RFR: 8353597: Refactor handling VM options for AOT cache input and output
Ioi Lam
iklam at openjdk.org
Thu Apr 3 04:09:28 UTC 2025
Since [JEP 483: Ahead-of-Time Class Loading & Linking](https://openjdk.org/jeps/483), VM options such as `-XX:AOTCache `are implemented as aliases of "classical" CDS options such as `-XX:SharedArchiveFile`.
In anticipation of the [JEP: Ahead-of-time Command Line Ergonomics](https://bugs.openjdk.org/browse/JDK-8350022), we should refactor the code that deals with the AOT options. Specifically, as we expect the JVM to be able to load from an "input AOT cache" and write to an "output AOT cache", we should clearly identify the input and output caches in separate APIs:
const char* CDSConfig::input_static_archive_path();
const char* CDSConfig::input_dynamic_archive_path();
const char* CDSConfig::output_archive_path();
This PR also cleans up the code by:
- renaming a few function to reflect what they actually do
- moving more "config" management code into cdsConfig.cpp
There's also a behavioral bug fix: before this PR, `-XX:AOTCache` was handled by the `ergo_init_classic_archive_paths()` function, which allows two files to be specified. E.g., `java -XX:AOTCache=static.jsa:dynamic.jsa`. That's because `-XX:AOTCache` was implemented as an alias of `-XX:SharedArchiveFile`, and the latter allows this usage.
However, this behavior is not specified in JEP 483. Allowing two files in -XX:AOTCache will cause unnecessary complexity when we implement [JDK-8353598: Allow AOT cache to be used in training run](https://bugs.openjdk.org/browse/JDK-8353598). Therefore, I added new test cases to disallow the use of two files. This also means that we don't need to modify the already over-complicated `ergo_init_classic_archive_paths()` for the AOT use cases
-------------
Depends on: https://git.openjdk.org/jdk/pull/24272
Commit messages:
- Minimized changes in ergo_init_classic_archive_paths()
- Clean up CDS input/output path handling
Changes: https://git.openjdk.org/jdk/pull/24401/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24401&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8353597
Stats: 304 lines in 15 files changed: 156 ins; 55 del; 93 mod
Patch: https://git.openjdk.org/jdk/pull/24401.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/24401/head:pull/24401
PR: https://git.openjdk.org/jdk/pull/24401
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