RFR: 8256830: misc tests failed with "assert(env->is_enabled(JVMTI_EVENT_OBJECT_FREE)) failed: checking" [v2]

[Serguei Spitsyn]

On Mon, 30 Nov 2020 13:57:14 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> The ServiceThread cleaning used a stale ObjectFree state when calling remove_dead_entries, because another thread had concurrently set is_enabled to false.  Add a lock around setting/resetting the lock event state and retest the state under a lock.  Ran the test 100s of time without failure, where otherwise it fails very quickly.
>> Tested with tier2,3 and running tiers 4,5,6 in progress.
>> Thanks to Kim for his previous feedback.
>
> Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Make enable events lock unconditionally if tagmap present.

Hi Coleen,
The fix looks okay to me.
Of course, there is some overhead but I'm not sure the impact is significant.
Thanks,
Serguei

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Marked as reviewed by sspitsyn (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/1439