On Thu, 9 Jan 2025 05:03:33 GMT, Serguei Spitsyn <[email protected]> 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.
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PR Review Comment: https://git.openjdk.org/jdk/pull/22997#discussion_r1909124132
