On Mon, 28 Oct 2024 10:16:40 GMT, Aleksey Shipilev <sh...@openjdk.org> wrote:
> This is forked from > [JDK-8342642](https://bugs.openjdk.org/browse/JDK-8342642) and filed as a > general issue for archived boxed Integer cache when it's recreated at > runtime. In short, current code drops the entire primitive cache when the CDS > archived version of the cache is too short. This poses a problem with code > that uses CDS archived cache instances, since the boxed equality would break > when comparing the CDS-archived value and the IntegerCache value recreated at > runtime. > > Ioi suggested a fix here: > https://github.com/openjdk/jdk/pull/21672#issuecomment-2434359711. I > separately arrived to the same idea. This PR implements it. `IntegerCache` > gets the special treatment, because it is the only cache that can be tuned. > Other caches just prevent the use of bad archived cache (which I think should > realistically never happen) without re-creating it. > > Unfortunately, I was unable to create a standalone CDS test for this: I > somehow need to be able to put my own archived `Integer` instance into the > archive, and I don't clearly see how. I tested this patch with original > reproducer from [JDK-8342642](https://bugs.openjdk.org/browse/JDK-8342642) -- > and it starts to pass. I don't think we would be able to convert that > reproducer into a unit test, since > [JDK-8342642](https://bugs.openjdk.org/browse/JDK-8342642) itself would make > the reproducer ineffective. > > Additional testing: > - [x] macos-aarch64-server-fastdebug, > [JDK-8342642](https://bugs.openjdk.org/browse/JDK-8342642) reproducer now > passes > - [x] linux-aarch64-server-fastdebug, `all` You can add a test case into https://github.com/openjdk/jdk/blob/master/test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java `-XX:ArchiveHeapTestClass` allows you to to store extra objects into the CDS archive, so you can test for their values during runtime. This flags works only for non-product builds (to prevent mis-use, as the archiving of arbitrary objects is not supported). ------------- PR Comment: https://git.openjdk.org/jdk/pull/21737#issuecomment-2441916627
