Kresten Krab Thorup, Hacker, CTO of Trifork, JAOO Host

Kresten Krab Thorup

Biography: Kresten Krab Thorup

Kresten Krab Thorup is CTO of Trifork, a public Danish company providing software solutions to government and financial services providers.  Trifork is also creator of the long-running JAOO conference, and co-creator of QCon.  As Trifork CTO Kresten in responsible for technical strategy, and spends most of the time acting as internal consultant, researching future technologies, as well as being editor for JAOO and QCon conferences.  Kresten has also been a principal contributor to Trifork's own Java EE certified application server "Trifork T4", where he authored the built-in CORBA ORB, a custom Java RMI implementation (now part of Apache Yoko), the transaction manager, the database connection management system, and the Java byte code rewriting subsystem.

Kresten has been a contributor to several open source projects, including GCC, GNU Objective-C, GNU Compiled Java, Emacs, and Apache Geronimo/Yoko. Before joining Trifork, Kresten worked at NeXT Software (now acquired by Apple), where he was responsible for the development of the Objective-C tool chain, the debugger, and the runtime system.  Kresten was on the committee for JSR-14 (adding generics to Java) which was closely related to the subject of his Ph.D. thesis.  

Most recently, Kresten has founded the Erjang open source project (notice the J there), a virtual machine for Erlang running on the Java Virtual Machine.
Software Passion: My passion is creating software. The power of creation is the joy of conceiving a software solution, in the joy of good craftmanship in software construction, but most importantly the joy of seeing it’s effects unfold as it enters the real world. It is born…

Presentation: "Conference Opening & Introduction of Today's Speakers"

Time: Monday 08:30 - 09:00 / Location: Store Sal, Musikhuset

Presentation: "Introduction of Today's Speakers"

Time: Tuesday 08:30 - Wednesday 09:00 / Location: Store Sal, Musikhuset

Presentation: "Erjang - A JVM-based Erlang VM"

Track: CONCURRENCY & INTEGRITY / Time: Tuesday 10:15 - 11:15 / Location: Filuren, Musikhuset

Over the last few years, I have been meeting "Erlang people" more and more often, and I am getting the impression that they have a magical ability to reason intuitively about concurrent systems in a way that I have not. It corresponds somewhat to the way we "object heads" think intuitively about classes and objects - just in terms of processes. That bothered me, so I wanted to learn Erlang.  Being a language implementor, the most obvious way to do that is to just go ahead and implement an Erlang VM, right?

The result of this "little exercise" is Erjang, an open-source JVM-based Erlang VM. It has turned into a non-trivial project, Erjang is now 50k lines of Java code, it runs substantial erlang programs, including booting OTP so you can use the Eshell, it self-hosts the erlang compiler (erlc) and tcp/ip functionality works.

In this talk, I would like to take you through some of the issues, problems and solutions that I saw going through that exercise. And specifically, I will take you through what I think is wrong with "Java concurrency", and in which situations the conceptual model in Erlang is better.  In Erlang you model systems with Actors; but how do we evolve from object-heads to actor-heads?  How do we get to a point where processes are as intuitive and natural as objects and classes?  

In short: I will explain how Erjang works, what I learned along the way, and demonstrate that Erjang runs well enough to be obviously useful.

Keywords: Core, JVM, Concurrency, Scalability, Alternative languages
Target Audience: Java developers [preferrably ones that have felt the pain of concurrency]