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https://issues.apache.org/jira/browse/GROOVY-12191?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18099230#comment-18099230
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ASF GitHub Bot commented on GROOVY-12191:
-----------------------------------------
daniellansun commented on PR #2736:
URL: https://github.com/apache/groovy/pull/2736#issuecomment-5082573905
@paulk-asert
Thanks for your review.
| Point | Action |
|-------|--------|
| Array fan-out hole (`Object[]` final short-circuit) | Fixed via
`ClassHierarchyIndex` (full JLS array lattice) + single invalidate path; tests
for `Object[]` / interface arrays / multi-dim |
| Legacy `switchPoint` lost lock | Restored `synchronized
(IndyInterface.class)` |
| `switchPoint` semantics / javadoc over-claim | Docs: bulk-only rotation;
misses per-class MC; `@Deprecated(since="6.0.0", forRemoval=false)` |
| `incVersion()` no longer global flush | Documented + test; bulk callers →
`invalidateCallSites()` / `invalidateCategory()` |
| Scalability O(N×M) | **Shipped** weak ancestor→descendant index; typed MC
invalidation is O(subtypes). Category still full walk (cheap no-op detach) |
| Sonar S1186 / S6355 / S3077 | Empty-ctor comment; deprecate metadata; sync
rotation |
| `invokeColdReflective` | Documented as intentional cold-tier change (not
pure scoping) |
| Perf Alert bot | False alarm: 1841→2857 ops/ms is **faster** (throughput
misread as latency) |
Happy to adjust if anything still looks off.
> Scope indy SwitchPoint invalidation
> -----------------------------------
>
> Key: GROOVY-12191
> URL: https://issues.apache.org/jira/browse/GROOVY-12191
> Project: Groovy
> Issue Type: Improvement
> Reporter: Daniel Sun
> Priority: Major
>
> h3. Problem
> With invokedynamic enabled (default since Groovy 4), linked MOP call sites
> were guarded by a *single process-wide* {{SwitchPoint}}
> ({{{}IndyInterface.switchPoint{}}}).
> Any MetaClass registry change or category enter/leave invalidated that switch
> point, so *every* linked site fell back and re-linked — including sites whose
> receiver type was unrelated.
> That global invalidation is expensive when MetaClass churn is common (e.g.
> ExpandoMetaClass / mixins on startup or per-request paths, Grails-like
> patterns). Unrelated hot monomorphic sites pay re-link and JIT deopt cost
> they should not.
> h3. Goal
> Keep linked call sites optimized unless the *relevant* MetaClass state for
> that site actually changed.
> h3. Approach
> One SwitchPoint domain {*}per class{*}, stored on {{{}ClassInfo{}}}:
> * MetaClass change for type {{T}} retires {{{}T{}}}'s SwitchPoint *and*
> those of loaded subtypes / implementors (hierarchy fan-out).
> * Unrelated types keep their SwitchPoints; their call sites stay optimized.
> * Category enter/leave (and {{{}VMPlugin.invalidateCallSites(){}}})
> bulk-retire *all* loaded class SwitchPoints so sites re-link under the new
> category state. There is *no* second category SwitchPoint on the hot path.
> * Linked handles always install a *single* class-domain guard via
> {{IndyInvalidation.guardWithMopSwitchPoints(...)}} — same monomorphic guard
> shape as before, without global deopt on unrelated MetaClass churn.
> Final classes short-circuit hierarchy fan-out (no full {{ClassInfo}} scan).
> Non-final types batch retirements with {{{}SwitchPoint.invalidateAll{}}}.
> h3. Invalidation map
> ||Event||What is retired||
> |MetaClass change for type {{T}} (registry /
> {{{}ClassInfo.incVersion{}}})|{{T}} + loaded subtypes / implementors|
> |Category enter/leave, {{invalidateCallSites()}}|All loaded class
> SwitchPoints (bulk)|
> |Unattributed MetaClass registry event|All loaded class SwitchPoints (bulk)|
> |First MetaClass *install* on a class|Version bump only (no linked sites
> yet); replacement / clear retires that class's SwitchPoint|
>
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