Ensure deserializer class invalidation is complete #20068
Conversation
When a class is redefined, the old, invalidated RAM methods may be held in the "oldClass" or the "newClass", depending on whether or not the class was redefined in-place. To ensure that all the old RAM methods from the redefined class are purged from the JITServer AOT deserializer's caches, and to avoid having to detect the type of redefinition, both the old and new classes are now invalidated. The incomplete invalidation of classes is not currently a problem, as the only place the deserializer's method cache is queried for a stored RAM method during relocation happens to be reachable only if the defining class has not been invalidated. This change avoids a possible bug that would arise if this were ever not the case. Signed-off-by: Christian Despres <despresc@ibm.com>
|
Attn @mpirvu. I haven't actually been able to observe this code run - I've run various test suites and have never seen a RAM method be invalidated in the deserializer cache. I have seen some RAM classes invalidated in Actually, I've looked at the AOT cache code again, and I think that a method serialization record will end up only ever being created for a |
|
jenkins test sanity,extended,sanity.system,extended.system zlinuxjit,xlinuxjit jdk21 |
|
extended.functional on x86 failed due to infra: Everything else passed, so I am going to merge. |
When a class is redefined, the old, invalidated RAM methods may be held in the "oldClass" or the "newClass", depending on whether or not the class was redefined in-place. To ensure that all the old RAM methods from the redefined class are purged from the JITServer AOT deserializer's caches, and to avoid having to detect the type of redefinition, both the old and new classes are now invalidated.
The incomplete invalidation of classes is not currently a problem, as the only place the deserializer's method cache is queried for a stored RAM method during relocation happens to be reachable only if the defining class has not been invalidated. This change avoids a possible bug that would arise if this were ever not the case.