jmx-dev RFR: 8373464: Test JdkManagementCheckSince.java fails after JDK-8369736

[David Holmes]

On Thu, 11 Dec 2025 05:01:21 GMT, Ioi Lam <iklam at openjdk.org> wrote:

> Please review this small fix and the plan of action for backporting JDK-8369736 to JDK 26.
> 
> (JDK-8369736 is under https://openjdk.org/jeps/3#Late-Enhancement-Request-Process)
> 
> **Background**
> 
> The "actually introduced version" for `HotSpotAOTCacheMXBean` is found using the `ct.sym` file (JdkManagementCheckSince.java  uses test/jdk/tools/sincechecker/SinceChecker.java, which doesn't read `ct.sym` directly, but uses `JavacTool` with `--release N`, which in turn loads `ct.sym`)
> 
> 
> $ unzip -l ./images/jdk/lib/ct.sym | grep HotSpotAOTCacheMXBean.sig
>       167 2025-12-11 03:16 R/jdk.management/jdk/management/HotSpotAOTCacheMXBean.sig
> 
> 
> "R" is JDK 27 ("1" is JDK 1, "A" is JDK 10, "B" is JDK 11, etc ...)
> 
> In comparison, `VirtualThreadSchedulerMXBean` was first introduced in "O" = JDK 24, and its API has not changed since)
> 
> 
> $ unzip -l ./images/jdk/lib/ct.sym | grep VirtualThreadSchedulerMXBean.sig
>       313 2025-12-11 03:16 OPQR/jdk.management/jdk/management/VirtualThreadSchedulerMXBean.sig
> 
> 
> Note that if an API has evolved over time, we may have several `.sig` files:
> 
> 
> $ unzip -l ./images/jdk/lib/ct.sym | grep util/Vector.sig
>      3058 2025-12-11 03:16 8/java.base/java/util/Vector.sig
>      3182 2025-12-11 03:16 9A/java.base/java/util/Vector.sig
>      3272 2025-12-11 03:16 BCDEFGHIJKLMNOPQR/java.base/java/util/Vector.sig
> 
> 
> `ct.sym` is generated from files in [src/jdk.compiler/share/data/symbols](https://github.com/openjdk/jdk/tree/master/src/jdk.compiler/share/data/symbols)
> 
> 
> $ cd src/jdk.compiler/share/data/symbols
> $ grep VirtualThreadSchedulerMXBean *
> jdk.management-O.sym.txt:class name jdk/management/VirtualThreadSchedulerMXBean
> 
> 
> Because `HotSpotAOTCacheMXBean` is not listed in any of the `.sym.txt` files, it's added as version "R" in `ct.sym`
> 
> 
> $ grep HotSpotAOTCacheMXBean * | wc
>       0 0 0
> 
> 
> **Proposed plan of action**
> 
> 1. In the mainline, update HotSpotAOTCacheMXBean.java to use `@since 27` (this PR) to fix the current test failure in the mainline.
> 
> 2. When backporting HotSpotAOTCacheMXBean.java to JDK 26 (with approval), it should have `@since 26`.
> 
> 3. After JDK 26 is finalized, update the mainline:
>     - Add HotSpotAOTCacheMXBean to `jdk.management-Q.sym.txt`
>     - Update HotSpotAOTCacheMXBean.java to use `@since 26`.

Good and trivial. Thanks for fixing.

-------------

Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/28760#pullrequestreview-3565842150