On Fri, 7 Nov 2025 17:29:37 GMT, Jorn Vernee <[email protected]> wrote:
> The existing test uses the JVMTI `VMStart` callback to look up a class. This > works when using CDS, because the class is already available, but because > `VMStart` is called while the VM is still being initialized, it fails to find > the target class when CDS is turned off. > > Instead, the `VMInit` callback should be used, which runs after the VM has > been initialized. This patch does this. Additionally, it delays the call to > allocate `OTHER_SEGMENT`. If we call `FindClass` during `VMInit`, the > `<clinit>` of the class will run, which then ends up calling > `checkValidStateRaw` as a result of allocating `OTHER_SEGMENT`, and we get to > our method exit event code before the target class and method ID have been > initialized. > > As a side note: I had know about the difference between `VMInit` and > `VMStart`, and had actually intended to use `VMInit` in the first place, but > I seem to have gotten the two confused, because they are listed in reverse > chronological order in the list under 'Set Event Notification Mode' in the > JVMTI spec > (https://docs.oracle.com/en/java/javase/25/docs/specs/jvmti.html#SetEventNotificationMode). LGTM and fixes the issue. Thanks! ------------- Marked as reviewed by mdoerr (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/28202#pullrequestreview-3442830168
