RFR: 8284017: Improve handshake filtering mechanism

[David Holmes]

On Wed, 28 May 2025 15:10:09 GMT, Anton Artemov <duke at openjdk.org> wrote:

> Hi, please consider the following enhancement:
> 
> In this PR a new way of supplying multiple arguments to filter out / skip operations in handshake/safepoint poll is given. Multiple boolean arguments are combined in a hash table, where keys are taken from a new enum `HandshakeOperationProperty`, which is to be modified when there is a need for a new argument. 
> 
> Tested in GHA and tiers 1 - 3.

This seems rather heavyweight - having to create a ResourceHashtable for every call site, dynamically - and quite cumbersome to write out at the call-site versus the simple boolean args.

Do we have candidates for expanding the current set of "filters"? Two flags is quite manageable. Three is a stretch but still okay if we can take advantage of default args. Four or more would definitely cry out for some better mechanism, but I'm not sure this is it.

Sorry.

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PR Review: https://git.openjdk.org/jdk/pull/25497#pullrequestreview-2908845333