Definitely support the idea of investigation whether it impacts ThreadContext usage or not. I suspect certain thread-local usages might be broken too.
Why do you think this should be targeted for the master branch only? On Mon, May 16, 2022 at 8:37 PM Ralph Goers <ralph.go...@dslextreme.com> wrote: > Removing David, > > We are going to have to investigate this and determine how it impacts > ThreadContext usage. Note that this should be targeted for the master > branch only. > > Ralph > > > > On May 16, 2022, at 12:50 AM, David Delabassee < > david.delabas...@oracle.com> wrote: > > > > Welcome to a new Quality Outreach update! > > > > This time, we have one update but a major one: JEP 425 (Virtual Threads > preview) has been integrated into the OpenJDK mainline! JDK 19 Early-Access > builds 22 are the first mainline builds with Virtual Threads (preview) > support. So, Project Loom is now getting closer and closer! > > > > Please make sure to check the Heads-up below even if you don’t intend to > use virtual threads in the short future. > > > > > > ## Heads-up - JEP 425 Virtual Threads (preview) testing > > > > The goal of Project Loom is to introduce in the Java platform an > easy-to-use, high-throughput lightweight concurrency model, and a related > new concurrent programming model. > > > > Developed in Project Loom, JEP 425 introduces virtual threads to the > Java Platform. Virtual threads are lightweight threads that dramatically > reduce the effort of writing, maintaining, and observing high-throughput > concurrent applications. Note that virtual threads are a preview API in JDK > 19. Please make sure to read 'JEP 425: Virtual Threads (Preview)' for a > detailed explanation. > > > > A lot of testing has already been done but we are asking, once again, > your help to test your project(s) with the latest JDK 19 Early-Access > builds, even if you don’t intend to use virtual threads any time soon. > > > > There are two approaches to test your project: > > 1. Update your code to use virtual threads …or > > 2. Simply test your existing unchanged code with the preview feature > enabled. > > > > Both approaches should yield valuable feedback. > > > > If you choose to adapt your application to use virtual threads (cf. > JavaDoc [2]), be aware that in some cases it’s not just about updating your > code to use virtual threads instead of platform threads; there are some > additional considerations. For example, virtual threads shouldn’t be pooled > [3], code that relies heavily on thread locals [4] will require some work > to move to a world where there is a new thread for each task, etc. > > > > Given that are some minor behavior changes and that `ThreadGroup` has > been degraded, testing your code as-is, i.e., without using virtual threads > but with the preview feature enabled at runtime, will also be useful. For > more details, please check 'JEP 425 - Risks and Assumptions' [5]. > > > > One difference between to the EA builds published by Project Loom and > the latest JDK 19 EA builds is that the `--enable-preview` flag is required > at run-time to use the new APIs. It’s not possible to use the APIs with > core reflection to avoid the need for `--enable-preview`. > > > > Finally, some tools especially tools relying on JVM TI agents might not > be fully ready for virtual threads. > > > > Your help testing this important update is greatly appreciated, all > feedback should be sent to the 'loom-dev' mailing list [6]. > > > > [1] https://openjdk.java.net/jeps/425 > > [2] > https://download.java.net/java/early_access/jdk19/docs/api/java.base/java/lang/Thread.html > > [3] https://openjdk.java.net/jeps/425#Do-not-pool-virtual-threads > > [4] https://openjdk.java.net/jeps/425#Thread-local-variables > > [5] https://openjdk.java.net/jeps/425#Risks-and-Assumptions > > [6] https://mail.openjdk.java.net/pipermail/loom-dev/ > > > > > > ## JDK 19 Early-Access builds > > > > JDK 19 Early-Access builds 22 are now available [7], and are provided > under