Category Archives: Research

Research work.

Paper: Mint: Java Multi-stage Programming Using Weak Separability

Posted on January 31, 2010 by Mathias

Mint: Java Multi-stage Programming Using Weak Separability 2010 ACM SIGPLAN Conference on Programming Language Design and Implementation (PLDI 2010) Multi-stage programming (MSP) provides a disciplined approach to run-time code generation. In the purely functional setting, it has been shown how … Continue reading →

Posted in Mint, Publications | 2 Comments

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Java Bug 4396719 Work-Around?

Posted on January 31, 2010 by Mathias

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 … Continue reading →

Posted in Concurrent Unit Testing, DrJava | 1 Comment

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Soot Build Instructions

Posted on January 30, 2010 by Mathias

While trying to create a call graph of DrJava using Soot, I ran into some problems that were supposed to have been fixed in the Soot nightly builds already. Unfortunately, the nightly builds I could find were all many months … Continue reading →

Posted in Concurrent Unit Testing | 1 Comment

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A HotSpot Java Error, a Bus Error and a Segmentation Fault

Posted on January 30, 2010 by Mathias

When I run Soot to create a call graph of DrJava, I get the aforementioned HotSpot Java error on Windows with Java 1.6.0_18. On Mac OS X 10.4 with Java 1.5.0_19, I get a “Bus error” (Java exit status 138). … Continue reading →

Posted in Concurrent Unit Testing, Ramblings | Leave a comment

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Mint Paper Accepted to PLDI 2010

Posted on January 30, 2010 by Mathias

I’m happy to report that our Mint paper “Mint: Java Multi-stage Programming Using Weak Separability” has been accepted to PLDI 2010 in Toronto! I couldn’t find the deadline for submitting the camera-ready version yet, and the reviewer and referee comments … Continue reading →

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More Details on Soot and -allow-phantom-refs

Posted on January 29, 2010 by Mathias

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 … Continue reading →

Posted in Concurrent Unit Testing, DrJava | 1 Comment

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Java Bug 4396719 – Mark Sweep stack overflow on deeply nested Object arrays

Posted on January 29, 2010 by Mathias

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 … Continue reading →

Posted in Concurrent Unit Testing, DrJava, Ramblings | 4 Comments

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Another Possible Improvement

Posted on January 12, 2010 by Mathias

On the other hand, I think I can re-enable checking if the event thread has finished and generating EventThreadStillProcessingErrors in the “update” Runnable that sets the test thread group the event thread uses, at least in certain cases. It is … Continue reading →

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Another Possible Problem

Posted on January 12, 2010 by Mathias

I think I have just realized that this still isn’t good enough. Now we know that there aren’t any more events, but it is conceivable that a Runnable executing just before the token Runnable has started new threads. Those threads … Continue reading →

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New Release of ConcJUnit: 20100112

Posted on January 12, 2010 by Mathias

I’ve just made a new release of ConcJUnit: 20100112. This release contains an important addition that I had been thinking about for a while. ConcJUnit already detected failures and uncaught exceptions in the event thread, but since the event thread … Continue reading →

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Submitted Publication Version of SIGCSE 2010 Paper

Posted on December 4, 2009 by Mathias

I just submitted the publication version of our SIGCSE 2010 paper, Test-First Java Concurrency for the Classroom. Now I’m waiting for the copyright form to be sent, and I’m wondering why that’s not done automatically…

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Another Sample Bug for Yield

Posted on December 2, 2009 by Mathias

I coded up two more examples to test the yield strategy. The “split synchronized” example doesn’t work that well (yet), because it fails even without the added yields. I’m looking for common bugs that aren’t obvious. Thread remover = new … Continue reading →

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Getting Back on That Concurrency Horse

Posted on December 2, 2009 by Mathias

After a lot of work on Mint, I’m now focusing on the concurrent unit testing project again. I had to fight some apparent code rot, which was probably caused by changes from Java 5 to Java 6, but now everything … Continue reading →

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CSEE&T Paper Not Accepted

Posted on November 28, 2009 by Mathias

As expected, the paper I submitted for CSEE&T back in October did not get accepted. But that was a long shot anyway, and I already have something else for it in mind.

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Huzzah for Sleeping In!

Posted on November 21, 2009 by Mathias

Today I slept in for the first time in a while. It’s been a tough fortnight, but we finished our PLDI 2010 submission. I feel it is considerably stronger than our previous submissions. Let’s home my confidence is justified.

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New Mint Release

Posted on November 13, 2009 by Mathias

I just created a new release of Mint and DrJava with Mint. JavaMint-r14577.tar.gz JavaMint-r14577-binaries.zip drjava-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 … Continue reading →

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Boring Backport

Posted on November 13, 2009 by Mathias

I’m in the process of porting some scientific code originally written in Fortran, which was then ported to Java, which was then ported to Habanero Java, back to Java, while maintaining a Habanero Java feature called array views. It’s incredibly … Continue reading →

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Lifting for Primitive and Boxed Types and Strings

Posted on November 4, 2009 by Mathias

When we examined the code that was generated for the sparse matrix multiplication benchmark of Mint, we noticed that variables containing loop indices had become cross-stage persistent (CSP) variables, which necessitated an array lookup. This was much more expensive than … Continue reading →

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Mint Matrix Market Reader for Sparse Matrix Multiply Benchmark

Posted on October 31, 2009 by Mathias

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 … Continue reading →

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Mint Compile Time Improvement

Posted on October 27, 2009 by Mathias

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 … Continue reading →

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