Integrated: 8352299: GenShen: Young cycles that interrupt old cycles cannot be cancelled

[William Kemper]

On Tue, 18 Mar 2025 21:51:34 GMT, William Kemper <wkemper at openjdk.org> wrote:

> The sequence of events that creates this state:
> 1. An old collection is trying to finish marking by flushing SATB buffers with a Handshake
> 2. The regulator thread cancels old marking to start a young collection
> 3. A mutator thread shortly follows and attempts to cancel the nascent young collection
> 4. Step `3` fails (because of this bug) and cancellation reason does _not_ become `allocation failure`
> 5. The mutator thread enters a tight loop in which it retries allocations without `waiting`
> 6. The mutator thread remains in the `thread_in_vm` state and prevents the VM thread from completing step `1`.

This pull request has now been integrated.

Changeset: dbc620fb
Author:    William Kemper <wkemper at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/dbc620fb1f754ca84f2a07abfdfbd4c5fcb55087
Stats:     15 lines in 2 files changed: 7 ins; 0 del; 8 mod

8352299: GenShen: Young cycles that interrupt old cycles cannot be cancelled

Reviewed-by: shade

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PR: https://git.openjdk.org/jdk/pull/24105