Great news: Lucene 9.4 (optionally) uses mapped MemorySegments when JDK 19 is detected

[Remi Forax]

Hi Uwe,
i wonder if you will not be in trouble when Java 20 will be out with your multi-releases jar,
because the VM 10 will try to run the bytecodes under the 19 folder and because it is compiled with --enable-preview --source 19, it will not work.

(Alan in CC, to check i'm not saying something stupid.)

regards,
Rémi

----- Original Message -----
> From: "Uwe Schindler" <uschindler at apache.org>
> To: "Maurizio Cimadamore" <maurizio.cimadamore at oracle.com>, panama-dev at openjdk.org
> Sent: Thursday, September 29, 2022 5:46:40 PM
> Subject: Great news: Lucene 9.4 (optionally) uses mapped MemorySegments when JDK 19 is detected

> Hi all, hi Maurizio,
> 
> I just wanted to inform you that after Java 19 was released we jumped on
> the train and we will most likely release Apache Lucene 9.4 already
> tomorrow with support for project Panama. Users can run Lucene-based
> applications with "--enable-preview" and all should work automatically
> thanks to MR-JAR.
> 
> The PR was merged on Monday after Eclipse Adoptium made the JDK 19
> builds available, so Gradle was able to pick them up to compile the
> MR-JAR part against it without having the Lucene developer to install
> JDK 19 in addition to Java 11/17. You can see the Panama code and also
> the Gradle setup and classloading tricks at runtime (that create/support
> the MR-JAR) here: https://github.com/apache/lucene/pull/912
> 
> I also opened issues in Elasticsearch ad Opensearch, so users can test
> it and report slowness/bugs earlier:
> https://github.com/elastic/elasticsearch/issues/90526,
> https://github.com/opensearch-project/OpenSearch/issues/4637
> 
> Uwe
> 
> --
> Uwe Schindler
> uschindler at apache.org
> ASF Member, Member of PMC and Committer of Apache Lucene and Apache Solr
> Bremen, Germany
> https://lucene.apache.org/
> https://solr.apache.org/