Platform Updates

Oracle GraalVM Enterprise Edition 21.1 is based on Oracle JDK version 1.8.0_291 and Oracle JDK version 11.0.11. GraalVM Community Edition in 21.1 is based on OpenJDK version 1.8.0_292 and OpenJDK version 11.0.11.

GraalVM 21.1 introduces new experimental binaries based on JDK 16 for both Enterprise and Community editions based on JDK 16.0.1.

The experimental status means that all components in the JDK 16 based binaries are considered experimental regardless what their status is in other distribution versions.

The JIT mode for Java applications is perhaps the most tested capability for these builds, so if you are interested in running your Java applications with the GraalVM compiler or are currently using the JVMCI compiler in any other JDK 16 OpenJDK builds, consider trying out the GraalVM binaries. These include the latest OpenJDK changes and the latest GraalVM compiler changes which is the best of both worlds setup.

Java 16 is the current release of Java and we are looking forward to providing support for the upcoming Java 17 LTS release. Note that due to the decommissioning of the aging macOS 10.7 build infrastructure, GraalVM Community Edition releases based on JDK 8 are no longer being built. Node.js included in GraalVM 21.1 has been updated to 14.16.1, which is recommended for most users.

There’s one more significant change regarding Node in GraalVM. As of GraalVM 21.1, Node.js support is no longer included in the base GraalVM download. It’s now a separate component that you can install with the gu install nodejs command. JavaScript support continues to be a part of the base download, it’s just the Node.js support that’s installable separately. This change is for speed and clarity — it aims to reduce the size of the base GraalVM download, and to reduce confusion among some users who want to use GraalVM primarily as their main JDK.

Compiler Updates

Updates to the compiler are especially exciting because they improve GraalVM across the board since the compiler underpins the performance of all the various languages supported on GraalVM!

In 21.1 there are two particularly interesting compiler improvements:

One new optimization eliminates unneeded memory barriers on sequential volatile writes on x86. Numerous volatile writes sometimes occur in a sequence after the code has been inlined. The GraalVM compiler now omits the memory barrier for all but the last write in the sequence, nicely speeding up methods like ConcurrentHashMap.transfer().

Loops Updates

This release includes support in the GraalVM Enterprise compiler for vectorizing loops that have the hashCode-like pattern. Hashcode is often computed with an idiom like: hash = c * hash + array[i] , which the compiler can now recognize and vectorize.

Another improvement in this regard is a novel loop inversion optimization. This adds compiler support to GraalVM Enterprise to generate inverted loops from regular ones. Inverted loops have superior characteristics for instruction-level parallelism and optimization capabilities compared to regular, head counted loops.

Native Image

GraalVM 21.1 adds support for multiple locales in Native Image. Now you can specify at build time which locales should be included in the generated executable. For example, to switch the default locale to German and also include French and English, use -H:DefaultLocale=de -H:IncludeLocales=fr,en. All locales can be included via –H:+IncludeAllLocales. ResourceBundles are included by default for all selected locales, but this can be changed by providing a locale-specific substring when requesting the bundle.


The version of Node.js GraalVM supports has been updated to 14.16.1. In this release, the node and npm binaries are not included in the base download, but are instead available to be installed separately.

JavaScript in GraalVM 21.1 includes Truffle’s support for iterators, iterables, and byte buffers, which allows JavaScript iterators to be used via the Value API hasIterator(), getIterator(), hasIteratorNextElement(), getIteratorNextElement(); iterable objects from other languages to be iterated in GraalVM’s JavaScript runtime, e.g., via for-of loops and vice versa; for the host ByteBuffers and buffers from other languages to be used with JavaScript typed arrays, e.g., new Uint8Array(foreignBuffer), and DataView without copying; and to access ArrayBuffers via the Value API: readBuffer*, writeBuffer*.


One of the more significant improvements in GraalVM 21.1 for Python is the enhanced support for Java subclassing and new interop APIs for better Jython migration path. Iteration over Python types from Java, catching and re-throwing Java exceptions in Python code, as well as implementing Java abstract classes and interfaces from Python are often-requested Jython features that GraalVM now provides, making the migration easier.


Tooling is a very important part of the GraalVM Ecosystem. In every release we’re trying to improve the developer experience by improving the tools that are part of the GraalVM distribution, including the debugger and profilers, etc. GraalVM 21.1 is no exception.

For example, VisualVM now also works on JDK 16 and has support for running on Apple M1 chips. The new version of the VS Code GraalVM Extensions, which includes a collection of features to make working with GraalVM, Java, and Micronaut applications easier:

Added unit test results visualization

  • Improved Micronaut support: YAML support and content assistance for configuration files, and more Java code editing features
  • Added new supported refactorings for Java code
  • Added support for Docker build commands for Micronaut projects
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