A Concurrent Affair

An Addiction, or Two?

Mathias — Sat, 28 Apr 2012 09:14:42 +0000

I absolutely love my Kindle Touch. I’ve already read two books, which embarrassingly is as much as I read all last year. I was skeptical about how easy it is to read, but it’s just as good as reading on paper. Perhaps better. I also would have expected that I’d be more careful with an electronic device, but interestingly, it’s just the opposite: I put it in my pocket, because I’m not worried about bending or tearing pages.

I also bought Legend of Grimrock a couple of weeks ago. Tonight, I finally installed it, and it looks and plays great. I think it could turn into another addiction. You can’t imagine how big this is: It’s the first video game I’ve bought in probably 15 years.

Three Years Left?

Mathias — Fri, 27 Apr 2012 06:08:10 +0000

According to a Bloomberg article, I have about three years left before my employability as a software engineer will start to decline.

There was some discussion about this on Slashdot. I particularly liked this comment, in response to why software engineers have a relatively high starting salary:

You’ve got it right when you say “compared to normal people”. Being a (good) software engineer takes a better-than-average brain. Better-than-average as in 98% of the world population won’t ever be a good software engineer, no matter how much time and effort they put in it, because they simply don’t have the brains for it.

I have a hard time believing that my comparative skills will decline so soon. At least right now, I don’t feel like I need to be worried about losing my job to a new grad or having it outsourced. And there is still so much more to learn and master.

My First 10 km Run

Mathias — Tue, 24 Apr 2012 14:52:49 +0000

Yesterday, for the first time in my life, I ran 10 km without stopping. It felt good. Last year, I had come close several times, but always decided to take it slow, maybe just run 8 km, and then something always happened that prevented me from running 10 km.

This time, after about 6 km, I still felt good. I decided to go for it.

I’m glad I did. I don’t even feel as sore as I would have expected. My average mile time was only 10:40, but I’m still elated about finishing the 10 km. When I was younger, I never would have thought this is something I could do.

Relaxing and reading after my 10 km run.

A Fantastic Dinner

Mathias — Fri, 20 Apr 2012 15:57:53 +0000

On Wednesday night, I went to Chez Shea in Seattle for dinner. It was fantastic. The food was delicious, and our waitress was great: knowledgeable, polite, attentive, but not pushy.

As appetizers, we had new potatoes and braised fennel salad with tarragon creme fraiche, pickled mustard seed vinaigrette and frisee; as well as Gruyere, spring onion and mushroom tart with baby arugula and jicama salad. The new potatoes were simple, clean, and appealing, and the Gruyere tart was decadent and rich.

Because our next dishes were running a bit behind, we got to try English pea soup, which had a hint of mint in it.

As main course, we chose pan-seared sockeye salmon on green lentils, shiitake mushrooms with bacon, rapini and caper brown butter; and potato gnocchi with parsley and arugula pesto, roasted tomatoes, parmigiano reggiano, and toasted pine nuts.

Desert chocolate mousse and vanilla creme brulee. As drinks, we had a glass of La Chablisienne, a 2010 French Sauvignon Blanc; a glass of Chateau d’Oupia, a 2010 French Carignan/Syrah/Grenache blend; as well as something called “French Connection”, which was an mandarine-orange flavored drink with green chartreuse in it (can’t find the recipe for that version).

It was a fabulous meal and a great evening. Chez Shea could easily be my favorite Seattle restaurant. Unfortunately, it is closing at the end of this month. So it goes.

Showers, Chance of Rain, Rain

Mathias — Fri, 16 Mar 2012 15:58:50 +0000

Weather forecast for Seattle:

Showers likely. Cloudy with chance of rain in the evening. Then rain likely after midnight.

I’m not even kidding. Those are the first three sentences of the current weather forecast on my phone.

Communication

Mathias — Mon, 12 Mar 2012 15:27:42 +0000

Something anyone writing a paper or doing a presentation needs to keep in mind: Communication.

Here’s the mouseOver text for the image: “Anyone who says that they’re great at communicating but ‘people are bad at listening’ is confused about how communication works.”

Thanks, xkcd.

Input/Output Redirection in DrJava?

