Modify the algorithm that allocates a file descriptor for the open() and socket() calls. Implement a per-process variable availableFileDescriptor whose value is always the number of the first available file descriptor. Make sure that when a process closes a file descriptor and or a socket, availableFileDescriptor is properly updated. Use your driver harness to compare the performance of your modified kernel with the original kernel, both for situations in which the original algorithm should work fast and situations in which the original algorithm should not work fast. You might want to remove the restrictions in the kernel on the setrlimit(RLIMIT_NOFILE,...) call.

I banged around on that thing for almost two weeks, variously getting a modified kernel that would a) segfault immediately, b) fail to reach the login prompt and just kind of hang out, or c) reach the login prompt but fail to allow me to log in. Turned out one of my main problems was that the sorting function I was using, an implementation of merge sort that I had found posted on a Linux kernel mailing list, was eating my nodes instead of just sorting them. It would delete one at a time in a sneaky fashion. I thought I had checked the thing, and who knows, maybe it worked it at first and then I changed something that caused it to grow an appetite for my struct type. At any rate, I replaced the function with my own implementation of selection sort since it was quick and easy to implement. Upon doing that, things started to behave as I expected, and it was a short road to getting my modified kernel to work properly then.

Poor Jon was sick this past weekend and so he did a lot of sleeping and sniffling. This actually worked out okay for me because, while he slept, I worked on my Linux project. He still has to go to work this week, which sucks for him, and his job is in Cincinnati, which sucks even more because of the traffic. I’m hoping he’ll be well by this weekend so he’ll be back to his usual self, plus the two of us could then go to Carly’s birthday party.

• requirements engineering book – $50.69
• human factors engineering book – $76.95 — This bitch (the book, not the professor—I think I’m going to <3 my professor, she seems awesome) is like 700 pages and costs as much as $199 new. Even the international paperback version I bought is pretty expensive, and the seller didn’t have the highest feedback rating but I was like “screw it, I’m not paying $150 to have a slightly less shady seller”. I hate it when the choice comes down to paying way more to get the non-international version from a reputable mainstream seller, like Amazon, or some random Amazon Marketplace or individual bookseller.
• Linux kernel books – $21.49 and $23.96

Total: $173.09

Oh, and I forgot I also have to get a membership to access the digital archives of the Human Factors and Ergonomics Society for $35 to read some course material. And let’s not discuss how much I’m borrowing in loans just to attend graduate school. All I’m saying is I’d better make some good moolah after I have my Master’s, because I’m'a owe the government a lot of money.

In other news, sorry for the lack of blogging! You haven’t missed out on much, I’ve just been working before classes started (again with the money stuff…) and hanging out with Jon on the weekends. I had some excitement yesterday, though, when turning left on a green arrow and almost getting wiped out by some ass who ran the red light at the intersection. I swerved right, he swerved left, and I smoothly pulled into the gas station I was trying to get to anyway. It all happened so quickly, I barely realized what had almost occurred until I was going to fill up my tank. The guy had the strangest expression on his face, too, which I saw as I swerved to avoid him. It was the kind of expression one might make when they’re exasperated at spilling food on their shirt or something. Not what I expect from the responsible party in a near-collision. Or is that a near miss? Whatever.

So I don’t know if they breed us engineering majors to be dull or if I just got a lucky mix in my psychology class, but there are some awesome people in there. We did the usual go-around-the-room-and-introduce-yourself thing and right off the bat, first girl, she says she used to travel with a juggling and acrobatic group and she can still juggle torches. Our prof confirmed that she didn’t mean “torch” in the British sense of the word, a.k.a. “flashlight”, but rather real, honest-to-goodness sticks of fire. The girl looked totally normal, too, just your average skinny pretty brunette-with-blonde-highlights in some academic sweatshirt. She said she used to perform at Renaissance fairs which perked up the girl next to me, with whom I had spoken previously when she first entered the room and whose name I will not forget (more on that later), who had to add that Renaissance fairs were awesome even though torch-juggler said she was embarrassed and felt dorky. Several of us declared that she was not at all dorky and that torch juggling is way awesome.

The next cool person was another girl about halfway around the room: she breeds snakes. She launched into this discussion of how she took her “pewters” to some snake expo (?!) and didn’t sell any because kids were interested in paying $10 for some corn snake instead of “$120 to get something awesome”, as she put it. Haha. The guy sitting right next to her jumps out of airplanes, is apparently certified to do it, and is going to do something with the army next semester, I believe he said. Then finally you get to the girl next to me whose neatness was milder than the others, but still a bit interesting: she trains dogs. This is the girl whose name I won’t forget because she introduced herself as Virginia and I promptly asked, thinking of Harry Potter, if she goes by “Ginny” or “Virginia”. She then started telling me about how she gets called everything from Ginny to Virg to Catherine and Elizabeth, just because people recognize it’s some old classic name and they associate “Virginia” with British royalty. I suggested calling her “Vinny” to get the Italian mobster angle in there, and I also think “Queenie” could do if we’re sticking to the royalty idea.

