4 ms·

One huge feature in my opinion is the JVM compiler interface (JVMCI), which allows you to use Graal (which is used by Truffle) with an unmodified JRE.

Traubenfuchs 10y ago
All of those are things the majority of professional Java developers will never ever hear about, let alone actively use.
- geodel 10y ago
  This Graal/Truffle/Maxine etc effort is going on for a decade or so, I think. Some folks first at Sun and then Oracle are trying to prove that Java is low level/performant enough to write JVM runtime/compilers etc. I believe this effort is still not production ready. Meanwhile Oracle has put some bits on github, and other made closed source to see if some business can be generated out of it.
  - ianopolous 10y ago
    Graal and Truffle are already open source. The other related (but not necessary for many uses) component is SubtrateVM, and that will be open sourced in a few months too.
  - pjmlp 10y ago
    Actually Graal is capable of more optimizations than Hotspot, for example it has more aggressive escape analysis heuristics. Twitter is reporting their experience in production at FOSDEM https://fosdem.org/2017/schedule/event/graal/ https://fosdem.org/2017/schedule/event/graal/
    - Traubenfuchs 10y ago
      That sounds very interesting indeed.
- pjmlp 10y ago
  Sure they will, unless they don't care about performance. This the first step to eventually replace Hotspot with Graal. Twitter already experimented with it and is giving a presentation at FOSDEM this weekend. https://fosdem.org/2017/schedule/event/graal/ https://fosdem.org/2017/schedule/event/graal/ So any Java developer conscious of what to make the most out of the JVM will need to learn it.
- lemming 10y ago
  So are many of the existing underlying JVM features today - most developers don't use them directly. However they do use the features they enable all the time. Personally I think Truffle/Graal are by far the most exciting features in Java 9. They'll enable really amazing innovation in all sorts of JVM languages.

Traubenfuchs 10y ago

All of those are things the majority of professional Java developers will never ever hear about, let alone actively use.

geodel 10y ago
This Graal/Truffle/Maxine etc effort is going on for a decade or so, I think. Some folks first at Sun and then Oracle are trying to prove that Java is low level/performant enough to write JVM runtime/compilers etc. I believe this effort is still not production ready. Meanwhile Oracle has put some bits on github, and other made closed source to see if some business can be generated out of it.
- ianopolous 10y ago
  Graal and Truffle are already open source. The other related (but not necessary for many uses) component is SubtrateVM, and that will be open sourced in a few months too.
- pjmlp 10y ago
  Actually Graal is capable of more optimizations than Hotspot, for example it has more aggressive escape analysis heuristics. Twitter is reporting their experience in production at FOSDEM https://fosdem.org/2017/schedule/event/graal/ https://fosdem.org/2017/schedule/event/graal/
  - Traubenfuchs 10y ago
    That sounds very interesting indeed.
pjmlp 10y ago
Sure they will, unless they don't care about performance. This the first step to eventually replace Hotspot with Graal. Twitter already experimented with it and is giving a presentation at FOSDEM this weekend. https://fosdem.org/2017/schedule/event/graal/ https://fosdem.org/2017/schedule/event/graal/ So any Java developer conscious of what to make the most out of the JVM will need to learn it.
lemming 10y ago
So are many of the existing underlying JVM features today - most developers don't use them directly. However they do use the features they enable all the time. Personally I think Truffle/Graal are by far the most exciting features in Java 9. They'll enable really amazing innovation in all sorts of JVM languages.