Mathias — Thu, 08 Mar 2012 07:12:28 +0000

On the AP Computer Science mailing list, there was a teacher who wanted to do input/output redirection and who asked why the following didn’t work:

java LetterCounter < input.txt

The Interactions Pane in DrJava is not a DOS command line or Unix-type shell, and it does not support I/O redirection.

The java MyClass arg0 arg1 arg2 thing is only “syntactic sugar” for

1	MyClass.main(new String[] {"arg0", "arg1", "arg2"})

While the Interactions Pane doesn’t support I/O redirection and piping with <, > and |, it is a fully functional Java interpreter.

You can, therefore, create a FileInputStream and use it as System.in before starting your program.

For example, if my program is the following:

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import java.io.*;

public class ReadFromStdIn {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String line;
while((line = br.readLine()) != null) {
System.out.println(line);
}
}
}

Then I can start it the following way in DrJava to make it read from the test.txt file on my desktop:

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Welcome to DrJava. Working directory is C:\Users\mgricken\Documents\Dev\Java
> import java.io.FileInputStream
> System.setIn(new FileInputStream("C:/Users/mgricken/Desktop/test.txt"))
> java ReadFromStdIn
Foo
Bar
Fuzz
Bam
>

The four lines with "Foo Bar Fuzz Bam" are coming from the test.txt file.

I realize that this is different from how Java programs are started in DOS or Unix shells, but it’s only because the main method is a very special method. DrJava’s Interaction Pane becomes elegant because you can run any method.

I could write the program this way, for example:

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import java.io.*;

public class ReadFromStream {
public void readFromStream(InputStream is) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(is));
String line;
while((line = br.readLine()) != null) {
System.out.println(line);
}
}
}

Then I could run the program in the following ways:

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Welcome to DrJava. Working directory is C:\Users\mgricken\Documents\Dev\Java
> import java.io.FileInputStream
>
> // read from standard in
> new ReadFromStream().readFromStream(System.in)
>
> // read from test.txt
> new ReadFromStream().readFromStream(new FileInputStream("C:/Users/mgricken/Desktop/test.txt"))

I generally advise to do as little processing in the main method and rely as little as possible on magic like “where is my standard in coming from?”, and to write as much general purpose code as possible like the readFromStream() method. It will make code more reusable and work better in DrJava’s Interaction Pane.

I hope this helps. Thanks for using DrJava!

BSD License for the Reflection-Based S-Expression Parser

Mathias — Mon, 05 Mar 2012 03:53:21 +0000

About a year and a half ago, I wrote a class in Java that uses reflection to create a parser for S-expressions, based on a class hierarchy.

Today, a reader had found the class and wanted to use it in a commercial product. He was kind enough to inquire about the license. I wanted people to use it, otherwise I wouldn’t have made it available, but I also wanted to avoid giving expressed or implied warranties.

I decided to make it available under the BSD license. In fact, anything on this site or my graduate school site that’s not governed by another license is now available under the BSD license.

Finally, the reader thanked me for “writing such a nice piece of well-designed software.” As you can tell, flattery gets you everywhere.

Photography Class

Mathias — Sun, 12 Feb 2012 01:49:01 +0000

I went to a “Capturing True Emotion” photography workshop today. I’ve had my Canon G12 for over a year now, and I’ve passed my trusted Canon A610 on to my mom, but I still haven’t used the G12 very much. In fact, I probably still take better pictures with the A610 than with the G12, just because I don’t know it.

I figured I needed to spend some time with it, and what better way than to pay for it? I’m frugal, so there’s no skipping out of a paid workshop.

The first four hours of the workshop weren’t so great. It was at the Museum of Flight, in movie theater-style seating, for about 200 people. The information density was incredibly low in the first hour and the half, and anyone easily could have skipped that without missing any relevant information. It was mostly the instructor talking about how cool traveling and shooting weddings was. After that, we started talking about ISO, aperture, shutter speed, and so on. That was more interesting and useful.

The last two hours, after lunch, were by far the most useful. We went outside, where it was freezing, and practiced different ways to shoot. The trick that I got down pretty well was blurring the background using aperture. I think I took some neat pictures.

