On Mon, 19 Sep 2022 20:22:54 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:
>> Serguei Spitsyn has updated the pull request incrementally with one
>> additional commit since the last revision:
>>
>> fixed typo in VirtualThread.c
>
> src/hotspot/share/prims/jvmtiExport.cpp line 1055:
>
>> 1053: if (JavaThread::current()->is_in_tmp_VTMS_transition()) {
>> 1054: return false;
>> 1055: }
>
> You mentioned this in the PR description. However, it's not clear to me why
> this is ok. Also, it should be commented.
>
> Same thing for changes in JvmtiExport::post_class_load() and
> JvmtiExport::post_class_prepare().
I initially wanted to consult on this with Alan. It feels like it'd be better
if I did it before posting this PR.
We have just two possible approaches here. The best approach is to move any
class loading out of the temporary transition code path. Then we already have
the relevant asserts in place. However, this is not that easy to solve. Alan
already suggested a couple of patches which I've tested but new places with
class loads were discovered. Another approach is to skip all ClassLoad,
ClassPrepare and CFLH events in context of temporary transitions. It is hard to
estimate how acceptable it is. At least, I've not found any failing tests
because of it which means it most likely does not impact the debugger. My
current suggestion is to file a bug and try to address it later as Alan may
need more time for analysis.
-------------
PR: https://git.openjdk.org/jdk/pull/10321
