jmx-dev RFR: 8369736 - Add management interface for AOT cache creation

[Alan Bateman]

On Tue, 28 Oct 2025 01:17:57 GMT, Mat Carter <macarte at openjdk.org> wrote:

> Add jdk.management.AOTCacheMXBean. The interface provides a single action that when called will cause any hosted JVM currently recording AOT information will stop recording. Existing functionality is preserved: when stopped the JVM will create the required artifacts based on the execution mode. Conveniently as the application running on the JVM has not stopped (as was previously the only way to stop recording), the application will resume execution after the artifacts have been generated.
> 
> The interface will return TRUE if a recording was successfully stopped, in all other cases (not recording etc.) will return FALSE
> 
> It follows that invoking the action on a JVM that is recording, twice in succession, should (baring internal errors) produce the following two responses:
> 
> TRUE
> FALSE
> 
> Passes tier1 on linux (x64) and windows (x64)

src/jdk.management/share/classes/jdk/management/HotSpotAOTCacheMXBean.java line 29:

> 27: import java.lang.management.ManagementFactory;
> 28: import java.lang.management.PlatformManagedObject;
> 29: import java.util.concurrent.ForkJoinPool;

I assume there is no need to import ForkJoinPool.

src/jdk.management/share/classes/jdk/management/HotSpotAOTCacheMXBean.java line 36:

> 34:  * Management interface for the JDK's Ahead of Time (AOT) optimizations.
> 35:  *
> 36:  * Currently, {@code HotSpotAOTCacheMXBean} defines one operation at this time to end the AOT recording.

I think you drop "Currently, ", it will be a bit clearer without it.

test/hotspot/jtreg/runtime/cds/appcds/aotCache/HotSpotAOTCacheMXBeanTest.java line 98:

> 96:     public static void main(String[] args) {
> 97:         System.out.println("Hello Leyden " + args[0]);
> 98:         var aotBean = ManagementFactory.getPlatformMXBean(HotSpotAOTCacheMXBean.class);

This uses MF.getPlatformMXBean in the child VM. A more complete test would repeat with:

        MBeanServer server = ManagementFactory.getPlatformMBeanServer();
        HotSpotAOTCacheMXBean bean = ManagementFactory.newPlatformMXBeanProxy(server,
                "jdk.management:type=HotSpotAOTCacheMXBean",
                HotSpotAOTCacheMXBean.class);


In any case, it might be simpler to test that the MXBean is registered in the test itself, it doesn't need to be in the child VM.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28010#discussion_r2468799292
PR Review Comment: https://git.openjdk.org/jdk/pull/28010#discussion_r2468801255
PR Review Comment: https://git.openjdk.org/jdk/pull/28010#discussion_r2468824691