On Wed, 11 Feb 2026 20:28:15 GMT, Ioi Lam <[email protected]> wrote:
> We are seeing intermittent failures (12 times in Jan 2026) where the CDS
> archives generated in the JDK build is not deterministic.
>
> The symptom is that (perhaps due to the peculiarity of hash codes and memory
> addressing??) the constant pool entry for `ReferenceKey<?>` in the
> `WeakReferenceKey` class is not resolved when the failure happens.
>
> The fix is for the JVM to call a method in `WeakReferenceKey` to force this
> entry to be resolved.
> I think a better approach might be in ReferencedKeyMap.prepareForAOTCache,
> after
>
> ```
> for (ReferenceKey<K> key : map.keySet()) {
> Object referent = key.get();
> ```
>
> inject a call `key.equals(new StrongReferenceKey(referent))`, so that we hit
> the instanceof. What do you think? This code should be less reliant to weird
> translation hacks and requires less VM hacks.
> A better approach might be as simple as calling `MethodType.methodType()` to
> retrieve an existing method type, maybe `MethodType.methodType(void.class)`
> would be sufficient, in `MethodType::assemblySetup`.
`ReferencedKeyMap.prepareForAOTCache()` is only called only when
`AOTClassLinking` is true. However, when creating the default CDS archives,
`AOTClassLinking` is false.
Also, I am not sure if we should insert unnecessary code to try to achieve some
unobvious side effect.
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PR Comment: https://git.openjdk.org/jdk/pull/29678#issuecomment-3888436219