1. The Ph. D. student we had as a substitute mentioned that my professor is his advisor, the student is doing C# stuff, and my professor is not all that familar with C#. This would give my professor more experience with it, and in a case where he already knows what the expected result of the program is.
2. The same Ph. D. student pointed out that if you know C++ and you know Java (which my professor certainly does), you can read C# fine.
3. You can use Mono in Linux to run C#–there’s no need to have .NET or use Windows. This point stems from the fact that my prof is a big Linux person and either dislikes Windows/Microsoft or perhaps just GUI interfaces… He has brought his laptop to class before to show code examples and he’s so hardcore that his window manager, fvwm2, doesn’t even have title bars on the windows, by his configuration, so to move a window you have to hold down some key combination and drag it with the mouse.
4. For our first program, he let me work in Ruby instead of Python. Ruby is to Python as C# is to Java.
5. Recently on StackOverflow, I was reading someone’s response about learning a new programming language, and I thought he had a good point. He said that if you already know Java, there’s not much point in learning C#, but instead perhaps learn ML or C because those are different kinds of languages. If this programming project is intended to teach us about object-oriented programming, then it doesn’t seem like it would matter whether we wrote in Java or C# because they’re so similar.

He told me in class he had been considering my request, but had decided that since I code in C# all day at work, it wouldn’t be helpful for me to write the assignment in C#, too, so I should do it in Java since I’ve barely worked in Java before. Then he went on to say that anyone else, however, that isn’t familiar with C# can use that over Java. My classmates started laughing and I had to say “Damnit, that’s not what I intended at all!” Grumble grumble.

I haven’t had a calculus class or even a math class in a couple years, so I’ve forgotten a lot. I reasoned that 5ⁱ is much like i, so surely the solution would be much like this one. So I “solved” it as: . When I got out of the exam and talked it over with classmates, several said they had left the sum in sigma notation, not attempting to simplify it. I explained my process, feeling all smart, before getting shut down with “you can’t do that.” Oh, wait… Yeah, I guess you can’t.

However! Today, I was vindicated because while I did lose one point for my crappy summing skills, the others that left it in sigma notation lost three points for not trying. So solve those sums, students, and solve them shoddily! …All right, enough with the ’s’ stuff.

Oh yeah, and I totally used Wolfram Alpha to generate the images above.

Him: “Oh, that won’t matter, it’s case insensitive.”
Me: “Oh! …So it’s like Visual Basic.”

That made him cringe a bit, being a language purist and a bit of an open source/Linux zealot to boot. Visual Basic was the only other language I could think of though where there’s any kind of case insensitivity, e.g. if expr then is the same as If expr Then in VB.

Prove the contention on page 40 that when a CLU iterator terminates, indicating to its parent for loop that there are no more values, the iterator’s activation record is actually at the top of the stack.
— Advanced Programming Language Design by Raphael Finkel, p. 61

The guy’s answer wasn’t the funny part, but he did summarize with something like “those were the only cases I could think of, and the claim is true for those”, which led our professor to call his proof a “proof by failure of imagination.” He then told us about another proof by failure of imagination: intelligent design. He explained it thus: “The universe is too complicated to have just sprung up and I can’t think of any other explanation, therefore someone must have created it.” Ha!

Algorithms looks like my hardest class, and the book is ginormous. (On a side note, when Firefox didn’t underline “ginormous” in red just now, I got quite confused and had to look it up in a dictionary. That’s a real bloody word! I’m now trying to remember if I knew this at one point or if I’ve always been under the impression that it was a made-up portmanteau, like ‘chillax’. Jeez…) Programming languages seems like it’ll be fun; we’ll have four major programming projects in there, the first involving Python and C, another using ML, one I don’t know about yet, and the last involving Smalltalk and Java. For our first homework, we were each assigned one question from the book which we’ll present in class next week. I got assigned a small program which I implemented recursively in Ruby very quickly, but unfortunately my professor told me I couldn’t use recursion because it defeats the point of the problem. Shucks.

In other news, my uncle that I mentioned in the last entry, the one that had cancer, passed away the day after my mom, aunt, and I visited him. I couldn’t believe it; none of us could. I got back in Lexington that day and saw I had a missed call from my brother. I called him back and he broke the news to me; I was just flabbergasted, because when I had visited my uncle, he looked swollen and seemed weak, but I didn’t think he looked on the verge of death or anything. He sat up in bed and talked with us, napped some while we were there, and made jokes like usual. My aunt thought he looked really swollen since the last time we’d seen him. I called Mom after getting off the phone with my brother, and we talked about his death, each of us expressing that we’d expected my uncle to live for another couple of years, maybe, but certainly not for only a single day more. His funeral was the following Wednesday and I didn’t go at my parents’ suggestion; it was a long drive, I had to work, and they reasoned that I had seen him just before he died. My brother was a pall bearer. Apparently there were a ton of people at the funeral; he was loved by many. He was the first of my mother’s siblings to die, and he was the oldest.

