[lilliput-jdk17u:lilliput] RFR: 8319799: Recursive lightweight locking: x86 implementation

[Aleksey Shipilev]

On Wed, 10 Apr 2024 10:48:43 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

> Backports https://github.com/openjdk/jdk/commit/7f6bb71eb302e8388c959bdaa914b758a766d299
> 
> Implements the x86_64 parts of recursive lightweight locking.
> 
> Unclean, mostly because of biased locking.

Looks okay, but I have a minor comment.

It looks like `lightweight_lock` does not need pre-loaded header anymore. Yet, some uses of it still load the header. I see the original commit moved header loading to `!LM_LIGHTWEIGHT` branches: https://github.com/openjdk/jdk/commit/7f6bb71eb302e8388c959bdaa914b758a766d299#diff-4ce1e880593668bead8462bc6b550bb21e11ad7dd1d8a43d77d5dac7510ba9c3L63

Seems like at least here we load the `hdr`: https://github.com/openjdk/lilliput-jdk17u/pull/84/files#diff-4ce1e880593668bead8462bc6b550bb21e11ad7dd1d8a43d77d5dac7510ba9c3R73-R74

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Marked as reviewed by shade (Committer).

PR Review: https://git.openjdk.org/lilliput-jdk17u/pull/84#pullrequestreview-2008682373