Native Image Committer and Community Meeting 2022-12-14

[christianwimmer]

List of all past and upcoming meetings: #3933

New and Noteworthy

• OpenJDK Project Galahad: call for discussion is out

• JDK 20 support is work in progress, PRs will come soon.

• GraalVM 23.0 will be base on JDK 20 only. But we will keep some testing on JDK 17 for the forseeable future, so that will be the Java language level we can use.

• Use new JVMCI API: merge only after next OpenJDK release, or not a problem if we merge now?
  [GR-41977] Adapt to JVMCI API changes. #5455

• Open source Ideal Graph Visualizer #4998 IGV will be soon in the Graal repository, so open source again

• Native Image API:
  [GR-42823] Add native-image API for defining built-in system-properties for image-runtime #5557. #5559

• Use only stdout for output in the image generator, instead of mixing stdout and stderr:
  [GR-42804] Disallow System.err in c.o.svm.(core|hosted). #5614

• Peak performance improvements:
  [GR-34100] Use non-object owner thread identifiers in JavaMonitor. #5544
  [GR-34100] Java monitor improvements. #5461
  [GR-34100] ParkEvent improvements. #5486
  [GR-29145] Strengthen graphs with constants propagated through static analysis. #5454

• Improve static analysis time by doing more in parallel:
  [GR-36810] Parallelize reflection analysis code #5613

• Improve tracking why an element is reachable:
  [GR-41279] Provide reason for AnalysisType reachability. #5515
  [GR-41279] Add reason for AnalysisType instantiation. #5453
  [GR-41279] Track AnalysisMethod invoke reason. #5543

• Monitoring / tools:
  [GR-42375] Introduce -H:±GenerateBuildArtifactsFile option. #5441
  [GR-42666] Report correct generation capacities in SerialGCPerfData. #5554
  [GR-41668] JFR and Sampler code improvements and bug fixes. #5518

Deep Dive

Tracking in the analysis why an element is reachable

All "reachable" flags in the static analysis are now of type Object instead of boolean. When non-null, the element is reachable, and the value stores the reason why the element is reachable.

Image heap connected components

#5618 is work-in-progress to show a partitioning of the image heap based on root pointers. This allows identifying groups of image heap objects that are only reachable from one or a few methods.

Possible deep dive topics for next meeting

• Upcoming improvements to reflection configuration: distinguish between "method not found" and "method not registered for reflection".

Please send suggestions in the GraalVM Slack channel