still waiting for a reply!), but I think it's been good for me.

The day after we arrived, I managed to catch serendipity_wpg's last show on the Fringe, where I met wlach, cpirate and scjody, without anything being scheduled. After a choriço poutine at Mondo Fritz, I even crossed pzion on the way home. This was pretty cool, for a first day out, having such nice random encounters even in a city of three million people!

After getting all my money turned into Canadian currency, I tried to pick myself a nice Linksys WRTSL54GS, to hook ourselves up with some wireless Internet (with some hackability in mind!), to no avail. I ran into the WRT350N the next day, which seems to be the replacement model (had some issues with it at first, but it works perfectly for me once I restricted it to "b" and "g" wireless).

I also went for a drink with azrhey, cpirate, liberation_now and tygrbabe, which had me somewhat fiddly, but (of course!) proved to be quite enjoyable.

There was a visit by sps, swestrup and taxlady, where Settlers of Catan was played and I was soundly beaten to a pulp. I had cheese curds to console myself, which I was missing terribly!

I saw some of my old gang from cégep, where Mare Nostrum was played and I almost won, but Brain won finally. The usual...

I got myself some new shoes, which I find pretty nifty, but I then had the very silly idea of going for a walk before going to lab-synthèse-01. Going for a walk with new shoes, gah. I had soft ice cream to console myself. I had to leave before lautreamax got on, due to logistical constraints (also known as "living way the hell over there"), but I did catch (and enjoy!) his co-conspirator's set. More electronic music, more!

And today, we went downtown where I chatted with people for a bit while sipping coffee, walked around lazily and managed to randomly catch a 60% off deal on memory for my laptop at Compusmart's closing sale. Now writing this sitting on the lawn of the Place-des-Arts, from a spot in the shade, taking it easy with the Jazz Fest in the background... Nice!

As it turns out, this year's change in the implementation of daylight "savings" ended up not saving anything, and actually just causing extra annoyance. The US Congress seems completely taken by surprise by the fact that changing the time does not magically create more sunlight. That extra hour in the evening, scientists and the Department of Energy reminds them, is actually offset by an hour less in the morning! Imagine that!

Seems like there is not even a measurable energy savings. If anything, the biggest impact of the daylight savings change is that a bunch of computerized gadgets needed to be updated, and people with their Blackberry and Palm not being sure if the time was adjusted (some changed the time manually, only to have it change by another at the old switch-over date, for example).

Down with daylight savings! End the madness!

OMG, I so want one of these!

lkcl posted a reply to my previous post...

Oh, lkcl, you're a bit of a pessimistic, there. unlink is also atomic, not just rename. ;-)

But what I'm looking after right now isn't just a general message-passing operation (I already do that at a higher level, between various subsystems, using shared memory for local or sockets for remote recipients), more specifically the best way to take advantage of multiple cores as much as possible to process file descriptor events.

You have to cut the libc people some slack, though, they don't have locks around every single functions. I'd be amazingly appalled if strncmp() took a lock, for example! And as I described, I already used processes and shared-memory for higher-level concurrency, this threading is only for the very lowest level, when I have no choice and I'm pushed to the edge. Note that the code is already written as a state machines, using the threads to run more than one state machine at once (there is one state machine per connection or so, more or less). I'm planning on having a lock on the state machine instance, so that a single state machine cannot be executed on more than one thread at once, so that the code inside of it can make that assumption (that still allows me to handle multiple independent connections at once).

On Linux, epoll already does that in an atomic way, for me, in its edge-triggered mode. You can just have multiple threads call epoll_wait(), a given event will be sent to only one thread, until it is re-armed. But the specific requirement here is "compatibility layer for portability to other POSIX platforms", hence the use of crummy old select(). Of course, if I need high-load scalability on some big iron, I'll be sure to not use that layer, and go for epoll, kqueue() or something like that!

That said, I'd like a link to that message-passing work, it sounds interesting.

Here's the challenge: a select()-based event dispatcher that can scale from single-threaded to multi-threaded efficiently, preferably as simple as possible and able to be effectively edge-triggered (even if select() itself is level-triggered).

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Anyone has suggestions for improvements? They are most welcome!

We drank cheap sparkling wine the other day. When I say cheap, I mean 0.87 euro for a bottle. That's 1.34 CAD at the current rate.

I am also hacking on a modern C++ implementation of property lists. I am also getting rather hooked by some aspects of Boost. The binder is astonishingly clever and asio looks very promising. I'm also told their boost::function does not use a virtual method (unlike my attempt, WvCallback), which I'll have to look into.

No, there is no relation between the drinking and the hacking. :-P

Okay, so I'm not writing a music player (yet). One could say my "faith" has weakened, where I am taking the opportunity of a re-ripping of my music library to switch from Ogg Vorbis to MP3. Yeah, yeah, I know, I'm a terrible human being, my soul will burn and everything.

A quick reminder on why MP3 is evil and how Ogg Vorbis will save your eternal soul: Thomson holds some patents on key technologies involved in the MP3 format, those technologies being in the form of mathematical concepts. Some people find the patenting of such intangible things to be stifling innovation, that many these concepts are inherent in nature, and that as such, anyone should be free to use them (some comparing this to patenting something like the Pythagorean theorem, as an algorithm to find the length of the hypothenuse of a right triangle).

After some soul searching, I feel that while this is true to some degree, it is not the most evil aspect of software patents. My issues with software patents are two-fold.

First, the way the process of obtaining those patents seems rather sketchy at best, quite regularly granting completely frivolous patents. Upon application, those often get overturned, but still, this costs money, and if I were to be sued over one, I would most likely be in deep financial trouble, no matter how frivolous the patent. In the case of MP3, I do not feel this is one of those, the thing being filled with psychoaccoustics, modified cosine transforms, polyphase quadrature filter, alias reduction formulas, and other such things guaranteed to give me a headache. These guys are no fly-by-night lawyers trying to make a quick buck, from what I can see.

Second, the duration of patents, for a low cost/revenue ratio industry (like software, as opposed to cars, which are expensive to manufacture) anyway, is quite excessive, in these days of rapid technological advances. Maybe that, yes, Pythagoras should have been granted a patent for his theorem, but the question is how soon should it have expired? Again, in the case of MP3, the oldest reference to those technologies I could find (didn't check very thoroughly!) was around 1986, which isn't shockingly old, but in terms of technology, is starting to get a little dated. I'd say that a 15-20 years expiration on that kind of patent wouldn't be too ridiculous either way, and I'm sure smart inventors would manage to make quite a bit of money in even less time.

So, in short, I'm not technically against software patents, but more against the way they are implemented right now. I suppose I also dislike the way some patent holders keep quiet about their portfolio, until everyone is using the technology, at which point they helpfully point out that every bloody living organism owes them money. Those make me angry.

In any case, for most users, patents are a bit immaterial, it's mostly for developers (especially of free software). It inflates the cost of their iPod by a few dollars, but they can't really tell the difference between that and the rest of the cost.

What's material to people right now, though is DRM, the so-called "digital rights management". Ensuring your rights are properly limited and constrained, that the rights of the poor media corporations aren't being trampled on by nasty people that want to listen or watch the content they lawfully paid for (pesky, those people!).

It's too bad this isn't being done with the arguably superior Ogg Vorbis, but compared to many of the other choices, MP3 is the choice with more freedom, compared to the PlaysForSure and FairPlays of the world. Pirates aren't being stopped, honest people get screwed and I forgot my point.