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A comment on Eclipse OpenJ9 – Open-source JVM. Parent comment

Re:Eclipse OpenJ9 – Open-source JVM by kuschku on Sunday September 17, 2017 @03:16AM (#15268600)
> That's not the RTSJ solution. RTSJ uses arenas, which are great if you have regular allocation/deallocation cycles, like, say, a frame in a game.

So how do I get a user’s Oracle JRE installation to use arenas? The only realistic scenario is to preallocate and reuse.

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Re:Eclipse OpenJ9 – Open-source JVM by pron on Sunday September 17, 2017 @06:08AM (#15268970)
You don't. You use an RTSJ JVM.
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Re:Eclipse OpenJ9 – Open-source JVM by kuschku on Sunday September 17, 2017 @08:58AM (#15269397)
That’s not an option, that was the whole point of the discussion.
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Re:Eclipse OpenJ9 – Open-source JVM by pron on Sunday September 17, 2017 @11:12AM (#15269963)
If changing the JVM spec is an option, then surely so is using an existing spec. IBM has an RTSJ JVM[1], which, I believe, is based on J9.

[1]: https://www.ibm.com/support/knowledgecenter/en/SSSTCZ_3.0.0/...

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Re:Eclipse OpenJ9 – Open-source JVM by kuschku on Sunday September 17, 2017 @04:04PM (#15271434)
Changing the JVM spec has a chance at being applied in future normal JVMs. Using an entirely separate solution has not.
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Re:Eclipse OpenJ9 – Open-source JVM by pron on Sunday September 17, 2017 @04:30PM (#15271539)
It's not an entirely separate solution, but a Java standard. In any event, it's probably overkill if all you need are acceptable pause-times for games (RTSJ is for hard-realtime, safety-critical systems, where even 2us jitter may kill someone). There are "pauseless" GCs for the JVM (with 1-10ms max pause, depending on the GC) without hard realtime guarantees. We just need more free implementations.
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Re:Eclipse OpenJ9 – Open-source JVM by mstoodle on Monday September 18, 2017 @02:11AM (#15273708)
Eclipse OpenJ9's -Xgcpolicy:metronome is one of those GCs. Depending on how you well you configure your operating system, it defaults to 3ms pauses along with an application utilization contract.
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