- java-devroom - lists.fosdem.org

Java DEV Room (Apache Maven Team)
by Karl Heinz Marbaise 13 Dec '15

13 Dec '15

Hi, i have made a proposale for a "Ask The Apache Maven Team" in penta...(https://penta.fosdem.org/submission/FOSDEM16/event/4459): Abstract: This sessions will give the Maven users community the chance to ask questions about Maven or suggest improvements or discuss ideas how to improve or any other questions or idea directly with Maven developers. Furthermore the Maven developers can give an overview of the current development. any other informations needed... Kind regards Karl Heinz Marbaise

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CFP: Bug hunting with Apache Lucene
by Uwe Schindler 12 Dec '15

12 Dec '15

Title: Bug hunting with Apache Lucene Abstract: When Oracle released Java 7 GA, it contained a serious loop optimization bug, affecting Apache projects like Lucene, Solr, or Elasticsearch. Since that time, the Apache Lucene team works together with the Oracle and OpenJDK developers to test early-access releases with Apache Lucene's codebase. Due to Apache Lucene's heavy, low level code with many tight loops and unusual code patterns, it is an ideal testing environment for the Hotspot optimizer. Loops, iterators, and bitset operations are executed millions of times per full text query to execute finite state automata, collect and filter results, and sort them. Bugs caused by mis-compilation of code that are hard to reproduce in isolation can be easily reproduced with Lucene. In addition, Lucene uses a pseudo-randomized testing infrastructure triggering different Hotspot optimizations on each test execution. In this talk, Uwe will show the current state of Java 9 EA testing. He will also present the problems caused by hard to reproduce issues, e.g. occurred after the changes to arraycopy or AVX optimizations in Hotspot. [Optional: As a short excursion, he will also present typical changes that had to be made, to make Lucene's Java code work with Jigsaw.] Bio: Uwe is committer and PMC member of Apache Lucene and Solr. His main focus is on development of Lucene Java. He implemented fast numerical search and is maintaining the new attribute-based text analysis API. After the release of Java 7 in 2011 he started to intensify communication of Apache Lucene team with Oracle and OpenJDK team members and introduced the Java EA testing, running of his company's servers. He studied Physics at the University of Erlangen-Nuremberg and works as managing director for SD DataSolutions GmbH in Bremen, Germany, a company that provides consulting and support for Apache Lucene, Elasticsearch, and Apache Solr. He also works for “PANGAEA – Publishing Network for Geoscientific & Environmental Data” where he implemented the portal's geo-spatial retrieval functions with Lucene Java. Uwe had talks about Lucene at various international conferences like the previous FOSDEM, Berlin Buzzwords, ApacheCon EU/US, Lucene Revolution, Lucene Eurocon, and various local meetups. Recording/streaming on audio/video is acceptable under a CC-BY license. I am either fine with a short or long track, because the talk can be made as detailed as time allows :-) ----- Uwe Schindler uschindler(a)apache.org ASF Member, Apache Lucene PMC / Committer Bremen, Germany http://lucene.apache.org/

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IMPORTANT
by Mario Torre 11 Dec '15

11 Dec '15

Hello all! Did I say "please don't count on a further extension"? Well, of course, I meant "do" it ;) By popular demand, I'm extending the deadline until December the 15th, 23:59 CET, this is the last chance though, so please don't miss it!! Cheers, Mario -- pgp key: http://subkeys.pgp.net/ PGP Key ID: 80F240CF Fingerprint: BA39 9666 94EC 8B73 27FA FC7C 4086 63E3 80F2 40CF Java Champion - Blog: http://neugens.wordpress.com - Twitter: @neugens Proud GNU Classpath developer: http://www.classpath.org/ OpenJDK: http://openjdk.java.net/projects/caciocavallo/ Please, support open standards: http://endsoftpatents.org/

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Talk Proposal: Fault Injection Testing With BMUnit
by Andrew Dinn 11 Dec '15