I have noticed, though, that my point-and-shoot definitely has some limitations, and I almost want a DSLR now. I can’t go to a very small aperture, for example, and when I zoom, I can’t have a very large aperture anymore. A lens for my camera might help, but I’m not sure if that makes sense. I’ll see how much I use the G12 this year and then decide what to purchase.

Time Wasted

Mathias — Tue, 07 Feb 2012 07:11:10 +0000

Today was a true Monday — not a pleasant day. Except for maybe an hour at work and two hours at the gym, it was nothing but wasted time. I took my car to the shop today to have the damage from the January 4 accident repaired, then drove a rental car directly to work. It’s a Toyota Corolla. I like the Corolla a lot, but compared to my Camry, it’s decidedly less sophisticated. At least traffic wasn’t bad. On Wednesday or Thursday, I’m supposed to get my car back. Even though the other driver’s insurance is paying, this incident is probably going to cost me about $200 and 15 hours of my spare time.

When I arrived at work, I found that construction workers had built an office around two cubes nearby, and all our computers had been unplugged. Without warning. My desktop wasn’t starting up anymore. I got it to boot with the integrated graphics again, but the dual-head on the dedicated card wasn’t working anymore.

I tried to re-position the video card, but after about four hours, I gave up and started working with just one monitor. IT support later took a look at it. The desktop must have really been knocked around. There was a big, biiig dent in the case, and the video card had to be bent back into the slot with more force than I was willing to exert. But fortunately, all is working again.

Dent in my work desktop.

All in all, I probably got one hour of work in today. I’m disappointed. What turned my Monday around, though, was my visit at the gym. I swam more than I’ve probably ever swum before. It felt good.

Fun in the Snow, Work from Home

Mathias — Fri, 20 Jan 2012 23:01:20 +0000

Today is the third snow day in a row. I’m glad that my job offers me the flexibility to work from home, because the last two days, it was dangerous out there, and now it is just nasty. I can’t wait to go back to the office, though. Even though my productivity has been descent (better than I expected — maybe it’s the lack of meetings), working from home does get a bit lonely.

Sliding in the snow, January 18, 2012

It’s been a long time since I’ve seen this much snow. Definitely an experience.

Seattle, a Winter Wonderland

Mathias — Mon, 16 Jan 2012 02:40:09 +0000

Before I moved to Seattle, people told me it “never snows in Seattle.” In the first few months of 2011, I had already found that to be incorrect. But today, more snow fell than I’ve seen here before. It’s really quite pretty, but it’s also Sunday, and I don’t have to go anywhere.

We’ll see how I feel about the snow tomorrow. Fortunately, my manager is great and has already said we could all work from home if necessary. I do have a meeting, though, that I don’t want to miss.

People Who Crash into Cars I’m in Continue to Suck

Mathias — Sat, 14 Jan 2012 01:19:45 +0000

The accident last week was the second time that I was involved in a car accident (it happened more often if you count cars hitting me on a bike).

The first time, a Houston rapper rear-ended my friend’s car, with my friend and me in it, and totaled it. He had an insurance card that he handed over, but what we didn’t know was that he had canceled the policy. He had had enough money to buy his new car in cash, but then he was too stingy to have the legally-required insurance.

You suck, man.

The accident last week wasn’t nearly as bad. Some people might not even care. There is some bent metal on the fender and a bunch of long scratches. The woman gave me her insurance card and her phone number. I talked to her insurance last week, but they didn’t get anywhere, because the phone number they had wasn’t working. I tried calling her, and it was the same number. She had given me a phone number that didn’t work.

That sucks too.

I tracked her down on Google and called her at work. I’m glad she honored my request to call her insurance as soon as possible. She acknowledged she was at fault, and now I can go get an estimate. She stunned me a little, though, when she grumpily said “I’m disappointed you got the insurance involved. I wish you had just gotten an estimate, and I would have paid for the repairs.” Tough luck, missy.

A co-worker of mine had the perfect response. He asked, “Did you say ‘I’m disappointed you hit my car’?” I wish I had.

