On Thu, 9 Jan 2025 16:28:00 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:
>> This is a fix of one more deadlock issue related to `interruptLock` critical
>> sections. When the `interruptLock` is hold by the target virtual thread it
>> is unsafe to suspend or post JVMTI events. This update is to ignore the
>> JVMTI events when the `interruptLock` is hold. It is additionally to the
>> cases when the target JavaThread is in a `VTMS` transition. It is based on
>> the existing mechanism disallowing JVMTI suspends while the `interruptLock`
>> is hold. In order to support this the target JavaThread has the
>> `_is_disable_suspend` bit.
>>
>> Testing:
>> - Ran mach5 tiers 1-6
>> - There is no regression test for this issue as it is not hard to construct
>> one. Originally, the issue was reported by JGroups which is using the
>> `Async` profiler.
>
> src/hotspot/share/prims/jvmtiExport.cpp line 1105:
>
>> 1103:
>> 1104: if (JavaThread::current()->hide_jvmti_events()) {
>> 1105: return false; // no events should be posted if thread is in VTMS
>> alike transition
>
> I don't think your use of "alike" is what you mean here. Did you mean
> "VTMS-like", or maybe something like "VTMS transition or similar state".
>
> Also `hide_jvmti_events()` is a pretty self explanatory name already.
> Probably no comment is needed at the call sites, and instead you should just
> add a comment where `hide_jvmti_events()` is declared.
Thanks. Good suggestion. Will address.
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PR Review Comment: https://git.openjdk.org/jdk/pull/22997#discussion_r1909665062
