Perf: move Lite background pipeline + full refresh off the UI thread (P1)#1110
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…(P1) Root cause (verified against the shipped DuckDB.NET.Data.dll: no async method overrides; Lite has 0 ConfigureAwait(false)): every "await ...Async()" DuckDB call completes synchronously on the calling thread, so all Lite data work runs on the WPF dispatcher. - Start CollectionBackgroundService off the UI thread (Task.Run around StartAsync). Pool threads have no SynchronizationContext, so the entire collection / checkpoint / archive pipeline now stays off the dispatcher — kills the per-minute collection jank and the multi-second-to-minutes freeze on archive/reset. Verified safe: the pipeline only touches DuckDB + the email/webhook AnalysisNotificationService; the UI reads data by polling DuckDB on its own timers, fully decoupled. - RefreshAllTabsAsync (first load / manual refresh / time-range change): wrap each of the ~36 queries in Task.Run so the fan-out runs on pool threads instead of serially on the dispatcher. Each query's ReaderWriterLockSlim read lock is acquired AND released inside one synchronous run, so thread affinity holds. Bonus: the WhenAll fan-out is now genuinely parallel. UI-update code after the awaits unchanged. Build: Lite builds clean (net10). Lite.Tests 428/429 (the 1 failure is a known flake — CredentialProfileTests touch the machine-global Windows Credential Manager and pass 13/13 in isolation; unrelated to these edits). Still to come on this effort (same Task.Run-wrap pattern): the 60s-timer sub-tab refreshes, picker charts, status timer, drill-down, slicer, grid-selection, connect; then a bounded read lock. Threading change — please validate on a running Lite. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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First increment of the UI-responsiveness work (P1 of the perf effort), focused on the CRITICAL Lite finding: DuckDB.NET is synchronous (verified — the shipped DLL has no async overrides) and Lite has zero
ConfigureAwait(false), so all Lite DuckDB work — UI queries and the background collect/checkpoint/archive pipeline — runs on the WPF dispatcher thread.In this PR
Task.RunaroundCollectionBackgroundService.StartAsync. Pool threads have noSynchronizationContext, so the whole collection/checkpoint/archive pipeline stays off the dispatcher. Kills the per-minute collection jank and the multi-second-to-minutes freeze on archive/reset. Verified safe: the pipeline only touches DuckDB + the email/webhook notification service; the UI polls DuckDB on its own timers (decoupled).RefreshAllTabsAsyncoff the UI thread — the first-load / manual-refresh / time-range-change path wraps each of ~36 queries inTask.Run(correctReaderWriterLockSlimaffinity: each query acquires+releases its read lock inside one synchronous run). Bonus: the fan-out is now genuinely parallel.Still on this effort (same pattern, not deferred)
The 60s-timer sub-tab refreshes, picker charts, status timer, drill-down, slicer, grid-selection, connect; then a bounded read lock. Then the shared-UI crosshair/hover hot path, the Dashboard timer/throttle/SQL-aggregation chunk, and the leak cluster — both apps.
Validation
Lite.Tests428/429 — the 1 failure (CredentialProfileTests.SwitchToProfile_DeletesOrphanedPerServerSecret) is a known flake: those tests hit the machine-global Windows Credential Manager and pass 13/13 in isolation; unrelated to these edits.🤖 Generated with Claude Code