On Tue, 27 May 2025 22:48:15 GMT, Alex Menkov <amen...@openjdk.org> wrote:
>> This is first (hotspot) part of the update for
>> `HotSpotDiagnosticMXBean.dumpThreads` and `jcmd Thread.dump_to_file` to
>> include lock information in thread dumps (JDK-8356870).
>> The update has been split into parts to simplify reviewing.
>> The fix contains an implementation of `jdk.internal.vm.ThreadSnapshot` class
>> to gather required information about a thread.
>> Second (dependent) part includes changes in
>> `HotSpotDiagnosticMXBean.dumpThreads`/`jcmd Thread.dump_to_file`, spec
>> updates and tests for the functionality.
>>
>> Testing: new `HotSpotDiagnosticMXBean.dumpThreads`/`jcmd
>> Thread.dump_to_file` functionality was tested in loom repo;
>> sanity tier1 (this fix only)
>
> Alex Menkov has updated the pull request incrementally with one additional
> commit since the last revision:
>
> move to ThreadService
src/hotspot/share/services/threadService.cpp line 1160:
> 1158:
> 1159: Type _type;
> 1160: OopHandle _obj;
Nit: Short comments for `_depth` and `_obj` fields (lines: 1142, 1144, 1160)
would be nice to have.
src/hotspot/share/services/threadService.cpp line 1172:
> 1170: Handle _java_thread;
> 1171: JavaThread* _thread;
> 1172: int _depth;
Nit: This naming is confusing and not consistent with naming in JVMTI and other
places.
The name `java_thread` is normally used for a `JavaThread*` object.
I would suggest to make it like this:
Handle _thread_h; // (or _thread_oop_h, or thread_obj_h)
JavaThread* _java_thread;
src/hotspot/share/services/threadService.cpp line 1180:
> 1178: GrowableArray<OwnedLock>* _locks;
> 1179: Blocker _blocker;
> 1180: OopHandle _blocker_owner;
Nit: Some short comments explaining the fields would be nice to have, at least
for `_depth`, `_retry_handshake`, `_locks`, `_blocker` and `_blocker_owner`.
src/hotspot/share/services/threadService.cpp line 1317:
> 1315: const ContinuationEntry* ce = _thread->vthread_continuation();
> 1316: if (ce == nullptr || ce->cont_oop(_thread) !=
> java_lang_VirtualThread::continuation(_java_thread())) {
> 1317: // TODO: handle
Q: What `TODO` is expected here?
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/25425#discussion_r2111158038
PR Review Comment: https://git.openjdk.org/jdk/pull/25425#discussion_r2110831057
PR Review Comment: https://git.openjdk.org/jdk/pull/25425#discussion_r2110834293
PR Review Comment: https://git.openjdk.org/jdk/pull/25425#discussion_r2111194148
