RFR: 8265932: Move safepoint related fields from class Thread to JavaThread

[David Holmes]

On Mon, 26 Apr 2021 15:01:41 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

> Hi,
> 
> Please review the following change. A left over from 8265453 was moving _poll_data from class Thread to JavaThread. There are also other fields like _no_safepoint_count and _visited_for_critical_count that should be moved.
> Tested in mach5 tiers 1-5. Tested it builds ppc, arm and s390. Tested it builds in release, optimized and fastdebug modes.
> 
> Thanks,
> Patricio

Hi Patricio,

Changes looks good. I had to double-check a few JavaThread conversions actually appear in code that can only be executed by a JavaThread, but they seem okay.

One comment below.

Thanks,
David

src/hotspot/share/runtime/mutex.cpp line 423:

> 421: 
> 422: // NSV implied with locking allow_vm_block or !safepoint_check locks.
> 423: void Mutex::no_safepoint_verifier(Thread* thread, bool enable) {

Wouldn't it have been simpler to add the is_Java_thread() check in here rather than "inlining" this at the call-sites?

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Marked as reviewed by dholmes (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/3695