On Wed, 16 Oct 2024 00:03:25 GMT, Ioi Lam <ik...@openjdk.org> wrote: >> This is the 6th PR for [JEP 483: Ahead-of-Time Class Loading & >> Linking](https://bugs.openjdk.org/browse/JDK-8315737). >> >> The implementation of java.lang.invoke uses SoftReferences so that unused >> MethodHandles, LambdaForms, etc, can be garbage collected. >> >> However, if we want to store java.lang.invoke objects in the AOT cache >> ([JDK-8293336](https://bugs.openjdk.org/browse/JDK-8293336), the final step >> in JEP 493), it's difficult to cache these SoftReferences -- SoftReferences >> in turn point to ReferenceQueues, etc, which have dependencies on the >> current execution state (Threads, etc) which are difficult to cache. >> >> The proposal is to add a new flag: `MethodHandleStatics.NO_SOFT_CACHE`. When >> this flag is true, we avoid using SoftReferences, and store a direct >> reference to the target object instead. >> >> [JDK-8293336](https://bugs.openjdk.org/browse/JDK-8293336) stores only >> java.lang.invoke objects that refer to classes loaded by the >> boot/platform/app loaders. These classes are never unloaded, so it's not >> necessary to point to them using SoftReferences. >> >> This RFE modifies only the LambdaFormEditor and MethodTypeForm classes, as >> that's the minimal modification required by >> [JDK-8293336](https://bugs.openjdk.org/browse/JDK-8293336). >> >> --- >> See [here](https://bugs.openjdk.org/browse/JDK-8315737) for the sequence of >> dependent RFEs for implementing JEP 483. > > Ioi Lam has updated the pull request with a new target base due to a merge or > a rebase. The incremental webrev excludes the unrelated changes brought in by > the merge/rebase. The pull request contains 16 additional commits since the > last revision: > > - Merge branch 'jep-483-step-05-8293337-archive-method-handle-intrinsics' of > /jdk3/yam/open into > jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke > - reviews from @iwanowww and @rose00 -- move USE_SOFT_CACHE to > MethodHandleNatives as a @Stable field; use system prop for init > - Merge branch 'jep-483-step-05-8293337-archive-method-handle-intrinsics' of > /jdk3/yam/open into > jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke > - Merge branch 'jep-483-step-05-8293337-archive-method-handle-intrinsics' of > /jdk3/yam/open into > jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke > - Merge branch 'jep-483-step-05-8293337-archive-method-handle-intrinsics' of > /jdk3/yam/open into > jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke > - Merge branch 'jep-483-step-05-8293337-archive-method-handle-intrinsics' of > /jdk3/yam/open into > jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke > - @liach and @cl4es comments > - Merge branch 'jep-483-step-05-8293337-archive-method-handle-intrinsics' of > /jdk3/yam/open into > jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke > - @dholmes-ora review comments > - Merge branch 'jep-483-step-05-8293337-archive-method-handle-intrinsics' of > /jdk3/yam/open into > jep-483-step-06-8311071-avoid-soft-refs-in-java-lang-invoke > - ... and 6 more: https://git.openjdk.org/jdk/compare/31f55db0...11391c39
Still looks good except `@Stable` on `USE_SOFT_CACHE`. As it is implemented now, I don't see any point in dropping `final` in favor of `@Stable` since it is initialized only once and only from static initializer. @iklam I'd be surprised if this class is AOT-initialized. I hope it's not the case here. ------------- PR Comment: https://git.openjdk.org/jdk/pull/21049#issuecomment-2420771205
