On Wed, 28 Jul 2021 10:03:10 GMT, David Holmes <dhol...@openjdk.org> wrote:
> If a thread is attaching via JNI and has not yet created its Thread object it > can be caught in a ThreadSnapshot during a thread dump (VM_DumpThreads) of > all threads**, and the threadObj() will be NULL, so we can't pass it to > get_thread_status(). > > ** JMM dumpThreads API > > The initial fix simply checks for a NULL threadObj() and reports thread > status NEW in that case. > > Alternatively we could filter the attaching thread out completely in > VM_DumpThreads::doit by expanding: > > if (jt->is_exiting() || > jt->is_hidden_from_external_view()) { > // skip terminating threads and hidden threads > continue; > } > > to also check jt->is_attaching_via_jni(). > > Note that higher-level code already filters out ThreadSnapshots with NULL > threadObj() anyway so we could go either way. > > Testing: manual hacks - see bug report. > - tier 1-3 sanity testing > > Thanks, > David This looks good to me. ..Thomas ------------- Marked as reviewed by stuefe (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/4921