RFR: 8261391: ZGC crash - SEGV in RevokeOneBias::do_thread [v2]

[Daniel D.Daugherty]

On Wed, 17 Feb 2021 13:34:16 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

>> Handshakes may contain oop Handles from the requesting thread.
>> A handshake may be executed by another thread than the requester.
>> We must make sure any such Handle is safe to use by other threads before executing the handshake.
>> This change-set adds SWS::start_process() for the requesting thread also (we already do this for the target JavaThread).
>> 
>> Passes t1-5
>
> Robbin Ehn has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - prepare() on self execution and a rename
>  - Merge branch 'master' into 8261391-sws-handshaker
>  - SWS start processing on handshaker

Looks good.

src/hotspot/share/runtime/handshake.cpp line 289:

> 287:   }
> 288:   if (current_target != executing_thread) {
> 289:     // Only when the target is not executing the handshake it self.

nit typo: s/it self/itself/

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Marked as reviewed by dcubed (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2571