Per Minborg

📢 Announcement 📢

#Java peers, the 2026 #JavaOne call for papers is now LIVE. Please make your submissions by November 11, 2025 5:00 p.m. PT by visiting the conference website:

➡️ social.ora.cl/6013A7UXF

Performance Improvements in JDK 25 Java is constantly evolving with ever increasing performance. JDK 25 comes with significant performance improvements compared to previous versions including scoped values, improved GCs, lots of compil...

@pminborg.bsky.social and I wrote a bit about some of the many performance improvements in JDK 25: inside.java/2025/10/20/j...

tl;dr: upgrade to JDK 25 and add -XX:+UseCompactObjectHeaders

You can't have both laziness and immutability at the same time in #java ... until Lazy Constant arrives ...

JEP 526: Lazy Constants (Second Preview) is now a Candidate for JDK 26!

Read all about it here: openjdk.org/jeps/526

Looking forward to Java One next year!

My talk "Java Performance Update 2025: From JDK 21 to JDK 25" for @devoxx.com‬ was accepted!

I am looking forward to returning to Antwerp and meeting members of the #java community!

I will also do another talk: "Finally, final means final - A deep dive into field immutability in Java"

#Java peers, #JavaOne IS BACK AGAIN IN 2026 (March 17-19). Read our blog to learn more and sign up w/interest if you want to attend, speak, or sponsor: social.ora.cl/6011fdkbH

We integrated #java 's new Stable Values feature just now!

This will allow developers and library developers to benefit from the "secret" @Stable annotation that the internal JDK code has been using for years. This can bring significant performance improvements to your code!

openjdk.org/jeps/502

We just integrated a performance improvement to Java String that will provide a ~10x performance boost in some applications where Strings are used as keys and where the associated values are constant foldable. This will make JDK 25 faster.

github.com/openjdk/jdk/...

Thank you @jeanneboyarsky.bsky.social for this write up.

Performance Improvements in JDK 24 Java is constantly evolving with ever increasing performance. JDK 24 comes with significant performance improvements compared to previous versions including improved virtual thread handling, reduced s...

#java 24 is out and here is a summary of the performance improvements we made:

inside.java/2025/03/19/p...

Thanks!

[GR-58659] [GR-58660] Add FFM Support for {darwin,linux}-aarch64 on SubstrateVM by graalvmbot · Pull Request #10856 · oracle/graal Adds support for AArch64 platforms. This is based on the x86_64 implementation and adapted accordingly.

You asked, we delivered: we merged FFM support in @graalvm.org Native Image on MacOS/AArch64!🚀😍
github.com/oracle/graal...
This means that you can now also build and run locally apps like github.com/mukel/llama3... (cc @stephanjanssen.be :))
Coming soon in GraalVM for JDK 25 EA builds!🎉

#java 's new Stable Values API (Preview) was just targeted for JDK 25!

Don't miss my talk at #JavaOne about Stable Values: reg.rf.oracle.com/flow/oracle/...

AtomicReference cannot be constant folded by the VM as its content can change arbitrary. Also, there is no invoke-at-most lambda feature.

Checkout JEP 502 where there are some basic examples. Happy reading!

Great work!

`final` variables will still be needed in most cases, but stable values give you a new choice.

We have been working hard on a new feature for #java called "Stable Values".

Don't miss my talk at #JavaOne where I uncover what this can mean in terms of improved performance and maintainability for your Java code.

Early bird discounts are still available!

reg.rf.oracle.com/flow/oracle/...

YouTube video by Java Java Performance Update

My talk at Devoxx BE on "Java Performance Update" for JDK24 seems to attract much attention — almost 50K views in the first week alone.

Find out what you think about it and let me know your thoughts: www.youtube.com/watch?v=rXv2...

Hey #Java Developers, ☕️

JavaOne is happening March 18-20 in Redwood Shores, CA. JavaOne is your opportunity to learn about the future of Java from experts like @pminborg.bsky.social on features like Stable Value

Buy your tickets now: inside.java/j1?utm_sourc...

The new StableValues JEP for #java is now one step closer to being finalized: openjdk.org/jeps/8312611

Stable Values will provide the benefits of final fields but with flexible initialization, much like combining the benefits of final and non-final fields.

This appears to be a thing with American car manufacturers with four-letter surnames. Jokes aside, this is horrific.

Section 3; 14th amendment ...

#Java developers!

@JavaOne is BACK (18-20 Mar). Early bird registration is available through Feb 9th. Please (re)join us at THE conference that started it all...

Blog ➡️ social.ora.cl/6015Qne5z
Event ➡️ javaone.com

#JavaOne #OpenJDK #JDK

The JDK 24 train has left the station, and now we are working on JDK 25. I am hoping to see some cool improvements in this one:

This is useful if you want to convert a C-string from a native call to a Java String.

8345120: A likely bug in StringSupport::chunkedStrlenShort by minborg · Pull Request #22451 · openjdk/jdk This PR proposes to rewrite the StringSupport::chunkedStrlen* methods, fixing a bug in the short_strlen variant for odd offsets (offset % 2 != 0). This PR also improves performance on modern hardw...

The fork for JDK24 is approaching and we are about to integrate a PR that will improve string-length performance for the Foreign Function & Memory API (FFM) by about 30% for common cases.

It started out as a bug (which was also solved) and ended with better performance.

github.com/openjdk/jdk/...