A Concurrent Affair

I added a Matrix Market file reader for the MatrixMultiplySparse benchmark and used the 183-by-138 matrix we had picked out.

The reader seems to work, and if I set the heap size to 1.3 GB, then the compiler almost gets through, but it then blows up in Code.checkLimits. I believe the we are hitting the code [...]

Funny feature request of the day: Zoom In Zoom Out

I would like to request you to please kindly add Zoom in Zoom out feature in print preview. Please do it as soon as possible bcz we are having difficulties to view the code clearly as we r having eye problem.

(Emphasis mine.)

I’m afraid this has rather [...]

I just committed a small change as a result of profiling Mint programs: We are now treating all compiler invocations as one long compile session, instead of having many short ones during the execution of a Mint program. This reduces overhead since each symbol only needs to be completed once.

Compile times are cut by a [...]

I received an email from Chase, and it seems to be legitimate, but gmail flags it as suspicious. No wonder, it contains the following link:

1<a href="http://click2.cardmemberservices.com/33270655.1225.1009279985663.129">www.Chase.com</a>

The domain cardmemberservices.com belongs to JPMorgan Chase as well, but it is not the same domain as visible, www.Chase.com.

I don’t click on links that take me to important account websites [...]

DrJava has been included in the Softpedia software database. Furthermore, their staff certifies with their “100% Clean” award that our software is free from malware:

DrJava has been tested in the Softpedia labs using several industry-leading security solutions and found to be completely clean of adware/spyware components. We are impressed with the quality of your product and [...]

Test-First Java Concurrency for the Classroom

41st Technical Symposium on Computer Science Education (SIGCSE 2010)

Concurrent programming is becoming more important due to the growing dominance of multi-core processors and the prevalence of graphical user interfaces (GUIs). To prepare students for the concurrent future, instructors have begun to address concurrency earlier in their curricula. Unfortunately, test-driven development, [...]

The paper that I submitted to SIGCSE a month and a half ago, “Test-First Java Concurrency for the Classroom”, got accepted!

That means I’m going to Milwaukee in March.

Update:

I just realized that if my other paper currently under review also gets accepted, it will get a little stressful:

March 9-12, 2010: CSEE&T in Pittsburgh March 10-13, 2010: SIGCSE [...]

I’m hating SourceForge again, and this is a very frequent thing.

This time, I’m hating it for two reasons:

News submission is broken. I made a new DrJava development release, drjava-20091021-r5004, but I can’t post a news release, because the submission website just goes nowhere. I filed a ticket, but as usual, SourceForge [...]

I guess I should mention that I changed the ConcJUnit annotations (@Test) and method name suffixes (testFoo_NOJOIN) a little bit.

I had noticed that putting a _NOJOIN suffix on a test method or using a @Test(forceThreadJoin=false) annotation entirely disabled the test thread group. That’s not really what I wanted to happen, and even if it had [...]

I just made a new release of the all-in-one DrJava with Mint:

drjava-r5121-mint-r14186.jar

On the Mint side, there is only one small change: Previously, the Mint compiler only appeared in the “Compiler” drop-down box if the “Display all compiler versions” preference was enabled, which by default was not the case.

Happy experimentation with Mint!

(Re-posted from The Java Mint [...]

I’m in the process of wrapping up today’syesterday’s loose ends:

I made a new ConcJUnit release, 20091019, containing the files for versions 3.8.2 and 4.7, as described at the end of the last post. There is a new version of DrJava with Mint, DrJava-r5121-Mint-r14186. It is too big to [...]

A while ago, I was told by our one-and-only client of Mint that the version of DrJava with Mint does not display Mint as a compiler, even though it is included in the jar file and therefore should be available. I couldn’t reproduce this, so I set it aside for a while.

Yesterday I realized that [...]

At the Rice Computer Science Affiliates Meeting, I just listened to an interesting talk by Keith Cooper about the PACE (platform-aware compilation environment) project.

Keith mainly talked about resource and configuration detection, e.g. detecting cache sizes and alignment. Moshe Vardi commented that it was “a high-tech solution to a low-tech problem” that could be solved with [...]

When testing ConcJUnit some more from inside DrJava, I noticed some weird behavior. I had a JUnit 3.8.2 version of a test, and an equivalent JUnit 4 version. Run independently, they behaved as expected (which in my line of work usually means the tests failed), but if I ran them in sequence, then the second [...]

And the annoying twit of the month award goes to… this guy, a student at the Ozarks Technical Community College, for his truly legendary effort of generating 38 support emails to us without considering that the problem might be in his own code.

Over the course of just two days, he managed to open five bug [...]

After moving our Hudson server to a new server, we started to experience a very confusing test failure in the Java Language Levels module.

The test that failed was AdvancedLevelTest.testShouldBeErrors. It compiles the files in javalanglevels/testFiles/forAdvancedLevelTest/shouldBreak/ and makes sure that they all convert with errors.

I had tried to figure out what causes this, since we haven’t [...]

Corky just notified me that the very pesky ArrayIndexOutofBoundsException in DrJava that has been reported in numerous bug reports (assigned to be duplicates of the first report, 2831821: Caret updating is broken) is actually a JVM bug, not a bug in DrJava:

This is a documented bug in Java 6 which is supposed be fixed very [...]

It has been a long time since the last item went on the code pranger. I’ve pulled my hair out over many things during the last months, but this is the first time in a long while that I slapped my forehead and wanted to run away.

The issue was first discovered by one of our [...]

I just migrated our Hudson continuous integration server from my workstation (finland.cs, now a Dell Studio 435 with a 2.66 GHz i7 — thanks Corky!) to denmark.cs, a dedicated server (my former workstation, a Dell Dimension 9200 with a 3 GHz Pentium 4).

The builds now take a bit longer again (currently about 10 minutes instead [...]

After integrating Mint into DrJava last week, we have now made it even simpler to experiment with Mint: You can download a copy of DrJava that already includes the Mint compiler, all in one file:

DrJava with Mint (check the implementation page for newer versions)

That means on Windows and Linux, provided you have installed the JDK [...]