RFR: 8318757 ObjectMonitor::deflate_monitor fails "assert(prev == old_value) failed: unexpected prev owner=0x0000000000000002, expected=0x0000000000000000"

[Aleksey Shipilev]

On Mon, 6 Nov 2023 09:46:11 GMT, Stefan Karlsson <stefank at openjdk.org> wrote:

> A safepointed monitor deflation pass can run interleaved with a paused async monitor deflation pass. The code is not written to handle that situation and asserts when it finds a DEFLATER_MARKER in the owner field. @pchilano also found other issues with having to monitor deflation passes interleaved. More info below ...

Could you please rename the bug and PR to something that captures the essence of the bug, rather than the assert message?

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Changes requested by shade (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/16519#pullrequestreview-1714746354