Native Image Committer and Community Meeting 2023-03-09

[christianwimmer]

List of all past and upcoming meetings: #3933

New and Noteworthy

• Feature freeze for GraalVM 23.0 is Friday March 10 (tomorrow). Bugfixes can be merged for another few weeks.

• [GR-44216] Include native-image in GraalVM JDK. #5995 Starting with GraalVM 23.0, native image will be part of the core GraalVM download, so gu install native-image is no longer necessary.

• [GR-42112] Missing registration errors for reflection calls #6139 improvements to reflection configuration: distinguish between "method not found" and "method not registered for reflection".

• [GR-43971] Support native-image environment variable capturing in bundles. #6095 Environment variables are no longer passed to the image generator.

• [GR-44110] Add -march option and target x86-64-v3 by default. #6112 Targeting AVX2 on Intel by default, to allow vectorization, prefetching, ...

• [GR-40641] Dynamic linking of AWT libraries on Linux. #6088 Dynamic linking of AWT libraries, which was used on Windows all the time, is now used on Linux too. Darwin support is still pending.

• [GR-44201] Check more invariants for @Uninterruptible. #6124 Tightening the rules for @Uninterruptible a bit.

• Compatibility:
  [GR-36033] Properly calculate root module sets when not running on module path #5813 Some more module system support, including the --limit-modules option
  [GR-44025] [GR-39855] Disallow Cleanable and jdk.internal.ref.Cleaner on the image heap. #6062
  [GR-44245] Obsolete UseContainerCpuShares and PreferContainerQuotaForCPUCount flags. #6051

• Performance:
  [GR-44303] Never burden @ValueBased objects with a monitor field, including boxed primitives. #6046
  [GR-44099] Optimize card table scanning. #5963

• Monitoring / tools:
  [GR-10518] Heap dumping. #6135 new heap dump implementation that is allocation free, so can also produce heap dumps when out of memory.
  [GR-42740] [GR-44248] Experimental support for JFR event streaming. #6146 JFR event streaming
  [GR-40463] Add experimental support for JMX to Native Image. #5596 JMX support is finally merged
  [GR-38414] [GR-44546] MemoryPoolMXBean improvements for serial and epsilon GC. #6102
  [GR-44087] Support JFR event JavaMonitorInflate. #5987

Deep Dive

Environment variables are no longer passed to the image generator

When creating a bundle, then capturing all environment variables in a bundle is not feasible (would be a major leak of environment information). To make things consistent between bundle and non-bundle executions, now environment variables are cleared also in regular native image runs. Only environment variables listed explicitly via -E are preserved.

#6095 enables this by default, with a compatibility option to revert to the old behavior (which will go in the next release). But if it turns out in the next week that this change causes too many compatibility problems, we can still revert it.

Improvements to reflection configuration: distinguish between "method not found" and "method not registered for reflection"

See the following (older) writeup of the problem: https://github.com/graalvm/taming-build-time-initialization/blob/main/metadata-exceptions/Exceptions%20proposal.md

Possible deep dive topics for next meeting

• Upcoming improvements to reflection configuration: distinguish between "method not found" and "method not registered for reflection".
• Simulation of class initializer at image build time, to allow the new class initialization strategy where all classes can be used at image build time.

Please send suggestions in the GraalVM Slack channel