In less depressing news that’s still bad, my car is acting up again. It was driving fine, but when I went to start it the other day, I turned the key and… nothing. No engine noises, it doesn’t turn over at all. I tried rolling around all my fuses and replacing the fuel injection ones with others that I robbed from less vital features, like my radio and seat heaters. That didn’t fix it, and I didn’t see any obviously messed-up things under the hood. My dad suggested the battery, so Jon and I removed it and took it inside to let it warm up overnight because it has been ridiculously cold here of late. When we replaced it, the car still wouldn’t start, so we hauled the battery in to AutoZone today to have it tested; it tested good. The next guess is my starter, which for the part alone was around $200 at AutoZone, so I’m prepared to spend bank again on parts and service getting my car drivable. I’m still paying off the last $1,054.36 expense on my credit cards.

I had to meet with my artificial intelligence professor today to do a demo of my checkers project. The whole idea was to implement the alpha-beta pruning algorithm in a program such that the computer could pick good checkers moves to make against a human opponent, the user. My alpha-beta didn’t work so well, but the whole project was worth 250 points, 150 of which were not necessary, but just bonus points. There’s some debate over that 250, though: the project PDF actually states 200 points, with 100 being bonus, but he said in the meeting today 250. Who knows. Anyway, he thought the appearance of my program was great, which it ought to have been since I did a Ruby on Rails app and thus I had a web interface to work with; I got the full 50 points that could be won for a nice user interface. I then got 100 points for having a good heuristic function, and he said I lost 100 points for not having a correct alpha-beta function. Not having a good α-β function meant that my program was not so intelligent… The poor dear often let me win. :( However, that left me with 150 points out of 100, so I got an A and some bonus points. This allows me to skip the final and still get an A in the class, so hot dog!

Oppositely, in applicable algebra, I didn’t mind a bit when my crazy Swedish professor went off-topic from the final. He started out teaching mathematical theories about juggling, which was a bit dry, but interesting. He tossed some chalk to illustrate and dropped it all, so I thought he couldn’t juggle. I joked with him “Should you really be breaking all that chalk with the recent budget cuts?”, so he gave me a few pieces to keep in reserve. They sat on my desk just fine till a little later when I picked up my drink, against which they’d been resting, and they rolled off and broke on the floor. “Uhh, crap. We just lost our reserves,” I said, and he chastised me about how I was supposed to be protecting them. The whole class was enjoying things: the lecture, the chalk reserves, him tossing chalk willy-nilly while he scribbled math-based juggling patterns on the board.

Then, however, things got really good: he pulled out this previously hidden sport bag, from whence he took balls, sticks, juggling batons, and other equipment. He then started to juggle for us, and he was awesome! One thing he used was crazy: it was two thin batons with one end on each strung together with a long length of string. On that string, he balanced what looked like a large thread spool, and he did wild stuff with it. He flipped it up into the air and caught it, sometimes flipping it across the front of his body, over one leg, and catching it again on the other side of his body. One juggling trick he did with a ball was to lift a leg really high, throw the ball under his leg, catch it on the other side, and continue juggling. He tricked us, too, and it took a minute to catch on, then we all laughed: he juggled two balls with one hand, but he had a third in his other hand and all he did with it was just hold on to the ball while raising and lowering his hand. It was a good optical illusion with the craziness of the other two flying balls. All the while he was juggling the various objects, he’d talk calmly to us. When we would look amazed at some particular act, he’d ask as if we were silly “What do you do at night?”

Our “quiz” in there was a series of questions about why there are so few math majors at UK, if it’s a boring subject, if the faculty is boring, etc. I suggested he take his juggling act to local high and middle schools, juggle for them, and teach them the math behind it, too. His suggested reading list for the summer included about 6 books by Douglas Adams, who he’s a big fan of. :) It was an awesome end to the semester.

As for good news in my life, I won $200 the other night at UK’s Undergraduate Student Showcase. I submitted a bioinformatics programming project of mine earlier this semester to a university-wide competition, and I came in second place in the Physical and Engineering Sciences category, as announced at the Showcase. Now, ask me who got first place. The answer? No one! The judges award first place, etc. based on the merit of the project on its own, not relative to any other entry, so apparently they thought I did only a second-place job. :P One category didn’t even get an honorable mention, which must suck. Personally, I think it’s a crock. My professors and parents have agreed, thinking the school was just being cheap since first place carries a $300 prize. My dad commented that it’s nonsensical, since you can’t have a second place without a first, unless they’ve come up with a new way of counting. Ah well, at least the $200 will help with rent and groceries.

