On Mon, 25 Sep 2023 18:32:19 GMT, Roman Kennke <rken...@openjdk.org> wrote:
>> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/Threads.java >> line 247: >> >>> 245: // Java code and locking state can change at any time. >>> This code is not >>> 246: // expected to be precise, so we return null here. >>> 247: return null; >> >> If the JVM is in a consistent state, do we expect that this should not >> happen? If so, then a warning message would be the usual SA approach. >> Basically let the user know we detected an issue rather than just quietly >> succeeding. > > Yes. But unless we run this at a safepoint, there is no consistent state when > we race with locking. I don't think we want to spam users with warnings > whenever we run into anonymous owners (which is not too infrequent). Existing > (pre-lightweight-) locking doesn't print warnings either, when a thread > that's expected to lock on an object has moved on or otherwise encounters > racy state. I need a better understanding of anonymous owners and the race you think is going on here. 99+% of the time if we are not at a safepoint, pretty much everything still works fine with SA. Safe points guarantee safe access, but not being at a safepoint does not guarantee there will be an issue for SA. It usually still works, and we try to report when it doesn't. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/15907#discussion_r1336297000
