Invalidate JNI IDs for unloaded classes #18519
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If the -XX:+KeepJNIIDs option is specified, invalidate IDs for unloaded classes rather than freeing them. Detect invalidated IDs in JVMTI calls and return the appropriate error. JNI calls may be updated in a future PR (we will need to decide how to handle invalid IDs in those cases as there is no standard error handling mechanism in JNI). Related: eclipse-openj9#17466 Signed-off-by: Graham Chapman <[email protected]>
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Tested internally with the new option off and forced on. |
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jenkins test sanity alinux64 jdk21 |
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Is the plan to document the option? |
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If we go to production with this, probably (though requiring new options seems to be problematic in general for people). A probably worse alternative is to auto-enable this when we detect ClassLoadHook has been enabled (the hack required to enabled ASGCT). |
Im not in favour of this. AGCT is an undocumented best effort solution. Documenting an option to better support it legitimize the API in a manner I feel is mis-leading.
If it comes to it, this is probably the least worst outcome IMO. It puts us at parity with the RI. |
If the -XX:+KeepJNIIDs option is specified, invalidate IDs for unloaded classes rather than freeing them.
Detect invalidated IDs in JVMTI calls and return the appropriate error.
JNI calls may be updated in a future PR (we will need to decide how to handle invalid IDs in those cases as there is no standard error handling mechanism in JNI).
Related: #17466