A Grammar Change Saves the Day

Mathias — Fri, 06 Jan 2012 16:47:14 +0000

At work, we deployed the latest version of our code on Wednesday night. It included a new query language. We used ANTLR to do the parsing.

We had never tested the new queries in a production setting, but the deployments to our Alpha, Gamma, and two regional clusters worked without problems. A few hours after deploying to the last clusters, a customer started using it, and that’s when all hell broke lose. I ended up rolling back to the previous version at 4 AM on Thursday.

A quick analysis by my coworkers yesterday showed that most of the time was spent doing the parsing.

The grammar that we used was essentially this one, which required backtracking by ANTLR:

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E ::= ( E )
| C
C ::= ( E and E )
| ( E or E )

We never even let our test query finish, but it had been running for 45 minutes non-stop. I suggested a small change, which amounted to something like this:

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E ::= ( E R
R ::= )
| and E )
| or E )

Sometimes it is helpful that I spent grad school in the programming languages group.

The parser that ANTLR generated now parsed our test query in under a second. Sure, we changed an LL(*) parser into an LL(1) parser, but I never would have thought that changing the grammar could result in an improvement by a factor of 2700.

Happy New Year (?)

Mathias — Fri, 06 Jan 2012 16:33:05 +0000

Happy new year!

I haven’t written in a while, but I’ve also been busy. You know the story. I’ve done some traveling in private matters, but mostly it was large scale designs and some important improvements for work. I took every Monday off in December, and I still think that was a genial idea. Now it’s back to work without time off. It’s a marathon of sprints.

This year has not started so well for me, though. The girl I had been dating says she “needs some time.” I don’t know what that means. I don’t know if I am single or still in a relationship. Not that that really matters, I don’t have the nerve to meet anyone new right now anyway. I’ll just bury myself in work as a distraction.

On January 4, a woman drove her car into mine when she tried to squeeze into the left turn lane as I was stopped at a red light. So unnecessary. The damage isn’t bad, but it’s annoying. My car wasn’t even a year old. And now I have to deal with insurance and repairs. The hours wasted are what annoy me the most.

And yesterday I missed my bus because I ripped my shoelace when I put on my left boot. Argh.

Makes me kind of worry about Friday, January 13.

Where Citations Come From — xkcd: Citogenesis

Mathias — Wed, 16 Nov 2011 16:34:36 +0000

via xkcd: Citogenesis.

Something similar actually happened with the Karl-Theodor zu Guttenberg, who used to be the German Minister for Economics and Technology and later the Minister of Defense, before it became clear that he had plagiarized his doctoral dissertation.

DrJava DefinitionsPaneMemoryLeakTest fails on Mac

Mathias — Mon, 14 Nov 2011 06:28:38 +0000

I submitted a bugfix for a problem with the debug panel when no debugger is available.

I noticed that on the Mac, the DefinitionsPaneMemoryLeakTest now fails:

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[junit] DefinitionsPaneMemoryLeakTest 26.92 sec
[junit] Testsuite: edu.rice.cs.drjava.ui.DefinitionsPaneMemoryLeakTest
[junit] Tests run: 1, Failures: 1, Errors: 0
[junit] ------------- Standard Error -----------------
[junit] Skipped analysing class java.security.ProtectionDomain
because of java.lang.AssertionError
[junit] ------------- ---------------- ---------------
[junit] Testcase:
testDocumentPaneMemoryLeak(edu.rice.cs.drjava.ui.DefinitionsPaneMemoryLeakTest): FAILED
[junit] Document 0 leaked:
[junit] private static sun.awt.AppContext
sun.awt.AppContext.mainAppContext->
[junit] sun.awt.AppContext@4998a455-table->
[junit] java.util.HashMap@7f1bfcfc-table->

...

