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What's new in the OpenJ9 project

Find out what's happening at the project. Read about the highlights of our latest release. Catch the latest blog posts from our blog site; get top tips or deep dives about key features of OpenJ9 or simply read about experiences of working in the community.

Latest release

Eclipse OpenJ9 version 0.32.0 released

April 2022

We're pleased to announce the availability of Eclipse OpenJ9 v0.32.0.

This release supports OpenJDK version 8, 11, 17, and 18. For more information about supported platforms and OpenJDK versions, see Supported environments.

This release includes an early access build for Apple Silicon (AArch64) macOS. You can use this build for evaluation purposes; it is not yet suitable for use in production environments.

Other updates in this release include the following:

  • The JITServer technology feature is now fully supported on Linux for IBM Z® (64-bit)
  • In Java 11 and later, the default value of the -XX:MaxDirectMemorySize option, which limits the amount of heap memory that is used for direct byte buffers, is now the same as the maximum heap size. Previously, the limit was 87.5% of the maximum heap size.
  • You can now use the SharedClassStatistics API to get the name, path, and directory of a shared classes cache. Depending on the operating system, you can also get the number of attached VMs for a non-persistent cache. This information is available through the following new methods: cacheDir(), cacheName(), cachePath(), and numberAttached(). For more information, see the API documentation.

To read more about these and other changes, see the OpenJ9 user documentation.

Other performance highlights include exploitation of the new IBM® z16™ hardware platform, for example:

  • External decimal conversion acceleration with the Vector Packed Decimal Facility in the data access accelerator library
  • Acceleration of the Integer.toString(), Long.toString(), and BigDecimal.toString() methods
New release info

Recent blogs

Collecting native stack traces on MacOS with libunwind

16 March 2022

Eclipse OpenJ9 uses the omrintrospect library in Eclipse OMR to incorporate native stack traces in the javacores (diagnostic files). This library allows the collection of thread call stacks in a process by suspending and iterating over each thread. On MacOS, all stacks are generated using the libunwind library, a simple and efficient API for register…

Copyforward&Mark Hybrid Collector

17 December 2021

Background Xgcpolicy:balanced Open J9’s Balanced GC policy is a region based, incremental generational collector, unlike the default generational concurrent policy (gencon), which is probably best suited for the most traditional java application, Balanced GC is designed to be used on large heap to reduce maximum pause times. In Balanced GC The Java heap is divided…

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OpenJ9 is an Eclipse Incubator Project
OpenJ9 is an Eclipse Incubator Project
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