Telemetry: Await pending operations in getLastEvents to prevent race conditions

[valentinpalkovic]

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Summary by CodeRabbit

• Bug Fixes
  • Fixed a race condition in event cache retrieval that could result in inconsistent or stale event data during concurrent operations.

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☁️ Nx Cloud last updated this comment at 2025-12-08 22:14:29 UTC

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📝 Walkthrough

Walkthrough

A race condition fix in the telemetry event cache. The getLastEvents function now awaits the global operation promise before reading cached entries, ensuring all pending set operations complete prior to retrieval.

Changes

Cohort / File(s)	Summary
Telemetry event-cache race condition fix code/core/src/telemetry/event-cache.ts	Added await on global operation promise inside getLastEvents to ensure in-flight set mutations complete before reading lastEvents

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

• Single-file, targeted fix addressing a specific race condition
• Straightforward addition of an await statement with no signature changes
• No complex logic or multi-faceted changes to evaluate

Possibly related PRs

• Core: Add preview-first-load telemetry #32770: Directly modifies getLastEvents in the same file with the same race condition fix to ensure pending set operations complete before retrieval
• Telemetry: Fix preview-first-load event #32859: Also modifies telemetry event-cache logic, specifically the behavior and handling of cached entries in getLastEvents

✨ Finishing touches

• 📝 Generate docstrings

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📒 Files selected for processing (1)

• code/core/src/telemetry/event-cache.ts (1 hunks)

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🔇 Additional comments (1)

code/core/src/telemetry/event-cache.ts (1)

37-40: Excellent race condition fix with clear documentation.

The synchronization mechanism correctly ensures that all pending set operations complete before reading from the cache, preventing stale reads. The comment clearly explains the rationale.

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