On Wed, 27 Sep 2023 17:54:51 GMT, Roman Kennke <rken...@openjdk.org> wrote:
>> The SA can run concurrently with Java threads, SA code that inspects locking >> state should be able to deal with that. On the other hand, the particular >> code is only used in printing routine and is not expected to be precise. >> When resolving an anonymous owner, we may not find one, because Java threads >> may already have moved on. Instead of crashing with a stacktrace, we should >> gracefully return null here. >> >> Testing: >> - [x] sun/tools/jhsdb/JStackStressTest.java >> - [x] sun/tools/jhsdb >> - [x] serviceability/sa > > Roman Kennke has updated the pull request incrementally with one additional > commit since the last revision: > > Print warning when anonymous lock cannot be found Changes requested by dholmes (Reviewer). src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/Threads.java line 245: > 243: } > 244: // We should have found the owner. However, the code can > run concurrently with > 245: // Java code and locking state can change at any time. > This code is not The second sentence is not accurate as things are not running concurrently and cannot change state at any time. Suggestion: // We should have found the owner, however, as the VM could be in any state, including the middle // of performing GC, it is not always possible to do so. Just return null if we can't locate it. ------------- PR Review: https://git.openjdk.org/jdk/pull/15907#pullrequestreview-1647736396 PR Review Comment: https://git.openjdk.org/jdk/pull/15907#discussion_r1339374587
