Native Image Committer and Community Meeting 2026-07-30

[wirthi]

List of all past and upcoming meetings: #3933

The meeting will be at our regular time of 17:00 CET: https://www.timeanddate.com/worldclock/fixedtime.html?iso=20260730T08&p1=224

The meeting after this one is planned for August 27th, 2026. The meeting will typically be on the last Thursday of each month.

PRs listed below were merged between June 25th and July 28rd (roughly).

External contributions

Thanks to the external contributors whose work is included in this Native Image-focused report:

• Galder Zamarreno @galderz contributed a Native Image Layers singleton fix on AArch64 (Fix singletons not allowed building native image layers on aarch64 #13867).
• Bruno Verachten @gounthar contributed Native Image POSIX/RISC-V fixes (fix(riscv64): implement fixed-parameter and return-saving calling convention #13826, fix(posix): map pthread_key_tPointer to pthread_key_t instead of size_t #13391).

New and Noteworthy

Native Image Layers and Analysis improvements

• [GR-71856] [GR-72071] Add support for multiple layered image build in the same process #13954
  Adds support for building multiple layered images in the same process, including reusable layer path digests and application-layer singleton handling. Useful for batch testing.
• [GR-77727] Close the graph channel with a try-with-resources block #14045
  Fix memory leak during failed layered build in the same process.
• [GR-65437] [GR-77499] Use containing method and bci to make lambda name stable #14013
  Improves generated lambda names matching by using the containing method and BCI and updates layer snapshot persistence for lambda capture sites. Increases the number of lambdas we can reliably link between layers.
• Fix singletons not allowed building native image layers on aarch64 #13867
  Thank you to @galderz for the original contribution.
• [GR-77608] [GR-77711] [GR-77719] Remove Darwin AMD64 from the layer support matrix #14011
  Supported platforms: LINUX AMD64, LINUX AARCH64, DARWIN AARCH64, WINDOWS AMD64.
• [GR-76805] Parallelize static-final field relinking #13870
  This improves the application layer build time for a larger Micronaut app by around 17% .
• [GR-77859] Support user directory heap detection in layered base images. #14066
• [GR-72070] Make ReportUnsupportedElementsAtRuntime behave better with base layer build. #14071
• [GR-75553] Support an updated value of null in the CrossLayerFieldUpdaterFeature #14000
• [GR-77163] Safely publish object type id cache. #14006
• [GR-75591] Don't add empty TimeZoneSupport in OS other than Windows #13999
• [GR-73527] Rename Disallowed trait to DisallowLayered #13877

Project Crema

• [GR-76673] [GR-76674] [GR-76675] Implement JNI FindClass support for Crema runtime-loaded classes #13962
  Implements JNI FindClass support for Crema runtime-loaded classes.
• [GR-71358] [GR-73664] JNI upcall support for Crema #14017
  Adds JNI upcall support for Crema.
• [GR-76480] Fix declaringClass in JNINativeLinkage #13878
• [GR-76635] Support running JDK tests on Crema #14020
  This covers tests under https://github.com/openjdk/jdk/tree/master/test using jtreg wrapped via mx run-jdk-test
• [GR-72095] Crema threaded interpreter #14035
  Implements the Crema threaded interpreter, using indirect tail jumps between bytecode handlers to reduce dispatch overhead and improve branch prediction. Improves interpreter performance across the board: on average around 30%, up to 70% for some workloads.
• [GR-76015] Enable signal handling for libjvm #13885
  Matches support available in HotSpot. Runtime-loaded classes can install handlers through jdk.internal.misc.Signal, and install the default Native Image SIGSEGV/SIGBUS handlers.
• [GR-76264] Align Java thread minimum stack handling with HotSpot #13862
  Add a HotSpot-style Java thread minimum stack size for explicit Thread constructor stack sizes, separate from the default stack size.
• [GR-75596] Bind caller-sensitive method handles. #13927
• [GR-71427] Invokespecial checks receiver type if target method is an interface method. #13915
• [GR-77852] [GR-77853] Improve ffm terminal compatibility and avoid build-time path capture in libjvm #14062
• [GR-76139] Set sun.boot.library.path lazily and libjvm soname. #14033

