RFR[JDK11]: 8204691: HeapRegion.apply_to_marked_objects_other_vm_test fails with assert(!hr->is_free() || hr->is_empty()) failed: Free region 0 is not empty for set Free list #

[Kim Barrett]

> On Jul 5, 2018, at 4:03 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
> 
>> On Jul 5, 2018, at 3:57 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
>> 
>> Hi,
>> 
>> On Wed, 2018-07-04 at 20:13 -0400, Kim Barrett wrote:
>>> Please review this fix of the HeapRegion gtest.
>>> 
>>> The test modifies a region's "top" to unexpected values without
>>> ensuring that no allocation might use the region and no GC might run
>>> while the region is in that invalid state.  We solve this by
>>> executing the test code in its very own safepoint, and by saving and
>>> then restoring the region's top back to its original value before
>>> completing the test.  And since we are doing all that, there's no
>>> longer any reason to run the test in a separate VM.
>> 
>> looks good, but the actual test is still run in a separate VM.
>> Intentional?
> 
> Unintentional. And now I’m not sure what I last ran through mach5.
> I’ll re-test with TEST_OTHER_VM => TEST_VM.
> 
> I know that failed in an obscure way earlier, but I think that was because
> of an unrelated recently introduced bug that’s been fixed in the repo.

Verified that I really have tested in same VM.  New webrev:
http://cr.openjdk.java.net/~kbarrett/8204691/open.01/

The only change is TEST_OTHER_VM => TEST_VM.