On Fri, 22 Aug 2025 17:24:18 GMT, Ioi Lam <ik...@openjdk.org> wrote:
>> This PR loads the classes for the boot/platform/app loaders with
>> `AOTLinkedClassBulkLoader::preload_classes()`. This happens at the very
>> beginning of `vmClasses::resolve_all()`, before any Java code is executed.
>>
>> - We essentially iterate over all the classes inside the
>> `AOTLinkedClassTable` and adds them into the system dictionary using the new
>> method `SystemDictionary::preload_class()`.
>> - `SystemDictionary::preload_class(..., k)` is lightweight because it's
>> called in a single thread after all super types of `k` have been loaded. So
>> most of the complicated work (such as place holders, circularity detection,
>> etc) in `SystemDictionary::resolve_or_null(..., k)` can be skipped. We also
>> don't need to call into `ClassLoader::load_class()` as the boot/platform/app
>> loaders are well-behaved.
>> - In the assembly phase, we record the mirror, package, protection domain,
>> code source, etc, of these classes. So there's no need to programmatically
>> create them in the production run. See `HeapShared::copy_java_mirror()` and
>> also changes in ClassLoader.java and SecureClassLoader.java.
>
> Ioi Lam has updated the pull request incrementally with one additional commit
> since the last revision:
>
> @DanHeidinga comment -- assembly phase should check if URLStreamHandler
> might be overridden in the production run
src/hotspot/share/cds/aotOopChecker.cpp line 52:
> 50: // Make sure we are not caching objects with assumptions that can be
> violated in
> 51: // the production run.
> 52: void AOTOopChecker::check(oop obj) {
Should this also return a `bool` to indicate if the oop failed the check? It
would make it easier to bail out in the caller if the oop was bad.
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PR Review Comment: https://git.openjdk.org/jdk/pull/26375#discussion_r2294377983
