Withdrawn: 8305898: Alternative self-forwarding mechanism

[duke]

On Wed, 3 May 2023 13:03:17 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

> Currently, the Serial, Parallel and G1 GCs store a pointer to self into object headers, when compaction fails, to indicate that the object has been looked at, but failed compaction into to-space. This is problematic for compact object headers ([JDK-8294992](https://bugs.openjdk.org/browse/JDK-8294992)) because it would (temporarily) over-write the crucial class information, which we need for heap parsing. I would like to propose an alternative: use the bit #3 (previously biased-locking bit) to indicate that an object is 'self-forwarded'. That preserves the crucial class information in the upper bits of the header until the full header gets restored.

This pull request has been closed without being integrated.

-------------

PR: https://git.openjdk.org/jdk/pull/13779