11 Dec '15

Hi Mario, This talk is a potential fallback in case it is not possible to provide a talk on Byteman-Thermostat. Title: Fault Injection Testing With BMUnit Duration: 45 minutes? Abstract: BMUnit is the package which integrates Byteman into JUnit and TestNG, enabling you to locally redefine the behaviour of application or JDK runtime code for the duration of a single test or group of related tests. BMUnit is very simple to use; just add a few annotations to your test classes and place a few jars in your classpath. This talk will explain how BMUnit works by presenting and executing tests which exemplify the 3 most common use cases: injecting trace code so you can be sure your tests enter the expected code paths injecting validation rules so you can assert that specific outcomes do occur injecting 'faults' to modify state or control flow, driving the application or JDK runtime down the path needed to exercise a desired test scenario Bio: Andrew Dinn is a member of Red Hat's OpenJDK team. He also leads JBoss project Byteman. regards, Andrew Dinn -----------

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Talk Proposal: Shenandoah, Theory and Practice
by Christine Flood 10 Dec '15

10 Dec '15

The Difference between Theory and Practice is greater in practice then it is in theory. We are on the brink of our first official release of Shenandoah. It took two weeks to write up the design and over two years to implement it. This talk will discuss the differences between what we initially proposed and what we now have working. An honest look at compromises, wrong turns, and innovations. We will finish the talk with the theory of what comes next: A high level design for NUMA aware GC, a sketch of a plan for truly pauseless GC, a brief consideration of reference counting... Christine

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CfP: Marlin renderer, a successful fork and join the OpenJDK 9 project
by Laurent Bourgès 02 Dec '15

02 Dec '15

Here is my talk proposal (25 minutes) on my personal contribution to open source software: Title: Marlin renderer, a successful fork and join the OpenJDK 9 project Abstract: The Marlin renderer is an open source java2D anti-aliasing renderer, forked from the OpenJDK's Pisces renderer, i.e. a pure-Java software renderer. This small project, with only 2 contributors (Me and Andrea Aimé), is hosted on my github (GPL v2) since 01/2014 to provide a faster alternative with very good scalability to both Pisces & Ductus (closed-source C) renderers. I made an important personal effort to optimize the memory footprint, rewrite Pisces's algorithms, run regression tests & our MapBench benchmarks (serialized maps). Many binary releases were published in 2014, compatible with both OpenJDK & Oracle JDK 7 / 8, but mainly used by the GeoServer & gvSIG CE projects (web and desktop open source GIS) which provided complex rendering use cases and user feedbacks. Thanks to my participation to FOSDEM 2015, I discussed with the OpenJDK community how to contribute the Marlin renderer back. I joined the graphics-rasterizer project in march 2015 to contribute Marlin as a new standalone renderer for OpenJDK9. I worked hard with Jim Graham & Phil Race (java2d team) and we proposed the JEP 265: Marlin Graphics Renderer in July 2015. It is now integrated and that intensive work made Marlin even faster ! In this session, you will learn how Marlin works (java2d pipeline, AA algorithm, tuning & benchmark results), how to use it, what performance optimizations were made and of course, my feedback on contributing to OpenJDK. Of course, I will also make a demo comparing OpenJDK Pisces vs Marlin on intensive rendering tasks (based on MapBench). Finally I would really like to get people helping me to implement new algorithms (clipping, more precise pixel coverage computation, efficient gamma correction) or just try Marlin with their applications to gather more user feedbacks. Recording me on audio and/or video: acceptable under a CC-BY-2.0 license (DEFAULT) Bio: Laurent Bourgès lives in Grenoble, France, and works as a software engineer for a public astronomical research laboratory but contributes to several open source java projects (eclipselink, openjdk, gvsig CE and astronomical software libraries). He is developing java desktop and web applications for 15 years (since 1.1.7) on unix machines (sun, linux) but is strongly interested by performance and concurrency issues (profiling, benchmarking, algorithms). He started contributions to OpenJDK 8 in 2013 (core-libs patches) and joined the graphics-rasterizer project in march 2015 to contribute the Marlin renderer back to OpenJDK9. Project URL: https://github.com/bourgesl/ <https://github.com/bourgesl/marlin-renderer> Microblog URL: @laurent_bourges <https://twitter.com/laurent_bourges> -- Laurent Bourgès

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CFP: The HotSpot Whitebox-Testing API
by Volker Simonis 30 Nov '15

