Will a Java expert (JVM developer) please answer this question? Thank you.
How impossible would it be to add a delete keyword to the JVM, and why?
Eclipse OpenJ9 – Open-source JVM
21–30 of 105 posts
Re: Eclipse OpenJ9 – Open-source JVM
#22So is this OpenJDK-derived? If so, too bad, I've been hoping for a truly independent implementation. If not, does it pass the TCK?
Ex-J9 engineer here, J9 was built completely in a clean-room. It does pass the TCK tests.
I was intern'd at IBM Toronto Lab about 10+ yrs ago to add instruction sets for this compiler/JVM. It was fucking awesome experience back then!
Re: Eclipse OpenJ9 – Open-source JVM
#23Will a Java expert (JVM developer) please answer this question? Thank you. How impossible would it be to add a delete keyword to the JVM, and why?
Why would you want to add a delete keyword? Are you trying to add explicit memory management to simplify the work of the garbage collector?
Re: Eclipse OpenJ9 – Open-source JVM
#24Will a Java expert (JVM developer) please answer this question? Thank you. How impossible would it be to add a delete keyword to the JVM, and why?
Java does memory recovery strictly by garbage collection. To delete an object remove all references to that object and wait.
A "delete now" operation imposes requirements on implementations that are not strictly required.
Any advantages gained from destructors can be realized via explicit cleanup methods and (as a hedge against mis-use) state checking for initialized and destroyed objects. A delete operation also adds risk that an object that has been deleted may be referenced again (although with esoteric stuff like PhantomReferences you can almost do it).
Re: Eclipse OpenJ9 – Open-source JVM
#25Will a Java expert (JVM developer) please answer this question? Thank you. How impossible would it be to add a delete keyword to the JVM, and why?
Why would you want to add a delete keyword? Are you trying to add explicit memory management to simplify the work of the garbage collector?
One example would be game development, where people end up doing object pooling to avoid GC pauses dropping frames.
Re: Eclipse OpenJ9 – Open-source JVM
#26Will a Java expert (JVM developer) please answer this question? Thank you. How impossible would it be to add a delete keyword to the JVM, and why?
Java does memory recovery strictly by garbage collection. To delete an object remove all references to that object and wait. A "delete now" operation imposes requirements on implementations that are not strictly required. Any advantages gained from destructors can be realized via explicit cleanup methods and (as a hedge against mis-use) state checking for initialized and destroyed objects. A delete operation also add…
Would it be impossible (or prohibitively difficult) to add it to an implementation, though?
Re: Eclipse OpenJ9 – Open-source JVM
#27Wonder if it will be possible to compile under OS X. Curiously OS X binaries have never been available for J9.
Re: Eclipse OpenJ9 – Open-source JVM
#28Wonder if it will be possible to compile under OS X. Curiously OS X binaries have never been available for J9.
I expect it's just a matter of time now. The build is out there.
Re: Eclipse OpenJ9 – Open-source JVM
#29The "Welcome to the Eclipse OpenJ9 repository" is just brilliant. So many product blogs and source code repositories fail to introduce the product first.
I'm confused. Do you think they're doing it right with that as an intro?
Re: Eclipse OpenJ9 – Open-source JVM
#30That's awesome. It was always some weird situation with abstract JVM specification but only one de-facto standard implementation which everyone used. I hope J9 will be a viable alternative, so everyone wins.