RFR: 8369736 - Add management interface for AOT cache creation [v8]

[Kevin Walls]

On Tue, 25 Nov 2025 12:22:21 GMT, Alan Bateman <alanb at openjdk.org> wrote:

>> src/jdk.management/share/classes/com/sun/management/internal/PlatformMBeanProviderImpl.java line 192:
>> 
>>> 190:                 HotSpotAOTCacheMXBean impl = this.impl;
>>> 191:                 if (impl == null) {
>>> 192:                     this.impl = impl = new HotSpotAOTCacheImpl(ManagementFactoryHelper.getVMManagement());
>> 
>> This assignment is unusual.  Are we trying to avoid a synchronized block? Other nameToMBeanMap() methods are like:
>> 	return Collections.singletonMap(ManagementFactory.MEMORY_MXBEAN_NAME, ManagementFactoryHelper.getMemoryMXBean());
>> 	
>> ..where the ManagementFactoryHelper.getMemoryMXBean() method is synchronized and creates the impl if needed.
>
> I don't see a correctly issue with this. Maybe in the future we will be able to use LazyConstant here.

Sure, I'm just pointing out that we have a load of existing nameToMBeanMap() methods that do things differently.
OK I now see this one is doing what the new VirtualThreadSchedulerMXBean did.

The others are different: commonly the nameToMBeanMap() methods in PlatformMBeanProviderImpl.java are synchronized, or they call a getXXMXBean() method which is synchronized.

Maybe these old methods don't need to be synchronized, if this all gets done at startup in PlatformMBeanProviderImpl init(), the mbeans will always be created once.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28010#discussion_r2564720463