30 Nov '15

Title: The HotSpot Whitebox-Testing API Abstract: One of the not so well-known tools of the HotSpot VM is its Whitebox-Testing API. Introduced in Java 7 it has been significantly improved and extended in Java 8 and 9. It can be used to query or change HotSpot internals which are not otherwise exposed to Java-land. While its features make it an indispensable tool for writing good HotSpot regression tests, it can also be used for experiments or for the mere fun of peeking into the VM. This talk will give an overview of the Whitebox-Testing API, it will show you how to build and use it and finally it will explain how the API can be easily extend to fit your own needs. Bio: Volker Simonis works in the SAP JVM Technology team. He is an OpenJDK contributor from the very beginning and helped SAP to engage in the OpenJDK project. He's the project lead of the OpenJDK PowerPC/AIX porting project, JDK8 committer and JDK9 reviewer. Recording me on audio/video is acceptable under a CC-BY-2.0 license.

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Proposal: Hunting the bug from Hell
by Andrew Haley 30 Nov '15

30 Nov '15

Abstract: Imagine you receive a report of a bug which causes a segfault (i.e. a memory exception) in the HotSpot Java VM very occasionally. This bug only occurs about one time in ten; it might take many hours before it happens. It has only been observed when running one particular piece of proprietary software. It only seems to occur on one large machine when running many concurrent threads and a huge heap. There is a clue: it only seems to happen when running the parallel scavenge garbage collector. But you've no real idea of how the garbage collector works. This happened to me in 2015. I'm used to being able to find and fix bugs, but this one resisted all of my attempts for a long time. As far as I can recall it's the most difficult bug I've ever fixed. In hunting this bug I used every tool available to me as a HotSpot developer. I'll describe them and how they were used. We don't much talk about debugging. Many of us spend much of our time doing it, but not talking or writing about this important activity. We should talk about it more. If there's time it would be good to swap war stories. Andrew.

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IMPORTAT: CFP Deadline extended
by Mario Torre 27 Nov '15

27 Nov '15

Hello all, As usual :) we will extend the CFP deadline for an additional [a bit more than a] week. The new deadline is set to Friday 11th December 1015 23.59 CET. This leaves us in a very critical time frame for accepting the proposals, so please don't count on a further extension! Cheers, Mario -- pgp key: http://subkeys.pgp.net/ PGP Key ID: 80F240CF Fingerprint: BA39 9666 94EC 8B73 27FA FC7C 4086 63E3 80F2 40CF Java Champion - Blog: http://neugens.wordpress.com - Twitter: @neugens Proud GNU Classpath developer: http://www.classpath.org/ OpenJDK: http://openjdk.java.net/projects/caciocavallo/ Please, support open standards: http://endsoftpatents.org/

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CFP: Adoption's Group Cultural Guide to OpenJDK
by Mario Torre 27 Nov '15

27 Nov '15

Title: Adoption's Group Cultural Guide to OpenJDK Abstract: OpenJDK is now a well established Free Software Ecosystem, with a vibrant Community and lots of interesting stuff going on, with projects, repositories, bug database and above all experiments! This is exciting and fun, but given the challenges of such massive project, it is intimidating and it is easy to get lost. It is also easy to forget that such massive infrastructure requires well defined rules, that are sometime perceived as blocking rather than aiding the participation. To help people wanting to contribute keep track of this intricate forest of development and find their way in, the Adoption Group was created (http://openjdk.java.net/groups/adoption/) This session is an exchange between few of the hackers directly involved with the Adoption Group and the public, we will answer questions the audience may have in relation to getting involved with OpenJDK, try to define and explain workarounds for most common problems (and blockers!) that newcomers face, discuss some of the projects we are currently involved with, and hope to be your Ariadne's thread to win back the fun of contributing and participating at all levels, without ever getting lost! Speakers: Adoption Group Members -- pgp key: http://subkeys.pgp.net/ PGP Key ID: 80F240CF Fingerprint: BA39 9666 94EC 8B73 27FA FC7C 4086 63E3 80F2 40CF Java Champion - Blog: http://neugens.wordpress.com - Twitter: @neugens Proud GNU Classpath developer: http://www.classpath.org/ OpenJDK: http://openjdk.java.net/projects/caciocavallo/ Please, support open standards: http://endsoftpatents.org/

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