This is the 7th and final PR for [JEP 483: Ahead-of-Time Class Loading & Linking](https://bugs.openjdk.org/browse/JDK-8315737).
This PR implements the AOT-linking of invokedynamic callsites: - We only link lambda expressions (`LambdaMetafactory::metafactory`) and string concat (`StringConcatFactory::makeConcatWithConstants()`) as the results of these bootstrap methods do not have environment dependencies and can be safely cached. - The resolved CallSites are represented as Java heap objects. Thus, this optimizations is supported only for the static CDS archive, which can store heap objects. The dynamic CDS archive is not supported. **Review Notes:** - Start with `AOTConstantPoolResolver::preresolve_indy_cp_entries()` -- it checks all indys that were linked during the training run, and aot-links only those for lambdas and string concats - `SystemDictionaryShared::find_all_archivable_classes()` finds all the hidden classes that are reachable from the indy CallSites - In `MetaspaceShared::preload_and_dump_impl()` we call `MethodType::createArchivedObjects()` to record all MethodTypes that were created in the assembly phase. This is necessary because the identity of MethodTypes is significant (they are compared with the `==` operator). Also see MethodType.java for the corresponding code that are used in the production run. - Afterwards, we enter the safepoint (`VM_PopulateDumpSharedSpace::doit()`). In this safepoint, `ConstantPoolCache::remove_resolved_indy_entries_if_non_deterministic()` is called to remove any resolved indy callsites that cannot be archived. (Such CallSites may be created as a side effect of Java code execution in the assembly phase. E.g., the bootstrap of the module system). **Rough Edges:** - Many archived CallSites references (directly or indirectly) the static fields of the classes listed under `AOTClassInitializer::can_archive_initialized_mirror()`, where the object identity of these static fields is significant. Therefore, we must preserve the initialized states of these classes. Otherwise, we might run into problems such as [JDK-8340836](https://bugs.openjdk.org/browse/JDK-8340836). Unfortunately, the list is created by trial-and-error, and may need to be updated to match changes in the `java.lang.invoke` and `jdk.internal.constant` packages. We expect Project Leyden to come with a general solution to this problem. - If the identity is significant for a static field in a complex class, but not all of the static fields of this class can be archived, I use the `AOTHolder` pattern to break out the fields that need to be archived. See discussion on [leyden-dev](https://mail.openjdk.org/pipermail/leyden-dev/2024-August/000911.html). --- See [here](https://bugs.openjdk.org/browse/JDK-8315737) for the sequence of dependent RFEs for implementing JEP 483. ------------- Depends on: https://git.openjdk.org/jdk/pull/21049 Commit messages: - improve checks for not changing <clinit> order for aot linking of lambda; added comprehensive test cases: AOTLinkedLambdasApp::testClinitOrder() - Clean up of aotClassInitializer and cdsHeaVerifier; added lambda test cases for <clinit> order of app classes - Merge branch 'jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke' into jep-483-step-07-8293336-store-lambda-forms-in-cds-archive - Require all <clinit> of supertypes of aot-inited classes to be executed in assembly phase - Limit the use of AOTHolder - Merge branch 'jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke' into jep-483-step-07-8293336-store-lambda-forms-in-cds-archive - Merge branch 'remerge' into jep-483-step-07-8293336-store-lambda-forms-in-cds-archive - more clean up - Cleaned up AOTClassInitializer::can_archive_initialized_mirror() - more clean up - ... and 14 more: https://git.openjdk.org/jdk/compare/1b067b7b...195303f2 Changes: https://git.openjdk.org/jdk/pull/21143/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21143&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8293336 Stats: 1674 lines in 52 files changed: 1534 ins; 39 del; 101 mod Patch: https://git.openjdk.org/jdk/pull/21143.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21143/head:pull/21143 PR: https://git.openjdk.org/jdk/pull/21143