the GNU General Public License v2, with the Classpath Exception. Make > sure to check the Release Notes [8] and the JavaDoc [9]. > > > > [7] https://jdk.java.net/19/ > > [8] https://jdk.java.net/19/release-notes > > [9] https://download.java.net/java/early_access/jdk19/docs/ > > > > ### Current JDK 19 JEPs > > - 405: Record Patterns (Preview) - Proposed to target > > - 422: Linux/RISC-V Port - Integrated > > - 424: Foreign Function & Memory API (Preview) - Integrated > > - 425: Virtual Threads (Preview) - Integrated > > - 426: Vector API (4th Incubator) - Targeted > > - 427: Pattern Matching for switch (3rd Preview) - Targeted > > > > ### Recent changes that may be of interest: > > > > Build 22: > > - JDK-8284161: Implementation of Virtual Threads (Preview) > > - JDK-8285947: Avoid redundant HashMap.containsKey calls in ZoneName > > - JDK-8212136: Remove finalizer implementation in SSLSocketImpl > > - JDK-8285872: JFR: Remove finalize() methods > > - JDK-8285914: AppCDS crash when using shared archive with old class file > > - JDK-8286163: micro-optimize Instant.plusSeconds > > - JDK-8282420: JFR: Remove event handlers > > - JDK-8282559: Allow multiple search terms in javadoc search > > > > Build 21: > > - JDK-8255552: Add DES/3DES/MD5 to jdk.security.legacyAlgorithms > > - JDK-8278370: [win] Disable side-by-side installations of multiple JDK > updates in Windows JDK installers > > - JDK-8281010: [macos] Disable side-by-side installations of multiple > JDK updates in macOS JDK installers > > - JDK-8236128: Allow jpackage create installers for services > > - JDK-8279598: provide adapter from RandomGenerator to Random > > > > Build 20: > > - JDK-8284553: Deprecate the DEFAULT static field of OAEPParameterSpec > > - JDK-8283620: System.out does not use the encoding/charset specified in > the Javadoc > > - JDK-8285445: Enable Windows Alternate Data Streams by default > > - JDK-8284930: Re-examine FilterInputStream mark/reset > > - JDK-8284890: Support for Do not fragment IP socket options > > - JDK-8282823: javac should constrain more uses of preview APIs > > - JDK-8285477: Add a PRECISION public static field to j.l.Float and > j.l.Double > > > > Build 19: > > - JDK-8186958: New Methods to Create Preallocated HashMaps > > - JDK-8284775: Simplify String.substring(_, length()) calls > > - JDK-8283892: Compress and expand bits > > - JDK-8280915: Better parallelization for AbstractSpliterator and > IteratorS… > > - JDK-8284681: compiler/c2/aarch64/TestFarJump.java fails with > "RuntimeExce… > > - JDK-8283790: G1: Remove redundant card/heap-address transition > > - JDK-8285001: Simplify StringLatin1.regionMatches > > - JDK-8284880: Re-examine sun.invoke.util.Wrapper hash tables > > - JDK-8278356: Improve file creation > > > > > > ## Topics of Interest > > > > - Java Cryptographic Roadmap update > https://java.com/en/jre-jdk-cryptoroadmap.html > > - Virtual Thread Deep Dive > https://inside.java/2022/04/07/insidejava-newscast-023/ > > - Why Write an Empty finalize() Method? > https://stuartmarks.wordpress.com/2022/04/27/why-write-an-empty-finalize-method/ > > - WHEN and NULL In Pattern Matching > https://inside.java/2022/05/05/insidejava-newscast-024/ > > - JDK 8 to JDK 18 in GC: 10 Releases, 2000+ Enhancements > https://inside.java/2022/05/02/odl-jdk8-to-jdk18-gc/ > > - ZGC - What's new in JDK 18 https://malloc.se/blog/zgc-jdk18 > > - Java Next - From Amber to Loom, from Panama to Valhalla > https://inside.java/2022/05/09/java-next/ > > > > > > ## JDK Update Patch Release > > > > As announced with the April 2022 CPU release, we have produced update > patch releases for all Java SE supported versions. The new versions are JDK > 18.0.1.1 (publicly available), 17.0.3.1 (publicly available), 11.0.15.1, > 8u333, 7u343, and OpenJDK 18.0.1.1 (publicly available). > > > > > > As usual, let us know if you find any issues while testing your > project(s) on the latest JDK early-access builds. Thanks for your support! > > > > --David > > > > > > > > > >
