Native Image Committer and Community Meeting 2024-12-19

[wirthi]

List of all past and upcoming meetings: #3933

The meeting after this one is planned for January 30th, 2025. After that, there will be a meeting on the last Thursday of each month.

New and Noteworthy

• JDK 24 is feature complete
  [GR-60307] Start 25.0.0 dev cycle. #10299

• Native Image Layers
  [GR-57117] Make --layer-create=package=... take package name instead of cp entry. #10291
  [GR-57826] Layered images binary snapshot format. #10262
  [GR-59875] Fix graph strengthening for open world. #10261
  [GR-59009] [GR-59571] Improve trackAcrossLayers #10325
  [GR-60533] Fix NonSnippetLowerings ClassCastException. #10314
  [GR-60534] Make sure JFR EventConfiguration is scanned. #10312
  [GR-60100] Persist and load all possible annotation values #10306
  [GR-59867] Enable more testing with Native Image Layers. #10297
  [GR-59912] Persist all strengthened graphs from tracked methods #10289
  [GR-60044] Use runtime ClassLoader for unique name support. #10227

• GuestGraal

• Streamline reachability metadata
  [GR-60234] Register superclass serialization constructors by default #10213
  [GR-60237] Introduce serializable flag to reflection metadata #10215

• Usability
  [GR-60094] Test and review Native Image guides with JDK 24-EA. Part 2 #10315
  [GR-60429] Remove library exclusion for libraries with fixed issues #10284
  [GR-60383] Avoid recursive printing of exception causes #10260 (Red Hat)

• Monitoring / tools
  [GR-60550] Fix registration of VM diagnostics. #10322
  [GR-60176] JFR Old Object Sampler fixes #10190 (Red Hat)

• Debugging

• JEP 472 (Restrict use of JNI) - Integrity by Default
  [GR-60382] Handle Enable-Native-Access manifest attribute if present #10009 (Red Hat)
  [GR-57608] Support --enable-native-access hosted option in native image #10076

• FFM API / Panama
  [GR-52576] Introduce specialized upcalls for direct method handles. #10235
  [GR-60395] Allow combination of captureCallState and critical(true). #10301
  Adapt JDK-8336768: Allow captureCallState and critical linker options to be combined #10305 (Red Hat)

• Performance and Image Size

• WP-SCCP
  [GR-58668] Enable WP SCCP by default #10263
  [GR-60300] Fix -H:+PrintPointsToStatistics option and make it compatible with WP-SCCP #10281

• Other
  [GR-59749] Use a contiguous address space for the Native Image Java heap. #10323
  [GR-32682] [GR-52145] Add initial version of the Bytecode DSL. #9556 (Not Native Image, but still a good improvement for Truffle-based languages)
  [GR-60081] Update aarch64 to use the 8.1-a instruction set by default. #10173
  [GR-60343] Add change tracking for AdaptiveCollectionPolicy. #10310
  [GR-49635] [GR-59954] Update ClassLoaderValue maps to properly support modular service loading #10202
  [GR-24929] Add Alias for ConcurrentHashMap.NCPU and similar. #10246
  [GR-60242] Some methods must not be executed before feature registration has finished. #10228
  [GR-60173] Register custom module-info compilation participant for JDK builds without JMODs #10161 (Red Hat)

Questions

Deep Dive: Whole-Program Sparse Conditional Constant Propagation (WP-SCCP)

WP-SCCP is an extension of the points-to analysis in GraalVM Native Image that tracks primitive values and evaluates branching conditions during the run of the analysis. It allows us to produce binaries that are, on average, 6.5% smaller without increasing the build time. I will provide a high-level overview of WP-SCCP, focusing on its key features, impact on frameworks, and debugging support. The presentation should take approximately 20 minutes including questions.