6

I recently heard of Jikes RVM and i was trying to go though its features what it offers that other virtual machines don't offer and how scalable it is.

So, while going though feature list on the website i found an interesting points

High performance. Jikes RVM is a high performance compiler, making it ideal for use with larger projects

Questions

  1. How authentic is the statement above because I have been working with Java for the last 5 yrs and have never heard of Jikes RVM before. Most of the development is done on Hot Spot VM (Provided by Sun). I know, there are other VM's also but never heard of Jikes RVM. Possibly one of the reasons could be my lack of awareness about Jikes RVM but then it becomes very hard to digest that so many people people were unaware of such a High performance VM.

  2. What exactly is the scenario which should prompt you to use Jikes RVM?

mpapis
  • 52,729
  • 14
  • 121
  • 158
Bagira
  • 2,149
  • 4
  • 26
  • 55
  • 1
    Make sure you're not confusing [Jikes RVM](http://jikesrvm.org/) (which is a experimental JVM) with [Jikes](http://jikes.sourceforge.net/) (which is a Java compiler written in C). – Joachim Sauer Jul 03 '12 at 13:07
  • Thanks for pointing it put, I am indeed talking about Jikes RVM. – Bagira Jul 03 '12 at 13:30

1 Answers1

9

You're talking about two different products here, although they're related because they both originally came from the same group at IBM.

  1. The Jikes Java compiler. Unlike Sun's javac, which is written in Java, jikes is written in C++. A long time ago, that meant it was much faster than javac, and it saw widespread use. Nowadays, being written in native code is not a performance advantage at all, and indeed, as far as I know the compiler is a dead project, having not been updated in years.

  2. The Jikes "Research VM" (RVM) is a project to create a Java virtual machine which was itself written mostly in Java. This makes it possible to experiment with things like new garbage collection algorithms by writing Java code, rather than native code. The RVM is slow compared to other JVMs and was never intended for actual production use, just (as the name implies) for research. Unlike the compiler, the Jikes RVM still has an active academic research community.

Ernest Friedman-Hill
  • 80,601
  • 10
  • 150
  • 186
  • As you say Jikes RVM is slower than other JVM's available but them why http://jikes.sourceforge.net/ states that it is a High performance VM for large projects? – Bagira Jul 03 '12 at 13:34
  • 3
    @Bala, as I said, that's the page for the *compiler*. A compiler is a program that turns Java code into `*.class` files. The RVM is a program that executes class files. The *compiler* was fast; the RVM is slow. – Ernest Friedman-Hill Jul 03 '12 at 14:11