Hacker News Reader

Comment by maltalex | Hacker News Reader

Can someone please explain this?

> Are you working on a Java application? Do you want a faster runtime? Enhance your code with JavaScript!

First, the JVM already has the Nashorn JS engine. Second, if I'm "working on a Java app", that means that it's already running in a JVM. Where does the faster runtime come from? Is executing JS from Java using Graal faster than running actual Java code? Is it just faster than Nashorn? Something else?

View on HN

The Graal compiler is compiling Java code to faster machine code on top of the JVM. Also GraalVM's JavaScript implementation uses an entirely different approach by using Truffle for its implementation making it significantly faster. Also GraalVM ships with Node.js support, tooling and other languages.

Here is a full list of reasons: http://www.graalvm.org/docs/why-graal/

Here are some (maybe a bit outdated, but independent) benchmarks comparing it to Nashorn: http://blog.nidi.guru/tech/javascript/2018/04/02/javascript-...

We have some way to go to beat V8.

From the provided link:

- graal has superior compiler technology based off of a research paper [1] that:

-- has superior ability to remove costly object allocations in many scenarios

-- has better inlining and more aggressive speculative optimizations

-- has smarter jit compilation

[1] http://www.ssw.uni-linz.ac.at/Research/Papers/Stadler14/Stad... (pdf)

A few additional papers with details on Graal IR and optimizations:

http://lafo.ssw.uni-linz.ac.at/papers/2013_VMIL_GraalIR.pdf

https://dl.acm.org/citation.cfm?doid=2245276.2232084

http://aleksandar-prokopec.com/resources/docs/graal-collecti...

I think that copy is best read in two parts.

"Are you working on a Java application? Do you want a faster runtime?"

Graal provides an ahead of time compiler for Java, which can speed things up by removing JVM warm up time. I'm unsure how much faster Graal is compared to steady-state JVM.

"Enhance your code with JavaScript!"

Embedding Graal is an alternative to Nashorn.

So Graal can do more than Hotspot's C2 compiler so may be able to run your code faster than a stick JVM, Twitter have had some very good experiences with it. The JS implementation is very different to Nashorn's so it may be faster for your application.

Note that Nashorn is very slow - Graal.JS is orders of magnitude faster, and its peak performance is very close to V8 (although with a somewhat slower startup, currently).

Also more modern JS than Nashorn.

Reply on news.ycombinator.com