On Wed, 2 Jul 2025 18:47:58 GMT, Chen Liang <[email protected]> wrote:
>> I have updated this patch to avoid a redundant `runtimeSetup` annotation -
>> we have agreed that the requirement for setup is a side effect of
>> initialization, and such methods in AOTCI classes must be automatically
>> recognized. This latest revision implements that model.
>>
>> I intentionally avoided handling Class and ClassLoader `resetArchivedStates`
>> and `MethodType::assemblySetup` - we talked about a generic
>> `assemblyCleanup` method, but I did not find out where is the best place to
>> call such a method in the assembly phase. We cna handle this in a subsequent
>> patch.
>>
>> In particular, please review the new AOT.md design document - I split it
>> from the AOTCI annotation to prevent jamming; we can put general AOT
>> information there when we have more AOT-specific annotations.
>>
>> ---
>>
>> Old description:
>> Currently, the list of classes that have <clinit> interdependencies and
>> those that need runtimeSetup are maintained in a hardcoded list in CDS. This
>> makes it risky for core library developers as they might introduce new
>> interdependencies and observe CDS to fail. By moving the mechanism of these
>> lists to core library annotations as a first step, we can gradually expose
>> the AOT contracts as program semantics described by internal annotations,
>> and also helps us to explore how we can expose these functionalities to the
>> public later.
>
> Chen Liang has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Documentation
Changes requested by iklam (Reviewer).
src/hotspot/share/cds/aotClassInitializer.cpp line 219:
> 217: // MethodHandleStatics is an example of a class that must NOT get
> the aot-init treatment,
> 218: // because of its strong reliance on (a) final fields which are (b)
> environmentally determined.
> 219: if (ik->has_aot_safe_initializer()) {
I think the above 4 lines of comments can be deleted, as this topic is already
covered in AOTSafeClassInitializer.java.
src/hotspot/share/classfile/classFileParser.cpp line 5171:
> 5169: InstanceKlass* intf = _transitive_interfaces->at(i);
> 5170: if (intf->class_initializer() != nullptr) {
> 5171: if (!intf->has_aot_safe_initializer()) {
I think this is better, so you don't need to annotate a supertypes that have no
`<clinit>`
if (intf->class_initializer() != nullptr && !intf->has_aot_safe_initializer()) {
src/hotspot/share/oops/instanceKlassFlags.hpp line 58:
> 56: flag(has_final_method , 1 << 13) /* True if klass
> has final method */ \
> 57: flag(has_aot_safe_initializer , 1 << 14) /* has
> @AOTSafeClassInitializer annotation */ \
> 58: flag(is_runtime_setup_required , 1 << 15) /* has a
> runtimeSetup method to be called */ \
This information is useful only during CDS dumping. Since `_flags` has limited
width (only 16 bits) we should avoid using these bits but rather put the
information inside `DumpTimeClassInfo`. However, there's a complication here,
as `DumpTimeClassInfo` is not yet created when you call
`set_has_aot_safe_initializer()`.
I think you can go ahead with the current design. I will make a follow-up PR to
move the creation of `DumpTimeClassInfo` to an earlier time. Then I'll move
these two bits into `DumpTimeClassInfo`. That way we can accommodate more
annotations in the future.
-------------
PR Review: https://git.openjdk.org/jdk/pull/25922#pullrequestreview-2980604461
PR Review Comment: https://git.openjdk.org/jdk/pull/25922#discussion_r2180955211
PR Review Comment: https://git.openjdk.org/jdk/pull/25922#discussion_r2180988960
PR Review Comment: https://git.openjdk.org/jdk/pull/25922#discussion_r2180982768
