The unifying principle of this book is:
Everything costs something. Everything worth talking about has benefits. Nothing is free; nothing has infinite value.
This sounds very simple and unobjectionable, but experience shows people have a hard time putting it into practice and realizing how pervasive the principle is.
I wanted to file this away in my blog where I can find it easily in the future: The Problem with Threads, a rather sedate name for an article that end up calling them insane.... and pretty much meaning it wholeheartedly.
I think in coming years this will come to be considered one of the seminal papers in software engineering, if it isn't already. The topic has been covered before, elsewhere, but I don't know of any other single work that demolishes threads as thoroughly and undeniably as this.
The programmer certification debate seems never ending and I usually never like the arguments in favor of it... but I could totally get behind this certification, a certification largely based on testing and quality control, with some other related concepts. Like the author, I probably couldn't immediately pass either, but I've gotten far enough to know how important it is.
IM IN YR LOOP, INCRMENTNG YR VRS
(OK, as a bone to my non-programming readers, consider the natural evolution of pet pictures on the web. It actually seems to have a consistent, emergent grammar. It doesn't meet the technical requirements of a Pidgin language, but it bears a certain resemblance; call it a faked pidgin. Gaim (open source IM client) recently renamed itself to Pidgin, and despite using a pigeon as a logo, pidgin is where the name came from. IM servers are what I will be working on in my new job starting Wednesday. That stream of conciousness ought to keep you busy clickin' some links even if you don't care about me being in your loop and incrementing your variables.)
I want to be clear about my purpose here. My point is not to claim that the uniqueness of programming is itself unique. Every interesting field is unique in its own special way. For each field, it is helpful to understand why it is unique if you wish to truly excel, or you may bring inappropriate concepts from other domains in, or export inappropriate programming concepts to other domains. I say that programming has several unique aspects and that these aspects are worth thinking about, but this does not mean that programming is privileged somehow.
The most common complaint about software is that it is "too buggy". The question is, "What does too buggy mean?" People making this complaint are often holding software to absurdly high standards, even when making comparisions to other engineering disciplines. In fact, bridges do fall down. Architects fail; often the designs can be seen to fail and corrected or maintained before catastrophic collapse, but it happens. Software is no more likely to be absolutely perfect than any other human endeavor.
Software is an engineering concern, and one of the things that means is that you can't have anything for free. If faced with the choice between a $100 piece of buggy or incomplete software, and a $50,000 piece of production-quality bullet-proof highly-tested quality software, it's unfair to complain that the $100 piece of software is buggy and incomplete.
Some guy took a crack at answering that question. Or more accurately, he claimed to take a crack at it; he never actually got around to answering it. It occurred to me the questioner does have a point, though.
What is computer science, anyhow?
In my continuing series on why software is special, motivating writing a book about it, this post discusses how software is chaotic.
Here I refer to the mathematical definition of chaos, which I will define as: "A chaotic system is one in which small changes in the initial conditions can cause large and unpredictable changes in the system's iterated state." This is based on the mathematical definition(s), but simplified for our purposes. It's not just a word, it's a quasi-formal concept.
In 2007, with a well-loaded Linux desktop installation, my /usr/bin is 257 megabytes, with debugging off and dynamically-linked libraries not contributing to that count. My particular copy of the Linux kernel 2.6.19 with certain Gentoo patches has 202,381,268 bytes of C code alone. If I'm computing this correctly, at a constant 100 words per minute (5 chars/word), that's 281 24-hour days just to re-type the C code in the kernel.
I've gone on before about how distrustful of metaphors I am, and it seems like every year I'm getting more distrustful of them. Either deal with the thing as it is, or just give up understanding it. Metaphors lead to the beginning of understanding, but no farther.
Programmers aren't immune to the metaphor sickness, and if there's one metaphor you can expect to see trotted out at the earliest available opportunity, it's the "programming as construction" metaphor. This metaphor has been skillfully deconstructed many many times before, but I'm going to deconstruct it from the opposite angle... what if construction was like software engineering?