Living room:

Balcony:

Washer/dryer:

Kitchen:

Dining room:

Bathrooms:

Bedrooms:

Applicable algebra was awesome today because 1) we had it outside and 2) my professor is crazy. (This is the crazy Swedish professor I’ve mentioned before, just to clarify.) So the class was trooping outside when somehow our professor picked up an extra student, a girl who isn’t in the class. We passed a group of girls sitting under a tree and the extra student called to them:

“Do you know why class is cancelled?”
“No… What are you doing?” they replied
“I don’t know, this professor just came along and is now insisting that I follow him.”

Me and my classmates were cracking up at this, of course; our guy knows no bounds. The lot of us settled under some trees out in the middle of several campus buildings. He proceeded to lecture us, as we sat in a circle around him, about error correcting codes and their application to the hat puzzle with 3 or 7 people. He asked our extra girl something and she responded with “This is the weirdest thing I’ve ever seen,” I think referring to randomly joining a class rather than the hat problem.

We proceeded to try out our professor’s suggested strategy for guessing the correct “hat color” we were wearing, though in reality he just had other students sit behind the chosen 7 and hold up a card with either 1 or 0 on it, representing white and black hats. I convinced him that a version of the game should be our Friday quiz, so that should be more fun than a written one. I also asked the extra girl what her major was: Spanish. Our professor brought her into the center of the circle and asked if she understood what was going on; she didn’t and said she didn’t even know how to add vectors, which was part of the game. I can’t imagine being drug into some random, say, psychology class, which would be way outside my major.

I had a linear algebra test Tuesday and, apparently, she already has them graded and ready to hand back today (one of my classmates texted me last night to tell me this). I can’t believe how prompt she is. She’s just a grad student, not a professor, and I swear that has something to do with it. All the professors I’ve had take maybe a week to return a test or paper, and some are worse than that. My applicable algebra professor doesn’t get around to handing back graded quizzes for months; I still think he has some of my quizzes from when I took Calculus IV with him a semester ago.

I’m going to Jessica’s house this weekend to relax for a while but also to help her varnish the dining room set we’re to have in our new apartment. It’s a set of table and chairs that have been sitting around her barn for years, but they’re in good enough condition to still be used, so we’re going to sand them down and re-varnish them. I don’t think I’ve varnished anything for maybe six years, when I helped my dad sand and varnish a computer desk he made. Though I try to avoid them, I always end up with runs that dry into hard little lumps that I then have to sand down.

Varnish fascinates me, actually, both because I like its color and also because of how rock hard it gets when it’s dry. I think it’d be infinitely fun to get some ball-shaped mould and fill it with varnish. I have this idea that it would never really set up, but would instead remain this amorphous blob that I could squish around, so long as I didn’t break through the outer, solid crust. Oh, and it would smell horrible, since it would be varnish and all.

I got my linear algebra test back this morning and was disgruntled and surprised to find I’d made a B on it. I well expected an A because I can totally do row operations and matrix algebra. On most sections I did well, and I got full points on several sections. I did lose a few points here and there, mostly on definitions because, in my view, so long as I can apply the definition to solve problems, I don’t care so much about remembering the exact lettering of theorems from the textbook. I can work with linear transformations, I can find images, I can get an augmented matrix into reduced echelon form, I can make a matrix linearly independent based on some variable, but by God, if I give a geometric description of a span of vectors and leave off saying whether they’re scalar multiples of each other or not, heaven forbid I get more than 2 points out of 10 on the section. Hence, I got a damn B on the test, and I have a B as a midterm grade.

It doesn’t help that on the homeworks, she cares just as much that we write down the question as she does if we solve the problem and solve it correctly. That reeks of busywork to me, though she says it’s for our benefit in studying. Thank you, lady, but I know how to study without having the textbook’s lengthy instructions on my homework. So for the first few homeworks when I wasn’t explicit enough in writing out directions, I lost half a point on nearly every problem. That hurt my overall homework grade, adding to the problem of getting a B at midterm.

I’m pretty incensed about this and think it’s a bitchy, anal way of teaching. I miss my old numerical methods teacher, who was a darn good lecturer and a fair grader. I ended up with an A in that class even though I found the material much more difficult than linear algebra has been so far. Personally, I think a class should be difficult because its subject is more challenging, not because the teacher makes needless demands upon the students. If she had just given us a practical examination asking for us to apply what we’ve learned to solving systems of equations, working with matrices, and performing linear transformations, I would have been much more satisfied, but because I didn’t regurgitate facts from the textbook, my grade suffered.