fix: stop Roslyn worker revive after server reset or reload shutdown

[hatayama]

Summary

• After server reset / domain reload / Editor quit, an in-flight shared Roslyn compile retry no longer starts a replacement worker.
• Ordinary crash/retry cleanup still may restart the worker within the same compile conversation.

User Impact

• Before: Shutdown could interleave with retry → EnsureWorkerReady briefly resurrected a worker (stdin EOF self-exits; no lasting leak, but wrong lifecycle).
• After: Full lifecycle Shutdown advances a generation latch; stale retries fail closed without starting a new process. The next compile after reset captures the new generation and works normally.

Design

• Generation latch on SharedRoslynCompilerWorkerSession (not sticky bool + GetRuntimeFacade clear).
• Shutdown() advances generation under the state lock, then kills the process.
• ShutdownProcessLocked alone does not advance generation (legitimate retry).
• TryCompileWithRetriesAsync captures generation via lock; EnsureWorkerReady / StartWorkerProcess compare+start atomically under the same lock.
• Non-retryable failure reason: shared_worker_lifecycle_closed.

Out of scope (umbrella notes)

• Mapping shared_worker_lifecycle_closed to PR 6-2 restarting NextActions if/when it becomes user-visible.

Verification

• uloop compile → Success
• 3 EditMode tests: Shutdown advances gen; process-only shutdown still allows restart; stale gen refuses start → Passed

Test plan

• Confirm process-only kill still allows StartProcessLocked for the captured generation
• Confirm full Shutdown advances generation and refuses stale starts
• Optional Editor: reset during compile should not leave a resurrected worker for that conversation

Made with Cursor

[coderabbitai]

Warning

Review limit reached

@hatayama, you've reached your PR review limit, so we couldn't start this review.

Next review available in: 27 minutes

Enable usage-based reviews in Billing to review now. Otherwise, wait until the next included review is available.
You're only billed for reviews past your plan's rate limits ($0.25/file).

How can I continue?

After more reviews become available, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

To avoid repeated limits, reduce automatic review volume by pausing incremental auto-reviews earlier, using label-based review opt-in, excluding WIP or generated PR titles, or requesting reviews manually when the PR is ready. If your team needs uninterrupted high-volume reviews, an organization admin can enable usage-based reviews.

How do review limits work?

CodeRabbit enforces per-developer PR review limits for each organization. Most developers receive the normal plan review availability.

For paid Pro and Pro+ PR reviews, CodeRabbit uses adaptive limits for sustained high-volume activity. When a developer's recent PR review activity reaches the 95th percentile or higher among CodeRabbit users, additional reviews become available more gradually as earlier reviews age out of the rolling window.

Please refer docs for additional details.

Review details

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: fcee9335-38fa-4f95-a9e6-61cbbaa39891

📥 Commits

Reviewing files that changed from the base of the PR and between f16dd0c and 50bb7d1.

📒 Files selected for processing (3)

• Assets/Tests/Editor/DynamicCodeToolTests/SharedRoslynCompilerWorkerHostTests.cs
• Packages/src/Editor/FirstPartyTools/ExecuteDynamicCode/DynamicCompilation/SharedRoslynCompilerWorkerHost.cs
• Packages/src/Editor/FirstPartyTools/ExecuteDynamicCode/DynamicCompilation/SharedRoslynCompilerWorkerSession.cs

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/roslyn-worker-no-revive-after-shutdown

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[hatayama]

@coderabbitai review

[coderabbitai]

✅ Action performed

Review finished.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.