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As in previous years, Jikes RVM will apply to Google Summer of Code for funding for student projects.

The GSoC 2013 timeline has been published. The first date of importance is: Organization application deadline on March 29 2013

Our current task is to collate a set of interesting project proposals and encourage students to apply for GSoC. We can re-use ideas from previous proposals, or come up with totally new ideas.

Hints for students

The application for mentoring organizations hasn't been opened yet. However, it's not too early to read the Google Summer of Code documentation. Students should read at least the GSoC FAQ and Google's advice for students. There's also a lot of helpful information about GSoC that's provided by mentoring organizations and previous GSoC students (use your favorite search engine to find it).

If the Jikes RVM project sounds like it could be a good fit for you, you can already start to get familiar with Jikes RVM. Checkout the source code and read the user guide. Build the Jikes RVM, run some tests and take a look at the codebase. You should have your development environment already set up before applying. Don't hesitate to ask on the mailing lists if you need help.

If/when we've been accepted as a mentoring organization, students can take a look at our guidelines on making an application. We expect that students get familiar with the Jikes RVM and the Jikes RVM community before applying.

What's in it for me?

All mentors get a smart Google t-shirt. The project gets some new contributors, and the students get substantial amounts of cash and experience in open source development. 

The Jikes RVM project has seen substantial benefits from GSoC in previous years, including a new native threading model and additions to the core team of developers.

Adding new project suggestions

Please add your ideas to the wiki below, ideally using the template shown below. You can also contribute an idea if you don't have a wiki account: just describe it on on the researchers mailing list.


Project Titlefoo
RVM area
{compiler, classlib, MMTk, infrastructure...}
outlineparagraph description of project idea

links to related projects, academic papers, etc

needed skills

skills that the student should have and/or needs to acquire during the project


a difficulty estimate for the project, e.g. easy, medium, difficult

interested mentor

your name and a contact link or "TBD" if you can't mentor

Project suggestions (aka idea list)


Project TitleImplement the Java Management extensions (JMX) API
RVM area
classlib, MMTk, threading, compiler

The Java Management Extensions provide a way to monitor and manage Java Virtual machines. The Jikes RVM can collect significantly more profiling data and runtime statistics than an average JVM as a result of it being focussed on research activities. These statistics would ideally be exported using JMX and could potentially provide a standard mechanism for monitoring the performance and health of the virtual machine and its components.

As a first step, students should focus on laying groundwork for a suitable implementation of the API:

  • Update the JMX code from GSoC 2007 (written by Andrew John Hughes) to work with the current Jikes RVM
  • Implement all the parts of the API that are required
  • Write automated tests that can be integrated into our test frameworks

After that has happened, students should implement the optional parts of the API and Jikes RVM-specific features. The exact set of features will need to be discussed with the community at the appropriate time.


Blog post about JMX with links to further documentation

Our bugtracker entry for JMX

Web view of the JMX branch in the historic svn repository (use "svn checkout svn://" to checkout the code)

needed skillsJava
interested mentorTBD



Project TitleImplement the JVM Tool Interface (JVMTI)
RVM area
threading, JNI

The JVM Tool interface is part of the Java Platform Debugger Architecture that JVMs can implement to provide debugging capabilities. We would like to have a full JMVTI implementation to allow debugging of Java applications that are running on Jikes RVM. Another benefit of JVMTI is that it allows low-level access to JVM internals. This can be used for instrumenting and monitoring the Jikes RVM using low-level code.

There is already a partial JMVTI implementation that was written by James Bornholt for GSoC 2011. His implementation should be used as a basis for this project.


Writeup of James Bornholt on the GSoC 2011 page

Web view of previous GSoC 2011 JVMTI work

needed skillsC, C++, Java, willingness to deal with low-level details
interested mentorTBD



Project TitleImprove (or rethink) CatTrack
RVM area

The Jikes RVM project currently uses the Ruby-on-Rails application CatTrack to track test results. CatTrack is also responsible for sending regression mails.

This project would consist of upgrading CatTrack to use a more recent version of Ruby-on-Rails instead of the ancient Ruby-on-Rails 1.2.6. Potential candidates must have experience in Ruby-on-Rails to be able to take on this project: we don't have the necessary expertise to provide adequate mentoring to RoR beginners. The exact version numbers and the upgrade process need to be coordinated with our contacts at the Australian National University (where the servers are located). New features can be added to CatTrack after the upgrade is complete.

An alternative approach would be to get rid of CatTrack completely and move to a more general open-source solution. Note that this would be a much more disruptive change. A student proposal that suggests this approach must be very convincing to be considered. Another constraint for proposals of this kind is that we want to avoid using yet another language in our build infrastructure (see RVM-85 ). It might be acceptable to replace Ruby with another language but this must be discussed before such a proposal is submitted.

The X10 language project also uses CatTrack for their regression mails. Candidates should be prepared to coordinate with somebody from the X10 team to ensure that an upgraded version of CatTrack (or a replacement) is also a viable solution for them.

referencesWeb view of the CatTrack repository
needed skillsprior Ruby-on-Rails experience, XML, basic knowledge about databases
interested mentorTBD



Project TitleImprove testing situation for JIkes RVM
RVM area
infrastructure, (additional subsystems as chosen by the student)

An infrastructure for unit tests and some initial unit tests were added to the Jikes RVM in GSoC 2012 by João Reys Santos. However, there is still a lot of work to do before we can consider the codebase to be reasonably well tested. We need more unit tests as well as more black-box tests.

Students should pick an area of interest (e.g. compilers, JNI, MMTk, classloading, threading, ...) and/or motivating use cases (e.g. get benchmark X or application Y running on Jikes RVM), identify and fix the corresponding problems and introduce adequate (unit) tests.

Note that extra effort will be required if students want to use mocking. Mockito does not work with GNU Classpath-based JVMs and our OpenJDK-port is not yet ready.


book: Michael Feathers, Working effectively with legacy code, Pearson Education, 2004

book: Andreas Zeller, Why programs fail: A guide to systematic debugging, Morgan Kaufmann, 2009

needed skillsJava, Ant, debugging without a debugger
difficultyeasy to difficult (depends on the chosen tasks and areas)
interested mentorTBD



Project TitleBytecode verifier
RVM area
classloading, compilers

Jikes RVM currently does not implement a bytecode verifier. We would like to have a bytecode verifier that can verify classfiles at least up until Java 6 (we don't support Java 7 yet). The verifier needs to work with the baseline compiler as well as the optimizing compiler. Ideally, it should be possible to use the verifier from the command line without actually running the bytecode that is supposed to be checked. This could be done in a similar way to the OptTestHarness which enables users to control the compilers.

The verifier should be designed to support custom verification constraints. Some examples for possible constraints are listed in the JIRA issue linked below.


JIRA issue for the bytecode verifier

Jasmin assembler (useful for creating test cases that trigger verifier errors)

Chapter 4 of the JVM Specification

needed skills

Java, reading papers and specifications, implementing algorithms from specifications and papers

interested mentorTBD
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