(0.48) Ensure JIT/AOT code is not invalidated post-restore under -XX:+DebugOnRestore
#20219
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Cache the status of JVMTI events such as exception throw/catch as well as whether method trace and FSD were enabled pre-checkpoint. Signed-off-by: Irwin D'Souza <[email protected]>
Under -XX:+DebugOnRestore, the VM will enable some capabilities that will be reset on restore (if the user does not want debug on restore). However, if the JIT detects these capabilities via the J9HookDisable call, there is no way for the JIT to know whether the capability was set by the VM or a user pre-checkpoint. With the recent change to the isDebugOnRestoreEnabled to check if a uesr specified an JDWP agent pre-checkpoint, the JIT can simply return early from isFSDNeeded. Under -XX:+DebugOnRestore, the JIT already generates FSD code so there is on need to check the caps that were set by the VM pre-checkpoint. isFSDNeeded is called on restore, so at that point it is appropriate for the JIT to execute the rest of the method at that point. Signed-off-by: Irwin D'Souza <[email protected]>
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Mostly a straightforward cherry-pick of #20047 (had to resolve a merge conflict). FYI @pshipton @TobiAjila |
dsouzai
added this to the Release 0.48 (Java 8, 11, 17, 21, 23) October refresh milestone
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I'll set this as draft until #20233 is resolved. |
dsouzai
changed the title
-XX:+DebugOnRestore (0.48)-XX:+DebugOnRestore
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#19754 adds VM Support for Debug On Restore. As the code stands, this will result in the JIT invalidating all code post-restore because it is unable to distinguish between FSD mode caused by the VM or the user.
This PR fixes this by adding the following changes:
-XX:+DebugOnRestoreDepends on #20191