A Concurrent Affair

I found a nice review of DrJava today, written by Julian Jaic.

DrJava is a simple and light IDE for Java development. It is a free, open source IDE primarily designed for students. But it also includes powerful features for more advanced users. It has integrated debuggers, support unit testing with Junit and tools to generate [...]

I received a message from Danny Dig, the project lead of the ReLooper project. ReLooper is a refactoring tool that enables Java programmers to parallelize loops over arrays or vectors using Java’s upcoming ParallelArray framework. I assume Danny searched for all Java projects on SourceForge and contacted all “expert programmers” of those projects.

I know [...]

Java’s latest version, JDK 1.6.0 Update 18, seems to have fixed the most frequent DrJava bug report, which Corky determined to be Sun’s problem (Oracle’s problem now). We have been filing all of the bug reports as duplicates of bug 2831821″Caret updating is broken”.

So far, there hasn’t been a single bug report describing the same [...]

Corky just informed me that there is a talk by Daniel L. Schuster at SIGCSE 2010 about Java, games, and the Free Java Book. I’ll definitely check out the talk and the book. I’ll also examine how concurrency is handled in the ACM Java Library.

Daniel is kind enough to state the following in his book:

Dr. [...]

It seems like I can get around the garbage collector bug if I use -XX:+UseConcMarkSweepGC JVM argument.

Now I’m having more Soot problems, but they actually make sense. In addition to being cross-platform, DrJava is also “cross-JDK version”: We support JDK versions 5 and 6 and OpenJDK version 6. In the past, we also supported JDK [...]

In the previous post I mentioned that I’m trying to create a call graph of all of DrJava using Soot. Since DrJava is a cross-platform application, there are classes that get compiled and used only on certain operating systems. The classes in the com.apple.eawt package, for instance, are only used on the Mac.

That means that [...]

I’m trying to create a call graph of all of DrJava using Soot. DrJava is a cross-platform application that has some classes that get compiled and used only on certain operating systems; for example, the com.apple.eawt package is only used on the Mac. That means that Soot doesn’t normally find these classes when generating the [...]

Sometimes I have those moments when something small that I did brings me tremendous joy.

This just happened when I was using DrJava with Soot. I don’t know the Soot framework, so the “Additional Javadoc URLs” feature that I introduced some time in 2009 comes in really handy.

I just entered “http://www.sable.mcgill.ca/soot/doc” as URL, and now I [...]

I got myself into a bit of a problem when I tried to set the automatic end-of-line style property for our text files in Subversion. I wanted to use “native”, because that should automatically convert all line endings to LF (“\n”) on Unix and Mac, and to CR LF (“\r\n”) on Windows.

This seemed to work, [...]

I just fixed two bugs in DrJava that had to do with boxed floating-point comparisons of NaN and -0.0.

Both bugs had the same cause, a difference between the behavior of primitive == and the equals method in Double and Float.

According to IEEE 754, any NaN isn’t equal to anything, not even itself. Therefore, Double.NaN==Double.NaN should [...]

Memories can be strange. A lot of people around me are probably now having memories triggered by (turkey) smells. I have memories triggered by numbers.

Our Hudson build server just notified us of a unit test failure after a recent commit. It was a:

java.lang.NullPointerException at edu.rice.cs.drjava.model.definitions.CompoundUndoManager$1.run(CompoundUndoManager.java:216)

The line number, 216 immediately hat [...]

A few days ago, I noticed that double-clicking on a *.java file in Windows Explorer caused an AssertionError in DrJava. This wasn’t a huge issue, because it only shows with assertions enabled (i.e. -ea in the JVM Arguments for the Main JVM).

It’s still something I wanted to fix, because under some circumstances, opening a file [...]

Open source is not the same as public domain material. It is not content that is not owned by anyone.

The fact that we give something away for free does not allow you to just steal it.

DrJava is an open source project, made available under the BSD license. We freely distribute our source code and hope [...]

I just created a new release of Mint and DrJava with Mint.

JavaMint-r14577.tar.gzJavaMint-r14577-binaries.zipdrjava-r5130-mint-r14577.jar

There were some dramatic performance improvements in the Mint compiler thanks to base type lifting instead of performing cross-stage persistence for them. I also fixed a bug that didn’t allow escaping into bracket statements. And DrJava with Mint now has a simple logo (mostly [...]

We got a question today about how the output of a Java program running in DrJava’s Interactions pane could be redirected into a file, just like it could be done in a Unix or DOS shell:

java Motion > motion.dat

The Interactions pane supports a simulated java command, but this is merely for convenience. java Motion actually [...]

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 [...]

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 [...]

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 [...]

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 [...]

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 [...]