On Mon, 11 Aug 2025 10:55:44 GMT, Francesco Andreuzzi <[email protected]> wrote:
> In this PR I add an `autoconfigure` check to make sure that `jfr` is not
> built without the feature `services`, which would lead to the following error:
>
> /jdk/src/hotspot/share/jfr/periodic/jfrPeriodic.cpp: In member function
> ‘virtual void VM_GC_SendObjectCountEvent::doit()’:
> /jdk/src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:402:5: error:
> ‘ObjectCountEventSender’ has not been declared
> 402 | ObjectCountEventSender::enable_requestable_event();
> | ^~~~~~~~~~~~~~~~~~~~~~
> /jdk/src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:404:5: error:
> ‘ObjectCountEventSender’ has not been declared
> 404 | ObjectCountEventSender::disable_requestable_event();
> | ^~~~~~~~~~~~~~~~~~~~~~
>
>
> To reproduce:
>
> sh configure --with-jvm-variants=custom --with-conf-name=cstm
> --enable-jvm-feature-jfr --enable-jvm-feature-serialgc
> make -j hotspot CONF_NAME=cstm
I think it is not that simple, unfortunately. I tried changing the ifdef but
ran into additional issues. In gcTrace.cpp we have:
virtual void do_cinfo(KlassInfoEntry* entry) {
if (should_send_event(entry)) {
ObjectCountEventSender::send(entry, _timestamp);
}
}
private:
bool should_send_event(const KlassInfoEntry* entry) const {
double percentage_of_heap = ((double) entry->words()) /
_total_size_in_words;
return percentage_of_heap >= _size_threshold_percentage;
}
which requires KlassInfoEntry (defined in
src/hotspot/share/memory/heapInspection.hpp). When I tried to change that ifdef
to INCLUDE_JFR, building with the `jfr` feature succeeded, but building with
`services` failed.
So it seems there is some shared code here. Either heapInspection needs to be
included if either `jfr` or `services` are enabled, or we should go the route
of this PR and say that JFR is dependent on services. I think the latter seems
cleaner.
-------------
PR Comment: https://git.openjdk.org/jdk/pull/26723#issuecomment-3175002573