Project Terminus: Towards the "Hello, Espresso World!" #12236

• [GR-76910] Rename VMAccess host proxy API #13886
  (summarized change) Renames the VMAccess callback proxy API to createHostProxy, consistently describing the host-to-guest proxy boundary.
• [GR-76723] Classify Native Image modules by owning context #13909
  (summarized change) Classifies Native Image builder and core guest modules in their owning VM contexts and resolves guest module membership through VMAccess.
• [GR-76695] Move JavaMainSupport to guest staging #13859
  (summarized change) Lands Java-main state and argument support in guest staging and introduces a temporary guest-owned entry-point stub for fully isolated Terminus builds; moving the full Java main wrapper remains follow-up work.
• [GR-76784] Move image heap map support to guest staging #13880
  (summarized change) Moves image-heap map infrastructure to guest staging and introduces shared and guest-safe access to image-layer build state.
• [GR-76993] Move runtime option state to guest staging #13928
  (summarized change) Moves runtime option keys, values, validation, runtime support, and shutdown state to guest staging while providing explicit hosted access to guest option metadata.
• [GR-76998] Move runtime option parser to guest staging #14048
  (summarized change) Moves runtime option parser support to guest staging. This includes the runtime option parser, X options, GC options, heap-size verification, and related support behind explicit guest/core bridges.
• [GR-77565] Support substratevm immutable options in engine.IsolateOption. #14032
  (summarized change) Supports applying immutable SubstrateVM options through engine.IsolateOption when creating isolated contexts.
• [GR-77508] Convert guest annotation values in host proxies #14036
  (summarized change) Adds bidirectional annotation conversion across VMAccess host proxies, including nested annotations, enums, class literals, defaults, arrays, and deferred failures.
• [GR-73163] [GR-77441] Convert package and record components through VMAccess #14096
  (summarized change) Adds VMAccess conversion for Package and RecordComponent, including external Espresso JVMCI metadata and annotation transport.
• [GR-77564] [GR-77627] [GR-73521] [GR-77606] [GR-77642] Batch Terminus prerequisite moves #14004
  (summarized change) Batches several Terminus prerequisite moves across runtime options, GC options, runtime support, and guest-staging bridges. Concretely, the landed batch separates libc identity, moves context-neutral runtime utilities and uninterruptible atomic helpers, and shares NeverInline metadata.
• [GR-77747] [GR-77748] [GR-77749] [GR-77750] Batch thread-runtime migration prerequisites #14091
  (summarized change) Batches four thread-runtime migration prerequisites: guest-staging ThreadLocalHandles, platform-based code-synchronization checks, non-String uninterruptible utilities, and basic thread-runtime contracts.
• [GR-77851] Add @GuaranteeFolded to fields containing HotSpot in their name #14058
  (summarized change) Marks remaining HotSpot-named compatibility fields as guaranteed folded so host-specific state cannot enter the runtime image.

Streamline reachability metadata

• [GR-70895] Preserve duplicate resource indexes in resource paths. #13802
  (PR description) Preserves duplicate resource indexes in resource paths.
• [GR-77071] Handle incomplete Externalizable classes #13950
  (summarized change) Handles incomplete Externalizable classes.
• [GR-76332] Preserve reflection linkage errors. #13738
• [GR-76936] [GR-76925] Ignore Micronaut static service definitions singleton. #13907
• [GR-77486] Document how to access embedded resources. #14016

Usability

• [GR-61365] Use reflection and service providers for protocol handling. #13689
  (PR description) Deprecates --enable-http, --enable-https, --enable-url-protocols, and -H:DisableURLProtocols in favor of metadata
• [GR-73199] Separate executable VM arguments with -- between VM and application arguments #14029
  (summarized change) Separates native executable VM arguments from application arguments with --. Makes it possible to pass application arguments that look like VM options, such as -D... or another literal --.
• [GR-76804] Improve agent config write diagnostics. #13906
  (PR description) Improves native-image agent configuration write diagnostics.
• [GR-76964] Prevent bundle extraction outside temporary directory #13888
• [GR-53330] Document resource folder options in the embedders guide. #13873
• [GR-76872] GraalVM 25.1.3 Maven isolate artifacts missing native payloads on non-Linux platforms. #13884
• [GR-77536] Update Native Image libcontainer to jvmci-25.2-b20 #14053
• [GR-77790] Fix transient EADDRINUSE in agent-adminserver.test #14039

