On Sun, 25 May 2025 05:08:12 GMT, Chen Liang <li...@openjdk.org> wrote:
>> Updates the thread dump generated by HotSpotDiagnosticMXBean.dumpThreads and >> jcmd Thread.dump_to_file to include thread state and lock information. Also >> update the HotSpotDiagnosticMXBean.dumpThreads API description to link to a >> description of the JSON format dump as that format is intended to be >> parseable/read by tools. >> >> This PR is dependent on >> [pull/25425](https://github.com/openjdk/jdk/pull/25425). As noted in that >> PR, the changes accumulated in the loom repo, and have been split up to make >> it easier to review. The change to src/hotspot and TheadShapshot are in >> pull/25425. >> >> The changes include some re-implementation of ThreadDumper. This is because >> it used PrintStream and didn't fail if there was an I/O error, e.g. file >> system full. Furthermore, the indentation to pretty print the json was >> fragile and hard to maintain so this is changed to use a supporting writer >> class to do this. >> >> Test coverage is significantly expanded, including updating the test library >> that is used by several tests to parse the thread dump. >> >> Testing: tier1-6 > > src/hotspot/share/classfile/javaClasses.cpp line 5519: > >> 5517: oop >> java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(oop >> obj) { >> 5518: assert(_owner_offset != 0, "Must be initialized"); >> 5519: return obj->obj_field_acquire(_owner_offset); > > Is this a preexisting bug? If yes we should have this fixed in a separate > patch so it is eligible for backporting, etc. This is a dependent PR, there are no changes to src/hotspot in this PR. Maybe I should left this PR in draft until pull/25425 is integrated to avoid any confusion. In any case, it is changed to use obj_field_acquire because the field is volatile and accessed (asynchronously) from the thread handshake. So different to the access from VM_ThreadDump which is a VM operation. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25429#discussion_r2106095164