[junit] [Ljava.beans.PropertyChangeListener;@67b50846-[373]->
[junit] javax.swing.JViewport$1@7ceade87-this$0->
[junit] javax.swing.JViewport@48be3a5e-component->
[junit] java.util.ArrayList@6b333f77-elementData->
[junit] [Ljava.lang.Object;@559b52d3-[0]->
[junit] edu.rice.cs.drjava.ui.DefinitionsPane@2a38d0a8-_doc->
[junit] edu.rice.cs.drjava.model.DefaultGlobalModel$ConcreteOpenDefDoc@557e5cbd
[junit] at
org.netbeans.test.MemoryTestUtils.assertGC(MemoryTestUtils.java:137)

It passes on Windows, and I haven’t tried it on Linux. I rolled back as far as revision 5266, which was from June 3, 2010, and it was still failing on the Mac. I have a feeling that something must have changed in Mac OS (Lion) or the Java version I have running (1.6.0_29). I know I’ve successfully run the unit tests many times since then on the Mac, even on my MacBook Pro. I even think I have run them successfully on Mac OS Lion.

It would be great if I could still run the unit tests on an older Mac, with an older Mac OS. I’ll dig into this, but it may take some time.

Awful King County Metro Changes Coming Up

Mathias — Thu, 27 Oct 2011 06:20:47 +0000

I just found out that King County Metro is planning to cut off service for Route 27 at 12th Avenue at non-peak times. This is awful.

Route 27 is the only bus that takes me directly to my office. It already takes me 40 to 45 minutes with that bus; in fact, I can walk faster, which I do when the weather is nice. Coming back from work on the 27, or any bus for that matter, is already bad enough with the current service running outside of peak times. I would have hoped that service improves instead of being cut. I guess buses are really more intended for the homeless, who don’t care where the route ends, and not for people who aren’t going home from work at 6 PM yet, when peak time ends.

If these changes go into effect, I guess I’ll just drive every day. That means I’ll have to pay for parking, but I’m not going to change buses and spend two hours every day commuting in the company of the drunk, drugged, and unwashed when I can drive to work in under 15 minutes.

Back from SPLASH 2011

Mathias — Wed, 26 Oct 2011 04:29:54 +0000

I returned from SPLASH 2011 in Portland tonight. I attended only the Educators’ Symposium on Monday and the first day of the conference proper, but it was worth it. And how could it not be, given that it was so close, in Portland, even though the still-new-for-me title “SPLASH — Systems, Programming, Languages and Applications: Software for Humanity” has something very hippy-like.

I got to see Corky, Vivek and Vincent again, my doctoral advisor and two of my collaborators. I ran into a bunch of people I had met before, like Matthew Flatt, Eelco Visser, Michael Ernst, and Eugene Wallingford, but Igor Peshansky was one of the few people who seemed to recognize me as well. Thanks, and that’s just the way it goes for folks like me.

Vivek and Vincent did a great job with our DrHJ demonstration. Of the other presentations that I watched, I think PREFAIL impressed me the most. That was really good work. I liked the idea of the DSL to test languages and wish I’d had something like that for my work on Mint. And Zef Hemel’s mobl language demo was just damn cool.

I’m glad that I got to go, and I wish I had had more time, time to stay and be involved. I have more interests and responsibilities now, but I enjoy keeping in touch.

Here are some pictures:

Portland from the top of the Hilton, where the Educators' Symposium was held.

Turing Award-winner Ivan Sutherland speaking.

PREFAIL talk by Pallavi Joshi, UC Berkeley.

PREFAIL Talk, finishing slide.

Integrated Language Definition Testing Talk by Lennart Kats, Delft University of Technology

Integrated Language Definition Testing, example slide.

John McCarthy Died

Mathias — Tue, 25 Oct 2011 04:18:20 +0000

John McCarthy, Turing Award winner and one of the luminaries of computer science, died yesterday. I’ve spent the evening after the SPLASH Educators’ Symposium listening to McCarthy’s OOPSLA 2007 keynote speech (mp3).

Dick Gabriel introducing Stanford professor McCarthy's keynote at OOPSLA'07 in Montreal

John McCarthy was one of the earliest collaborators of my doctoral advisor, Robert “Corky” Cartwright. They worked on first-order programming logic in 1978 (Recursive programs as functions in a first order theory) and 1979 (First order programming logic).

McCarthy was on Corky’s committee. In Germany, the doctoral advisor is called “Doktorvater”, doctor father. If I haven’t quite lost a doctoral grandfather, I have at least lost a doctoral granduncle.