Monitoring / Tooling / Debugging

• [GR-76793] Improve usefulness of jitdump support by allowing inclusion without default enablement. #13852
  (PR description) Improves Native Image jitdump support by allowing inclusion without enabling it by default.
• [GR-76779] [GR-76986] Emit JFR shutdown event and remove VM-level shutdown hooks. #13911
  (summarized change) Emits the JFR shutdown event and removes VM-level shutdown hooks.
• [GR-74294] Recompute the JFR throttler lock #14086
  (PR description) Recomputes the JFR throttler lock to avoid retaining a hosted worker thread in the runtime image.
• [GR-76624] Apply JFR JVMEventTask substitution on all Platforms. #13914
• [GR-77109] JFR Event and container config fix. #13945
• [GR-76972] Add DumpOtherThreadStacksOnFatalError for crash diagnostics. #13894
• [GR-77057] Publish frame anchor data before thread status. #13910

Garbage Collector / Memory Management

• [GR-19645] Support G1 on Windows/AMD64. #13872
  (summarized change) Adds G1 support on Windows/AMD64.
• [GR-77358] [GR-77615] Introduce compressed (32-bit) references. #13981
  (PR description) Introduces compressed 32-bit references and updates Native Image memory-management documentation.
• [GR-76718] Outline G1 write barriers in Native Image. #13956 reduces binary size with PGO (up to 8%) and -Os.
• [GR-73826] Cover all serial GC phases with JFR events. #14047

Other & fixes

• [GR-73735] Enable Vector API support by default. #13959
• [GR-76920] Revive RISC-V backend #13926
• [GR-77717] LLVM backend: preserve thread register in entry points. #14021
  (summarized change) Preserves the thread register in LLVM backend entry points.
• fix(riscv64): implement fixed-parameter and return-saving calling convention #13826
  (external contribution) Thank you to gounthar for the original contribution.
• fix(posix): map pthread_key_tPointer to pthread_key_t instead of size_t #13391
  (external contribution) Thank you to gounthar for the original contribution.
• [GR-77092] Fix compact object header hub read #13921
• [GR-69111] Introduce CheckSVMInvariants. #13929
• [GR-76603] Port P-256 IntegerPolynomial stubs #14023
• [GR-76604] Port SHA3Parallel doubleKeccak to Graal #14042
• [GR-76605] Port DigestBase multi-block stubs #14063
• [GR-74813] Reduce libgraal runtime classpath reachability. #13871
• [GR-77844] [GR-77845] Add missing Web Image ImageSingletons #14084
• [GR-75818] Restore OOME allocation edges during SVM graph decoding #13934

Graal compiler / JIT-related

• [GR-76919] Use initValue in rawConstantMaxTripCount #13890
• [GR-71911] Change childBci encoding to byte offset. #13889
• [GR-76944] Revert debug-info frame-state cache #13892
• [GR-76772] Support AMD64 pairwise vector multiply add #13902
• [GR-76979] Intrinsify VectorSupport.indexVector #13898
• [GR-60501] Encapsulate HotSpot field locations #13904
• [GR-76984] Fix Vector API guard hoisting condition insertion. #13935
• [GR-76980] Optimize Vector API library calls #13942
• [GR-76901] Reset tail-call handler loop counters #13938
• [GR-77541] Improve implications between signed and unsigned integer comparisons for non-negative operands. #13976
• [GR-77552] Conditional int/double merge deopt loop. #13983
• [GR-77546] Handle narrow integer abs helpers #13973
• [GR-70013] Support JDT builds with project compliance 25 #13997
• [GR-77351] Update to LLVM 22.1.8. #14040
• [GR-77815] Use unaligned loads for P256 constants #14041
• [GR-76615] Avoid using equals when checking type equivalence of composite types. #14056
• [GR-77664] Use GuardPriorities to order propagation in ConvertDeoptimizeToGuard #14068
• [GR-77663] Migrate InvocationPlugin type metadata to JVMCI #14079

Questions

GraalVM Deep Dive: No presentation today

• If there is any other topic you would think worthwhile to present, let us know.
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